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| author | Nic Gaffney <gaffney_nic@protonmail.com> | 2023-12-17 13:21:21 -0600 |
|---|---|---|
| committer | Nic Gaffney <gaffney_nic@protonmail.com> | 2023-12-17 13:21:21 -0600 |
| commit | 9dbc5231dd738d97eea13f8ecf9005e5b78ea0d3 (patch) | |
| tree | 86f69ed6156254fd2df2dede5cea0c4397de2ac4 /src/boot | |
| parent | 5d5535adeeb71a5e5de78925ddd296d776ccaba5 (diff) | |
| download | gftos-9dbc5231dd738d97eea13f8ecf9005e5b78ea0d3.tar.gz | |
Restructured
Diffstat (limited to 'src/boot')
| -rw-r--r-- | src/boot/boot.s | 59 | ||||
| -rw-r--r-- | src/boot/crti.s | 11 | ||||
| -rw-r--r-- | src/boot/crtn.s | 7 |
3 files changed, 77 insertions, 0 deletions
diff --git a/src/boot/boot.s b/src/boot/boot.s new file mode 100644 index 0000000..aba32ff --- /dev/null +++ b/src/boot/boot.s @@ -0,0 +1,59 @@ +MBALIGN equ 1<<0 ; Align loaded modules on page boundries */ +MBMEMINFO equ 1<<1 ; Provide memory map*/ +MBFLAGS equ MBALIGN | MBMEMINFO ; Multiboot flag field*/ +MAGIC equ 0x1BADB002 ;Lets bootloader find header*/ +CHECKSUM equ -(MAGIC + MBFLAGS) ; Proves we are multiboot via checksum*/ +CODESEG equ 0x08 +DATASEG equ 0x10 + +section .multiboot +align 4 + dd MAGIC + dd MBFLAGS + dd CHECKSUM + +section .bss +align 16 +stack_bottom: +resb 16384 +stack_top: + +section .text +global gdtr +gdtr: + dw 0 + dd 0 +global _start:function (_start.end - _start) +_start: + mov esp, stack_top + + extern get_gdtr + call get_gdtr + cli + lgdt [gdtr] + mov eax, cr0 + or al, 1 + mov cr0, eax + + call reloadSegments + + [bits 32] + extern kernel_main + call kernel_main + + + cli +.hang: hlt + jmp .hang +.end: + +reloadSegments: + JMP CODESEG:.reload_CS ; should def define a CODESEG +.reload_CS: + MOV AX, DATASEG + MOV DS, AX + MOV ES, AX ; TODO: Setup proper extra segment + MOV FS, AX ; TODO: Setup proper General purpose segments + MOV GS, AX ; ... + MOV SS, AX ; TODO: Setup proper stack segment + RET diff --git a/src/boot/crti.s b/src/boot/crti.s new file mode 100644 index 0000000..26d677a --- /dev/null +++ b/src/boot/crti.s @@ -0,0 +1,11 @@ +section .init +global _init:function +_init: + push ebp + mov ebp, esp, + +section .fini +global _fini +_fini: + push ebp + mov ebp, esp diff --git a/src/boot/crtn.s b/src/boot/crtn.s new file mode 100644 index 0000000..46f8de6 --- /dev/null +++ b/src/boot/crtn.s @@ -0,0 +1,7 @@ +section .init + pop ebp + ret + +section .fini + pop ebp + ret |