Kernel: Multiboot data and kernel command lines are now global variables

kernel/arch/i386/VESA.cpp

@@ -90,13 +90,13 @@ namespace VESA
 
 	bool Initialize()
 	{
-		if (!(s_multiboot_info->flags & MULTIBOOT_FLAGS_FRAMEBUFFER))
+		if (!(g_multiboot_info->flags & MULTIBOOT_FLAGS_FRAMEBUFFER))
 		{
 			derrorln("bootloader did not provide a memory map");
 			return false;
 		}
 
-		auto& framebuffer = s_multiboot_info->framebuffer;
+		auto& framebuffer = g_multiboot_info->framebuffer;
 		s_addr		= framebuffer.addr;
 		s_bpp		= framebuffer.bpp;
 		s_pitch		= framebuffer.pitch;

kernel/arch/i386/boot.S

@@ -7,7 +7,7 @@
 .set MB_CHECKSUM,	-(MB_MAGIC + MB_FLAGS)		#checksum of above, to prove we are multiboot
 
 # Multiboot header
-.section .multiboot
+.section .multiboot, "aw"
 	.align 4
 	.long MB_MAGIC
 	.long MB_FLAGS
@@ -19,28 +19,111 @@
 	.long 600
 	.long 32
 
+.section .bss, "aw", @nobits
  	# Create stack
-.section .bss
 	stack_bottom:
-	.skip 16384		# 16 KiB
+		.skip 16384
 	stack_top:
 	
-.section .text
+	.global g_kernel_cmdline
+	g_kernel_cmdline:
+		.skip 4096
+
+	# Reserve memory for paging structures,
+	# we will identity map first 4 MiB
+
+	# 0 MiB -> 2 MiB: kernel
+	# 2 MiB -> 3 MiB: kmalloc
+	# 3 MiB -> 4 Mib: kmalloc_eternal
+	.align 32
+	boot_page_directory_pointer_table:
+		.skip 4 * 8
+	.align 4096
+	boot_page_directory1:
+		.skip 512 * 8
+
+	
+
+.section .text, "a"
+
+.global g_multiboot_info
+g_multiboot_info:
+	.skip 4
+.global g_multiboot_magic
+g_multiboot_magic:
+	.skip 4
+
+has_cpuid:
+	pushfl
+	pushfl
+	xorl $0x00200000, (%esp)
+	popfl
+	pushfl
+	popl %eax
+	xorl (%esp), %eax
+	popfl
+	andl $0x00200000, %eax
+	ret
+
+has_pae:
+	call has_cpuid
+	cmpl $0, %eax
+	jz .exit
+	movl $0, %eax
+	cpuid
+	movl %edx, %eax
+	andl $0x40, %eax # PAE is bit 6 in edx
+.exit:
+	ret
+
 .global _start
 .type _start, @function
 _start:
+	# Initialize stack and multiboot info
 	movl $stack_top, %esp
+	movl %eax, g_multiboot_magic
+	movl %ebx, g_multiboot_info
 
-	pushl %eax
-	pushl %ebx
 
+	# Copy kernel command line to known location
+	movl %ebx, %esi
+	addl $16, %esi
+	movl (%esi), %esi
+	movl $1024, %ecx
+	movl $g_kernel_cmdline, %edi
+	rep movsl
+
+	call has_pae
+	cmpl $0, %eax
+	jz system_halt
+
+	# identity map first 4 MiB
+	movl $(0x00000000           + 0x83), boot_page_directory1 + 0
+	movl $(0x00200000           + 0x83), boot_page_directory1 + 8
+	movl $(boot_page_directory1 + 0x01), boot_page_directory_pointer_table
+
+	# enable PAE
+	movl %cr4, %ecx
+	orl $0x20, %ecx
+	movl %ecx, %cr4
+
+	# set address of paging structures
+	movl $boot_page_directory_pointer_table, %ecx
+	movl %ecx, %cr3
+
+	# enable paging
+	movl %cr0, %ecx
+	orl $0x80000000, %ecx
+	movl %ecx, %cr0
+
+	xchgw %bx, %bx
+	# call global constuctors
 	call _init
 
+	# call to the kernel itself
 	call kernel_main
 
+system_halt:
 	cli
-1:
+1:	hlt
-	hlt
 	jmp 1b
-
-.size _start, . - _start

kernel/arch/i386/linker.ld

@@ -2,7 +2,7 @@ ENTRY(_start)
 
 SECTIONS
 {
-	. = 1M;
+	. = 0x00100000;
 
 	.text BLOCK(4K) : ALIGN(4K)
 	{
@@ -22,4 +22,6 @@ SECTIONS
 		*(COMMON)
 		*(.bss)
 	}
+
+	g_kernel_end = .;
 }

kernel/arch/i386/make.config

@@ -9,5 +9,6 @@ $(ARCHDIR)/boot.o		\
 $(ARCHDIR)/CPUID.o		\
 $(ARCHDIR)/GDT.o		\
 $(ARCHDIR)/IDT.o		\
+$(ARCHDIR)/MMU.o		\
 $(ARCHDIR)/Paging.o		\
 $(ARCHDIR)/VESA.o		\

kernel/include/kernel/multiboot.h

@@ -48,4 +48,5 @@ struct multiboot_info_t
 	framebuffer_info_t framebuffer;
 } __attribute__((packed));
 
-extern multiboot_info_t* s_multiboot_info;
+extern "C" multiboot_info_t*	g_multiboot_info;
+extern "C" uint32_t				g_multiboot_magic;

kernel/kernel/TTY.cpp

@@ -1,3 +1,4 @@
+#include <BAN/Memory.h>
 #include <kernel/kmalloc.h>
 #include <kernel/Panic.h>
 #include <kernel/Serial.h>

kernel/kernel/kernel.cpp

@@ -4,6 +4,7 @@
 #include <kernel/Input.h>
 #include <kernel/kmalloc.h>
 #include <kernel/kprint.h>
+#include <kernel/MMU.h>
 #include <kernel/multiboot.h>
 #include <kernel/Paging.h>
 #include <kernel/PIC.h>
@@ -17,8 +18,7 @@
 #define DISABLE_INTERRUPTS() asm volatile("cli")
 #define ENABLE_INTERRUPTS() asm volatile("sti")
 
-
+extern "C" const char g_kernel_cmdline[];
-multiboot_info_t* s_multiboot_info;
 
 using namespace BAN;
 

kernel/kernel/kmalloc.cpp

@@ -9,6 +9,8 @@
 
 #define ALIGN (alignof(max_align_t))
 
+extern "C" uintptr_t g_kernel_end;
+
 /*
 	#### KMALLOC ################
 */
@@ -47,14 +49,17 @@ static bool s_initialized = false;
 
 void kmalloc_initialize()
 {
-	if (!(s_multiboot_info->flags & (1 << 6)))
+	if (!(g_multiboot_info->flags & (1 << 6)))
 		Kernel::Panic("Kmalloc: Bootloader didn't provide a memory map");
 
+	if (g_kernel_end > s_kmalloc_node_base)
+		Kernel::Panic("Kmalloc: Kernel end is over kmalloc base");
+
 	// Validate kmalloc memory
 	bool valid = false;
-	for (size_t i = 0; i < s_multiboot_info->mmap_length;)
+	for (size_t i = 0; i < g_multiboot_info->mmap_length;)
 	{
-		multiboot_memory_map_t* mmmt = (multiboot_memory_map_t*)(s_multiboot_info->mmap_addr + i);
+		multiboot_memory_map_t* mmmt = (multiboot_memory_map_t*)(g_multiboot_info->mmap_addr + i);
 
 		if (mmmt->type == 1)
 		{