diff options
| author | EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com> | 2023-06-15 22:36:39 -0400 |
|---|---|---|
| committer | EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com> | 2023-06-15 22:36:39 -0400 |
| commit | a78033acc941fc4bcf6188f1d48fd8e012673fff (patch) | |
| tree | ac92adae5e40274fd9e0b78352a24840cc88eab4 /kernel/arch/i386/boot.asm | |
initial commit
Diffstat (limited to 'kernel/arch/i386/boot.asm')
| -rw-r--r-- | kernel/arch/i386/boot.asm | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/kernel/arch/i386/boot.asm b/kernel/arch/i386/boot.asm new file mode 100644 index 0000000..a2dccce --- /dev/null +++ b/kernel/arch/i386/boot.asm @@ -0,0 +1,82 @@ +; multiboot header constants
+MBALIGN equ 1 << 0
+MEMINFO equ 1 << 1
+MBFLAGS equ MBALIGN | MEMINFO
+MAGIC equ 0x1BADB002
+CHECKSUM equ -(MAGIC+MBFLAGS)
+
+; multiboot header
+section .multiboot
+align 4
+ dd MAGIC
+ dd MBFLAGS
+ dd CHECKSUM
+
+section .data
+%include "arch/i386/gdt.asm"
+
+; defines the stack
+section .bss
+align 16
+stack_bottom:
+resb 16384 ; 16 KiB
+stack_top:
+
+
+section .text
+global _start:function (_start.end - _start)
+_start:
+ cli
+ ; setup stack
+ mov esp, stack_top
+
+ extern _init
+ call _init
+
+ lgdt [gdt_descriptor]
+ jmp 0x08:.gdt_jmp
+
+.gdt_jmp:
+ mov ax, DATA_SEG
+ mov ds, ax
+ mov es, ax
+ mov fs, ax
+ mov gs, ax
+ mov ss, ax
+ jmp .gdt_jmp2
+
+.gdt_jmp2:
+
+ ; setup idt
+ extern idt_setup
+ call idt_setup
+ extern idtr
+ lidt [idtr]
+
+ ; initialize pic
+ push ebp
+ mov ebp, esp
+ mov ebx, 0x28
+ push ebx
+ mov ebx, 0x20
+ push ebx
+
+ extern pic_remap
+ call pic_remap
+
+ pop ebx
+ pop ebx
+ mov esp, ebp
+ pop ebp
+
+ sti
+
+ ; enter the kernel
+ extern kernel_main
+ call kernel_main
+
+ ; indefinite loop once system exits
+ ;cli
+.hang: hlt
+ jmp .hang
+.end:
\ No newline at end of file |