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Kernel/Userspace: Start initial work on userspace and syscalls

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This commit is contained in:
Bananymous
2023-03-13 15:32:46 +02:00
parent af854ec9e1
commit 8b8e3cbbf0
10 changed files with 231 additions and 5 deletions
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31
kernel/arch/i386/IDT.cpp
View File

@@ -151,6 +151,29 @@ found:
"popa;"
"iret;"
);
extern "C" void syscall_asm();
asm(
".global syscall_asm;"
"syscall_asm:"
"pusha;"
"pushw %ds;"
"pushw %es;"
"pushw %ss;"
"pushw %ss;"
"popw %ds;"
"popw %es;"
"pushl %edx;"
"pushl %ecx;"
"pushl %ebx;"
"pushl %eax;"
"call cpp_syscall_handler;"
"addl $16, %esp;"
"popw %es;"
"popw %ds;"
"popa;"
"iret;"
);
static void flush_idt()
{
@@ -175,6 +198,12 @@ found:
flush_idt();
}
void register_syscall_handler(uint8_t offset, void(*handler)())
{
register_interrupt_handler(offset, handler);
s_idt[offset].DPL = 3;
}
void initialize()
{
constexpr size_t idt_size = 0x100 * sizeof(GateDescriptor);
@@ -219,6 +248,8 @@ found:
REGISTER_HANDLER(0x1E);
REGISTER_HANDLER(0x1F);
register_syscall_handler(0x80, syscall_asm);
flush_idt();
}

13
kernel/arch/i386/linker.ld
View File

@@ -11,7 +11,9 @@ SECTIONS
}
.rodata BLOCK(4K) : ALIGN(4K)
{
*(.rodata)
g_rodata_start = .;
*(.rodata.*)
g_rodata_end = .;
}
.data BLOCK(4K) : ALIGN(4K)
{
@@ -24,4 +26,13 @@ SECTIONS
}
g_kernel_end = .;
. = 0x00A00000;
g_userspace_start = .;
.userspace BLOCK(4K) : ALIGN(4K)
{
*(.userspace)
}
g_userspace_end = .;
}

10
kernel/arch/x86_64/IDT.cpp
View File

@@ -148,6 +148,12 @@ namespace IDT
descriptor.flags = 0x8E;
}
static void register_syscall_handler(uint8_t index, void(*handler)())
{
register_interrupt_handler(index, handler);
s_idt[index].flags = 0xEE;
}
void register_irq_handler(uint8_t irq, void(*handler)())
{
s_irq_handlers[irq] = handler;
@@ -203,6 +209,8 @@ namespace IDT
extern "C" void irq14();
extern "C" void irq15();
extern "C" void syscall_asm();
void initialize()
{
s_idt = (GateDescriptor*)kmalloc(0x100 * sizeof(GateDescriptor));
@@ -262,6 +270,8 @@ namespace IDT
REGISTER_IRQ_HANDLER(14);
REGISTER_IRQ_HANDLER(15);
register_syscall_handler(0x80, syscall_asm);
flush_idt();
}

29
kernel/arch/x86_64/interrupts.S
View File

@@ -34,6 +34,23 @@
popq %rax
.endm
.macro popaq_no_rax
popq %r15
popq %r14
popq %r13
popq %r12
popq %r11
popq %r10
popq %r9
popq %r8
popq %rsi
popq %rdi
popq %rbp
popq %rdx
popq %rcx
popq %rbx
.endm
isr_stub:
pushaq
@@ -138,3 +155,15 @@ irq 12
irq 13
irq 14
irq 15
.global syscall_asm
syscall_asm:
cli
pushaq
movq %rax, %rdi
movq %rbx, %rsi
xchgq %rcx, %rdx
call cpp_syscall_handler
popaq_no_rax
addq $8, %rsp
iretq

15
kernel/arch/x86_64/linker.ld
View File

@@ -11,7 +11,9 @@ SECTIONS
}
.rodata BLOCK(4K) : ALIGN(4K)
{
*(.rodata)
g_rodata_start = .;
*(.rodata.*)
g_rodata_end = .;
}
.data BLOCK(4K) : ALIGN(4K)
{
@@ -22,6 +24,15 @@ SECTIONS
*(COMMON)
*(.bss)
}
g_kernel_end = .;
. = 0x00A00000;
g_userspace_start = .;
.userspace BLOCK(4K) : ALIGN(4K)
{
*(.userspace)
}
g_userspace_end = .;
}