BuildSystem: Fix xbps port packaging

running yes and pressing ctrl+c paniced the kernel :nekocatwoah:

BAN/include/BAN/Math.h

@@ -2,6 +2,7 @@
 
 #include <BAN/Limits.h>
 #include <BAN/Numbers.h>
+#include <BAN/Swap.h>
 #include <BAN/Traits.h>
 
 #include <float.h>
@@ -81,6 +82,37 @@ namespace BAN::Math
 		return x + 1;
 	}
 
+	template<unsigned_integral T>
+	requires is_same_v<T, unsigned int> || is_same_v<T, unsigned long> || is_same_v<T, unsigned long long>
+	inline constexpr int clz(T x)
+	{
+		if constexpr (is_same_v<T, unsigned int>)
+			return __builtin_clz(x);
+		if constexpr (is_same_v<T, unsigned long>)
+			return __builtin_clzl(x);
+		return __builtin_clzll(x);
+	}
+
+	template<unsigned_integral T> requires(sizeof(T) <= sizeof(unsigned long long))
+	inline constexpr int ctz(T x)
+	{
+		if constexpr (sizeof(T) <= sizeof(unsigned int))
+			return __builtin_ctz(x);
+		if constexpr (sizeof(T) <= sizeof(unsigned long))
+			return __builtin_ctzl(x);
+		return __builtin_ctzll(x);
+	}
+
+	template<unsigned_integral T> requires(sizeof(T) <= sizeof(unsigned long long))
+	inline constexpr int popcount(T x)
+	{
+		if constexpr (sizeof(T) <= sizeof(unsigned int))
+			return __builtin_popcount(x);
+		if constexpr (sizeof(T) <= sizeof(unsigned long))
+			return __builtin_popcountl(x);
+		return __builtin_popcountll(x);
+	}
+
 	template<integral T>
 	__attribute__((always_inline))
 	inline constexpr bool will_multiplication_overflow(T a, T b)
@@ -101,11 +133,7 @@ namespace BAN::Math
 	requires is_same_v<T, unsigned int> || is_same_v<T, unsigned long> || is_same_v<T, unsigned long long>
 	inline constexpr T ilog2(T x)
 	{
-		if constexpr(is_same_v<T, unsigned int>)
+		return sizeof(T) * 8 - clz(x) - 1;
-			return sizeof(T) * 8 - __builtin_clz(x) - 1;
-		if constexpr(is_same_v<T, unsigned long>)
-			return sizeof(T) * 8 - __builtin_clzl(x) - 1;
-		return sizeof(T) * 8 - __builtin_clzll(x) - 1;
 	}
 
 // This is ugly but my clangd does not like including
@@ -308,36 +336,6 @@ namespace BAN::Math
 		return exp2<T>(y * log2<T>(x));
 	}
 
-	template<floating_point T>
-	inline constexpr T scalbn(T x, int n)
-	{
-		asm("fscale" : "+t"(x) : "u"(static_cast<T>(n)));
-		return x;
-	}
-
-	template<floating_point T>
-	inline constexpr T ldexp(T x, int y)
-	{
-		const bool exp_sign = y < 0;
-		if (exp_sign)
-			y = -y;
-
-		T exp = (T)1.0;
-		T mult = (T)2.0;
-		while (y)
-		{
-			if (y & 1)
-				exp *= mult;
-			mult *= mult;
-			y >>= 1;
-		}
-
-		if (exp_sign)
-			exp = (T)1.0 / exp;
-
-		return x * exp;
-	}
-
 	template<floating_point T>
 	inline constexpr T sqrt(T x)
 	{
@@ -470,7 +468,17 @@ namespace BAN::Math
 	template<floating_point T>
 	inline constexpr T hypot(T x, T y)
 	{
-		return sqrt<T>(x * x + y * y);
+		x = abs(x);
+		y = abs(y);
+
+		if (x < y)
+			swap(x, y);
+
+		if (y == (T)0.0)
+			return x;
+
+		const T r = y / x;
+		return x * sqrt<T>((T)1.0 + r * r);
 	}
 
 #ifdef BAN_MATH_POP_OPTIONS

CMakeLists.txt

@@ -27,6 +27,12 @@ set(BUILD_SHARED_LIBS True)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
+find_program(CCACHE_PROGRAM "ccache")
+if (CCACHE_PROGRAM)
+	set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+	set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+endif()
+
 # include headers of ${library} to ${target}
 function(banan_include_headers target library)
 	target_include_directories(${target} PUBLIC $<TARGET_PROPERTY:${library},SOURCE_DIR>/include)

README.md

@@ -9,7 +9,7 @@ This is my hobby operating system written in C++. Currently supports x86\_64 and
 
 You can find a live demo [here](https://bananymous.com/banan-os)
 
-If you want to try out DOOM, you should first enter the GUI environment using the `start-gui` command. Then you can run `doom` in the GUI terminal.
+![screenshot from qemu running banan-os](assets/banan-os.png)
 
 ### Features
 
@@ -18,6 +18,8 @@ If you want to try out DOOM, you should first enter the GUI environment using th
 - [x] SMP (multiprocessing)
 - [x] Linear framebuffer (VESA and GOP)
 - [x] Network stack
+- [x] USB stack
+- [x] Audio support
 - [x] ELF executable loading
 - [x] AML interpreter (partial)
 - [x] Basic graphical environment
@@ -27,16 +29,14 @@ If you want to try out DOOM, you should first enter the GUI environment using th
   - [ ] Some nice apps
 - [x] ELF dynamic linking
 - [x] copy-on-write memory
-  - [x] file mappings
-  - [ ] anonymous mappings
 
 #### Drivers
 - [x] NVMe disks
 - [x] ATA (IDE, SATA) disks
 - [x] E1000 and E1000E NICs
 - [x] RTL8111/8168/8211/8411 NICs
-- [x] PS2 keyboard (all scancode sets)
+- [x] AC97 and iHDA audio cards
-- [x] PS2 mouse
+- [x] PS2 keyboard and mouse
 - [x] USB
   - [x] xHCI
   - [ ] EHCI
@@ -46,7 +46,8 @@ If you want to try out DOOM, you should first enter the GUI environment using th
   - [x] Mouse
   - [x] Mass storage
   - [x] Hubs
-  - [ ] ...
+  - [ ] Network
+  - [ ] Audio
 - [ ] virtio devices (network, storage)
 
 #### Network
@@ -54,7 +55,7 @@ If you want to try out DOOM, you should first enter the GUI environment using th
 - [x] ICMP
 - [x] IPv4
 - [x] UDP
-- [x] TCP (partial and buggy)
+- [x] TCP
 - [x] Unix domain sockets
 - [ ] SSL
 
@@ -65,7 +66,6 @@ If you want to try out DOOM, you should first enter the GUI environment using th
 - [x] Dev
 - [x] Ram
 - [x] Proc
-- [ ] Sys
 - [ ] 9P
 
 #### Bootloader support
@@ -73,8 +73,6 @@ If you want to try out DOOM, you should first enter the GUI environment using th
 - [x] Custom BIOS bootloader
 - [ ] Custom UEFI bootloader
 
-![screenshot from qemu running banan-os](assets/banan-os.png)
-
 ## Code structure
 
 Each major component and library has its own subdirectory (kernel, userspace, libc, ...). Each directory contains directory *include*, which has **all** of the header files of the component. Every header is included by its absolute path.
@@ -125,8 +123,22 @@ If you have corrupted your disk image or want to create new one, you can either
 ./bos image-full
 ```
 
+To test on real hardware, I have a script to generate a compressed ISO. The ISO can be copied directly to an USB drive with for example `dd`. The file is created at build/banan-os.iso and can be generated with
+```sh
+./bos iso
+```
+
 I have also created shell completion script for zsh. You can either copy the file in _script/shell-completion/zsh/\_bos_ to _/usr/share/zsh/site-functions/_ or add the _script/shell-completion/zsh_ to your fpath in _.zshrc_.
 
+### Package Manager
+
+banan-os uses xbps as its package manager for ports. All upstream ports are packaged into xbps packages hosted on a [repository on my server](https://packages.bananymous.com/banan-os). You can manage sysroot's xbps packages with `./bos` wrapper. You can use `xbps-install`, `xbps-remove` and `xbps-query` with repository and sysroot set to the correct values. For example to install xbps that can be used inside banan-os you can use
+```sh
+./bos xbps-install -S xbps
+```
+For xbps usage see [their documentation](https://docs.voidlinux.org/xbps/index.html).
+
+
 ## Contributing
 
 As the upstream is hosted on my server https://git.bananymous.com/Bananymous/banan-os, merging contributions is not as trivial as it would be on GitHub. You can still send PRs in GitHub in which case I should be able to download the diff and apply it manually. If you want, I can also provide you an account to my git server. In this case please contact me ([email](mailto:[email protected]), [discord](https://discord.gg/ehjGySwYdK)).

bootloader/bios/command_line.S

@@ -35,13 +35,13 @@ read_user_command_line:
 	cmpb $'\n', %al
 	je .read_user_command_line_done
 
-	pushw %ax
+	movb %al, %bl
 
 	call isprint
 	testb %al, %al
 	jz .read_user_command_line_loop
 
-	popw %ax
+	movb %bl, %al
 
 	# put byte to buffer
 	movb %al, (%di)

bootloader/bios/framebuffer.S

@@ -108,9 +108,11 @@ vesa_find_video_mode:
 	cmpb $0x4F, %al; jne .vesa_unsupported
 	cmpb $0x00, %ah; jne .vesa_error
 
-	# check whether in graphics mode
+	# check whether in graphics mode and linear framebuffer
-	testb $0x10, (vesa_mode_info_buffer + 0)
+	movb (vesa_mode_info_buffer + 0), %al
-	jz .vesa_find_video_mode_next_mode
+	andb $(0x80 | 0x10), %al
+	cmpb $(0x80 | 0x10), %al
+	jne .vesa_find_video_mode_next_mode
 
 	# compare mode's dimensions
 	movw -2(%ebp), %ax; cmpw %ax, (vesa_mode_info_buffer + 0x12)

bootloader/bios/memory_map.S

@@ -2,6 +2,8 @@
 
 .section .stage2
 
+.set mmap_entry_size, 24
+
 # fills memory map data structure
 # doesn't return on error
 # NO REGISTERS SAVED
@@ -12,7 +14,7 @@ get_memory_map:
 	movl $0x0000E820, %eax
 	movl $0x534D4150, %edx
 	xorl %ebx, %ebx
-	movl $20, %ecx
+	movl $mmap_entry_size, %ecx
 	movw $memory_map_entries, %di
 
 	clc
@@ -24,15 +26,15 @@ get_memory_map:
 	cmpl $0x534D4150, %eax
 	jne .get_memory_map_error
 
-	# FIXME: don't assume BIOS to always return 20 bytes
+	# confirm that we got at least 20 bytes
 	cmpl $20, %ecx
-	jne .get_memory_map_error
+	jl .get_memory_map_error
 
 	# increment entry count
 	incl (memory_map_entry_count)
 
 	# increment entry pointer
-	addw %cx, %di
+	addw $mmap_entry_size, %di
 
 	# BIOS can indicate end of list by 0 in ebx
 	testl %ebx, %ebx
@@ -107,7 +109,7 @@ print_memory_map:
 
 	call print_newline
 
-	addw $20, %si
+	addw $mmap_entry_size, %si
 
 	decl %edx
 	jnz .loop_memory_map
@@ -127,6 +129,8 @@ memory_map_error_msg:
 memory_map:
 memory_map_entry_count:
 	.skip 4
-# 100 entries should be enough...
+memory_map_padding:
+	.skip 4
+# 128 entries should be enough...
 memory_map_entries:
-	.skip 20 * 100
+	.skip mmap_entry_size * 128

kernel/CMakeLists.txt

@@ -41,6 +41,7 @@ set(KERNEL_SOURCES
 	kernel/FS/USTARModule.cpp
 	kernel/FS/VirtualFileSystem.cpp
 	kernel/GDT.cpp
+	kernel/Graphics/BGA.cpp
 	kernel/IDT.cpp
 	kernel/Input/InputDevice.cpp
 	kernel/Input/PS2/Controller.cpp
@@ -51,6 +52,8 @@ set(KERNEL_SOURCES
 	kernel/Interruptable.cpp
 	kernel/InterruptController.cpp
 	kernel/kernel.cpp
+	kernel/Lock/Mutex.cpp
+	kernel/Lock/RWLock.cpp
 	kernel/Lock/SpinLock.cpp
 	kernel/Memory/ByteRingBuffer.cpp
 	kernel/Memory/DMARegion.cpp
@@ -83,6 +86,7 @@ set(KERNEL_SOURCES
 	kernel/Processor.cpp
 	kernel/Random.cpp
 	kernel/Scheduler.cpp
+	kernel/SchedulerThreadNode.cpp
 	kernel/SSP.cpp
 	kernel/Storage/ATA/AHCI/Controller.cpp
 	kernel/Storage/ATA/AHCI/Device.cpp

kernel/arch/i686/Signal.S

@@ -59,7 +59,7 @@ signal_trampoline:
 	addl $24, %esp
 
 	// restore sigmask
-	movl $78, %eax      // SYS_SIGPROCMASK
+	movl $79, %eax      // SYS_SIGPROCMASK
 	movl $3,  %ebx      // SIG_SETMASK
 	leal 72(%esp), %ecx // set
 	xorl %edx, %edx     // oset

kernel/arch/i686/Syscall.S

@@ -63,7 +63,7 @@ sys_fork_trampoline:
 
 	call read_ip
 	testl %eax, %eax
-	jz .done
+	jz .Lsys_fork_trampoline_done
 
 	movl %esp, %ebx
 
@@ -73,7 +73,7 @@ sys_fork_trampoline:
 	call sys_fork
 	addl $16, %esp
 
- .done:
+ .Lsys_fork_trampoline_done:
 	popl %edi
 	popl %esi
 	popl %ebx

kernel/arch/i686/User.S

@@ -28,27 +28,26 @@ safe_user_strncpy:
 	testl %ecx, %ecx
 	jz safe_user_strncpy_fault
 
- .safe_user_strncpy_loop:
+ .Lsafe_user_strncpy_loop:
 	movb (%esi), %al
 	movb %al, (%edi)
 	testb %al, %al
-	jz .safe_user_strncpy_done
+	jz .Lsafe_user_strncpy_done
 
 	incl %edi
 	incl %esi
 	decl %ecx
-	jnz .safe_user_strncpy_loop
+	jnz .Lsafe_user_strncpy_loop
 
  safe_user_strncpy_fault:
 	xorl %eax, %eax
-	jmp .safe_user_strncpy_return
+	jmp .Lsafe_user_strncpy_return
 
- .safe_user_strncpy_done:
+ .Lsafe_user_strncpy_done:
 	movl $1, %eax
 
- .safe_user_strncpy_return:
+ .Lsafe_user_strncpy_return:
 	movl 4(%esp), %edi
 	movl 8(%esp), %esi
 	ret
-
 safe_user_strncpy_end:

kernel/arch/i686/boot.S

@@ -168,14 +168,12 @@ has_sse:
 
 check_requirements:
 	call has_cpuid
-	jz .exit
+	jz system_halt
 	call has_pae
-	jz .exit
+	jz system_halt
 	call has_sse
-	jz .exit
+	jz system_halt
 	ret
-.exit:
-	jmp system_halt
 
 enable_sse:
 	movl %cr0, %eax
@@ -225,8 +223,8 @@ _start:
 
 	# load boot GDT
 	lgdt V2P(boot_gdtr)
-	ljmpl $0x08, $V2P(gdt_flush)
+	ljmpl $0x08, $V2P(.Lgdt_flush)
-gdt_flush:
+.Lgdt_flush:
 	# set correct segment registers
 	movw $0x10, %ax
 	movw %ax, %ds
@@ -243,10 +241,10 @@ gdt_flush:
 	movl $g_boot_stack_top, %esp
 
 	# jump to higher half
-	leal higher_half, %ecx
+	leal .Lhigher_half, %ecx
 	jmp *%ecx
 
-higher_half:
+.Lhigher_half:
 	# call global constuctors
 	call _init
 
@@ -298,18 +296,18 @@ ap_ready:
 	.skip 4
 
 1:	cli; cld
-	ljmpl $0x00, $AP_REL(ap_cs_clear)
+	ljmpl $0x00, $AP_REL(.Lap_cs_clear)
 
-ap_cs_clear:
+.Lap_cs_clear:
 	# load ap gdt and enter protected mode
 	lgdt AP_REL(ap_gdtr)
 	movl %cr0, %eax
 	orb $1, %al
 	movl %eax, %cr0
-	ljmpl $0x08, $AP_REL(ap_protected_mode)
+	ljmpl $0x08, $AP_REL(.Lap_protected_mode)
 
 .code32
-ap_protected_mode:
+.Lap_protected_mode:
 	movw $0x10, %ax
 	movw %ax, %ds
 	movw %ax, %ss
@@ -323,13 +321,13 @@ ap_protected_mode:
 
 	# load boot gdt and enter long mode
 	lgdt V2P(boot_gdtr)
-	ljmpl $0x08, $AP_REL(ap_flush_gdt)
+	ljmpl $0x08, $AP_REL(.Lap_flush_gdt)
 
-ap_flush_gdt:
+.Lap_flush_gdt:
-	movl $ap_higher_half, %ecx
+	movl $.Lap_higher_half, %ecx
 	jmp *%ecx
 
-ap_higher_half:
+.Lap_higher_half:
 	movl AP_REL(ap_prepare_paging), %eax
 	call *%eax
 

kernel/arch/x86_64/Signal.S

@@ -61,7 +61,7 @@ signal_trampoline:
 	addq $40, %rsp
 
 	// restore sigmask
-	movq $78, %rdi       // SYS_SIGPROCMASK
+	movq $79, %rdi       // SYS_SIGPROCMASK
 	movq $3,  %rsi       // SIG_SETMASK
 	leaq 192(%rsp), %rdx // set
 	xorq %r10, %r10      // oset

kernel/arch/x86_64/Syscall.S

@@ -33,13 +33,13 @@ sys_fork_trampoline:
 
 	call read_ip
 	testq %rax, %rax
-	jz .done
+	jz .Lsys_fork_trampoline_done
 
 	movq %rax, %rsi
 	movq %rsp, %rdi
 	call sys_fork
 
- .done:
+ .Lsys_fork_trampoline_done:
 	popq %r15
 	popq %r14
 	popq %r13

kernel/arch/x86_64/User.S

@@ -20,28 +20,28 @@ safe_user_strncpy:
 	testq %rcx, %rcx
 	jz safe_user_strncpy_fault
 
- .safe_user_strncpy_align_loop:
+ .Lsafe_user_strncpy_align_loop:
 	testb $0x7, %sil
-	jz .safe_user_strncpy_align_done
+	jz .Lsafe_user_strncpy_align_done
 
 	movb (%rsi), %al
 	movb %al, (%rdi)
 	testb %al, %al
-	jz .safe_user_strncpy_done
+	jz .Lsafe_user_strncpy_done
 
 	incq %rdi
 	incq %rsi
 	decq %rcx
-	jnz .safe_user_strncpy_align_loop
+	jnz .Lsafe_user_strncpy_align_loop
 	jmp safe_user_strncpy_fault
 
- .safe_user_strncpy_align_done:
+ .Lsafe_user_strncpy_align_done:
 	movq $0x0101010101010101, %r8
 	movq $0x8080808080808080, %r9
 
- .safe_user_strncpy_qword_loop:
+ .Lsafe_user_strncpy_qword_loop:
 	cmpq $8, %rcx
-	jb .safe_user_strncpy_qword_done
+	jb .Lsafe_user_strncpy_qword_done
 
 	movq (%rsi), %rax
 	movq %rax, %r10
@@ -52,36 +52,36 @@ safe_user_strncpy:
 	notq %r11
 	andq %r11, %r10
 	andq %r9, %r10
-	jnz .safe_user_strncpy_byte_loop
+	jnz .Lsafe_user_strncpy_byte_loop
 
 	movq %rax, (%rdi)
 
 	addq $8, %rdi
 	addq $8, %rsi
 	subq $8, %rcx
-	jnz .safe_user_strncpy_qword_loop
+	jnz .Lsafe_user_strncpy_qword_loop
 	jmp safe_user_strncpy_fault
 
- .safe_user_strncpy_qword_done:
+ .Lsafe_user_strncpy_qword_done:
 	testq %rcx, %rcx
 	jz safe_user_strncpy_fault
 
- .safe_user_strncpy_byte_loop:
+ .Lsafe_user_strncpy_byte_loop:
 	movb (%rsi), %al
 	movb %al, (%rdi)
 	testb %al, %al
-	jz .safe_user_strncpy_done
+	jz .Lsafe_user_strncpy_done
 
 	incq %rdi
 	incq %rsi
 	decq %rcx
-	jnz .safe_user_strncpy_byte_loop
+	jnz .Lsafe_user_strncpy_byte_loop
 
  safe_user_strncpy_fault:
 	xorq %rax, %rax
 	ret
 
- .safe_user_strncpy_done:
+ .Lsafe_user_strncpy_done:
 	movb $1, %al
 	ret
 safe_user_strncpy_end:

kernel/arch/x86_64/boot.S

@@ -161,12 +161,10 @@ is_64_bit:
 
 check_requirements:
 	call has_cpuid
-	jz .exit
+	jz system_halt
 	call is_64_bit
-	jz .exit
+	jz system_halt
 	ret
-.exit:
-	jmp system_halt
 
 enable_sse:
 	movl %cr0, %eax
@@ -226,10 +224,10 @@ _start:
 
 	# flush gdt and jump to 64 bit
 	lgdt V2P(boot_gdtr)
-	ljmpl $0x08, $V2P(long_mode)
+	ljmpl $0x08, $V2P(.Llong_mode)
 
 .code64
-long_mode:
+.Llong_mode:
 	movw $0x10, %ax
 	movw %ax, %ds
 	movw %ax, %ss
@@ -240,10 +238,10 @@ long_mode:
 	addq $KERNEL_OFFSET, %rsp
 
 	# jump to higher half
-	movabsq $higher_half, %rcx
+	movabsq $.Lhigher_half, %rcx
 	jmp *%rcx
 
-higher_half:
+.Lhigher_half:
 	# call global constuctors
 	call _init
 
@@ -293,18 +291,18 @@ ap_ready:
 	.skip 8
 
 1:	cli; cld
-	ljmpl $0x00, $AP_REL(ap_cs_clear)
+	ljmpl $0x00, $AP_REL(.Lap_cs_clear)
 
-ap_cs_clear:
+.Lap_cs_clear:
 	# load ap gdt and enter protected mode
 	lgdt AP_REL(ap_gdtr)
 	movl %cr0, %eax
 	orb $1, %al
 	movl %eax, %cr0
-	ljmpl $0x08, $AP_REL(ap_protected_mode)
+	ljmpl $0x08, $AP_REL(.Lap_protected_mode)
 
 .code32
-ap_protected_mode:
+.Lap_protected_mode:
 	movw $0x10, %ax
 	movw %ax, %ds
 	movw %ax, %ss
@@ -318,14 +316,14 @@ ap_protected_mode:
 
 	# load boot gdt and enter long mode
 	lgdt V2P(boot_gdtr)
-	ljmpl $0x08, $AP_REL(ap_long_mode)
+	ljmpl $0x08, $AP_REL(.Lap_long_mode)
 
 .code64
-ap_long_mode:
+.Lap_long_mode:
-	movq $ap_higher_half, %rax
+	movq $.Lap_higher_half, %rax
 	jmp *%rax
 
-ap_higher_half:
+.Lap_higher_half:
 	movq AP_REL(ap_prepare_paging), %rax
 	call *%rax
 

kernel/icxxabi.cpp

@@ -38,25 +38,39 @@ extern "C" void __cxa_finalize(void* f)
 	}
 };
 
-namespace __cxxabiv1
+extern "C" int __cxa_guard_acquire(uint64_t* g)
 {
-	using __guard = uint64_t;
+	uint8_t* guard = reinterpret_cast<uint8_t*>(g);
 
-	extern "C" int __cxa_guard_acquire (__guard* g)
+	for (;;)
 	{
-		uint8_t* byte = reinterpret_cast<uint8_t*>(g);
+		if (BAN::atomic_load(guard[0], BAN::memory_order_acquire))
-		uint8_t zero = 0;
+			return 0;
-		return __atomic_compare_exchange_n(byte, &zero, 1, false, __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
-	}
 
-	extern "C" void __cxa_guard_release (__guard* g)
+		uint8_t expected = 0;
-	{
+		if (BAN::atomic_compare_exchange(guard[1], expected, 1, BAN::memory_order_acquire))
-		uint8_t* byte = reinterpret_cast<uint8_t*>(g);
+		{
-		__atomic_store_n(byte, 0, __ATOMIC_RELEASE);
+			if (BAN::atomic_load(guard[0], BAN::memory_order_acquire))
-	}
+			{
+				BAN::atomic_store(guard[1], 0, BAN::memory_order_release);
+				return 0;
+			}
+			return 1;
+		}
 
-	extern "C" void __cxa_guard_abort (__guard*)
+		while (BAN::atomic_load(guard[1], BAN::memory_order_acquire))
-	{
+			Kernel::Processor::pause();
-		Kernel::panic("__cxa_guard_abort");
 	}
 }
+
+extern "C" void __cxa_guard_release(uint64_t* g)
+{
+	uint8_t* guard = reinterpret_cast<uint8_t*>(g);
+	BAN::atomic_store(guard[0], 1, BAN::memory_order_release);
+	BAN::atomic_store(guard[1], 0, BAN::memory_order_release);
+}
+
+extern "C" void __cxa_guard_abort(uint64_t*)
+{
+	Kernel::panic("__cxa_guard_abort");
+}

kernel/include/kernel/ACPI/ACPI.h

@@ -4,6 +4,7 @@
 #include <kernel/ACPI/AML/Namespace.h>
 #include <kernel/ACPI/EmbeddedController.h>
 #include <kernel/ACPI/Headers.h>
+#include <kernel/Interruptable.h>
 #include <kernel/Memory/Types.h>
 #include <kernel/ThreadBlocker.h>
 
@@ -23,11 +24,7 @@ namespace Kernel::ACPI
 
 		const SDTHeader* get_header(BAN::StringView signature, uint32_t index);
 
-		// mode
+		BAN::ErrorOr<void> enter_acpi_mode();
-		//   0: PIC
-		//   1: APIC
-		//   2: SAPIC
-		BAN::ErrorOr<void> enter_acpi_mode(uint8_t mode);
 
 		BAN::ErrorOr<void> initialize_acpi_devices();
 
@@ -57,6 +54,7 @@ namespace Kernel::ACPI
 
 		BAN::ErrorOr<void> initialize_embedded_controller(const AML::Scope& embedded_controller);
 		BAN::ErrorOr<void> initialize_embedded_controllers();
+		void initialize_embedded_controller_gpes();
 
 		BAN::Optional<GAS> find_gpe_block(size_t index);
 		bool enable_gpe(uint8_t gpe);

kernel/include/kernel/ACPI/EmbeddedController.h

@@ -1,11 +1,12 @@
 #pragma once
 
 #include <BAN/Atomic.h>
+#include <BAN/Optional.h>
 #include <BAN/UniqPtr.h>
 
 #include <kernel/ACPI/AML/Scope.h>
 #include <kernel/Lock/Mutex.h>
-#include <kernel/Thread.h>
+#include <kernel/ThreadBlocker.h>
 
 namespace Kernel::ACPI
 {
@@ -13,7 +14,7 @@ namespace Kernel::ACPI
 	class EmbeddedController
 	{
 	public:
-		static BAN::ErrorOr<BAN::UniqPtr<EmbeddedController>> create(AML::Scope&& scope, uint16_t command_port, uint16_t data_port, BAN::Optional<uint8_t> gpe);
+		static BAN::ErrorOr<BAN::UniqPtr<EmbeddedController>> create(AML::Scope&& scope, uint16_t command_port, uint16_t data_port);
 		~EmbeddedController();
 
 		BAN::ErrorOr<uint8_t> read_byte(uint8_t offset);
@@ -21,21 +22,21 @@ namespace Kernel::ACPI
 
 		const AML::Scope& scope() const { return m_scope; }
 
+		static void handle_gpe_trampoline(void*);
+
 	private:
-		EmbeddedController(AML::Scope&& scope, uint16_t command_port, uint16_t data_port, bool has_gpe)
+		EmbeddedController(AML::Scope&& scope, uint16_t command_port, uint16_t data_port)
 			: m_scope(BAN::move(scope))
 			, m_command_port(command_port)
 			, m_data_port(data_port)
-			, m_has_gpe(has_gpe)
 		{ }
 
 	private:
-		void wait_status_bit(uint8_t bit, uint8_t value);
+		void wait_status_bit(uint8_t mask, bool set);
 
 		uint8_t read_one(uint16_t port);
 		void write_one(uint16_t port, uint8_t value);
 
-		static void handle_gpe_wrapper(void*);
 		void handle_gpe();
 
 		BAN::ErrorOr<void> call_query_method(uint8_t notification);
@@ -56,7 +57,6 @@ namespace Kernel::ACPI
 		const AML::Scope m_scope;
 		const uint16_t m_command_port;
 		const uint16_t m_data_port;
-		const bool m_has_gpe;
 
 		Mutex m_mutex;
 		ThreadBlocker m_thread_blocker;

kernel/include/kernel/APIC.h

@@ -2,6 +2,7 @@
 
 #include <BAN/Vector.h>
 #include <kernel/InterruptController.h>
+#include <kernel/InterruptNumbers.h>
 #include <kernel/Lock/SpinLock.h>
 #include <kernel/Memory/Types.h>
 
@@ -12,10 +13,10 @@ namespace Kernel
 	{
 	public:
 		virtual void eoi(uint8_t) override;
-		virtual void enable_irq(uint8_t) override;
+		virtual void enable_irq(uint8_t, bool level_triggered) override;
 		virtual bool is_in_service(uint8_t) override;
 
-		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq) override;
+		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq, bool shared) override;
 		virtual BAN::Optional<uint8_t> get_free_irq() override;
 
 		virtual void initialize_multiprocessor() override;
@@ -23,7 +24,7 @@ namespace Kernel
 		virtual void broadcast_ipi() override;
 		virtual void enable() override;
 
-		BAN::ErrorOr<uint8_t> reserve_gsi(uint32_t gsi);
+		BAN::ErrorOr<uint8_t> reserve_gsi(uint32_t gsi, bool shared = false);
 
 		void initialize_timer();
 		void set_timer_dealine(uint64_t ns);
@@ -71,7 +72,8 @@ namespace Kernel
 		Kernel::vaddr_t        m_local_apic_vaddr = 0;
 		BAN::Vector<IOAPIC>    m_io_apics;
 		uint8_t                m_irq_overrides[0x100] {};
-		uint8_t                m_reserved_gsis[m_irq_count / 8] {};
+		uint8_t                m_used_gsis[m_irq_count / 8] {};
+		uint8_t                m_excl_gsis[m_irq_count / 8] {};
 		uint64_t               m_lapic_timer_frequency_hz { 0 };
 	};
 

kernel/include/kernel/Audio/HDAudio/AudioFunctionGroup.h

@@ -67,6 +67,7 @@ namespace Kernel
 		BAN::Vector<BAN::Vector<const HDAudio::AFGWidget*>> m_output_paths;
 		BAN::Vector<const HDAudio::AFGWidget*> m_output_pins;
 		size_t m_output_path_index { SIZE_MAX };
+		size_t m_amplifier_idx { SIZE_MAX };
 
 		uint8_t m_stream_id    { 0xFF };
 		uint8_t m_stream_index { 0xFF };

kernel/include/kernel/Audio/HDAudio/Definitions.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <BAN/Optional.h>
 #include <BAN/Vector.h>
 
 namespace Kernel::HDAudio
@@ -64,6 +65,7 @@ namespace Kernel::HDAudio
 		};
 
 		BAN::Optional<Amplifier> output_amplifier;
+		BAN::Optional<Amplifier> input_amplifier;
 
 		BAN::Vector<uint16_t> connections;
 	};

kernel/include/kernel/BananBootloader.h

@@ -21,13 +21,17 @@ struct BananBootloaderMemoryMapEntry
 	uint64_t address;
 	uint64_t length;
 	uint32_t type;
-} __attribute__((packed));
+	uint32_t unused;
+};
+static_assert(sizeof(BananBootloaderMemoryMapEntry) == 24);
 
 struct BananBootloaderMemoryMapInfo
 {
 	uint32_t entry_count;
+	uint32_t padding;
 	struct BananBootloaderMemoryMapEntry entries[];
-} __attribute__((packed));
+};
+static_assert(sizeof(BananBootloaderMemoryMapInfo) == 8);
 
 struct BananBootloaderInfo
 {
@@ -35,4 +39,5 @@ struct BananBootloaderInfo
 	uint32_t framebuffer_addr;
 	uint32_t memory_map_addr;
 	uint32_t kernel_paddr;
-} __attribute__((packed));
+};
+static_assert(sizeof(BananBootloaderInfo) == 16);

kernel/include/kernel/Device/FramebufferDevice.h

@@ -6,15 +6,22 @@
 namespace Kernel
 {
 
+	class BGAController;
+
 	class FramebufferDevice : public CharacterDevice
 	{
 	public:
+		static BAN::ErrorOr<BAN::RefPtr<FramebufferDevice>> create(paddr_t paddr, uint32_t width, uint32_t height, uint32_t pitch, uint8_t bpp);
+		static BAN::ErrorOr<BAN::RefPtr<FramebufferDevice>> create(BAN::RefPtr<BGAController>);
 		static BAN::ErrorOr<BAN::RefPtr<FramebufferDevice>> create_from_boot_framebuffer();
 		static BAN::RefPtr<FramebufferDevice> boot_framebuffer();
 		~FramebufferDevice();
 
 		uint32_t width() const { return m_width; }
 		uint32_t height() const { return m_height; }
+		uint8_t bpp() const { return m_bpp; }
+
+		BAN::ErrorOr<void> set_bga_controller(BAN::RefPtr<BGAController>);
 
 		uint32_t get_pixel(uint32_t x, uint32_t y) const;
 		void set_pixel(uint32_t x, uint32_t y, uint32_t rgb);
@@ -50,14 +57,16 @@ namespace Kernel
 	private:
 		const BAN::String m_name;
 
-		vaddr_t			m_video_memory_vaddr { 0 };
+		vaddr_t m_video_memory_vaddr { 0 };
-		const paddr_t	m_video_memory_paddr;
+		paddr_t m_video_memory_paddr { 0 };
-		const uint32_t	m_width;
+
-		const uint32_t	m_height;
+		uint32_t m_width  { 0 };
-		const uint32_t	m_pitch;
+		uint32_t m_height { 0 };
-		const uint8_t	m_bpp;
+		uint32_t m_pitch  { 0 };
+		uint8_t  m_bpp    { 0 };
 
 		BAN::UniqPtr<VirtualRange> m_video_buffer;
+		BAN::RefPtr<BGAController> m_bga_controller;
 
 		friend class FramebufferMemoryRegion;
 	};

kernel/include/kernel/Epoll.h

@@ -3,6 +3,7 @@
 #include <BAN/HashMap.h>
 #include <kernel/FS/Inode.h>
 #include <kernel/Lock/Mutex.h>
+#include <kernel/ThreadBlocker.h>
 
 #include <sys/epoll.h>
 

kernel/include/kernel/FS/DevFS/FileSystem.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include <BAN/Vector.h>
-#include <kernel/Device/Device.h>
 #include <kernel/FS/TmpFS/FileSystem.h>
 #include <kernel/Lock/Mutex.h>
 #include <kernel/ThreadBlocker.h>
@@ -9,6 +8,8 @@
 namespace Kernel
 {
 
+	class Device;
+
 	class DevFileSystem final : public TmpFileSystem
 	{
 	public:

kernel/include/kernel/FS/EventFD.h

@@ -2,6 +2,7 @@
 
 #include <kernel/FS/Inode.h>
 #include <kernel/Lock/Mutex.h>
+#include <kernel/ThreadBlocker.h>
 
 namespace Kernel
 {
@@ -22,16 +23,16 @@ namespace Kernel
 		BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
 		BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
 
-		bool can_read_impl() const override { return m_value > 0; }
+		bool can_read_impl() const override;
-		bool can_write_impl() const override { return m_value < UINT64_MAX - 1; }
+		bool can_write_impl() const override;
 		bool has_error_impl() const override { return false; }
 		bool has_hungup_impl() const override { return false; }
 
 	private:
 		const bool m_is_semaphore;
-		BAN::Atomic<uint64_t> m_value;
+		uint64_t m_value;
 
-		Mutex m_mutex;
+		mutable Mutex m_mutex;
 		ThreadBlocker m_thread_blocker;
 	};
 

kernel/include/kernel/FS/Ext2/FileSystem.h

@@ -2,8 +2,9 @@
 
 #include <BAN/HashMap.h>
 #include <kernel/Device/Device.h>
-#include <kernel/FS/FileSystem.h>
 #include <kernel/FS/Ext2/Inode.h>
+#include <kernel/FS/FileSystem.h>
+#include <kernel/Memory/VirtualRange.h>
 
 namespace Kernel
 {
@@ -28,7 +29,7 @@ namespace Kernel
 			BAN_NON_COPYABLE(BlockBufferWrapper);
 
 		public:
-			BlockBufferWrapper(BAN::Span<uint8_t> buffer, void (*callback)(void*, const uint8_t*), void* argument)
+			BlockBufferWrapper(BAN::ByteSpan buffer, void (*callback)(void*, const uint8_t*), void* argument)
 				: m_buffer(buffer)
 				, m_callback(callback)
 				, m_argument(argument)
@@ -60,13 +61,13 @@ namespace Kernel
 			const uint8_t* data() const { return m_buffer.data(); }
 
 			BAN::ByteSpan span() { return m_buffer; }
-			BAN::ConstByteSpan span() const { return m_buffer.as_const(); }
+			BAN::ConstByteSpan span() const { return m_buffer; }
 
 			uint8_t& operator[](size_t index) { return m_buffer[index]; }
 			uint8_t operator[](size_t index) const { return m_buffer[index]; }
 
 		private:
-			BAN::Span<uint8_t> m_buffer;
+			BAN::ByteSpan m_buffer;
 			void (*m_callback)(void*, const uint8_t*);
 			void* m_argument;
 		};
@@ -128,7 +129,7 @@ namespace Kernel
 		private:
 			struct BlockBuffer
 			{
-				BAN::Vector<uint8_t> buffer;
+				BAN::ByteSpan buffer;
 				bool used { false };
 			};
 
@@ -144,6 +145,7 @@ namespace Kernel
 
 			Mutex m_buffer_mutex;
 			ThreadBlocker m_buffer_blocker;
+			BAN::UniqPtr<VirtualRange> m_buffer_data;
 			BAN::Array<BlockBuffer, max_threads * max_buffers_per_thread> m_buffers;
 			BAN::Array<ThreadInfo, max_threads> m_thread_infos;
 		};

kernel/include/kernel/FS/FAT/FileSystem.h

@@ -5,6 +5,7 @@
 #include <kernel/FS/FAT/Definitions.h>
 #include <kernel/FS/FAT/Inode.h>
 #include <kernel/FS/FileSystem.h>
+#include <kernel/Lock/Mutex.h>
 
 namespace Kernel
 {

kernel/include/kernel/FS/FileSystem.h

@@ -1,11 +1,12 @@
 #pragma once
 
-#include <kernel/Device/Device.h>
 #include <kernel/FS/Inode.h>
 
 namespace Kernel
 {
 
+	class BlockDevice;
+
 	class FileSystem : public BAN::RefCounted<FileSystem>
 	{
 	public:

kernel/include/kernel/FS/Inode.h

@@ -83,6 +83,7 @@ namespace Kernel
 	public:
 		virtual ~Inode() {}
 
+		static bool can_access(uid_t uid, gid_t gid, mode_t mode, const Credentials& credentials, int);
 		bool can_access(const Credentials&, int) const;
 
 		bool operator==(const Inode& other) const { return dev() == other.dev() && ino() == other.ino(); }

kernel/include/kernel/FS/ProcFS/FileSystem.h

@@ -2,11 +2,12 @@
 
 #include <kernel/FS/TmpFS/FileSystem.h>
 #include <kernel/FS/TmpFS/Inode.h>
-#include <kernel/Process.h>
 
 namespace Kernel
 {
 
+	class Process;
+
 	class ProcFileSystem final : public TmpFileSystem
 	{
 	public:

kernel/include/kernel/FS/ProcFS/Inode.h

@@ -2,11 +2,12 @@
 
 #include <kernel/FS/TmpFS/FileSystem.h>
 #include <kernel/FS/TmpFS/Inode.h>
-#include <kernel/Process.h>
 
 namespace Kernel
 {
 
+	class Process;
+
 	class ProcPidInode final : public TmpDirectoryInode
 	{
 		// FIXME: dynamically update ruid/rgid.

kernel/include/kernel/Graphics/BGA.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <BAN/RefPtr.h>
+#include <kernel/Lock/SpinLock.h>
+#include <kernel/PCI.h>
+
+#include <sys/framebuffer.h>
+
+namespace Kernel
+{
+
+	class BGAController : public BAN::RefCounted<BGAController>
+	{
+	public:
+		static BAN::ErrorOr<BAN::RefPtr<BGAController>> create(PCI::Device&);
+
+		fb_fix_info get_fb_fix_info() const;
+		fb_var_info get_fb_var_info() const;
+		BAN::ErrorOr<void> set_fb_var_info(const fb_var_info&);
+
+	private:
+		BGAController(PCI::Device&);
+		BAN::ErrorOr<void> initialize();
+
+		void write_reg(uint16_t reg, uint16_t value);
+		uint16_t read_reg(uint16_t reg);
+
+	private:
+		mutable RecursiveSpinLock m_lock;
+		PCI::Device& m_pci_device;
+		BAN::UniqPtr<PCI::BarRegion> m_lfb_bar;
+
+		fb_fix_info m_fix_info {};
+		fb_var_info m_var_info {};
+	};
+
+}

kernel/include/kernel/IDT.h

@@ -10,21 +10,6 @@
 namespace Kernel
 {
 
-	// IDT entries
-	//   0x00->0x1F (32):  ISR
-	//   0x20->0x7F (96):  PIC/IOAPIC
-	//   0x80->0xEF (112): MSI
-	//   0xF0->0xFE (15):  internal
-
-	constexpr uint8_t IRQ_VECTOR_BASE   = 0x20;
-	constexpr uint8_t IRQ_MSI_BASE      = 0x80;
-	constexpr uint8_t IRQ_MSI_END       = 0xF0;
-#if ARCH(i686)
-	constexpr uint8_t IRQ_SYSCALL       = 0xF0; // hard coded in kernel/API/Syscall.h
-#endif
-	constexpr uint8_t IRQ_IPI           = 0xF1;
-	constexpr uint8_t IRQ_TIMER         = 0xF2;
-
 #if ARCH(x86_64)
 	struct GateDescriptor
 	{

kernel/include/kernel/Input/PS2/Keyboard.h

@@ -36,6 +36,7 @@ namespace Kernel::Input
 		uint8_t m_byte_index { 0 };
 		bool m_basic { false };
 
+		bool m_scancode_set_uncertain { false };
 		uint8_t m_scancode_set { 0xFF };
 		uint16_t m_modifiers { 0 };
 

kernel/include/kernel/InterruptController.h

@@ -14,7 +14,7 @@ namespace Kernel
 		virtual ~InterruptController() {}
 
 		virtual void eoi(uint8_t) = 0;
-		virtual void enable_irq(uint8_t) = 0;
+		virtual void enable_irq(uint8_t, bool level_triggered = false) = 0;
 		virtual bool is_in_service(uint8_t) = 0;
 
 		static void initialize(bool force_pic);
@@ -26,7 +26,7 @@ namespace Kernel
 		virtual void broadcast_ipi() = 0;
 		virtual void enable() = 0;
 
-		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq) = 0;
+		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq, bool shared = false) = 0;
 		virtual BAN::Optional<uint8_t> get_free_irq() = 0;
 
 		bool is_using_apic() const { return m_using_apic; }

kernel/include/kernel/InterruptNumbers.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <kernel/Arch.h>
+
+namespace Kernel
+{
+
+	// IDT entries
+	//   0x00->0x1F (32):  ISR
+	//   0x20->0x7F (96):  PIC/IOAPIC
+	//   0x80->0xEF (112): MSI
+	//   0xF0->0xFE (15):  internal
+
+	constexpr uint8_t IRQ_VECTOR_BASE   = 0x20;
+	constexpr uint8_t IRQ_MSI_BASE      = 0x80;
+	constexpr uint8_t IRQ_MSI_END       = 0xF0;
+#if ARCH(i686)
+	constexpr uint8_t IRQ_SYSCALL       = 0xF0; // hard coded in kernel/API/Syscall.h
+#endif
+	constexpr uint8_t IRQ_IPI           = 0xF1;
+	constexpr uint8_t IRQ_TIMER         = 0xF2;
+
+}

kernel/include/kernel/Lock/BlockableSpinLock.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <kernel/Lock/SpinLock.h>
+#include <kernel/Lock/Mutex.h>
+
+namespace Kernel
+{
+
+	// FIXME: These classes are HACKS to allow passing spinlock
+	//        to unblock functions. Write a better API that either
+	//        allows passing spinlocks or do something cleaner that
+	//        whatever shit this is
+
+	template<typename Lock> requires requires (Lock& lock) { lock.lock(); lock.unlock(InterruptState::Disabled); lock.current_processor_has_lock(); }
+	class BlockableSpinLock : public BaseMutex
+	{
+	public:
+		BlockableSpinLock(Lock& lock)
+			: m_lock(lock)
+		{
+			ASSERT(m_lock.current_processor_has_lock());
+		}
+
+		void lock() override
+		{
+			m_lock.lock();
+		}
+
+		void unlock() override
+		{
+			m_lock.unlock(InterruptState::Disabled);
+		}
+
+		uint32_t lock_depth() const override { return m_lock.lock_depth(); }
+		bool is_locked_by_current_thread() const override { return m_lock.current_processor_has_lock(); }
+
+	private:
+		Lock& m_lock;
+	};
+
+}

kernel/include/kernel/Lock/Mutex.h

@@ -2,7 +2,6 @@
 
 #include <BAN/Atomic.h>
 #include <BAN/NoCopyMove.h>
-#include <kernel/Thread.h>
 
 #include <sys/types.h>
 
@@ -13,12 +12,10 @@ namespace Kernel
 	{
 	public:
 		virtual void lock() = 0;
-		virtual bool try_lock() = 0;
 		virtual void unlock() = 0;
 
-		virtual pid_t locker() const = 0;
-		virtual bool is_locked() const = 0;
 		virtual uint32_t lock_depth() const = 0;
+		virtual bool is_locked_by_current_thread() const = 0;
 	};
 
 	class Mutex final : public BaseMutex
@@ -29,63 +26,14 @@ namespace Kernel
 	public:
 		Mutex() = default;
 
-		void lock() override
+		bool try_lock();
-		{
+		void lock() override;
-			const auto tid = Thread::current_tid();
+		void unlock() override;
-			if (tid == m_locker)
-				ASSERT(m_lock_depth > 0);
-			else
-			{
-				ASSERT(!tid || !Thread::current().has_spinlock());
-				pid_t expected = -1;
-				while (!m_locker.compare_exchange(expected, tid))
-				{
-					ASSERT(Processor::get_interrupt_state() == InterruptState::Enabled);
-					Processor::yield();
-					expected = -1;
-				}
-				ASSERT(m_lock_depth == 0);
-				if (tid)
-					Thread::current().add_mutex();
-			}
-			m_lock_depth++;
-		}
 
-		bool try_lock() override
+		pid_t locker() const { return m_locker; }
-		{
+		bool is_locked() const { return m_locker != -1; }
-			const auto tid = Thread::current_tid();
-			if (tid == m_locker)
-				ASSERT(m_lock_depth > 0);
-			else
-			{
-				pid_t expected = -1;
-				if (!m_locker.compare_exchange(expected, tid))
-					return false;
-				ASSERT(m_lock_depth == 0);
-				if (tid)
-					Thread::current().add_mutex();
-			}
-			m_lock_depth++;
-			return true;
-		}
-
-		void unlock() override
-		{
-			const auto tid = Thread::current_tid();
-			ASSERT(m_locker == tid);
-			ASSERT(m_lock_depth > 0);
-			if (--m_lock_depth == 0)
-			{
-				m_locker = -1;
-				if (tid)
-					Thread::current().remove_mutex();
-			}
-		}
-
-		pid_t locker() const override { return m_locker; }
-		bool is_locked() const override { return m_locker != -1; }
 		uint32_t lock_depth() const override { return m_lock_depth; }
-		bool is_locked_by_current_thread() const { return m_locker == Thread::current_tid(); }
+		bool is_locked_by_current_thread() const override;
 
 	private:
 		BAN::Atomic<pid_t>	m_locker		{ -1 };
@@ -100,74 +48,14 @@ namespace Kernel
 	public:
 		PriorityMutex() = default;
 
-		void lock() override
+		bool try_lock();
-		{
+		void lock() override;
-			const auto tid = Thread::current_tid();
+		void unlock() override;
 
-			if (tid == m_locker)
+		pid_t locker() const { return m_locker; }
-				ASSERT(m_lock_depth > 0);
+		bool is_locked() const { return m_locker != -1; }
-			else
-			{
-				ASSERT(!tid || !Thread::current().has_spinlock());
-				bool has_priority = tid ? !Thread::current().is_userspace() : true;
-				if (has_priority)
-					m_queue_length++;
-				pid_t expected = -1;
-				while (!(has_priority || m_queue_length == 0) || !m_locker.compare_exchange(expected, tid))
-				{
-					ASSERT(Processor::get_interrupt_state() == InterruptState::Enabled);
-					Processor::yield();
-					expected = -1;
-				}
-				ASSERT(m_lock_depth == 0);
-				if (tid)
-					Thread::current().add_mutex();
-			}
-			m_lock_depth++;
-		}
-
-		bool try_lock() override
-		{
-			const auto tid = Thread::current_tid();
-
-			if (tid == m_locker)
-				ASSERT(m_lock_depth > 0);
-			else
-			{
-				bool has_priority = tid ? !Thread::current().is_userspace() : true;
-				pid_t expected = -1;
-				if (!(has_priority || m_queue_length == 0) || !m_locker.compare_exchange(expected, tid))
-					return false;
-				if (has_priority)
-					m_queue_length++;
-				ASSERT(m_lock_depth == 0);
-				if (tid)
-					Thread::current().add_mutex();
-			}
-			m_lock_depth++;
-			return true;
-		}
-
-		void unlock() override
-		{
-			const auto tid = Thread::current_tid();
-			ASSERT(m_locker == tid);
-			ASSERT(m_lock_depth > 0);
-			if (--m_lock_depth == 0)
-			{
-				bool has_priority = tid ? !Thread::current().is_userspace() : true;
-				if (has_priority)
-					m_queue_length--;
-				m_locker = -1;
-				if (tid)
-					Thread::current().remove_mutex();
-			}
-		}
-
-		pid_t locker() const override { return m_locker; }
-		bool is_locked() const override { return m_locker != -1; }
 		uint32_t lock_depth() const override { return m_lock_depth; }
-		bool is_locked_by_current_thread() const { return m_locker == Thread::current_tid(); }
+		bool is_locked_by_current_thread() const override;
 
 	private:
 		BAN::Atomic<pid_t>		m_locker		{ -1 };

kernel/include/kernel/Lock/RWLock.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include <kernel/Lock/SpinLock.h>
-#include <kernel/Lock/SpinLockAsMutex.h>
+#include <kernel/ThreadBlocker.h>
 
 namespace Kernel
 {
@@ -13,54 +13,10 @@ namespace Kernel
 	public:
 		RWLock() = default;
 
-		void rd_lock()
+		void rd_lock();
-		{
+		void rd_unlock();
-			SpinLockGuard _(m_lock);
+		void wr_lock();
-			while (m_writers_waiting > 0 || m_writer != -1)
+		void wr_unlock();
-			{
-				SpinLockGuardAsMutex smutex(_);
-				m_thread_blocker.block_indefinite(&smutex);
-			}
-			m_readers_active++;
-		}
-
-		void rd_unlock()
-		{
-			SpinLockGuard _(m_lock);
-			if (--m_readers_active == 0)
-				m_thread_blocker.unblock();
-		}
-
-		void wr_lock()
-		{
-			if (m_writer == Thread::current_tid())
-			{
-				m_writer_depth++;
-				return;
-			}
-
-			SpinLockGuard _(m_lock);
-
-			m_writers_waiting++;
-			while (m_readers_active > 0 || m_writer != -1)
-			{
-				SpinLockGuardAsMutex smutex(_);
-				m_thread_blocker.block_indefinite(&smutex);
-			}
-			m_writers_waiting--;
-
-			m_writer = Thread::current_tid();
-			m_writer_depth = 1;
-		}
-
-		void wr_unlock()
-		{
-			if (--m_writer_depth != 0)
-				return;
-			SpinLockGuard _(m_lock);
-			m_writer = -1;
-			m_thread_blocker.unblock();
-		}
 
 	private:
 		SpinLock m_lock;

kernel/include/kernel/Lock/SpinLock.h

@@ -61,9 +61,6 @@ namespace Kernel
 		uint32_t                             m_lock_depth { 0 };
 	};
 
-	template<typename Lock>
-	class SpinLockGuardAsMutex;
-
 	template<typename Lock>
 	class SpinLockGuard
 	{
@@ -85,7 +82,6 @@ namespace Kernel
 	private:
 		Lock& m_lock;
 		InterruptState m_state;
-		friend class SpinLockGuardAsMutex<Lock>;
 	};
 
 }

kernel/include/kernel/Lock/SpinLockAsMutex.h

@@ -1,64 +0,0 @@
-#pragma once
-
-#include <kernel/Lock/SpinLock.h>
-#include <kernel/Lock/Mutex.h>
-
-namespace Kernel
-{
-
-	// FIXME: These classes are HACKS to allow passing spinlock
-	//        to unblock functions. Write a better API that either
-	//        allows passing spinlocks or do something cleaner that
-	//        whatever shit this is
-
-	template<typename Lock>
-	class SpinLockAsMutex : public BaseMutex
-	{
-	public:
-		SpinLockAsMutex(Lock& lock, InterruptState state)
-			: m_lock(lock)
-			, m_lock_depth(lock.lock_depth())
-			, m_state(state)
-			, m_locker(Thread::current_tid())
-		{
-			ASSERT(m_lock.current_processor_has_lock());
-		}
-
-		void lock() override
-		{
-			m_lock.lock();
-			m_lock_depth++;
-		}
-
-		bool try_lock() override
-		{
-			lock();
-			return true;
-		}
-
-		void unlock() override
-		{
-			m_lock.unlock(--m_lock_depth ? InterruptState::Disabled : m_state);
-		}
-
-		pid_t locker() const override { return is_locked() ? m_locker : -1; }
-		bool is_locked() const override { return m_lock_depth; }
-		uint32_t lock_depth() const override { return m_lock_depth; }
-
-	private:
-		Lock& m_lock;
-		uint32_t m_lock_depth { 0 };
-		InterruptState m_state;
-		const pid_t m_locker;
-	};
-
-	template<typename Lock>
-	class SpinLockGuardAsMutex : public SpinLockAsMutex<Lock>
-	{
-	public:
-		SpinLockGuardAsMutex(SpinLockGuard<Lock>& guard)
-			: SpinLockAsMutex<Lock>(guard.m_lock, guard.m_state)
-		{}
-	};
-
-}

kernel/include/kernel/Memory/MemoryBackedRegion.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <BAN/Vector.h>
 #include <kernel/Memory/MemoryRegion.h>
 
 namespace Kernel

kernel/include/kernel/Memory/SharedMemoryObject.h

@@ -1,30 +1,27 @@
 #pragma once
 
 #include <BAN/HashMap.h>
+#include <BAN/RefPtr.h>
 #include <BAN/UniqPtr.h>
+#include <BAN/Vector.h>
 #include <kernel/Lock/Mutex.h>
 #include <kernel/Lock/SpinLock.h>
 #include <kernel/Memory/MemoryRegion.h>
 
-#include <fcntl.h>
+#include <sys/shm.h>
 
 namespace Kernel
 {
 
-	class SharedMemoryObject;
-
 	class SharedMemoryObjectManager
 	{
-	public:
-		using Key = size_t;
-
 	public:
 		static BAN::ErrorOr<void> initialize();
 		static SharedMemoryObjectManager& get();
 
-		BAN::ErrorOr<Key> create_object(size_t size, PageTable::flags_t);
+		BAN::ErrorOr<int> shmget(key_t key, size_t size, int shmflg);
-		BAN::ErrorOr<void> delete_object(Key);
+		BAN::ErrorOr<void> shmctl(int shmid, int cmd, struct shmid_ds* user_buf);
-		BAN::ErrorOr<BAN::UniqPtr<SharedMemoryObject>> map_object(Key, PageTable&, AddressRange);
+		BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>> shmat(int shmid, const void* shmaddr, int shmflg);
 
 	private:
 		SharedMemoryObjectManager() {}
@@ -32,49 +29,31 @@ namespace Kernel
 	private:
 		struct Object : public BAN::RefCounted<Object>
 		{
+			Object(key_t key, int id, shmid_ds info)
+				: key(key)
+				, id(id)
+				, info(info)
+			{ }
 			~Object();
 
-			Key key;
+			bool can_current_process_access(int flags) const;
-			size_t size;
+
-			PageTable::flags_t flags;
+			const key_t key;
+			const int id;
+			shmid_ds info;
+
+			Mutex mutex;
 			BAN::Vector<paddr_t> paddrs;
-			SpinLock spin_lock;
+			bool marked_for_deletion { false };
 		};
 
 	private:
 		Mutex m_mutex;
-		BAN::HashMap<Key, BAN::RefPtr<Object>> m_objects;
+		BAN::HashMap<key_t, int> m_ids;
+		BAN::HashMap<int, BAN::RefPtr<Object>> m_objects;
 
 		friend class SharedMemoryObject;
 		friend class BAN::UniqPtr<SharedMemoryObjectManager>;
 	};
 
-	class SharedMemoryObject : public MemoryRegion
-	{
-		BAN_NON_COPYABLE(SharedMemoryObject);
-		BAN_NON_MOVABLE(SharedMemoryObject);
-
-	public:
-		static BAN::ErrorOr<BAN::UniqPtr<SharedMemoryObject>> create(BAN::RefPtr<SharedMemoryObjectManager::Object>, PageTable&, AddressRange);
-
-		BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>> clone(PageTable& new_page_table) override;
-		BAN::ErrorOr<BAN::UniqPtr<MemoryRegion>> split(size_t offset) override;
-
-		BAN::ErrorOr<void> msync(vaddr_t, size_t, int) override { return {}; }
-
-	protected:
-		BAN::ErrorOr<bool> allocate_page_containing_impl(vaddr_t vaddr, bool wants_write) override;
-
-	private:
-		SharedMemoryObject(BAN::RefPtr<SharedMemoryObjectManager::Object> object, PageTable& page_table)
-			: MemoryRegion(page_table, object->size, MemoryRegion::Type::SHARED, object->flags, O_EXEC | O_RDWR)
-			, m_object(object)
-		{ }
-
-	private:
-		BAN::RefPtr<SharedMemoryObjectManager::Object> m_object;
-
-		friend class BAN::UniqPtr<SharedMemoryObject>;
-	};
-
 }

kernel/include/kernel/Networking/ARPTable.h

@@ -4,8 +4,6 @@
 #include <BAN/HashMap.h>
 #include <BAN/UniqPtr.h>
 #include <kernel/Networking/NetworkInterface.h>
-#include <kernel/Thread.h>
-#include <kernel/ThreadBlocker.h>
 
 namespace Kernel
 {

kernel/include/kernel/Networking/IPv4Layer.h

@@ -11,7 +11,6 @@
 #include <kernel/Networking/NetworkInterface.h>
 #include <kernel/Networking/NetworkLayer.h>
 #include <kernel/Networking/NetworkSocket.h>
-#include <kernel/Thread.h>
 
 namespace Kernel
 {

kernel/include/kernel/Networking/Loopback.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <kernel/Networking/NetworkInterface.h>
+#include <kernel/Memory/VirtualRange.h>
 
 namespace Kernel
 {

kernel/include/kernel/Networking/TCPSocket.h

@@ -7,7 +7,6 @@
 #include <kernel/Memory/ByteRingBuffer.h>
 #include <kernel/Networking/NetworkInterface.h>
 #include <kernel/Networking/NetworkSocket.h>
-#include <kernel/Thread.h>
 #include <kernel/ThreadBlocker.h>
 
 namespace Kernel

kernel/include/kernel/Networking/UNIX/Socket.h

@@ -6,6 +6,7 @@
 #include <kernel/FS/Socket.h>
 #include <kernel/FS/TmpFS/Inode.h>
 #include <kernel/FS/VirtualFileSystem.h>
+#include <kernel/Memory/VirtualRange.h>
 #include <kernel/OpenFileDescriptorSet.h>
 
 namespace Kernel

kernel/include/kernel/OpenFileDescriptorSet.h

@@ -34,6 +34,7 @@ namespace Kernel
 		BAN::ErrorOr<int> dup2(int, int);
 
 		BAN::ErrorOr<int> fcntl(int fd, int cmd, uintptr_t extra);
+		BAN::ErrorOr<long> ioctl(int fd, unsigned long request, void* arg);
 
 		BAN::ErrorOr<off_t> seek(int fd, off_t offset, int whence);
 		BAN::ErrorOr<off_t> tell(int) const;

kernel/include/kernel/PCI.h

@@ -3,6 +3,8 @@
 #include <BAN/UniqPtr.h>
 #include <BAN/Vector.h>
 #include <kernel/ACPI/AML/Node.h>
+#include <kernel/InterruptNumbers.h>
+#include <kernel/Interruptable.h>
 #include <kernel/Memory/Types.h>
 
 #include <sys/types.h>

kernel/include/kernel/PIC.h

@@ -10,10 +10,10 @@ namespace Kernel
 	{
 	public:
 		virtual void eoi(uint8_t) override;
-		virtual void enable_irq(uint8_t) override;
+		virtual void enable_irq(uint8_t, bool level_triggered) override;
 		virtual bool is_in_service(uint8_t) override;
 
-		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq) override;
+		virtual BAN::ErrorOr<void> reserve_irq(uint8_t irq, bool shared) override;
 		virtual BAN::Optional<uint8_t> get_free_irq() override;
 
 		virtual void initialize_multiprocessor() override;
@@ -29,7 +29,8 @@ namespace Kernel
 
 	private:
 		SpinLock m_lock;
-		uint16_t m_reserved_irqs { 1u << 2 };
+		uint16_t m_used_irqs { 1u << 2 };
+		uint16_t m_excl_irqs { 1u << 2 };
 
 		friend class InterruptController;
 	};

kernel/include/kernel/Process.h

@@ -19,6 +19,7 @@
 
 #include <poll.h>
 #include <sys/banan-os.h>
+#include <sys/epoll.h>
 #include <sys/mman.h>
 #include <sys/select.h>
 #include <sys/socket.h>
@@ -26,8 +27,6 @@
 #include <sys/time.h>
 #include <termios.h>
 
-struct epoll_event;
-
 namespace Kernel
 {
 
@@ -179,9 +178,10 @@ namespace Kernel
 		BAN::ErrorOr<long> sys_mprotect(void* addr, size_t len, int prot);
 		BAN::ErrorOr<long> sys_msync(void* addr, size_t len, int flags);
 
-		BAN::ErrorOr<long> sys_smo_create(size_t len, int prot);
+		BAN::ErrorOr<long> sys_shmget(key_t key, size_t size, int shmflg);
-		BAN::ErrorOr<long> sys_smo_delete(SharedMemoryObjectManager::Key);
+		BAN::ErrorOr<long> sys_shmctl(int shmid, int cmd, struct shmid_ds* buf);
-		BAN::ErrorOr<long> sys_smo_map(SharedMemoryObjectManager::Key);
+		BAN::ErrorOr<long> sys_shmat(int shmid, const void* shmaddr, int shmflg);
+		BAN::ErrorOr<long> sys_shmdt(const void* shmaddr);
 
 		BAN::ErrorOr<long> sys_ttyname(int fildes, char* name, size_t namesize);
 		BAN::ErrorOr<long> sys_posix_openpt(int flags);
@@ -255,6 +255,8 @@ namespace Kernel
 		const VirtualFileSystem::File& working_directory() const { return m_working_directory; }
 		const VirtualFileSystem::File& root_file() const { return m_root_file; }
 
+		BAN::ErrorOr<AddressRange> find_free_address_range(size_t size);
+
 	private:
 		Process(const Credentials&, pid_t pid, pid_t parent, pid_t sid, pid_t pgrp);
 		static Process* create_process(const Credentials&, pid_t parent, pid_t sid = 0, pid_t pgrp = 0);
@@ -280,13 +282,11 @@ namespace Kernel
 		// You must hold reader end of m_mapped_region_lock when calling this.
 		size_t find_mapped_region(vaddr_t) const;
 
-		BAN::ErrorOr<AddressRange> find_free_address_range(size_t size);
-
 		BAN::ErrorOr<VirtualFileSystem::File> find_file(int fd, const char* path, int flags) const;
 		BAN::ErrorOr<FileParent> find_parent_file(int fd, const char* path, int flags) const;
 		BAN::ErrorOr<VirtualFileSystem::File> find_relative_parent(int fd, const char* path) const;
 
-		BAN::ErrorOr<MemoryRegion*> validate_and_pin_pointer_access(const void*, size_t, bool needs_write);
+		BAN::ErrorOr<void> validate_and_pin_pointer_access(const void*, size_t, bool needs_write, BAN::Vector<MemoryRegion*>&);
 
 		uint64_t signal_pending_mask() const
 		{

kernel/include/kernel/Processor.h

@@ -1,17 +1,14 @@
 #pragma once
 
+#include <BAN/Array.h>
 #include <BAN/Atomic.h>
-#include <BAN/ForwardList.h>
+#include <BAN/NoCopyMove.h>
 #include <BAN/Math.h>
 
 #include <kernel/API/SharedPage.h>
 #include <kernel/Arch.h>
-#include <kernel/GDT.h>
-#include <kernel/IDT.h>
-#include <kernel/InterruptStack.h>
 #include <kernel/Memory/Types.h>
 #include <kernel/ProcessorID.h>
-#include <kernel/Scheduler.h>
 
 namespace Kernel
 {
@@ -22,6 +19,11 @@ namespace Kernel
 		Enabled,
 	};
 
+	class GDT;
+	class IDT;
+	class Scheduler;
+	class Thread;
+
 #if ARCH(x86_64) || ARCH(i686)
 	class Processor
 	{
@@ -51,8 +53,8 @@ namespace Kernel
 			union
 			{
 				TLBEntry flush_tlb;
-				SchedulerQueue::Node* new_thread;
+				Thread* new_thread;
-				SchedulerQueue::Node* unblock_thread;
+				Thread* unblock_thread;
 				bool dummy;
 			};
 		};
@@ -104,10 +106,17 @@ namespace Kernel
 		static void pause()
 		{
 			__builtin_ia32_pause();
-			if (is_smp_enabled())
+			if (is_smp_enabled() && !smp_messages_disabled())
 				handle_smp_messages();
 		}
 
+		static bool smp_messages_disabled() { return read_gs_sized<bool>(offsetof(Processor, m_smp_messages_disabled)); }
+		static void set_disable_smp_messages(bool disabled)
+		{
+			ASSERT(smp_messages_disabled() != disabled);
+			write_gs_sized<bool>(offsetof(Processor, m_smp_messages_disabled), disabled);
+		}
+
 		vaddr_t stack_top_vaddr() const { return m_stack_vaddr + s_stack_size; }
 		paddr_t stack_top_paddr() const { return m_stack_paddr + s_stack_size; }
 
@@ -172,17 +181,23 @@ namespace Kernel
 		}
 
 		template<typename T>
-		static T read_gs_sized(uintptr_t offset) requires(sizeof(T) <= 8 && BAN::Math::is_power_of_two(sizeof(T)))
+		static T read_gs_sized(uintptr_t offset) requires(sizeof(T) <= sizeof(uintptr_t) && BAN::Math::is_power_of_two(sizeof(T)))
 		{
 			T value;
-			asm volatile("mov %%gs:%a[offset], %[value]" : [value]"=r"(value) : [offset]"ir"(offset));
+			if constexpr (sizeof(T) == 1 && ARCH(i686))
+				asm volatile("mov %%gs:%a[offset], %[value]" : [value]"=q"(value) : [offset]"ir"(offset) : "memory");
+			else
+				asm volatile("mov %%gs:%a[offset], %[value]" : [value]"=r"(value) : [offset]"ir"(offset) : "memory");
 			return value;
 		}
 
 		template<typename T>
-		static void write_gs_sized(uintptr_t offset, T value) requires(sizeof(T) <= 8 && BAN::Math::is_power_of_two(sizeof(T)))
+		static void write_gs_sized(uintptr_t offset, T value) requires(sizeof(T) <= sizeof(uintptr_t) && BAN::Math::is_power_of_two(sizeof(T)))
 		{
-			asm volatile("mov %[value], %%gs:%a[offset]" :: [value]"r"(value), [offset]"ir"(offset) : "memory");
+			if constexpr (sizeof(T) == 1 && ARCH(i686))
+				asm volatile("mov %[value], %%gs:%a[offset]" :: [value]"q"(value), [offset]"ir"(offset) : "memory");
+			else
+				asm volatile("mov %[value], %%gs:%a[offset]" :: [value]"r"(value), [offset]"ir"(offset) : "memory");
 		}
 
 		void lock_tlb_lock();
@@ -198,6 +213,8 @@ namespace Kernel
 		ProcessorID m_id { 0 };
 		uint8_t m_index { 0 };
 
+		bool m_smp_messages_disabled { false };
+
 		vaddr_t m_thread_syscall_stack;
 
 		Thread* m_sse_thread { nullptr };

kernel/include/kernel/Scheduler.h

@@ -5,6 +5,7 @@
 #include <BAN/NoCopyMove.h>
 #include <kernel/InterruptStack.h>
 #include <kernel/ProcessorID.h>
+#include <kernel/SchedulerThreadNode.h>
 
 #include <sys/types.h>
 
@@ -14,29 +15,6 @@ namespace Kernel
 	class BaseMutex;
 	class Thread;
 	class ThreadBlocker;
-	struct SchedulerQueueNode;
-
-	class SchedulerQueue
-	{
-	public:
-		using Node = SchedulerQueueNode;
-
-	public:
-		void add_thread_to_back(Node*);
-		bool add_thread_with_wake_time(Node*); // return true if node was inserted as the first element
-		template<typename F>
-		Node* remove_with_condition(F callback);
-		void remove_node(Node*);
-		Node* front();
-		Node* pop_front();
-
-		bool empty() const { return m_head == nullptr; }
-
-	private:
-		Node* m_head { nullptr };
-		Node* m_tail { nullptr };
-	};
-
 	class Scheduler
 	{
 		BAN_NON_COPYABLE(Scheduler);
@@ -45,12 +23,12 @@ namespace Kernel
 	public:
 		struct NewThreadRequest
 		{
-			SchedulerQueue::Node* node;
+			SchedulerThreadNode* node;
 		};
 
 		struct UnblockRequest
 		{
-			SchedulerQueue::Node* node;
+			SchedulerThreadNode* node;
 		};
 
 	public:
@@ -58,14 +36,13 @@ namespace Kernel
 		BAN::ErrorOr<void> initialize();
 
 		void reschedule(YieldRegisters*);
-		void reschedule_if_idle();
+		void reschedule_if_needed();
 
 		void on_timer_interrupt();
 		void on_yield(YieldRegisters*);
 
-		static BAN::ErrorOr<void> bind_thread_to_processor(Thread*, ProcessorID);
+		static void bind_thread_to_processor(Thread*, ProcessorID);
-		// if thread is already bound, this will never fail
+		void add_thread(Thread*);
-		BAN::ErrorOr<void> add_thread(Thread*);
 
 		void block_current_thread(ThreadBlocker* thread_blocker, uint64_t wake_time_ns, BaseMutex* mutex);
 		void unblock_thread(Thread*);
@@ -79,9 +56,9 @@ namespace Kernel
 	private:
 		Scheduler() = default;
 
-		void add_current_to_most_loaded(SchedulerQueue* target_queue);
+		void add_current_to_most_loaded(void* target_list);
-		void update_most_loaded_node_queue(SchedulerQueue::Node*, SchedulerQueue* target_queue);
+		void update_most_loaded_node_list(SchedulerThreadNode*, void* target_list);
-		void remove_node_from_most_loaded(SchedulerQueue::Node*);
+		void remove_node_from_most_loaded(SchedulerThreadNode*);
 
 		void update_wake_up_deadline();
 		void wake_up_sleeping_threads();
@@ -90,13 +67,10 @@ namespace Kernel
 
 		class ProcessorID find_least_loaded_processor() const;
 
-		void add_thread(SchedulerQueue::Node*);
-		void unblock_thread(SchedulerQueue::Node*);
-
 	private:
-		SchedulerQueue m_run_queue;
+		SchedulerQueue m_run_list;
-		SchedulerQueue m_block_queue;
+		SchedulerHeap m_block_list;
-		SchedulerQueue::Node* m_current { nullptr };
+		SchedulerThreadNode* m_current { nullptr };
 
 		uint32_t m_thread_count { 0 };
 
@@ -108,8 +82,8 @@ namespace Kernel
 
 		struct ThreadInfo
 		{
-			SchedulerQueue*       queue { nullptr };
+			void*                list { nullptr };
-			SchedulerQueue::Node* node  { nullptr };
+			SchedulerThreadNode* node { nullptr };
 		};
 		BAN::Array<ThreadInfo, 10> m_most_loaded_threads;
 
@@ -118,6 +92,8 @@ namespace Kernel
 
 		bool m_should_calculate_max_load_threads { true };
 
+		bool m_has_pending_reschedule { false };
+
 		Thread* m_idle_thread { nullptr };
 
 		friend class ThreadBlocker;

kernel/include/kernel/SchedulerQueueNode.h

@@ -1,36 +0,0 @@
-#pragma once
-
-#include <kernel/ProcessorID.h>
-#include <kernel/Lock/SpinLock.h>
-
-namespace Kernel
-{
-
-	class Thread;
-	class ThreadBlocker;
-
-	struct SchedulerQueueNode
-	{
-		SchedulerQueueNode(Thread* thread)
-			: thread(thread)
-		{}
-
-		Thread* const thread;
-
-		SchedulerQueueNode* next { nullptr };
-		SchedulerQueueNode* prev { nullptr };
-
-		uint64_t wake_time_ns { static_cast<uint64_t>(-1) };
-
-		BAN::Atomic<ThreadBlocker*> blocker { nullptr };
-		SchedulerQueueNode* block_chain_prev { nullptr };
-		SchedulerQueueNode* block_chain_next { nullptr };
-
-		ProcessorID processor_id { PROCESSOR_NONE };
-		bool blocked { false };
-
-		uint64_t last_start_ns { 0 };
-		uint64_t time_used_ns  { 0 };
-	};
-
-}

kernel/include/kernel/SchedulerThreadNode.h

@@ -0,0 +1,96 @@
+#pragma once
+
+#include <BAN/Atomic.h>
+#include <BAN/NoCopyMove.h>
+#include <kernel/ProcessorID.h>
+
+namespace Kernel
+{
+
+	class Thread;
+	class ThreadBlocker;
+
+	struct SchedulerThreadNode
+	{
+		SchedulerThreadNode(Thread* thread)
+			: thread(thread)
+			, heap({ nullptr, nullptr, nullptr })
+		{}
+
+		Thread* const thread;
+
+		union
+		{
+			struct
+			{
+				SchedulerThreadNode* next;
+				SchedulerThreadNode* prev;
+			} queue;
+			struct
+			{
+				SchedulerThreadNode* parent;
+				SchedulerThreadNode* lchild;
+				SchedulerThreadNode* rchild;
+			} heap;
+		};
+
+		uint64_t wake_time_ns { static_cast<uint64_t>(-1) };
+
+		BAN::Atomic<ThreadBlocker*> blocker { nullptr };
+		SchedulerThreadNode* block_chain_prev { nullptr };
+		SchedulerThreadNode* block_chain_next { nullptr };
+
+		ProcessorID processor_id { PROCESSOR_NONE };
+		bool blocked { false };
+
+		uint64_t last_start_ns { 0 };
+		uint64_t time_used_ns  { 0 };
+	};
+
+	class SchedulerQueue
+	{
+		BAN_NON_COPYABLE(SchedulerQueue);
+		BAN_NON_MOVABLE(SchedulerQueue);
+	public:
+		SchedulerQueue() = default;
+
+		SchedulerThreadNode* front();
+		SchedulerThreadNode* pop_front();
+
+		void push(SchedulerThreadNode*);
+		void pop(SchedulerThreadNode*);
+
+		void walk(void (*)(const SchedulerThreadNode*, void*), void*) const;
+		bool empty() const { return m_head == nullptr; }
+
+	private:
+		SchedulerThreadNode* m_head { nullptr };
+		SchedulerThreadNode* m_tail { nullptr };
+	};
+
+	class SchedulerHeap
+	{
+		BAN_NON_COPYABLE(SchedulerHeap);
+		BAN_NON_MOVABLE(SchedulerHeap);
+	public:
+		SchedulerHeap() = default;
+
+		SchedulerThreadNode* front();
+		SchedulerThreadNode* pop_front();
+
+		void push(SchedulerThreadNode*);
+		void pop(SchedulerThreadNode*);
+
+		void walk(void (*)(const SchedulerThreadNode*, void*), void*) const;
+		bool empty() const { return m_root == nullptr; }
+
+	private:
+		void walk_impl(void (*)(const SchedulerThreadNode*, void*), void*, const SchedulerThreadNode*) const;
+		void swap_nodes(SchedulerThreadNode*, SchedulerThreadNode*);
+
+	private:
+		SchedulerThreadNode* m_root { nullptr };
+		SchedulerThreadNode* m_last { nullptr };
+	};
+
+}

kernel/include/kernel/Storage/ATA/AHCI/Controller.h

@@ -22,6 +22,7 @@ namespace Kernel
 
 		virtual void handle_irq() override;
 
+		bool supports_64bit() const { return m_supports_64bit; }
 		uint32_t command_slot_count() const { return m_command_slot_count; }
 
 	private:
@@ -38,9 +39,8 @@ namespace Kernel
 
 		BAN::Array<AHCIDevice*, 32> m_devices;
 
+		bool m_supports_64bit { false };
 		uint32_t m_command_slot_count { 0 };
-
-		friend class ATAController;
 	};
 
 }

kernel/include/kernel/Storage/ATA/AHCI/Definitions.h

@@ -32,8 +32,6 @@
 namespace Kernel
 {
 
-	static constexpr uint32_t s_hba_prdt_count { 8 };
-
 	struct FISRegisterH2D
 	{
 		uint8_t  fis_type;			// FIS_TYPE_REGISTER_H2D
@@ -61,7 +59,8 @@ namespace Kernel
 		uint8_t  control;
 
 		uint8_t  __reserved1[4];
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(FISRegisterH2D) == 20);
 
 	struct FISRegisterD2H
 	{
@@ -90,7 +89,8 @@ namespace Kernel
 		uint8_t  __reserved3[2];
 
 		uint8_t  __reserved4[4];
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(FISRegisterD2H) == 20);
 
 	struct FISDataBI
 	{
@@ -102,7 +102,8 @@ namespace Kernel
 		uint8_t  __reserved1[2];
 
 		uint32_t data[0];			// Payload (1 - 2048 dwords)
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(FISDataBI) == 4);
 
 	struct SetDeviceBitsD2H
 	{
@@ -117,7 +118,8 @@ namespace Kernel
 		uint8_t error;
 
 		uint32_t __reserved1;
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(SetDeviceBitsD2H) == 8);
 
 	struct PIOSetupD2H
 	{
@@ -149,7 +151,8 @@ namespace Kernel
 
 		uint16_t tc;				// Transfer count
 		uint8_t  __reserved4[2];
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(PIOSetupD2H) == 20);
 
 	struct DMASetupBI
 	{
@@ -163,8 +166,8 @@ namespace Kernel
 
 		uint8_t  __reserved1[2];
 
-		uint64_t dma_buffer_id;			// DMA Buffer Identifier. Used to Identify DMA buffer in host memory.
+		uint32_t dma_buffer_id_lo;		// DMA Buffer Identifier. Used to Identify DMA buffer in host memory.
-										// SATA Spec says host specific and not in Spec. Trying AHCI spec might work.
+		uint32_t dma_buffer_id_hi;		// SATA Spec says host specific and not in Spec. Trying AHCI spec might work.
 
 		uint32_t __reserved2;
 
@@ -173,7 +176,8 @@ namespace Kernel
 		uint32_t dma_transfer_count;	// Number of bytes to transfer. Bit 0 must be 0
 
 		uint32_t __reserved3;
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(DMASetupBI) == 28);
 
 	struct HBAPortMemorySpace
 	{
@@ -196,7 +200,8 @@ namespace Kernel
 		uint32_t fbs;		// FIS-based switch control
 		uint32_t __reserved1[11];
 		uint32_t vendor[4];
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(HBAPortMemorySpace) == 128);
 
 	struct HBAGeneralMemorySpace
 	{
@@ -217,7 +222,8 @@ namespace Kernel
 		uint8_t  vendor[0x100-0xA0];
 
 		HBAPortMemorySpace ports[0]; // 1 - 32 ports
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(HBAGeneralMemorySpace) == 256);
 
 	struct ReceivedFIS
 	{
@@ -235,7 +241,8 @@ namespace Kernel
 		uint8_t				ufis[64];
 
 		uint8_t				__reserved[0x100-0xA0];
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(ReceivedFIS) == 256);
 
 	struct HBACommandHeader
 	{
@@ -252,13 +259,14 @@ namespace Kernel
 
 		uint16_t prdtl;		// Physical region descriptor table length in entries
 
-		volatile uint32_t prdbc;	// Physical region descriptor byte count transferred
+		uint32_t prdbc;		// Physical region descriptor byte count transferred
 
 		uint32_t ctba;		// Command table descriptor base address
 		uint32_t ctbau;		// Command table descriptor base address upper 32 bits
 
 		uint32_t __reserved1[4];
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(HBACommandHeader) == 32);
 
 	struct HBAPRDTEntry
 	{
@@ -269,15 +277,17 @@ namespace Kernel
 		uint32_t dbc : 22;		// Byte count, 4M max
 		uint32_t __reserved1 : 9;
 		uint32_t i : 1;			// Interrupt on completion
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(HBAPRDTEntry) == 16);
 
 	struct HBACommandTable
 	{
 		uint8_t cfis[64];
 		uint8_t acmd[16];
 		uint8_t __reserved[48];
-		HBAPRDTEntry prdt_entry[s_hba_prdt_count];
+		HBAPRDTEntry prdt_entry[0];
-	} __attribute__((packed));
+	};
+	static_assert(sizeof(HBACommandTable) == 128);
 
 	enum class AHCIPortType
 	{

kernel/include/kernel/Storage/ATA/AHCI/Device.h

@@ -20,30 +20,39 @@ namespace Kernel
 			, m_port(port)
 		{ }
 		BAN::ErrorOr<void> initialize();
-		BAN::ErrorOr<void> allocate_buffers();
 		BAN::ErrorOr<void> rebase();
 		BAN::ErrorOr<void> read_identify_data();
 
+		paddr_t read_paddr(volatile uint32_t& lo, volatile uint32_t& hi) const;
+		void write_paddr(volatile uint32_t& lo, volatile uint32_t& hi, paddr_t paddr);
+
+		bool can_use_buffer_directly(BAN::ConstByteSpan buffer) const;
+
 		virtual BAN::ErrorOr<void> read_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ByteSpan) override;
 		virtual BAN::ErrorOr<void> write_sectors_impl(uint64_t lba, uint64_t sector_count, BAN::ConstByteSpan) override;
-		BAN::ErrorOr<void> send_command_and_block(uint64_t lba, uint64_t sector_count, Command command);
+		BAN::ErrorOr<size_t> send_command_sync(uint64_t lba, BAN::ConstByteSpan buffer, Command command);
 
-		BAN::Optional<uint32_t> find_free_command_slot();
+		BAN::ErrorOr<void> send_command_and_wait(uint32_t slot);
+		BAN::ErrorOr<uint32_t> find_free_command_slot();
 
 		void handle_irq();
 
-		BAN::ErrorOr<void> block_until_command_completed(uint32_t command_slot);
-
 	private:
-		Mutex m_mutex;
+		static constexpr uint32_t m_max_hba_prdt_count { 64 };
+
+		BAN::Atomic<uint32_t> m_prev_is { 0 };
+		uint32_t m_free_slots { 0 };
 
 		BAN::RefPtr<AHCIController> m_controller;
 		volatile HBAPortMemorySpace* const m_port;
 
 		BAN::UniqPtr<DMARegion> m_dma_region;
-		// Intermediate read/write buffer
+
-		// TODO: can we read straight to user buffer?
+		Mutex m_temp_buffer_mutex;
-		BAN::UniqPtr<DMARegion> m_data_dma_region;
+		BAN::UniqPtr<DMARegion> m_temp_buffer;
+
+		SpinLock m_command_lock;
+		ThreadBlocker m_command_blocker;
 
 		friend class AHCIController;
 	};

kernel/include/kernel/Terminal/PseudoTerminal.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <BAN/WeakPtr.h>
+#include <kernel/Memory/VirtualRange.h>
 #include <kernel/Terminal/TTY.h>
 
 namespace Kernel

kernel/include/kernel/Terminal/TTY.h

@@ -53,6 +53,8 @@ namespace Kernel
 
 		virtual bool master_has_closed() const { return false; }
 
+		virtual bool is_vtty() const { return false; }
+
 	protected:
 		TTY(termios termios, mode_t mode, uid_t uid, gid_t gid);
 
@@ -100,9 +102,9 @@ namespace Kernel
 		termios m_termios;
 
 	protected:
-		Mutex m_mutex;
+		Mutex m_input_mutex;
 
-		Mutex m_write_lock;
+		RecursiveSpinLock m_write_lock;
 		ThreadBlocker m_write_blocker;
 	};
 

kernel/include/kernel/Terminal/VirtualTTY.h

@@ -21,6 +21,9 @@ namespace Kernel
 
 		void clear() override;
 
+		bool is_vtty() const override { return true; }
+		BAN::ErrorOr<void> set_terminal_driver(BAN::RefPtr<TerminalDriver>);
+
 	protected:
 		BAN::StringView name() const override { return m_name; }
 		bool putchar_impl(uint8_t ch) override;
@@ -96,8 +99,6 @@ namespace Kernel
 		uint32_t m_last_cursor_row { static_cast<uint32_t>(-1) };
 		uint32_t m_last_cursor_column { static_cast<uint32_t>(-1) };
 
-		const Palette& m_palette;
-
 		TerminalDriver::Color m_foreground;
 		TerminalDriver::Color m_background;
 		bool m_colors_inverted { false };

kernel/include/kernel/Thread.h

@@ -5,8 +5,9 @@
 #include <BAN/RefPtr.h>
 #include <BAN/UniqPtr.h>
 #include <kernel/InterruptStack.h>
+#include <kernel/Lock/Mutex.h>
 #include <kernel/Memory/VirtualRange.h>
-#include <kernel/ThreadBlocker.h>
+#include <kernel/SchedulerThreadNode.h>
 
 #include <LibELF/AuxiliaryVector.h>
 
@@ -18,6 +19,7 @@ namespace Kernel
 
 	class MemoryBackedRegion;
 	class Process;
+	class ThreadBlocker;
 
 	class Thread
 	{
@@ -124,10 +126,14 @@ namespace Kernel
 
 		bool is_userspace() const { return m_is_userspace; }
 
-		uint64_t cpu_time_ns() const;
+		uint64_t cpu_time_total_ns() const;
+		void cpu_time_ns(uint64_t& user_ns, uint64_t& system_ns) const;
 		void set_cpu_time_start();
 		void set_cpu_time_stop();
 
+		void set_is_in_syscall(bool is_in_syscall);
+		bool is_in_syscall() const { return m_is_in_syscall; }
+
 		void update_processor_index_address();
 
 		void set_fsbase(vaddr_t base) { m_fsbase = base; }
@@ -187,7 +193,7 @@ namespace Kernel
 		vaddr_t                    m_fsbase               { 0 };
 		vaddr_t                    m_gsbase               { 0 };
 
-		SchedulerQueue::Node*      m_scheduler_node       { nullptr };
+		SchedulerThreadNode        m_scheduler_node;
 
 		YieldRegisters             m_yield_registers      { };
 
@@ -200,8 +206,10 @@ namespace Kernel
 		static_assert(_SIGMAX < 64);
 
 		mutable SpinLock           m_cpu_time_lock;
-		uint64_t                   m_cpu_time_ns          { 0 };
+		uint64_t                   m_cpu_time_user_ns     { 0 };
+		uint64_t                   m_cpu_time_system_ns   { 0 };
 		uint64_t                   m_cpu_time_start_ns    { UINT64_MAX };
+		BAN::Atomic<bool>          m_is_in_syscall        { false };
 
 		BAN::Atomic<uint32_t>      m_spinlock_count       { 0 };
 		BAN::Atomic<uint32_t>      m_mutex_count          { 0 };

kernel/include/kernel/ThreadBlocker.h

@@ -1,12 +1,14 @@
 #pragma once
 
 #include <BAN/Math.h>
+#include <kernel/Lock/Mutex.h>
 #include <kernel/Lock/SpinLock.h>
-#include <kernel/Scheduler.h>
 
 namespace Kernel
 {
 
+	class SchedulerThreadNode;
+
 	class ThreadBlocker
 	{
 	public:
@@ -27,11 +29,11 @@ namespace Kernel
 		}
 
 	private:
-		void add_thread_to_block_queue(SchedulerQueue::Node*);
+		void add_thread_to_block_queue(SchedulerThreadNode*);
-		void remove_thread_from_block_queue(SchedulerQueue::Node*);
+		void remove_thread_from_block_queue(SchedulerThreadNode*);
 
 	private:
-		SchedulerQueue::Node* m_block_chain { nullptr };
+		SchedulerThreadNode* m_block_chain { nullptr };
 		SpinLock m_lock;
 
 		friend class Scheduler;

kernel/include/kernel/USB/Definitions.h

@@ -30,6 +30,7 @@ namespace Kernel
 			Hub                        = 0x09,
 			BillboardDeviceClass       = 0x11,
 			DiagnosticDevice           = 0xDC,
+			WirelessController         = 0xE0,
 			Miscellaneous              = 0xEF,
 			VendorSpecific             = 0xFF,
 		};

kernel/include/kernel/USB/Device.h

@@ -23,6 +23,8 @@ namespace Kernel
 
 		virtual void handle_stall(uint8_t endpoint_id) = 0;
 		virtual void handle_input_data(size_t byte_count, uint8_t endpoint_id) = 0;
+
+		virtual bool is_hid_driver() const { return false; }
 	};
 
 	class USBDevice
@@ -62,6 +64,12 @@ namespace Kernel
 			uint8_t tt_think_time;
 		};
 
+		struct HIDInfo
+		{
+			BAN::Atomic<uint32_t> led_mask { 0 };
+			BAN::Vector<USBClassDriver*> led_controls;
+		};
+
 	public:
 		USBDevice(USBController& controller, USB::SpeedClass speed_class, uint8_t depth)
 			: m_controller(controller)
@@ -92,6 +100,8 @@ namespace Kernel
 		void register_hub_to_init() { m_controller.register_hub_to_init(m_depth + 1); };
 		void mark_hub_init_done() { m_controller.mark_hub_init_done(m_depth + 1); };
 
+		void update_led_mask(uint32_t led_mask);
+
 	protected:
 		void handle_stall(uint8_t endpoint_id);
 		void handle_input_data(size_t byte_count, uint8_t endpoint_id);
@@ -112,6 +122,7 @@ namespace Kernel
 		BAN::UniqPtr<DMARegion> m_dma_buffer;
 
 		BAN::Vector<BAN::UniqPtr<USBClassDriver>> m_class_drivers;
+		HIDInfo m_hid_info;
 	};
 
 }

kernel/include/kernel/USB/HID/HIDDriver.h

@@ -74,6 +74,7 @@ namespace Kernel
 		struct DeviceReport
 		{
 			BAN::Vector<USBHID::Report> inputs;
+			BAN::Vector<USBHID::Report> outputs;
 			BAN::RefPtr<USBHIDDevice> device;
 		};
 
@@ -81,27 +82,43 @@ namespace Kernel
 		void handle_stall(uint8_t endpoint_id) override;
 		void handle_input_data(size_t byte_count, uint8_t endpoint_id) override;
 
+		bool is_hid_driver() const override { return true; }
+
 		USBDevice& device() { return m_device; }
 		const USBDevice::InterfaceDescriptor& interface() const { return m_interface; }
 
+		bool has_led_control() const { return !m_led_controls.empty(); }
+		void set_leds(uint32_t led_mask);
+
 	private:
 		USBHIDDriver(USBDevice&, const USBDevice::InterfaceDescriptor&);
 		~USBHIDDriver();
 
 		BAN::ErrorOr<void> initialize() override;
 
-		BAN::ErrorOr<BAN::Vector<DeviceReport>> initializes_device_reports(const BAN::Vector<USBHID::Collection>&);
+		BAN::ErrorOr<void> initializes_device_reports(const BAN::Vector<USBHID::Collection>&);
+
+	private:
+		struct LEDControl
+		{
+			DeviceReport* report;
+			uint32_t report_id;
+			uint32_t report_bits;
+		};
 
 	private:
 		USBDevice& m_device;
 		USBDevice::InterfaceDescriptor m_interface;
 
 		bool m_uses_report_id { false };
-		BAN::Vector<DeviceReport> m_device_inputs;
+		BAN::Vector<DeviceReport> m_device_reports;
 
 		uint8_t m_data_endpoint_id = 0;
 		BAN::UniqPtr<DMARegion> m_data_buffer;
 
+		BAN::Vector<LEDControl> m_led_controls;
+		BAN::UniqPtr<DMARegion> m_led_region;
+
 		friend class BAN::UniqPtr<USBHIDDriver>;
 	};
 

kernel/include/kernel/USB/HID/Keyboard.h

@@ -11,8 +11,6 @@ namespace Kernel
 		BAN_NON_MOVABLE(USBKeyboard);
 
 	public:
-		BAN::ErrorOr<void> initialize() override;
-
 		void start_report() override;
 		void stop_report() override;
 
@@ -23,12 +21,9 @@ namespace Kernel
 		void update() override;
 
 	private:
-		USBKeyboard(USBHIDDriver& driver, BAN::Vector<USBHID::Report>&& outputs);
+		USBKeyboard(USBHIDDriver& driver);
 		~USBKeyboard() = default;
 
-		void set_leds(uint16_t mask);
-		void set_leds(uint8_t report_id, uint16_t mask);
-
 	private:
 		USBHIDDriver& m_driver;
 
@@ -38,11 +33,7 @@ namespace Kernel
 		BAN::Array<bool, 0x100> m_keyboard_state      { false };
 		BAN::Array<bool, 0x100> m_keyboard_state_temp { false };
 		uint16_t m_toggle_mask { 0 };
-
 		uint16_t m_led_mask { 0 };
-		BAN::UniqPtr<DMARegion> m_led_region;
-
-		BAN::Vector<USBHID::Report> m_outputs;
 
 		BAN::Optional<uint8_t> m_repeat_scancode;
 		uint8_t m_repeat_modifier { 0 };

kernel/include/kernel/USB/Hub/HubDriver.h

@@ -1,6 +1,5 @@
 #pragma once
 
-#include <kernel/Process.h>
 #include <kernel/USB/Device.h>
 
 namespace Kernel

kernel/include/kernel/USB/XHCI/Definitions.h

@@ -373,6 +373,33 @@ namespace Kernel::XHCI
 				uint32_t slot_id               : 8;
 			} configure_endpoint_command;
 
+			struct
+			{
+				uint32_t             : 32;
+				uint32_t             : 32;
+				uint32_t             : 32;
+				uint32_t cycle_bit   : 1;
+				uint32_t             : 8;
+				uint32_t tsp         : 1;
+				uint32_t trb_type    : 6;
+				uint32_t endpoint_id : 5;
+				uint32_t             : 3;
+				uint32_t slot_id     : 8;
+			} reset_endpoint_command;
+
+			struct
+			{
+				uint64_t new_tr_deque_pointer : 64;
+				uint32_t                      : 16;
+				uint32_t stream_id            : 16;
+				uint32_t cycle_bit            : 1;
+				uint32_t                      : 9;
+				uint32_t trb_type             : 6;
+				uint32_t endpoint_id          : 5;
+				uint32_t                      : 3;
+				uint32_t slot_id              : 8;
+			} set_tr_deque_pointer_command;
+
 			struct
 			{
 				uint64_t ring_segment_ponter     : 64;

kernel/kernel/ACPI/ACPI.cpp

@@ -6,9 +6,9 @@
 #include <kernel/BootInfo.h>
 #include <kernel/InterruptController.h>
 #include <kernel/IO.h>
-#include <kernel/Lock/SpinLockAsMutex.h>
 #include <kernel/Memory/PageTable.h>
 #include <kernel/Process.h>
+#include <kernel/Scheduler.h>
 #include <kernel/Timer/Timer.h>
 
 #define RSPD_SIZE	20
@@ -784,30 +784,10 @@ acpi_release_global_lock:
 
 	BAN::ErrorOr<void> ACPI::initialize_embedded_controller(const AML::Scope& embedded_controller)
 	{
-		BAN::Optional<uint8_t> gpe_int;
-
-		do {
-			auto [gpe_path, gpe_obj] = TRY(m_namespace->find_named_object(embedded_controller, TRY(AML::NameString::from_string("_GPE"_sv)), true));
-			if (gpe_obj == nullptr)
-			{
-				dwarnln("EC {} does have _GPE", embedded_controller);
-				break;
-			}
-
-			auto gpe = TRY(AML::evaluate_node(gpe_path, gpe_obj->node));
-			if (gpe.type == AML::Node::Type::Package)
-			{
-				dwarnln("TODO: EC {} has package _GPE");
-				break;
-			}
-
-			gpe_int = TRY(AML::convert_node(BAN::move(gpe), AML::ConvInteger, -1)).as.integer.value;
-		} while (false);
-
 		auto [crs_path, crs_obj] = TRY(m_namespace->find_named_object(embedded_controller, TRY(AML::NameString::from_string("_CRS"_sv)), true));
 		if (crs_obj == nullptr)
 		{
-			dwarnln("EC {} does have _CRS", embedded_controller);
+			dwarnln("EC {} does not have _CRS", embedded_controller);
 			return BAN::Error::from_errno(ENOENT);
 		}
 
@@ -857,7 +837,7 @@ acpi_release_global_lock:
 		const auto data_port = TRY(extract_io_port(crs_buffer));
 		const auto command_port = TRY(extract_io_port(crs_buffer));
 
-		TRY(m_embedded_controllers.push_back(TRY(EmbeddedController::create(TRY(embedded_controller.copy()), command_port, data_port, gpe_int))));
+		TRY(m_embedded_controllers.push_back(TRY(EmbeddedController::create(TRY(embedded_controller.copy()), command_port, data_port))));
 		return {};
 	}
 
@@ -877,6 +857,33 @@ acpi_release_global_lock:
 		return {};
 	}
 
+	void ACPI::initialize_embedded_controller_gpes()
+	{
+		const auto initialize_gpe = [this](EmbeddedController& embedded_controller) -> BAN::ErrorOr<void> {
+			auto [gpe_path, gpe_obj] = TRY(m_namespace->find_named_object(embedded_controller.scope(), TRY(AML::NameString::from_string("_GPE"_sv)), true));
+			if (gpe_obj == nullptr)
+			{
+				dprintln("EC {} does not have _GPE", embedded_controller.scope());
+				return {};
+			}
+
+			auto gpe = TRY(AML::evaluate_node(gpe_path, gpe_obj->node));
+			if (gpe.type == AML::Node::Type::Package)
+			{
+				dwarnln("TODO: EC {} has package _GPE");
+				return {};
+			}
+
+			const auto gpe_int = TRY(AML::convert_node(BAN::move(gpe), AML::ConvInteger, -1)).as.integer.value;
+			TRY(register_gpe_handler(gpe_int, &EmbeddedController::handle_gpe_trampoline, &embedded_controller));
+
+			return {};
+		};
+
+		for (auto& embedded_controller : m_embedded_controllers)
+			(void)initialize_gpe(*embedded_controller);
+	}
+
 	BAN::ErrorOr<void> ACPI::register_gpe_handler(uint8_t gpe, void (*callback)(void*), void* argument)
 	{
 		if (m_gpe_methods[gpe].method)
@@ -935,7 +942,7 @@ acpi_release_global_lock:
 		return false;
 	}
 
-	BAN::ErrorOr<void> ACPI::enter_acpi_mode(uint8_t mode)
+	BAN::ErrorOr<void> ACPI::enter_acpi_mode()
 	{
 		ASSERT(!m_namespace);
 
@@ -996,57 +1003,27 @@ acpi_release_global_lock:
 			// FIXME: add support for GPE blocks inside the ACPI namespace
 		}
 
-		if (auto ret = initialize_embedded_controllers(); ret.is_error())
-			dwarnln("Failed to initialize Embedded Controllers: {}", ret.error());
-
-		if (auto ret = m_namespace->post_load_initialize(); ret.is_error())
-			dwarnln("Failed to initialize ACPI namespace: {}", ret.error());
-
-		auto [pic_path, pic_obj] = TRY(m_namespace->find_named_object({}, TRY(AML::NameString::from_string("\\_PIC"_sv))));
-		if (pic_obj && pic_obj->node.type == AML::Node::Type::Method)
-		{
-			auto& pic_node = pic_obj->node;
-			if (pic_node.as.method.arg_count != 1)
-			{
-				dwarnln("Method \\_PIC has {} arguments, expected 1", pic_node.as.method.arg_count);
-				return BAN::Error::from_errno(EINVAL);
-			}
-
-			AML::Reference arg_ref;
-			arg_ref.node.type = AML::Node::Type::Integer;
-			arg_ref.node.as.integer.value = mode;
-			arg_ref.ref_count = 2;
-
-			BAN::Array<AML::Reference*, 7> arguments(nullptr);
-			arguments[0] = &arg_ref; // method call should not delete argument
-			TRY(AML::method_call(pic_path, pic_node, BAN::move(arguments)));
-		}
-
-		dprintln("Evaluated \\_PIC({})", mode);
-
 		uint8_t irq = fadt().sci_int;
 		if (auto ret = InterruptController::get().reserve_irq(irq); ret.is_error())
 			dwarnln("Could not enable ACPI interrupt: {}", ret.error());
 		else
 		{
-			auto hex_sv_to_int =
+			const auto hex_sv_to_int = [](BAN::StringView sv) -> BAN::Optional<uint32_t> {
-				[](BAN::StringView sv) -> BAN::Optional<uint32_t>
+				uint32_t ret = 0;
+				for (char c : sv)
 				{
-					uint32_t ret = 0;
+					ret <<= 4;
-					for (char c : sv)
+					if (c >= '0' && c <= '9')
-					{
+						ret += c - '0';
-						ret <<= 4;
+					else if (c >= 'A' && c <= 'F')
-						if (c >= '0' && c <= '9')
+						ret += c - 'A' + 10;
-							ret += c - '0';
+					else if (c >= 'a' && c <= 'f')
-						else if (c >= 'A' && c <= 'F')
+						ret += c - 'a' + 10;
-							ret += c - 'A' + 10;
+					else
-						else if (c >= 'a' && c <= 'f')
+						return {};
-							ret += c - 'a' + 10;
+				}
-						else
+				return ret;
-							return {};
+			};
-					}
-					return ret;
-				};
 
 			auto [gpe_scope, gpe_obj] = TRY(m_namespace->find_named_object({}, TRY(AML::NameString::from_string("\\_GPE"))));
 			if (gpe_obj && gpe_obj->node.is_scope())
@@ -1092,20 +1069,55 @@ acpi_release_global_lock:
 
 			if (auto thread_or_error = Thread::create_kernel([](void*) { get().acpi_event_task(); }, nullptr); thread_or_error.is_error())
 				dwarnln("Failed to create ACPI thread, power button will not work: {}", thread_or_error.error());
-			else if (auto ret = Processor::scheduler().add_thread(thread_or_error.value()); ret.is_error())
+			else
-				dwarnln("Failed to create ACPI thread, power button will not work: {}", ret.error());
+			{
+				Processor::scheduler().add_thread(thread_or_error.value());
+				dprintln("Initialized ACPI interrupts");
+			}
 		}
 
-		dprintln("Initialized ACPI interrupts");
+		if (auto ret = initialize_embedded_controllers(); ret.is_error())
+			dwarnln("Failed to initialize Embedded Controllers: {}", ret.error());
 
-		if (auto interrupt_link_devices_or_error = m_namespace->find_device_with_eisa_id("PNP0C0F"_sv); !interrupt_link_devices_or_error.is_error())
+		if (auto ret = m_namespace->post_load_initialize(); ret.is_error())
+			dwarnln("Failed to initialize ACPI namespace: {}", ret.error());
+
+		// NOTE: We cannot initialize EC GPEs before the post init is done, but post init does need ECs initialized
+		initialize_embedded_controller_gpes();
+
+		auto [pic_path, pic_obj] = TRY(m_namespace->find_named_object({}, TRY(AML::NameString::from_string("\\_PIC"_sv))));
+		if (pic_obj && pic_obj->node.type == AML::Node::Type::Method)
 		{
-			uint64_t routed_irq_mask = 0;
+			auto& pic_node = pic_obj->node;
-			auto interrupt_link_devices = interrupt_link_devices_or_error.release_value();
+			if (pic_node.as.method.arg_count != 1)
-			for (const auto& device : interrupt_link_devices)
+			{
-				if (auto ret = route_interrupt_link_device(device, routed_irq_mask); ret.is_error())
+				dwarnln("Method \\_PIC has {} arguments, expected 1", pic_node.as.method.arg_count);
-					dwarnln("failed to route interrupt link device: {}", ret.error());
+				return BAN::Error::from_errno(EINVAL);
-			dprintln("Routed interrupt link devices");
+			}
+
+			AML::Reference arg_ref;
+			arg_ref.node.type = AML::Node::Type::Integer;
+			arg_ref.node.as.integer.value = InterruptController::get().is_using_apic() ? 1 : 0;
+			arg_ref.ref_count = 2;
+
+			BAN::Array<AML::Reference*, 7> arguments(nullptr);
+			arguments[0] = &arg_ref; // method call should not delete argument
+			TRY(AML::method_call(pic_path, pic_node, BAN::move(arguments)));
+
+			dprintln("Evaluated \\_PIC({})", InterruptController::get().is_using_apic() ? 1 : 0);
+		}
+
+		if (InterruptController::get().is_using_apic())
+		{
+			if (auto interrupt_link_devices_or_error = m_namespace->find_device_with_eisa_id("PNP0C0F"_sv); !interrupt_link_devices_or_error.is_error())
+			{
+				uint64_t routed_irq_mask = 0;
+				auto interrupt_link_devices = interrupt_link_devices_or_error.release_value();
+				for (const auto& device : interrupt_link_devices)
+					if (auto ret = route_interrupt_link_device(device, routed_irq_mask); ret.is_error())
+						dwarnln("failed to route interrupt link device: {}", ret.error());
+				dprintln("Routed interrupt link devices");
+			}
 		}
 
 		return {};
@@ -1196,6 +1208,8 @@ acpi_release_global_lock:
 			continue;
 
 handle_event:
+			IO::outw(sts_port, pending);
+
 			if (pending & PM1_EVN_PWRBTN)
 			{
 				dprintln("Power button pressed");
@@ -1206,8 +1220,6 @@ handle_event:
 			{
 				dwarnln("Unhandled ACPI fixed event {H}", pending);
 			}
-
-			IO::outw(sts_port, pending);
 		}
 	}
 

kernel/kernel/ACPI/AML/OpRegion.cpp

@@ -494,8 +494,23 @@ namespace Kernel::ACPI::AML
 
 				return TRY(embedded_controller->read_byte(offset));
 			}
-			case GAS::AddressSpaceID::SMBus:
 			case GAS::AddressSpaceID::SystemCMOS:
+				if (byte_offset >= 64)
+				{
+					dwarnln("CMOS read from offset 0x{H}", byte_offset);
+					return BAN::Error::from_errno(ENOTSUP);
+				}
+				switch (access_size)
+				{
+					case 1:
+						IO::outb(0x70, offset);
+						return IO::inb(0x71);
+					default:
+						dwarnln("{} byte read from CMOS offset {2H}", access_size, byte_offset);
+						return BAN::Error::from_errno(EINVAL);
+				}
+				ASSERT_NOT_REACHED();
+			case GAS::AddressSpaceID::SMBus:
 			case GAS::AddressSpaceID::PCIBarTarget:
 			case GAS::AddressSpaceID::IPMI:
 			case GAS::AddressSpaceID::GeneralPurposeIO:
@@ -581,8 +596,24 @@ namespace Kernel::ACPI::AML
 				TRY(embedded_controller->write_byte(offset, value));
 				return {};
 			}
-			case GAS::AddressSpaceID::SMBus:
 			case GAS::AddressSpaceID::SystemCMOS:
+				if (byte_offset >= 64)
+				{
+					dwarnln("CMOS write to offset 0x{H}", byte_offset);
+					return BAN::Error::from_errno(ENOTSUP);
+				}
+				switch (access_size)
+				{
+					case 1:
+						IO::outb(0x70, offset);
+						IO::outb(0x71, value);
+						break;
+					default:
+						dwarnln("{} byte write to CMOS offset {2H}", access_size, byte_offset);
+						return BAN::Error::from_errno(EINVAL);
+				}
+				return {};
+			case GAS::AddressSpaceID::SMBus:
 			case GAS::AddressSpaceID::PCIBarTarget:
 			case GAS::AddressSpaceID::IPMI:
 			case GAS::AddressSpaceID::GeneralPurposeIO:

kernel/kernel/ACPI/BatterySystem.cpp

@@ -1,5 +1,6 @@
 #include <kernel/ACPI/BatterySystem.h>
-#include <kernel/FS/DevFS//FileSystem.h>
+#include <kernel/Device/Device.h>
+#include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/Timer/Timer.h>
 
 namespace Kernel::ACPI
@@ -35,34 +36,11 @@ namespace Kernel::ACPI
 			if (offset < 0)
 				return BAN::Error::from_errno(EINVAL);
 
-			if (SystemTimer::get().ms_since_boot() > m_last_read_ms + 1000)
+			auto target_str = TRY(BAN::String::formatted("{}", TRY(get_value())));
-			{
-				auto [method_path, method_ref] = TRY(m_acpi_namespace.find_named_object(m_battery_path, m_method_name));
-				if (method_ref == nullptr)
-					return BAN::Error::from_errno(EFAULT);
-
-				auto result = TRY(AML::method_call(method_path, method_ref->node, BAN::Array<AML::Reference*, 7>{}));
-				if (result.type != AML::Node::Type::Package || result.as.package->num_elements < m_result_index)
-					return BAN::Error::from_errno(EFAULT);
-
-				auto& target_elem = result.as.package->elements[m_result_index];
-				if (!target_elem.resolved || !target_elem.value.node)
-					return BAN::Error::from_errno(EFAULT);
-
-				auto target_conv = AML::convert_node(TRY(target_elem.value.node->copy()), AML::ConvInteger, sizeof(uint64_t));
-				if (target_conv.is_error())
-					return BAN::Error::from_errno(EFAULT);
-
-				m_last_read_ms = SystemTimer::get().ms_since_boot();
-				m_last_value = target_conv.value().as.integer.value;
-			}
-
-			auto target_str = TRY(BAN::String::formatted("{}", m_last_value.load()));
-
 			if (static_cast<size_t>(offset) >= target_str.size())
 				return 0;
 
-			const size_t ncopy = BAN::Math::min(buffer.size(), target_str.size() - offset);
+			const size_t ncopy = BAN::Math::min<size_t>(buffer.size(), target_str.size() - offset);
 			memcpy(buffer.data(), target_str.data() + offset, ncopy);
 			return ncopy;
 		}
@@ -84,14 +62,44 @@ namespace Kernel::ACPI
 			, m_result_index(index)
 		{ }
 
+		BAN::ErrorOr<uint64_t> get_value()
+		{
+			LockGuard _(m_mutex);
+
+			if (SystemTimer::get().ms_since_boot() < m_last_read_ms + 1000)
+				return m_last_value;
+
+			auto [method_path, method_ref] = TRY(m_acpi_namespace.find_named_object(m_battery_path, m_method_name));
+			if (method_ref == nullptr)
+				return BAN::Error::from_errno(EFAULT);
+
+			auto result = TRY(AML::method_call(method_path, method_ref->node, BAN::Array<AML::Reference*, 7>{}));
+			if (result.type != AML::Node::Type::Package || result.as.package->num_elements < m_result_index)
+				return BAN::Error::from_errno(EFAULT);
+
+			auto& target_elem = result.as.package->elements[m_result_index];
+			if (!target_elem.resolved || !target_elem.value.node)
+				return BAN::Error::from_errno(EFAULT);
+
+			auto target_conv = AML::convert_node(TRY(target_elem.value.node->copy()), AML::ConvInteger, sizeof(uint64_t));
+			if (target_conv.is_error())
+				return BAN::Error::from_errno(EFAULT);
+
+			m_last_read_ms = SystemTimer::get().ms_since_boot();
+			m_last_value = target_conv.value().as.integer.value;
+
+			return m_last_value;
+		}
+
 	private:
 		AML::Namespace& m_acpi_namespace;
 		AML::Scope m_battery_path;
 		AML::NameString m_method_name;
 		size_t m_result_index;
 
-		BAN::Atomic<uint64_t> m_last_read_ms = 0;
+		Mutex m_mutex;
-		BAN::Atomic<uint64_t> m_last_value = 0;
+		uint64_t m_last_read_ms = 0;
+		uint64_t m_last_value = 0;
 	};
 
 	BAN::ErrorOr<void> BatterySystem::initialize(AML::Namespace& acpi_namespace)

kernel/kernel/ACPI/EmbeddedController.cpp

@@ -4,6 +4,8 @@
 #include <kernel/ACPI/EmbeddedController.h>
 #include <kernel/IO.h>
 #include <kernel/Lock/LockGuard.h>
+#include <kernel/Scheduler.h>
+#include <kernel/Thread.h>
 #include <kernel/Timer/Timer.h>
 
 namespace Kernel::ACPI
@@ -28,28 +30,18 @@ namespace Kernel::ACPI
 		CMD_QUERY     = 0x84,
 	};
 
-	BAN::ErrorOr<BAN::UniqPtr<EmbeddedController>> EmbeddedController::create(AML::Scope&& scope, uint16_t command_port, uint16_t data_port, BAN::Optional<uint8_t> gpe)
+	BAN::ErrorOr<BAN::UniqPtr<EmbeddedController>> EmbeddedController::create(AML::Scope&& scope, uint16_t command_port, uint16_t data_port)
 	{
-		auto* embedded_controller_ptr = new EmbeddedController(BAN::move(scope), command_port, data_port, gpe.has_value());
+		auto* embedded_controller_ptr = new EmbeddedController(BAN::move(scope), command_port, data_port);
 		if (embedded_controller_ptr == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
 
 		auto* thread = TRY(Thread::create_kernel([](void* ec) { static_cast<EmbeddedController*>(ec)->thread_task(); }, embedded_controller_ptr));
-		TRY(Processor::scheduler().add_thread(thread));
+		Processor::scheduler().add_thread(thread);
 
 		auto embedded_controller = BAN::UniqPtr<EmbeddedController>::adopt(embedded_controller_ptr);
 		embedded_controller->m_thread = thread;
 
-		if (gpe.has_value())
-			TRY(ACPI::get().register_gpe_handler(gpe.value(), &handle_gpe_wrapper, embedded_controller.ptr()));
-		else
-		{
-			// FIXME: Restructure EC such that SCI_EVT can be polled.
-			//        Simple solution would be spawning another thread,
-			//        but that feels too hacky.
-			dwarnln("TODO: SCI_EVT polling without GPE");
-		}
-
 		return embedded_controller;
 	}
 
@@ -93,26 +85,25 @@ namespace Kernel::ACPI
 
 	uint8_t EmbeddedController::read_one(uint16_t port)
 	{
-		wait_status_bit(STS_OBF, 1);
+		wait_status_bit(STS_OBF, true);
 		return IO::inb(port);
 	}
 
 	void EmbeddedController::write_one(uint16_t port, uint8_t value)
 	{
-		wait_status_bit(STS_IBF, 0);
+		wait_status_bit(STS_IBF, false);
 		IO::outb(port, value);
 	}
 
-	void EmbeddedController::wait_status_bit(uint8_t bit, uint8_t value)
+	void EmbeddedController::wait_status_bit(uint8_t mask, bool set)
 	{
 		// FIXME: timeouts
-		const uint8_t mask = 1 << bit;
+		const uint8_t comp = set ? mask : 0;
-		const uint8_t comp = value ? mask : 0;
 		while ((IO::inb(m_command_port) & mask) != comp)
 			continue;
 	}
 
-	void EmbeddedController::handle_gpe_wrapper(void* embedded_controller)
+	void EmbeddedController::handle_gpe_trampoline(void* embedded_controller)
 	{
 		static_cast<EmbeddedController*>(embedded_controller)->handle_gpe();
 	}
@@ -215,7 +206,7 @@ namespace Kernel::ACPI
 
 		for (;;)
 		{
-			Command* const command = m_queued_command.has_value() ? m_queued_command.value() : nullptr;
+			auto* const command = m_queued_command.value_or(nullptr);
 			m_queued_command.clear();
 
 			if (command == nullptr)
@@ -224,27 +215,22 @@ namespace Kernel::ACPI
 				continue;
 			}
 
+			// TODO: use burst mode
+
 			m_mutex.unlock();
 
-			if (command)
+			write_one(m_command_port, command->command);
-			{
+			if (command->data1.has_value())
-				// TODO: use burst mode
+				write_one(m_data_port, command->data1.value());
-
+			if (command->data2.has_value())
-				write_one(m_command_port, command->command);
+				write_one(m_data_port, command->data2.value());
-				if (command->data1.has_value())
+			if (command->response)
-					write_one(m_data_port, command->data1.value());
+				*command->response = read_one(m_data_port);
-				if (command->data2.has_value())
-					write_one(m_data_port, command->data2.value());
-				if (command->response)
-					*command->response = read_one(m_data_port);
-
-				m_mutex.lock();
-				command->done = true;
-				m_thread_blocker.unblock();
-				m_mutex.unlock();
-			}
 
 			m_mutex.lock();
+
+			command->done = true;
+			m_thread_blocker.unblock();
 		}
 	}
 

kernel/kernel/APIC.cpp

@@ -351,17 +351,17 @@ namespace Kernel
 			// give processor upto 100 * 100 us + 200 us to boot
 			PageTable::with_fast_page(ap_init_paddr, [&] {
 				for (int i = 0; i < 100; i++, udelay(100))
-					if (__atomic_load_n(&PageTable::fast_page_as<ap_init_info_t>(8).ready, __ATOMIC_SEQ_CST))
+					if (BAN::atomic_load(PageTable::fast_page_as<ap_init_info_t>(8).ready))
 						break;
 			});
 
 			initialized_aps++;
 		}
 
-		__atomic_store_n(&g_ap_startup_done[0], 1, __ATOMIC_SEQ_CST);
+		BAN::atomic_store(g_ap_startup_done[0], 1);
 
 		const size_t timeout_ms = SystemTimer::get().ms_since_boot() + 500;
-		while (__atomic_load_n(&g_ap_running_count[0], __ATOMIC_SEQ_CST) < initialized_aps)
+		while (BAN::atomic_load(g_ap_running_count[0]) < initialized_aps)
 		{
 			if (SystemTimer::get().ms_since_boot() >= timeout_ms)
 				Kernel::panic("Could not start all APs ({}/{} started)", g_ap_running_count[0], initialized_aps);
@@ -487,17 +487,12 @@ namespace Kernel
 		write_to_local_apic(LAPIC_EIO_REG, 0);
 	}
 
-	void APIC::enable_irq(uint8_t irq)
+	void APIC::enable_irq(uint8_t irq, bool level_triggered)
 	{
 		SpinLockGuard _(m_lock);
 
 		const uint32_t gsi = m_irq_overrides[irq];
-
+		ASSERT(m_used_gsis[gsi / 8] & (1 << (gsi % 8)));
-		{
-			int byte = gsi / 8;
-			int bit  = gsi % 8;
-			ASSERT(m_reserved_gsis[byte] & (1 << bit));
-		}
 
 		IOAPIC* ioapic = nullptr;
 		for (IOAPIC& io : m_io_apics)
@@ -515,27 +510,30 @@ namespace Kernel
 		RedirectionEntry redir;
 		redir.lo_dword = ioapic->read(IOAPIC_REDIRS + pin * 2);
 		redir.hi_dword = ioapic->read(IOAPIC_REDIRS + pin * 2 + 1);
-		ASSERT(redir.mask); // TODO: handle overlapping interrupts
 
 		redir.vector = IRQ_VECTOR_BASE + irq;
+		redir.delivery_mode = 0; // fixed
+		redir.pin_polarity  = 0; // active high
+		redir.trigger_mode = level_triggered;
 		redir.mask = 0;
+		redir.destination_mode = 0; // physical
 		// FIXME: distribute IRQs more evenly?
 		redir.destination = Kernel::Processor::bsp_id().as_u32();
 
-		ioapic->write(IOAPIC_REDIRS + pin * 2,		redir.lo_dword);
+		ioapic->write(IOAPIC_REDIRS + pin * 2,     redir.lo_dword);
-		ioapic->write(IOAPIC_REDIRS + pin * 2 + 1,	redir.hi_dword);
+		ioapic->write(IOAPIC_REDIRS + pin * 2 + 1, redir.hi_dword);
 	}
 
 	bool APIC::is_in_service(uint8_t irq)
 	{
-		uint32_t dword = (irq + IRQ_VECTOR_BASE) / 32;
+		const uint32_t dword = (irq + IRQ_VECTOR_BASE) / 32;
-		uint32_t bit = (irq + IRQ_VECTOR_BASE) % 32;
+		const uint32_t bit   = (irq + IRQ_VECTOR_BASE) % 32;
 
-		uint32_t isr = read_from_local_apic(LAPIC_IS_REG + dword * 0x10);
+		const uint32_t isr = read_from_local_apic(LAPIC_IS_REG + dword * 0x10);
 		return isr & (1 << bit);
 	}
 
-	BAN::ErrorOr<void> APIC::reserve_irq(uint8_t irq)
+	BAN::ErrorOr<void> APIC::reserve_irq(uint8_t irq, bool shared)
 	{
 		SpinLockGuard _(m_lock);
 
@@ -557,20 +555,26 @@ namespace Kernel
 			return BAN::Error::from_errno(EINVAL);
 		}
 
-		int byte = gsi / 8;
+		const uint8_t byte =       gsi / 8;
-		int bit  = gsi % 8;
+		const uint8_t mask = 1 << (gsi % 8);
-		if (m_reserved_gsis[byte] & (1 << bit))
+
+		if (!shared && (m_excl_gsis[byte] & mask))
 		{
-			dwarnln("GSI {} is already reserved (IRQ {})", gsi, irq);
+			dwarnln("GSI {} is already reserved as exclusive", gsi);
-			return BAN::Error::from_errno(EFAULT);
+			return BAN::Error::from_errno(EINVAL);
 		}
-		m_reserved_gsis[byte] |= 1 << bit;
+
+		m_used_gsis[byte] |= mask;
+
+		if (!shared)
+			m_excl_gsis[byte] |= mask;
+
 		return {};
 	}
 
 	// FIXME: rewrite gsi and vector reserving
 	//        this is a hack to allow direct GSI reservation
-	BAN::ErrorOr<uint8_t> APIC::reserve_gsi(uint32_t gsi)
+	BAN::ErrorOr<uint8_t> APIC::reserve_gsi(uint32_t gsi, bool shared)
 	{
 		size_t irq = 0;
 		for (; irq < 0x100; irq++)
@@ -583,7 +587,7 @@ namespace Kernel
 			return BAN::Error::from_errno(ENOTSUP);
 		}
 
-		TRY(reserve_irq(irq));
+		TRY(reserve_irq(irq, shared));
 
 		return irq;
 	}
@@ -591,6 +595,7 @@ namespace Kernel
 	BAN::Optional<uint8_t> APIC::get_free_irq()
 	{
 		SpinLockGuard _(m_lock);
+
 		for (uint8_t irq = 0; irq < m_irq_count; irq++)
 		{
 			const uint8_t gsi = m_irq_overrides[irq];
@@ -608,13 +613,17 @@ namespace Kernel
 			if (!ioapic)
 				continue;
 
-			const uint8_t byte = gsi / 8;
+			const uint8_t byte =       gsi / 8;
-			const uint8_t bit  = gsi % 8;
+			const uint8_t mask = 1 << (gsi % 8);
-			if (m_reserved_gsis[byte] & (1 << bit))
+
+			if (m_used_gsis[byte] & mask)
 				continue;
-			m_reserved_gsis[byte] |= 1 << bit;
+			m_used_gsis[byte] |= mask;
+			m_excl_gsis[byte] |= mask;
+
 			return irq;
 		}
+
 		return {};
 	}
 

kernel/kernel/Audio/AC97/Controller.cpp

@@ -182,13 +182,22 @@ namespace Kernel
 		m_bdl_region = TRY(DMARegion::create(bdl_size + buffer_size * m_used_bdl_entries));
 		memset(reinterpret_cast<void*>(m_bdl_region->vaddr()), 0x00, m_bdl_region->size());
 
+		if (m_bdl_region->paddr() + m_bdl_region->size() > BAN::numeric_limits<uint32_t>::max())
+		{
+			dwarnln("Could not allocate 32 bit dma buffer");
+			return BAN::Error::from_errno(EFAULT);
+		}
+
+		auto* bdl_entries = reinterpret_cast<AC97::BufferDescriptorListEntry*>(m_bdl_region->vaddr());
 		for (size_t i = 0; i < m_bdl_entries; i++)
 		{
-			auto& entry = reinterpret_cast<AC97::BufferDescriptorListEntry*>(m_bdl_region->vaddr())[i];
+			bdl_entries[i] = {
-			entry.address = m_bdl_region->paddr() + bdl_size + (i % m_used_bdl_entries) * buffer_size;
+				.address = static_cast<uint32_t>(m_bdl_region->paddr() + bdl_size + (i % m_used_bdl_entries) * buffer_size),
-			entry.samples = 0;
+				.samples = 0,
-			entry.flags = 0;
+				.flags   = 1 << 15,
+			};
 		}
+		bdl_entries[m_bdl_entries - 1].flags |= 1 << 14;
 
 		m_bus_master->write32(BusMasterRegister::PO_BDBAR, m_bdl_region->paddr());
 
@@ -215,7 +224,12 @@ namespace Kernel
 	BAN::ErrorOr<void> AC97AudioController::set_volume_mdB(int32_t mdB)
 	{
 		m_volume_info.mdB = BAN::Math::clamp(mdB, m_volume_info.min_mdB, m_volume_info.max_mdB);
-		m_mixer->write16(AudioMixerRegister::MasterVolume, get_volume_data());
+
+		const uint32_t volume_data = get_volume_data();
+		m_mixer->write16(AudioMixerRegister::MasterVolume, volume_data);
+
+		m_volume_info.mdB = -(volume_data & 0xFF) * m_volume_info.step_mdB;
+
 		return {};
 	}
 
@@ -245,7 +259,6 @@ namespace Kernel
 
 			auto& entry = reinterpret_cast<AC97::BufferDescriptorListEntry*>(m_bdl_region->vaddr())[m_bdl_head];
 			entry.samples = sample_frames * get_channels();
-			entry.flags = (1 << 15);
 			memcpy(
 				reinterpret_cast<void*>(m_bdl_region->paddr_to_vaddr(entry.address)),
 				m_sample_data->get_data().data(),

kernel/kernel/Audio/Controller.cpp

@@ -3,7 +3,8 @@
 #include <kernel/Audio/HDAudio/Controller.h>
 #include <kernel/Device/DeviceNumbers.h>
 #include <kernel/FS/DevFS/FileSystem.h>
-#include <kernel/Lock/SpinLockAsMutex.h>
+#include <kernel/Lock/BlockableSpinLock.h>
+#include <kernel/Thread.h>
 
 #include <sys/ioctl.h>
 #include <sys/sysmacros.h>
@@ -65,8 +66,8 @@ namespace Kernel
 
 		while (m_sample_data->full())
 		{
-			SpinLockGuardAsMutex smutex(lock_guard);
+			BlockableSpinLock block(m_spinlock);
-			TRY(Thread::current().block_or_eintr_indefinite(m_sample_data_blocker, &smutex));
+			TRY(Thread::current().block_or_eintr_indefinite(m_sample_data_blocker, &block));
 		}
 
 		const size_t to_copy = BAN::Math::min(buffer.size(), m_sample_data->free());

kernel/kernel/Audio/HDAudio/AudioFunctionGroup.cpp

@@ -139,31 +139,27 @@ namespace Kernel
 
 	BAN::ErrorOr<void> HDAudioFunctionGroup::set_volume_mdB(int32_t mdB)
 	{
+		if (m_amplifier_idx == SIZE_MAX)
+			return BAN::Error::from_errno(ENOTSUP);
+
 		mdB = BAN::Math::clamp(mdB, m_volume_info.min_mdB, m_volume_info.max_mdB);
 
-		const auto& path = m_output_paths[m_output_path_index];
+		const auto* node = m_output_paths[m_output_path_index][m_amplifier_idx];
-		for (size_t i = 0; i < path.size(); i++)
-		{
-			if (!path[i]->output_amplifier.has_value())
-				continue;
 
-			const int32_t step_round = (mdB >= 0)
+		const int32_t step_round = (mdB >= 0)
-				? +m_volume_info.step_mdB / 2
+			? +m_volume_info.step_mdB / 2
-				: -m_volume_info.step_mdB / 2;
+			: -m_volume_info.step_mdB / 2;
-			const uint32_t step = (mdB + step_round) / m_volume_info.step_mdB + path[i]->output_amplifier->offset;
+		const uint32_t step = (mdB + step_round) / m_volume_info.step_mdB + node->output_amplifier->offset;
-			const uint32_t volume = 0b1'0'1'1'0000'0'0000000 | step;
+		const uint32_t volume = 0b1'0'1'1'0000'0'0000000 | step;
 
-			TRY(m_controller->send_command({
+		TRY(m_controller->send_command({
-				.data = static_cast<uint8_t>(volume & 0xFF),
+			.data = static_cast<uint8_t>(volume & 0xFF),
-				.command = static_cast<uint16_t>(0x300 | (volume >> 8)),
+			.command = static_cast<uint16_t>(0x300 | (volume >> 8)),
-				.node_index = path[i]->id,
+			.node_index = node->id,
-				.codec_address = m_cid,
+			.codec_address = m_cid,
-			}));
+		}));
 
-			break;
+		m_volume_info.mdB = (mdB + step_round) / m_volume_info.step_mdB * m_volume_info.step_mdB;
-		}
-
-		m_volume_info.mdB = mdB;
 
 		return {};
 	}
@@ -331,8 +327,8 @@ namespace Kernel
 	uint16_t HDAudioFunctionGroup::get_format_data() const
 	{
 		// TODO: don't hardcode this
-		// format: PCM, 48 kHz, 16 bit, 2 channels
+		// format: PCM, 48 kHz, 16 bit
-		return 0b0'0'000'000'0'001'0001;
+		return 0b0'0'000'000'0'001'0000 | (get_channels() - 1);
 	}
 
 	BAN::ErrorOr<void> HDAudioFunctionGroup::enable_output_path(uint8_t index)
@@ -346,6 +342,8 @@ namespace Kernel
 			{
 				using HDAudio::AFGWidget;
 				case AFGWidget::Type::OutputConverter:
+				case AFGWidget::Type::Mixer:
+				case AFGWidget::Type::Selector:
 				case AFGWidget::Type::PinComplex:
 					break;
 				default:
@@ -367,7 +365,7 @@ namespace Kernel
 			}));
 
 			// set connection index
-			if (i + 1 < path.size() && path[i]->connections.size() > 1)
+			if (i + 1 < path.size() && path[i]->connections.size() > 1 && path[i]->type != HDAudio::AFGWidget::Type::Mixer)
 			{
 				uint8_t index = 0;
 				for (; index < path[i]->connections.size(); index++)
@@ -407,6 +405,13 @@ namespace Kernel
 						.node_index = path[i]->id,
 						.codec_address = m_cid,
 					}));
+					// set channel count
+					TRY(m_controller->send_command({
+						.data = static_cast<uint8_t>(get_channels() - 1),
+						.command = 0x72D,
+						.node_index = path[i]->id,
+						.codec_address = m_cid,
+					}));
 					// set format
 					TRY(m_controller->send_command({
 						.data = static_cast<uint8_t>(format & 0xFF),
@@ -416,6 +421,28 @@ namespace Kernel
 					}));
 					break;
 
+				case AFGWidget::Type::Mixer:
+					if (path[i]->input_amplifier.has_value())
+					{
+						for (size_t idx = 0; idx < path[i]->connections.size(); idx++)
+						{
+							const uint8_t step = (path[i]->connections[idx] == path[i + 1]->id)
+								? path[i]->input_amplifier->offset
+								: 0b1'0000000;
+							const uint32_t volume = 0b0'1'1'1'0000'0'0000000 | (idx << 8) | step;
+							TRY(m_controller->send_command({
+								.data = static_cast<uint8_t>(volume & 0xFF),
+								.command = static_cast<uint16_t>(0x300 | (volume >> 8)),
+								.node_index = path[i]->id,
+								.codec_address = m_cid,
+							}));
+						}
+					}
+					break;
+
+				case AFGWidget::Type::Selector:
+					break;
+
 				case AFGWidget::Type::PinComplex:
 					// enable output and H-Phn
 					TRY(m_controller->send_command({
@@ -438,15 +465,25 @@ namespace Kernel
 			}
 		}
 
-		// update volume info to this path
+		int32_t max_steps { 0 };
-		m_volume_info.min_mdB = 0;
+		m_amplifier_idx = SIZE_MAX;
-		m_volume_info.max_mdB = 0;
+
-		m_volume_info.step_mdB = 0;
 		for (size_t i = 0; i < path.size(); i++)
 		{
 			if (!path[i]->output_amplifier.has_value())
 				continue;
-			const auto& amp = path[i]->output_amplifier.value();
+			if (auto steps = path[i]->output_amplifier->num_steps; steps > max_steps)
+			{
+				max_steps = steps;
+				m_amplifier_idx = i;
+			}
+		}
+
+		if (m_amplifier_idx == SIZE_MAX)
+			m_volume_info = {};
+		else
+		{
+			const auto& amp = path[m_amplifier_idx]->output_amplifier.value();
 
 			const int32_t step_mdB = (amp.step_size + 1) * 250;
 			m_volume_info.step_mdB = step_mdB;
@@ -463,16 +500,11 @@ namespace Kernel
 			TRY(m_controller->send_command({
 				.data = static_cast<uint8_t>(volume & 0xFF),
 				.command = static_cast<uint16_t>(0x300 | (volume >> 8)),
-				.node_index = path[i]->id,
+				.node_index = path[m_amplifier_idx]->id,
 				.codec_address = m_cid,
 			}));
-
-			break;
 		}
 
-		if (m_volume_info.min_mdB == 0 && m_volume_info.max_mdB == 0)
-			m_volume_info.mdB = 0;
-
 		return {};
 	}
 
@@ -496,6 +528,8 @@ namespace Kernel
 				using HDAudio::AFGWidget;
 
 				case AFGWidget::Type::OutputConverter:
+				case AFGWidget::Type::Mixer:
+				case AFGWidget::Type::Selector:
 					break;
 
 				case AFGWidget::Type::PinComplex:
@@ -635,11 +669,8 @@ namespace Kernel
 			m_bdl_tail = (m_bdl_tail + 1) % m_bdl_entry_count;
 			if (m_bdl_tail == m_bdl_head)
 			{
-				if (auto ret = reset_stream(); ret.is_error())
+				bar.write8(base + Regs::SDCTL, bar.read8(base + Regs::SDCTL) & 0xFD);
-				{
+				m_stream_running = false;
-					dwarnln("failed to reset HDA stream: {}", ret.error());
-					return;
-				}
 			}
 
 			queue_bdl_data();

kernel/kernel/Audio/HDAudio/Controller.cpp

@@ -1,8 +1,8 @@
 #include <kernel/Audio/HDAudio/AudioFunctionGroup.h>
 #include <kernel/Audio/HDAudio/Controller.h>
 #include <kernel/Audio/HDAudio/Registers.h>
+#include <kernel/Lock/BlockableSpinLock.h>
 #include <kernel/Lock/LockGuard.h>
-#include <kernel/Lock/SpinLockAsMutex.h>
 #include <kernel/MMIO.h>
 #include <kernel/Timer/Timer.h>
 
@@ -333,6 +333,20 @@ namespace Kernel
 			};
 		}
 
+		if (const uint32_t in_amp_cap = send_command_or_zero(0xF00, 0x0D))
+		{
+			const uint8_t offset    = (in_amp_cap >>  0) & 0x7F;
+			const uint8_t num_steps = (in_amp_cap >>  8) & 0x7F;
+			const uint8_t step_size = (in_amp_cap >> 16) & 0x7F;
+			const bool    mute      = (in_amp_cap >> 31);
+			result.input_amplifier = HDAudio::AFGWidget::Amplifier {
+				.offset = offset,
+				.num_steps = num_steps,
+				.step_size = step_size,
+				.mute = mute,
+			};
+		}
+
 		const uint8_t connection_info = send_command_or_zero(0xF00, 0x0E);
 		const uint8_t conn_width = (connection_info & 0x80) ? 2 : 1;
 		const uint8_t conn_count = connection_info & 0x3F;
@@ -369,8 +383,8 @@ namespace Kernel
 			{
 				if (SystemTimer::get().ms_since_boot() > waketime_ms)
 					return BAN::Error::from_errno(ETIMEDOUT);
-				SpinLockGuardAsMutex smutex(sguard);
+				BlockableSpinLock block(m_rb_lock);
-				m_rb_blocker.block_with_timeout_ms(10, &smutex);
+				m_rb_blocker.block_with_timeout_ms(10, &block);
 			}
 
 			const size_t offset = 2 * m_rirb.index * sizeof(uint32_t);

kernel/kernel/Banos.cpp

@@ -14,6 +14,8 @@
 #include <kernel/Lock/SpinLock.h>
 #include <kernel/UserCopy.h>
 
+#if ARCH(x86_64)
+
 using namespace LibELF;
 using namespace Kernel;
 
@@ -204,7 +206,7 @@ BAN::ErrorOr<size_t> Banos::load_driver_from_image(const char* u_image) {
 // NOTE: should be more than plenty ;)
 extern char g_drv_builtin_begin[];
 extern char g_drv_builtin_end[];
-void Banos::initialize_initial_drivers(void) {
+void Banos::initialize_initial_drivers() {
 	import_symbols(g_banos_export, g_banos_export_end - g_banos_export);
 	char* head = g_drv_builtin_begin;
 	while(head < g_drv_builtin_end) {
@@ -213,3 +215,14 @@ void Banos::initialize_initial_drivers(void) {
 		head += drv->driver_size;
 	}
 }
+
+#else
+void Banos::initialize_initial_drivers()
+{
+}
+BAN::ErrorOr<size_t> Banos::load_driver_from_image(const char* u_image)
+{
+	(void)u_image;
+	return BAN::Error::from_errno(ENOTSUP);
+}
+#endif

kernel/kernel/Device/FramebufferDevice.cpp

@@ -2,6 +2,7 @@
 #include <kernel/Device/DeviceNumbers.h>
 #include <kernel/Device/FramebufferDevice.h>
 #include <kernel/FS/DevFS/FileSystem.h>
+#include <kernel/Graphics/BGA.h>
 #include <kernel/Memory/Heap.h>
 #include <kernel/Terminal/FramebufferTerminal.h>
 
@@ -26,19 +27,14 @@ namespace Kernel
 		return s_boot_framebuffer;
 	}
 
-	BAN::ErrorOr<BAN::RefPtr<FramebufferDevice>> FramebufferDevice::create_from_boot_framebuffer()
+	BAN::ErrorOr<BAN::RefPtr<FramebufferDevice>> FramebufferDevice::create(paddr_t paddr, uint32_t width, uint32_t height, uint32_t pitch, uint8_t bpp)
 	{
-		ASSERT(g_boot_info.framebuffer.type == FramebufferInfo::Type::RGB);
+		if (bpp != 24 && bpp != 32)
-		if (g_boot_info.framebuffer.bpp != 24 && g_boot_info.framebuffer.bpp != 32)
 			return BAN::Error::from_errno(ENOTSUP);
 		auto* device_ptr = new FramebufferDevice(
 			0660, 0, 900,
 			makedev(DeviceNumber::Framebuffer, get_framebuffer_device_index()),
-			g_boot_info.framebuffer.address,
+			paddr, width, height, pitch, bpp
-			g_boot_info.framebuffer.width,
-			g_boot_info.framebuffer.height,
-			g_boot_info.framebuffer.pitch,
-			g_boot_info.framebuffer.bpp
 		);
 		if (device_ptr == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
@@ -49,6 +45,33 @@ namespace Kernel
 		return device;
 	}
 
+	BAN::ErrorOr<BAN::RefPtr<FramebufferDevice>> FramebufferDevice::create(BAN::RefPtr<BGAController> bga_controller)
+	{
+		const auto fix_info = bga_controller->get_fb_fix_info();
+		const auto var_info = bga_controller->get_fb_var_info();
+		auto controller = TRY(create(
+			fix_info.mem_start,
+			var_info.xres,
+			var_info.yres,
+			fix_info.pitch,
+			var_info.bpp
+		));
+		controller->m_bga_controller = bga_controller;
+		return controller;
+	}
+
+	BAN::ErrorOr<BAN::RefPtr<FramebufferDevice>> FramebufferDevice::create_from_boot_framebuffer()
+	{
+		s_boot_framebuffer = TRY(create(
+			g_boot_info.framebuffer.address,
+			g_boot_info.framebuffer.width,
+			g_boot_info.framebuffer.height,
+			g_boot_info.framebuffer.pitch,
+			g_boot_info.framebuffer.bpp
+		));
+		return s_boot_framebuffer;
+	}
+
 	FramebufferDevice::FramebufferDevice(mode_t mode, uid_t uid, gid_t gid, dev_t rdev, paddr_t paddr, uint32_t width, uint32_t height, uint32_t pitch, uint8_t bpp)
 		: CharacterDevice(mode, uid, gid)
 		, m_name(MUST(BAN::String::formatted("fb{}", minor(rdev))))
@@ -65,16 +88,20 @@ namespace Kernel
 	{
 		if (m_video_memory_vaddr == 0)
 			return;
-		size_t video_memory_pages = range_page_count(m_video_memory_paddr, m_height * m_pitch);
+		const size_t video_memory_bytes = m_bga_controller ? m_bga_controller->get_fb_fix_info().mem_size : m_height * m_pitch;
+		const size_t video_memory_pages = range_page_count(m_video_memory_paddr, video_memory_bytes);
 		PageTable::kernel().unmap_range(m_video_memory_vaddr, video_memory_pages * PAGE_SIZE);
 	}
 
 	BAN::ErrorOr<void> FramebufferDevice::initialize()
 	{
-		size_t video_memory_pages = range_page_count(m_video_memory_paddr, m_height * m_pitch);
+		const size_t video_memory_bytes = m_bga_controller ? m_bga_controller->get_fb_fix_info().mem_size : m_height * m_pitch;
+		const size_t video_memory_pages = range_page_count(m_video_memory_paddr, video_memory_bytes);
+
 		m_video_memory_vaddr = PageTable::kernel().reserve_free_contiguous_pages(video_memory_pages, KERNEL_OFFSET);
 		if (m_video_memory_vaddr == 0)
 			return BAN::Error::from_errno(ENOMEM);
+
 		PageTable::kernel().map_range_at(
 			m_video_memory_paddr & PAGE_ADDR_MASK,
 			m_video_memory_vaddr,
@@ -86,7 +113,7 @@ namespace Kernel
 		m_video_buffer = TRY(VirtualRange::create_to_vaddr_range(
 			PageTable::kernel(),
 			{ KERNEL_OFFSET, UINTPTR_MAX },
-			BAN::Math::div_round_up<size_t>(m_width * m_height * (BANAN_FB_BPP / 8), PAGE_SIZE) * PAGE_SIZE,
+			video_memory_pages * PAGE_SIZE,
 			PageTable::Flags::ReadWrite | PageTable::Flags::Present,
 			false
 		));
@@ -94,6 +121,37 @@ namespace Kernel
 		return {};
 	}
 
+	BAN::ErrorOr<void> FramebufferDevice::set_bga_controller(BAN::RefPtr<BGAController> bga_controller)
+	{
+		ASSERT(!m_bga_controller);
+
+		if (auto var_info = bga_controller->get_fb_var_info(); var_info.bpp != 32)
+		{
+			var_info.bpp = 32;
+			TRY(bga_controller->set_fb_var_info(var_info));
+		}
+
+		const auto fix_info = bga_controller->get_fb_fix_info();
+		const auto var_info = bga_controller->get_fb_var_info();
+
+		ASSERT(m_video_memory_vaddr);
+		PageTable::kernel().unmap_range(m_video_memory_vaddr, m_height * m_pitch);
+
+		m_video_memory_vaddr = 0;
+		m_video_memory_paddr = fix_info.mem_start;
+
+		m_width  = var_info.xres;
+		m_height = var_info.yres;
+		m_pitch  = fix_info.pitch;
+		m_bpp    = var_info.bpp;
+
+		m_bga_controller = bga_controller;
+
+		TRY(initialize());
+
+		return {};
+	}
+
 	BAN::ErrorOr<size_t> FramebufferDevice::read_impl(off_t offset, BAN::ByteSpan buffer)
 	{
 		// Reading from negative offset will fill buffer with framebuffer info

kernel/kernel/Epoll.cpp

@@ -1,6 +1,7 @@
 #include <kernel/Epoll.h>
+#include <kernel/Lock/BlockableSpinLock.h>
 #include <kernel/Lock/LockGuard.h>
-#include <kernel/Lock/SpinLockAsMutex.h>
+#include <kernel/Thread.h>
 #include <kernel/Timer/Timer.h>
 
 namespace Kernel
@@ -222,8 +223,8 @@ namespace Kernel
 			if (!m_ready_events.empty())
 				continue;
 
-			SpinLockGuardAsMutex smutex(guard);
+			BlockableSpinLock block(m_ready_lock);
-			TRY(Thread::current().block_or_eintr_or_waketime_ns(m_thread_blocker, waketime_ns, false, &smutex));
+			TRY(Thread::current().block_or_eintr_or_waketime_ns(m_thread_blocker, waketime_ns, false, &block));
 		}
 
 		return event_count;

kernel/kernel/FS/DevFS/FileSystem.cpp

@@ -7,8 +7,8 @@
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/FS/TmpFS/Inode.h>
 #include <kernel/Input/InputDevice.h>
+#include <kernel/Lock/BlockableSpinLock.h>
 #include <kernel/Lock/LockGuard.h>
-#include <kernel/Lock/SpinLockAsMutex.h>
 #include <kernel/Process.h>
 #include <kernel/Scheduler.h>
 #include <kernel/Storage/StorageDevice.h>
@@ -63,7 +63,7 @@ namespace Kernel
 				}
 			}, s_instance
 		));
-		MUST(Processor::scheduler().add_thread(updater_thread));
+		Processor::scheduler().add_thread(updater_thread);
 
 		auto* disk_cache_drop_thread = MUST(Thread::create_kernel(
 			[](void* _devfs)
@@ -77,8 +77,8 @@ namespace Kernel
 						bool expected = true;
 						if (!devfs->m_should_drop_disk_cache.compare_exchange(expected, false))
 						{
-							SpinLockGuardAsMutex smutex(guard);
+							BlockableSpinLock block(devfs->m_disk_cache_lock);
-							devfs->m_disk_cache_thread_blocker.block_indefinite(&smutex);
+							devfs->m_disk_cache_thread_blocker.block_indefinite(&block);
 							continue;
 						}
 					}
@@ -93,7 +93,7 @@ namespace Kernel
 				}
 			}, s_instance
 		));
-		MUST(Processor::scheduler().add_thread(disk_cache_drop_thread));
+		Processor::scheduler().add_thread(disk_cache_drop_thread);
 
 		auto* disk_sync_thread = MUST(Thread::create_kernel(
 			[](void* _devfs)
@@ -129,7 +129,7 @@ namespace Kernel
 				}
 			}, s_instance
 		));
-		MUST(Processor::scheduler().add_thread(disk_sync_thread));
+		Processor::scheduler().add_thread(disk_sync_thread);
 	}
 
 	void DevFileSystem::initiate_disk_cache_drop()

kernel/kernel/FS/EventFD.cpp

@@ -1,5 +1,6 @@
 #include <kernel/FS/EventFD.h>
 #include <kernel/Lock/LockGuard.h>
+#include <kernel/Thread.h>
 
 #include <sys/epoll.h>
 
@@ -43,7 +44,7 @@ namespace Kernel
 		while (m_value == 0)
 			TRY(Thread::current().block_or_eintr_indefinite(m_thread_blocker, &m_mutex));
 
-		const uint64_t read_value = m_is_semaphore ? 1 : m_value.load();
+		const uint64_t read_value = m_is_semaphore ? 1 : m_value;
 		m_value -= read_value;
 
 		buffer.as<uint64_t>() = read_value;
@@ -79,4 +80,16 @@ namespace Kernel
 		return sizeof(uint64_t);
 	}
 
+	bool EventFD::can_read_impl() const
+	{
+		LockGuard _(m_mutex);
+		return m_value > 0;
+	}
+
+	bool EventFD::can_write_impl() const
+	{
+		LockGuard _(m_mutex);
+		return m_value < UINT64_MAX - 1;
+	}
+
 }

kernel/kernel/FS/Ext2/FileSystem.cpp

@@ -2,6 +2,7 @@
 #include <BAN/Sort.h>
 #include <kernel/FS/Ext2/FileSystem.h>
 #include <kernel/Lock/LockGuard.h>
+#include <kernel/Thread.h>
 
 #define EXT2_DEBUG_PRINT 0
 #define EXT2_VERIFY_INODE 0
@@ -624,7 +625,7 @@ namespace Kernel
 				continue;
 			buffer.used = true;
 			return Ext2FS::BlockBufferWrapper {
-				buffer.buffer.span(),
+				buffer.buffer,
 				[](void* self, const uint8_t* buffer) { static_cast<BlockBufferManager*>(self)->destroy_callback(buffer); },
 				this
 			};
@@ -635,11 +636,23 @@ namespace Kernel
 
 	BAN::ErrorOr<void> Ext2FS::BlockBufferManager::initialize(size_t block_size)
 	{
-		for (auto& buffer : m_buffers)
+		m_buffer_data = TRY(VirtualRange::create_to_vaddr_range(
+			PageTable::kernel(),
+			{ KERNEL_OFFSET, BAN::numeric_limits<vaddr_t>::max() },
+			block_size * m_buffers.size(),
+			PageTable::ReadWrite | PageTable::Present,
+			false
+		));
+
+		auto buffer_data_span = BAN::ByteSpan { reinterpret_cast<uint8_t*>(m_buffer_data->vaddr()), m_buffer_data->size() };
+		for (size_t i = 0; i < m_buffers.size(); i++)
 		{
-			TRY(buffer.buffer.resize(block_size));
+			m_buffers[i] = {
-			buffer.used = false;
+				.buffer = buffer_data_span.slice(i * block_size, block_size),
+				.used = false,
+			};
 		}
+
 		return {};
 	}
 

kernel/kernel/FS/FAT/FileSystem.cpp

@@ -1,3 +1,4 @@
+#include <kernel/Device/Device.h>
 #include <kernel/FS/FAT/FileSystem.h>
 #include <kernel/Lock/LockGuard.h>
 
@@ -123,18 +124,6 @@ namespace Kernel
 	{
 		LockGuard _(m_mutex);
 
-		uint32_t block_count = 0;
-		{
-			uint32_t cluster = entry.first_cluster_lo;
-			if (m_type == Type::FAT32)
-				cluster |= static_cast<uint32_t>(entry.first_cluster_hi) << 16;
-			while (cluster >= 2 && cluster < cluster_count())
-			{
-				block_count++;
-				cluster = TRY(get_next_cluster(cluster));
-			}
-		}
-
 		uint32_t entry_cluster;
 		switch (m_type)
 		{
@@ -143,25 +132,34 @@ namespace Kernel
 				if (parent == m_root_inode)
 					entry_cluster = 1;
 				else
-				{
 					entry_cluster = parent->entry().first_cluster_lo;
-					for (uint32_t i = 0; i < cluster_index; i++)
-						entry_cluster = TRY(get_next_cluster(entry_cluster));
-				}
 				break;
 			case Type::FAT32:
 				if (parent == m_root_inode)
 					entry_cluster = m_bpb.ext_32.root_cluster;
 				else
 					entry_cluster = (static_cast<uint32_t>(parent->entry().first_cluster_hi) << 16) | parent->entry().first_cluster_lo;
-				for (uint32_t i = 0; i < cluster_index; i++)
-					entry_cluster = TRY(get_next_cluster(entry_cluster));
 				break;
 			default:
 				ASSERT_NOT_REACHED();
 		}
 
-		const ino_t ino = (static_cast<ino_t>(entry_cluster) << 32) | entry_index;
+		uint32_t block_count = 0;
+		for (uint32_t i = 0; i < cluster_index; i++)
+		{
+			block_count++;
+			entry_cluster = TRY(get_next_cluster(entry_cluster));
+		}
+
+		const uint32_t dirent_per_cluster = m_bpb.bytes_per_sector * m_bpb.sectors_per_cluster / sizeof(FAT::DirectoryEntry);
+		ASSERT(BAN::Math::is_power_of_two(dirent_per_cluster));
+		ASSERT(entry_index < dirent_per_cluster);
+
+		const uint32_t ino_cluster_shift = BAN::Math::ctz(dirent_per_cluster);
+		const ino_t ino = (static_cast<ino_t>(entry_cluster) << ino_cluster_shift) | entry_index;
+		if (ino >> ino_cluster_shift != entry_cluster)
+			dwarnln("FAT ino mapping not unique");
+
 		auto it = m_inode_cache.find(ino);
 		if (it != m_inode_cache.end())
 		{

kernel/kernel/FS/FAT/Inode.cpp

@@ -1,5 +1,6 @@
 #include <BAN/Time.h>
 
+#include <kernel/Device/Device.h>
 #include <kernel/FS/FAT/FileSystem.h>
 #include <kernel/FS/FAT/Inode.h>
 

kernel/kernel/FS/Inode.cpp

@@ -11,18 +11,18 @@
 namespace Kernel
 {
 
-	bool Inode::can_access(const Credentials& credentials, int flags) const
+	bool Inode::can_access(uid_t uid, gid_t gid, mode_t mode, const Credentials& credentials, int flags)
 	{
 		if (credentials.is_superuser())
 			return true;
 
 		if (flags & O_RDONLY)
 		{
-			if (mode().mode & S_IROTH)
+			if (mode & S_IROTH)
 			{ }
-			else if ((mode().mode & S_IRUSR) && credentials.euid() == uid())
+			else if ((mode & S_IRUSR) && credentials.euid() == uid)
 			{ }
-			else if ((mode().mode & S_IRGRP) && credentials.has_egid(gid()))
+			else if ((mode & S_IRGRP) && credentials.has_egid(gid))
 			{ }
 			else
 			{
@@ -32,11 +32,11 @@ namespace Kernel
 
 		if (flags & O_WRONLY)
 		{
-			if (mode().mode & S_IWOTH)
+			if (mode & S_IWOTH)
 			{ }
-			else if ((mode().mode & S_IWUSR) && credentials.euid() == uid())
+			else if ((mode & S_IWUSR) && credentials.euid() == uid)
 			{ }
-			else if ((mode().mode & S_IWGRP) && credentials.has_egid(gid()))
+			else if ((mode & S_IWGRP) && credentials.has_egid(gid))
 			{ }
 			else
 			{
@@ -44,13 +44,13 @@ namespace Kernel
 			}
 		}
 
-		if ((flags & O_EXEC) || (mode().ifdir() && (flags & O_SEARCH)))
+		if ((flags & O_EXEC) || (Mode { mode }.ifdir() && (flags & O_SEARCH)))
 		{
-			if (mode().mode & S_IXOTH)
+			if (mode & S_IXOTH)
 			{ }
-			else if ((mode().mode & S_IXUSR) && credentials.euid() == uid())
+			else if ((mode & S_IXUSR) && credentials.euid() == uid)
 			{ }
-			else if ((mode().mode & S_IXGRP) && credentials.has_egid(gid()))
+			else if ((mode & S_IXGRP) && credentials.has_egid(gid))
 			{ }
 			else
 			{
@@ -61,6 +61,11 @@ namespace Kernel
 		return true;
 	}
 
+	bool Inode::can_access(const Credentials& credentials, int flags) const
+	{
+		return can_access(uid(), gid(), mode().mode, credentials, flags);
+	}
+
 	BAN::ErrorOr<BAN::RefPtr<Inode>> Inode::find_inode(BAN::StringView name)
 	{
 		if (!mode().ifdir())

kernel/kernel/FS/ProcFS/FileSystem.cpp

@@ -1,6 +1,7 @@
 #include <kernel/BootInfo.h>
 #include <kernel/FS/ProcFS/FileSystem.h>
 #include <kernel/FS/ProcFS/Inode.h>
+#include <kernel/Process.h>
 
 namespace Kernel
 {

kernel/kernel/FS/ProcFS/Inode.cpp

@@ -1,4 +1,5 @@
 #include <kernel/FS/ProcFS/Inode.h>
+#include <kernel/Process.h>
 
 #include <ctype.h>
 

kernel/kernel/Graphics/BGA.cpp

@@ -0,0 +1,242 @@
+#include <kernel/Device/FramebufferDevice.h>
+#include <kernel/Graphics/BGA.h>
+#include <kernel/IO.h>
+#include <kernel/Terminal/FramebufferTerminal.h>
+#include <kernel/Terminal/VirtualTTY.h>
+
+namespace Kernel
+{
+
+	enum BGA_IO_PORT : uint16_t
+	{
+		BGA_IO_PORT_INDEX = 0x1CE,
+		BGA_IO_PORT_DATA  = 0x1CF,
+	};
+
+	enum BGA_REG : uint16_t
+	{
+		BGA_REG_ID          = 0,
+		BGA_REG_XRES        = 1,
+		BGA_REG_YRES        = 2,
+		BGA_REG_BPP         = 3,
+		BGA_REG_ENABLE      = 4,
+		BGA_REG_BANK        = 5,
+		BGA_REG_XRES_VIRT  = 6,
+		BGA_REG_YRES_VIRT = 7,
+		BGA_REG_XOFF    = 8,
+		BGA_REG_YOFF    = 9,
+	};
+
+	enum BGA_ID : uint16_t
+	{
+		BGA_ID_0 = 0xB0C0,
+		BGA_ID_1 = 0xB0C1,
+		BGA_ID_2 = 0xB0C2,
+		BGA_ID_3 = 0xB0C3,
+		BGA_ID_4 = 0xB0C4,
+		BGA_ID_5 = 0xB0C5,
+	};
+
+	enum BGA_ENABLE : uint16_t
+	{
+		BGA_ENABLE_ENABLE     = 0x01,
+		BGA_ENABLE_LFB_ENABLE = 0x40,
+		BGA_ENABLE_NOCLEARMEM = 0x80,
+	};
+
+	BAN::ErrorOr<BAN::RefPtr<BGAController>> BGAController::create(PCI::Device& pci_device)
+	{
+		auto* bga_controller_ptr = new BGAController(pci_device);
+		if (bga_controller_ptr == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+		auto bga_controller = BAN::RefPtr<BGAController>::adopt(bga_controller_ptr);
+		TRY(bga_controller->initialize());
+		return bga_controller;
+	}
+
+	BGAController::BGAController(PCI::Device& pci_device)
+		: m_pci_device(pci_device)
+	{ }
+
+	BAN::ErrorOr<void> BGAController::initialize()
+	{
+		auto boot_framebuffer = FramebufferDevice::boot_framebuffer();
+
+		m_lfb_bar = TRY(m_pci_device.allocate_bar_region(0));
+		if (m_lfb_bar->type() != PCI::BarType::MEM)
+		{
+			dwarnln("BGA LFB is not memory bar");
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		m_fix_info = {
+			.xpanstep = 1,
+			.ypanstep = 1,
+			.pitch = 0,
+			.mem_start = static_cast<uint64_t>(m_lfb_bar->paddr()),
+			.mem_size  = static_cast<uint32_t>(m_lfb_bar->size()),
+		};
+
+		const auto ready_to_use_flags = BGA_ENABLE_LFB_ENABLE | BGA_ENABLE_ENABLE;
+		if ((read_reg(BGA_REG_ENABLE) & ready_to_use_flags) == ready_to_use_flags)
+		{
+			m_var_info = {
+				.xres      = read_reg(BGA_REG_XRES),
+				.yres      = read_reg(BGA_REG_YRES),
+				.xres_virt = read_reg(BGA_REG_XRES_VIRT),
+				.yres_virt = read_reg(BGA_REG_XRES_VIRT),
+				.xoff      = read_reg(BGA_REG_XOFF),
+				.yoff      = read_reg(BGA_REG_YOFF),
+				.bpp       = read_reg(BGA_REG_BPP),
+			};
+
+			m_fix_info.pitch = m_var_info.xres_virt * m_var_info.bpp / 8;
+		}
+		else
+		{
+			const uint32_t xres = boot_framebuffer ? boot_framebuffer->width()  : 1280;
+			const uint32_t yres = boot_framebuffer ? boot_framebuffer->height() :  800;
+			const uint32_t bpp  = boot_framebuffer ? boot_framebuffer->bpp()    :   32;
+
+			TRY(set_fb_var_info({
+				.xres = xres,
+				.yres = yres,
+				.xres_virt = xres,
+				.yres_virt = yres * 2,
+				.xoff = 0,
+				.yoff = 0,
+				.bpp = bpp,
+			}));
+		}
+
+		if (boot_framebuffer)
+		{
+			// FIXME: check that this is actually the boot framebuffer
+			TRY(boot_framebuffer->set_bga_controller(this));
+		}
+		else
+		{
+			auto framebuffer_device = TRY(FramebufferDevice::create(this));
+			auto fb_terminal_driver = TRY(FramebufferTerminalDriver::create(framebuffer_device));
+
+			// FIXME: query vtty instead of checking the current tty
+			if (auto tty = TTY::current(); tty && tty->is_vtty())
+				TRY(static_cast<VirtualTTY*>(tty.ptr())->set_terminal_driver(fb_terminal_driver));
+			else
+				TRY(VirtualTTY::create(fb_terminal_driver));
+		}
+
+		return {};
+	}
+
+	BAN::ErrorOr<void> BGAController::set_fb_var_info(const fb_var_info& var_info)
+	{
+		const auto validate_u16 = [](auto value) -> BAN::ErrorOr<void> {
+			if (value > BAN::numeric_limits<uint16_t>::max())
+				return BAN::Error::from_errno(EINVAL);
+			return {};
+		};
+		TRY(validate_u16(var_info.xres));
+		TRY(validate_u16(var_info.xres));
+		TRY(validate_u16(var_info.xres_virt));
+		TRY(validate_u16(var_info.yres_virt));
+		TRY(validate_u16(var_info.xoff));
+		TRY(validate_u16(var_info.yoff));
+		TRY(validate_u16(var_info.bpp));
+
+		if (var_info.xres + var_info.xoff > var_info.xres_virt)
+			return BAN::Error::from_errno(EINVAL);
+		if (var_info.yres + var_info.yoff > var_info.yres_virt)
+			return BAN::Error::from_errno(EINVAL);
+		if (static_cast<uint64_t>(var_info.xres_virt) * var_info.yres_virt * var_info.bpp / 8 > m_lfb_bar->size())
+			return BAN::Error::from_errno(EINVAL);
+
+		SpinLockGuard _(m_lock);
+
+		const bool needs_reconf =
+			(m_var_info.xres      != var_info.xres) ||
+			(m_var_info.yres      != var_info.yres) ||
+			(m_var_info.xres_virt != var_info.xres_virt) ||
+			(m_var_info.yres_virt != var_info.yres_virt) ||
+			(m_var_info.bpp       != var_info.bpp);
+
+		if (!needs_reconf)
+		{
+			write_reg(BGA_REG_XOFF, var_info.xoff);
+			write_reg(BGA_REG_YOFF, var_info.yoff);
+			m_var_info.xoff = var_info.xoff;
+			m_var_info.yoff = var_info.yoff;
+			return {};
+		}
+
+		const auto old_enable = read_reg(BGA_REG_ENABLE);
+		write_reg(BGA_REG_ENABLE, 0);
+
+		write_reg(BGA_REG_BPP,       var_info.bpp);
+		write_reg(BGA_REG_XRES,      var_info.xres);
+		write_reg(BGA_REG_YRES,      var_info.yres);
+		write_reg(BGA_REG_XRES_VIRT, var_info.xres_virt);
+		write_reg(BGA_REG_YRES_VIRT, var_info.yres_virt);
+
+		const bool valid_config =
+			read_reg(BGA_REG_BPP)       == var_info.bpp &&
+			read_reg(BGA_REG_XRES)      == var_info.xres &&
+			read_reg(BGA_REG_YRES)      == var_info.yres &&
+			read_reg(BGA_REG_XRES_VIRT) == var_info.xres_virt;
+
+		if (!valid_config)
+		{
+			write_reg(BGA_REG_BPP,       m_var_info.bpp);
+			write_reg(BGA_REG_XRES,      m_var_info.xres);
+			write_reg(BGA_REG_YRES,      m_var_info.yres);
+			write_reg(BGA_REG_XRES_VIRT, m_var_info.xres_virt);
+			write_reg(BGA_REG_YRES_VIRT, m_var_info.yres_virt);
+
+			write_reg(BGA_REG_ENABLE, BGA_ENABLE_NOCLEARMEM | old_enable);
+
+			return BAN::Error::from_errno(EINVAL);
+		}
+
+		write_reg(BGA_REG_ENABLE, BGA_ENABLE_LFB_ENABLE | BGA_ENABLE_ENABLE);
+
+		// NOTE: At least qemu only sets virtual yres on enable and it will be
+		//       maximum that fits within vram. Our initial bounds check should
+		//       make sure this always succeeds
+		ASSERT(read_reg(BGA_REG_YRES_VIRT) >= var_info.yres_virt);
+
+		write_reg(BGA_REG_XOFF, var_info.xoff);
+		write_reg(BGA_REG_YOFF, var_info.yoff);
+
+		m_var_info = var_info;
+		m_fix_info.pitch = m_var_info.xres_virt * m_var_info.bpp / 8;
+
+		return {};
+	}
+
+	void BGAController::write_reg(uint16_t reg, uint16_t value)
+	{
+		SpinLockGuard _(m_lock);
+		IO::outw(BGA_IO_PORT_INDEX, reg);
+		IO::outw(BGA_IO_PORT_DATA, value);
+	}
+
+	uint16_t BGAController::read_reg(uint16_t reg)
+	{
+		SpinLockGuard _(m_lock);
+		IO::outw(BGA_IO_PORT_INDEX, reg);
+		return IO::inw(BGA_IO_PORT_DATA);
+	}
+
+	fb_fix_info BGAController::get_fb_fix_info() const
+	{
+		SpinLockGuard _(m_lock);
+		return m_fix_info;
+	}
+
+	fb_var_info BGAController::get_fb_var_info() const
+	{
+		SpinLockGuard _(m_lock);
+		return m_var_info;
+	}
+
+}

kernel/kernel/IDT.cpp

@@ -1,7 +1,9 @@
 #include <BAN/Array.h>
 #include <BAN/Errors.h>
+#include <kernel/GDT.h>
 #include <kernel/IDT.h>
 #include <kernel/InterruptController.h>
+#include <kernel/InterruptNumbers.h>
 #include <kernel/InterruptStack.h>
 #include <kernel/Memory/kmalloc.h>
 #include <kernel/Panic.h>
@@ -413,10 +415,14 @@ namespace Kernel
 
 	extern "C" void cpp_ipi_handler()
 	{
-		ASSERT(InterruptController::get().is_in_service(IRQ_IPI - IRQ_VECTOR_BASE));
+		if (!InterruptController::get().is_in_service(IRQ_IPI - IRQ_VECTOR_BASE))
-		InterruptController::get().eoi(IRQ_IPI - IRQ_VECTOR_BASE);
+			return;
+
 		Processor::handle_ipi();
-		Processor::scheduler().reschedule_if_idle();
+
+		InterruptController::get().eoi(IRQ_IPI - IRQ_VECTOR_BASE);
+
+		Processor::scheduler().reschedule_if_needed();
 	}
 
 	extern "C" void cpp_timer_handler()
@@ -429,13 +435,17 @@ namespace Kernel
 			asm volatile("cli; 1: hlt; jmp 1b");
 		}
 
-		ASSERT(InterruptController::get().is_in_service(IRQ_TIMER - IRQ_VECTOR_BASE));
+		if (!InterruptController::get().is_in_service(IRQ_TIMER - IRQ_VECTOR_BASE))
-		InterruptController::get().eoi(IRQ_TIMER - IRQ_VECTOR_BASE);
+			return;
 
 		if (Processor::current_is_bsp())
 			Process::update_alarm_queue();
 
 		Processor::scheduler().on_timer_interrupt();
+
+		InterruptController::get().eoi(IRQ_TIMER - IRQ_VECTOR_BASE);
+
+		Processor::scheduler().reschedule_if_needed();
 	}
 
 	extern "C" void cpp_irq_handler(uint32_t irq)
@@ -453,15 +463,14 @@ namespace Kernel
 		if (!InterruptController::get().is_in_service(irq))
 			return;
 
-		InterruptController::get().eoi(irq);
 		if (auto* handler = s_interruptables[irq])
 			handler->handle_irq();
 		else
 			dprintln("no handler for irq 0x{2H}", irq);
 
-		Processor::scheduler().reschedule_if_idle();
+		InterruptController::get().eoi(irq);
 
-		ASSERT(Thread::current().state() != Thread::State::Terminated);
+		Processor::scheduler().reschedule_if_needed();
 	}
 
 	extern "C" void cpp_check_signal()

kernel/kernel/Input/InputDevice.cpp

@@ -3,8 +3,10 @@
 #include <kernel/Device/DeviceNumbers.h>
 #include <kernel/FS/DevFS/FileSystem.h>
 #include <kernel/Input/InputDevice.h>
-#include <kernel/Lock/SpinLockAsMutex.h>
+#include <kernel/Lock/BlockableSpinLock.h>
+#include <kernel/Scheduler.h>
 #include <kernel/Terminal/TTY.h>
+#include <kernel/Thread.h>
 
 #include <LibInput/Joystick.h>
 #include <LibInput/KeyEvent.h>
@@ -245,8 +247,8 @@ namespace Kernel
 		while (m_event_count == 0)
 		{
 			// FIXME: should m_mutex be unlocked?
-			SpinLockGuardAsMutex smutex(guard);
+			BlockableSpinLock block(m_event_lock);
-			TRY(Thread::current().block_or_eintr_indefinite(m_event_thread_blocker, &smutex));
+			TRY(Thread::current().block_or_eintr_indefinite(m_event_thread_blocker, &block));
 		}
 
 		memcpy(buffer.data(), &m_event_buffer[m_event_tail * m_event_size], m_event_size);
@@ -289,8 +291,8 @@ namespace Kernel
 
 				if (s_tty_keyboard_events.empty())
 				{
-					SpinLockGuardAsMutex smutex(guard);
+					BlockableSpinLock block(s_tty_keyboard_event_lock);
-					s_tty_keyboard_event_blocker.block_indefinite(&smutex);
+					s_tty_keyboard_event_blocker.block_indefinite(&block);
 					continue;
 				}
 
@@ -305,8 +307,7 @@ namespace Kernel
 	BAN::ErrorOr<void> KeyboardDevice::initialize_tty_thread()
 	{
 		auto* thread = TRY(Thread::create_kernel(tty_keyboard_thread, nullptr));
-		ASSERT(thread);
+		Processor::scheduler().add_thread(thread);
-		TRY(Processor::scheduler().add_thread(thread));
 		return {};
 	}
 
@@ -350,8 +351,8 @@ namespace Kernel
 					return bytes;
 			}
 
-			SpinLockGuardAsMutex smutex(keyboard_guard);
+			BlockableSpinLock block(s_keyboard_lock);
-			TRY(Thread::current().block_or_eintr_indefinite(m_thread_blocker, &smutex));
+			TRY(Thread::current().block_or_eintr_indefinite(m_thread_blocker, &block));
 		}
 	}
 
@@ -407,8 +408,8 @@ namespace Kernel
 					return bytes;
 			}
 
-			SpinLockGuardAsMutex smutex(mouse_guard);
+			BlockableSpinLock block(s_mouse_lock);
-			TRY(Thread::current().block_or_eintr_indefinite(m_thread_blocker, &smutex));
+			TRY(Thread::current().block_or_eintr_indefinite(m_thread_blocker, &block));
 		}
 	}
 

kernel/kernel/Input/PS2/Controller.cpp

@@ -8,6 +8,8 @@
 #include <kernel/Input/PS2/Keyboard.h>
 #include <kernel/Input/PS2/Mouse.h>
 #include <kernel/IO.h>
+#include <kernel/Scheduler.h>
+#include <kernel/Thread.h>
 #include <kernel/Timer/Timer.h>
 
 namespace Kernel::Input
@@ -317,11 +319,18 @@ namespace Kernel::Input
 					if (crs_obj == nullptr)
 						return PS2ResourceSetting {};
 
+					const auto crs = TRY(ACPI::AML::evaluate_node(crs_path, crs_obj->node));
+					if (crs.type != ACPI::AML::Node::Type::Buffer)
+					{
+						dwarnln("PS/2 _CRS is not a buffer, but {}", crs);
+						return BAN::Error::from_errno(EINVAL);
+					}
+
 					PS2ResourceSetting result;
 					result.type = type;
 
 					BAN::Optional<ACPI::ResourceData> data;
-					ACPI::ResourceParser parser({ crs_obj->node.as.str_buf->bytes, static_cast<size_t>(crs_obj->node.as.str_buf->size) });
+					ACPI::ResourceParser parser({ crs.as.str_buf->bytes, static_cast<size_t>(crs.as.str_buf->size) });
 					while ((data = parser.get_next()).has_value())
 					{
 						switch (data->type)
@@ -345,7 +354,7 @@ namespace Kernel::Input
 									result.command_port = data->as.fixed_io_port.range_base;
 								break;
 							case ACPI::ResourceData::Type::IRQ:
-								if (__builtin_popcount(data->as.irq.irq_mask) != 1)
+								if (BAN::Math::popcount(data->as.irq.irq_mask) != 1)
 									break;
 								for (int i = 0; i < 16; i++)
 									if (data->as.irq.irq_mask & (1 << i))
@@ -386,14 +395,11 @@ namespace Kernel::Input
 			}
 
 			dprintln("Found {} PS/2 devices from ACPI namespace", acpi_devices.size());
-			if (acpi_devices.empty())
-				return {};
 
 			if (acpi_devices.size() > 2)
 			{
 				dwarnln("TODO: over 2 PS/2 devices");
-				while (acpi_devices.size() > 2)
+				MUST(acpi_devices.resize(2));
-					acpi_devices.pop_back();
 			}
 
 			if (acpi_devices.size() == 2)
@@ -419,42 +425,43 @@ namespace Kernel::Input
 				}
 			}
 
-			BAN::Optional<uint16_t> command_port;
+			if (!acpi_devices.empty())
-			command_port = acpi_devices[0].command_port;
-			if (!command_port.has_value() && acpi_devices.size() >= 2)
-				command_port = acpi_devices[1].command_port;
-			if (command_port.has_value())
-				m_command_port = command_port.value();
-
-			BAN::Optional<uint16_t> data_port;
-			data_port = acpi_devices[0].data_port;
-			if (!data_port.has_value() && acpi_devices.size() >= 2)
-				data_port = acpi_devices[1].data_port;
-			if (data_port.has_value())
-				m_data_port = data_port.value();
-
-			devices[0] = {
-				.type      = acpi_devices[0].type,
-				.interrupt = acpi_devices[0].irq.value_or(PS2::INTERRUPT_FIRST_PORT)
-			};
-
-			if (acpi_devices.size() > 1)
 			{
-				devices[1] = {
+				BAN::Optional<uint16_t> command_port;
-					.type      = acpi_devices[1].type,
+				command_port = acpi_devices[0].command_port;
-					.interrupt = acpi_devices[1].irq.value_or(PS2::INTERRUPT_SECOND_PORT)
+				if (!command_port.has_value() && acpi_devices.size() >= 2)
+					command_port = acpi_devices[1].command_port;
+				if (command_port.has_value())
+					m_command_port = command_port.value();
+
+				BAN::Optional<uint16_t> data_port;
+				data_port = acpi_devices[0].data_port;
+				if (!data_port.has_value() && acpi_devices.size() >= 2)
+					data_port = acpi_devices[1].data_port;
+				if (data_port.has_value())
+					m_data_port = data_port.value();
+			}
+
+			for (size_t i = 0; i < acpi_devices.size(); i++)
+			{
+				devices[i] = {
+					.type      = acpi_devices[i].type,
+					.interrupt = acpi_devices[i].irq.value_or(i == 0 ? PS2::IRQ::DEVICE0 : PS2::IRQ::DEVICE1),
 				};
 			}
 		}
-		else if (has_legacy_8042())
+
+		if (devices[0].type != DeviceType::None)
+			;
+		else if (scancode_set || has_legacy_8042())
 		{
 			devices[0] = {
 				.type = DeviceType::Unknown,
-				.interrupt = PS2::INTERRUPT_FIRST_PORT,
+				.interrupt = PS2::IRQ::DEVICE0,
 			};
 			devices[1] = {
 				.type = DeviceType::Unknown,
-				.interrupt = PS2::INTERRUPT_SECOND_PORT,
+				.interrupt = PS2::IRQ::DEVICE1,
 			};
 		}
 		else
@@ -551,7 +558,7 @@ namespace Kernel::Input
 				static_cast<PS2DeviceInitInfo*>(info)->controller->device_initialize_task(info);
 			}, &info
 		));
-		TRY(Processor::scheduler().add_thread(init_thread));
+		Processor::scheduler().add_thread(init_thread);
 
 		while (!info.thread_started)
 			Processor::pause();

kernel/kernel/Input/PS2/Keyboard.cpp

@@ -53,8 +53,9 @@ namespace Kernel::Input
 
 		if (command_data[0] == Command::CONFIG_SCANCODE_SET && m_scancode_set >= 0xFE)
 		{
-			dwarnln("Could not detect scancode set, assuming 2");
+			dwarnln("Could not detect scancode set, assuming 1");
-			m_scancode_set = 2;
+			m_scancode_set_uncertain = true;
+			m_scancode_set = 1;
 			m_keymap.initialize(m_scancode_set);
 			append_command_queue(PS2::DeviceCommand::ENABLE_SCANNING, 0);
 		}
@@ -89,6 +90,7 @@ namespace Kernel::Input
 			else
 			{
 				dwarnln("Could not detect scancode set, assuming 1");
+				m_scancode_set_uncertain = true;
 				m_scancode_set = 1;
 			}
 			m_keymap.initialize(m_scancode_set);
@@ -103,6 +105,17 @@ namespace Kernel::Input
 			return;
 		}
 
+		// If we could not detect scancode set, we assume it to be 1
+		// If we get byte 0xF0 which is indicates release in scancode set 2
+		// and nothing in scancode set 1, switch to scancode set 2
+		if (m_scancode_set_uncertain && byte == 0xF0)
+		{
+			dprintln("Switching to scancode set 2");
+			m_scancode_set_uncertain = false;
+			m_scancode_set = 2;
+			m_keymap.initialize(m_scancode_set);
+		}
+
 		m_byte_buffer[m_byte_index++] = byte;
 		if (byte == 0xE0)
 			return;

kernel/kernel/Lock/Mutex.cpp

@@ -0,0 +1,134 @@
+#include <kernel/Lock/Mutex.h>
+#include <kernel/Thread.h>
+
+namespace Kernel
+{
+
+	bool Mutex::try_lock()
+	{
+		const auto tid = Thread::current_tid();
+		if (tid == m_locker)
+			ASSERT(m_lock_depth > 0);
+		else
+		{
+			pid_t expected = -1;
+			if (!m_locker.compare_exchange(expected, tid))
+				return false;
+			ASSERT(m_lock_depth == 0);
+			if (tid)
+				Thread::current().add_mutex();
+		}
+		m_lock_depth++;
+		return true;
+	}
+
+	void Mutex::lock()
+	{
+		const auto tid = Thread::current_tid();
+		if (tid == m_locker)
+			ASSERT(m_lock_depth > 0);
+		else
+		{
+			ASSERT(!tid || !Thread::current().has_spinlock());
+			pid_t expected = -1;
+			while (!m_locker.compare_exchange(expected, tid))
+			{
+				ASSERT(Processor::get_interrupt_state() == InterruptState::Enabled);
+				Processor::yield();
+				expected = -1;
+			}
+			ASSERT(m_lock_depth == 0);
+			if (tid)
+				Thread::current().add_mutex();
+		}
+		m_lock_depth++;
+	}
+
+	void Mutex::unlock()
+	{
+		const auto tid = Thread::current_tid();
+		ASSERT(m_locker == tid);
+		ASSERT(m_lock_depth > 0);
+		if (--m_lock_depth == 0)
+		{
+			m_locker = -1;
+			if (tid)
+				Thread::current().remove_mutex();
+		}
+	}
+
+	bool Mutex::is_locked_by_current_thread() const
+	{
+		return m_locker == Thread::current_tid();
+	}
+
+	bool PriorityMutex::try_lock()
+	{
+		const auto tid = Thread::current_tid();
+
+		if (tid == m_locker)
+			ASSERT(m_lock_depth > 0);
+		else
+		{
+			bool has_priority = tid ? !Thread::current().is_userspace() : true;
+			pid_t expected = -1;
+			if (!(has_priority || m_queue_length == 0) || !m_locker.compare_exchange(expected, tid))
+				return false;
+			if (has_priority)
+				m_queue_length++;
+			ASSERT(m_lock_depth == 0);
+			if (tid)
+				Thread::current().add_mutex();
+		}
+		m_lock_depth++;
+		return true;
+	}
+
+	void PriorityMutex::lock()
+	{
+		const auto tid = Thread::current_tid();
+
+		if (tid == m_locker)
+			ASSERT(m_lock_depth > 0);
+		else
+		{
+			ASSERT(!tid || !Thread::current().has_spinlock());
+			bool has_priority = tid ? !Thread::current().is_userspace() : true;
+			if (has_priority)
+				m_queue_length++;
+			pid_t expected = -1;
+			while (!(has_priority || m_queue_length == 0) || !m_locker.compare_exchange(expected, tid))
+			{
+				ASSERT(Processor::get_interrupt_state() == InterruptState::Enabled);
+				Processor::yield();
+				expected = -1;
+			}
+			ASSERT(m_lock_depth == 0);
+			if (tid)
+				Thread::current().add_mutex();
+		}
+		m_lock_depth++;
+	}
+
+	void PriorityMutex::unlock()
+	{
+		const auto tid = Thread::current_tid();
+		ASSERT(m_locker == tid);
+		ASSERT(m_lock_depth > 0);
+		if (--m_lock_depth == 0)
+		{
+			bool has_priority = tid ? !Thread::current().is_userspace() : true;
+			if (has_priority)
+				m_queue_length--;
+			m_locker = -1;
+			if (tid)
+				Thread::current().remove_mutex();
+		}
+	}
+
+	bool PriorityMutex::is_locked_by_current_thread() const
+	{
+		return m_locker == Thread::current_tid();
+	}
+
+}

kernel/kernel/Lock/RWLock.cpp

@@ -0,0 +1,58 @@
+
+#include <kernel/Lock/BlockableSpinLock.h>
+#include <kernel/Lock/RWLock.h>
+#include <kernel/Thread.h>
+
+namespace Kernel
+{
+
+	void RWLock::rd_lock()
+	{
+		SpinLockGuard _(m_lock);
+		while (m_writers_waiting > 0 || m_writer != -1)
+		{
+			BlockableSpinLock block(m_lock);
+			m_thread_blocker.block_indefinite(&block);
+		}
+		m_readers_active++;
+	}
+
+	void RWLock::rd_unlock()
+	{
+		SpinLockGuard _(m_lock);
+		if (--m_readers_active == 0)
+			m_thread_blocker.unblock();
+	}
+
+	void RWLock::wr_lock()
+	{
+		if (m_writer == Thread::current_tid())
+		{
+			m_writer_depth++;
+			return;
+		}
+
+		SpinLockGuard _(m_lock);
+
+		m_writers_waiting++;
+		while (m_readers_active > 0 || m_writer != -1)
+		{
+			BlockableSpinLock block(m_lock);
+			m_thread_blocker.block_indefinite(&block);
+		}
+		m_writers_waiting--;
+
+		m_writer = Thread::current_tid();
+		m_writer_depth = 1;
+	}
+
+	void RWLock::wr_unlock()
+	{
+		if (--m_writer_depth != 0)
+			return;
+		SpinLockGuard _(m_lock);
+		m_writer = -1;
+		m_thread_blocker.unblock();
+	}
+
+}

kernel/kernel/Memory/FileBackedRegion.cpp

@@ -115,7 +115,7 @@ namespace Kernel
 			return {};
 
 		const vaddr_t first_page = BAN::Math::max(m_vaddr, address) & PAGE_ADDR_MASK;
-		const vaddr_t last_page = BAN::Math::div_round_up(BAN::Math::min(m_vaddr + m_size, address + size), PAGE_SIZE) * PAGE_SIZE;
+		const vaddr_t last_page = BAN::Math::div_round_up<vaddr_t>(BAN::Math::min(m_vaddr + m_size, address + size), PAGE_SIZE) * PAGE_SIZE;
 
 		RWLockRDGuard _(m_shared_data->rw_lock);
 		for (vaddr_t page_addr = first_page; page_addr < last_page; page_addr += PAGE_SIZE)