227 lines
No EOL
3.1 KiB
NASM
227 lines
No EOL
3.1 KiB
NASM
bits 32
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global syscall_isr
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global quit_isr
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global yield_isr
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global _start_user_mode
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global kbd_isr
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global udf_isr
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global dfa_isr
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global tsf_isr
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global npf_isr
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global ssf_isr
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global gpf_isr
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global pff_isr
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extern syscall_table
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extern active_task
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extern delete_task
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extern advance_active_task
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extern on_kbd_isr
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extern make_sure_tasks
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extern exception_halt
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extern pf_check_stack
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extern dump
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n_syscalls equ 0x1a
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;section .bss
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;_debug_is_start_task resb 1
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;extern switch_to_kernel_cr3
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;extern switch_to_task_cr3
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section .text
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syscall_isr:
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cmp eax, n_syscalls
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jge .bad
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; mov byte [_debug_is_start_task], 0
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; cmp eax, 0x4
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; jne .dont_set_debug
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; mov byte [_debug_is_start_task], 1
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;.dont_set_debug:
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mov eax, dword [syscall_table + eax * 4]
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push edi
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push esi
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push edx
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push ecx
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push ebx
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call eax
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add esp, 20
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; cmp byte [_debug_is_start_task], 0
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; je .dont_do_debug
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; push eax
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; call switch_to_kernel_cr3
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; jmp $
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; call switch_to_task_cr3
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; pop eax
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;.dont_do_debug:
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._before_return:
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iret
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.bad:
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mov eax, -1
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iret
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quit_isr:
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push dword [active_task]
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call delete_task
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call make_sure_tasks
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mov dword [esp], yield_isr.return_to_task
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jmp advance_active_task
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yield_isr:
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mov eax, dword [active_task]
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mov dword [eax + 8], ebx
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mov dword [eax + 12], ecx
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mov dword [eax + 16], edx
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mov dword [eax + 20], esi
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mov dword [eax + 24], edi
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mov dword [eax + 28], ebp
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mov edx, dword [esp]
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mov dword [eax], edx
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mov edx, cr3
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mov dword [eax + 4], edx
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mov edx, dword [esp + 12]
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mov dword [eax + 32], edx
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call advance_active_task
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.return_to_task:
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mov eax, dword [active_task]
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mov edx, dword [eax]
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mov dword [esp], edx
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mov edx, dword [eax + 4]
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mov cr3, edx
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mov edx, dword [eax + 32]
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mov dword [esp + 12], edx
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mov ebx, dword [eax + 8]
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mov ecx, dword [eax + 12]
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mov edx, dword [eax + 16]
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mov esi, dword [eax + 20]
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mov edi, dword [eax + 24]
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mov ebp, dword [eax + 28]
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._before_return:
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iret
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_start_user_mode:
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mov ax, 0x2b
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mov ds, ax
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mov es, ax
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push dword 0x2b
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sub esp, 4
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push dword 0x00000200;interrupt flag
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push dword 0x23
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sub esp, 4
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jmp yield_isr.return_to_task
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kbd_isr:
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push eax
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push ecx
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push edx
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call on_kbd_isr
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test eax, eax
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jz .no_debug
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push ebx
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push esi
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push edi
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push eax
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call dump
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add esp, 16
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.no_debug:
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mov al, 0x20
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out 0x0020, al
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pop edx
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pop ecx
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pop eax
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iret
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udf_isr:
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push 0
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push udid
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jmp exception
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dfa_isr:
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push dfid
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jmp exception
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tsf_isr:
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push tsid
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jmp exception
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npf_isr:
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push npid
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jmp exception
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ssf_isr:
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push ssid
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jmp exception
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gpf_isr:
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push gpid
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jmp exception
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pff_isr:
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push eax
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push ecx
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push edx
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mov eax, cr2
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push eax
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call pf_check_stack
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add esp, 4
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pop edx
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pop ecx
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test eax, eax
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jz .not_stack
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pop eax
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add esp, 4
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iret
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.not_stack:
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pop eax
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push pfid
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jmp exception
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exception:
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push edi
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push esi
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push edx
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push ecx
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push ebx
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push eax
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call exception_halt
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section .rodata
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udid db "UD", 0
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dfid db "DF", 0
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tsid db "TS", 0
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npid db "NP", 0
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ssid db "SS", 0
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gpid db "GP", 0
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pfid db "PF", 0 |