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bits 32
global syscall_isr
global quit_isr
global yield_isr
global _start_user_mode
global kbd_isr
global udf_isr
global dfa_isr
global tsf_isr
global npf_isr
global ssf_isr
global gpf_isr
global pff_isr
extern syscall_table
extern active_task
extern delete_task
extern advance_active_task
extern on_kbd_isr
extern make_sure_tasks
extern exception_halt
extern pf_check_stack
extern dump
n_syscalls equ 0x1c
;section .bss
;_debug_is_start_task resb 1
;extern switch_to_kernel_cr3
;extern switch_to_task_cr3
section .text
syscall_isr:
cmp eax, n_syscalls
jge .bad
; mov byte [_debug_is_start_task], 0
; cmp eax, 0x4
; jne .dont_set_debug
; mov byte [_debug_is_start_task], 1
;.dont_set_debug:
mov eax, dword [syscall_table + eax * 4]
push edi
push esi
push edx
push ecx
push ebx
call eax
add esp, 20
; cmp byte [_debug_is_start_task], 0
; je .dont_do_debug
; push eax
; call switch_to_kernel_cr3
; jmp $
; call switch_to_task_cr3
; pop eax
;.dont_do_debug:
._before_return:
iret
.bad:
mov eax, -1
iret
quit_isr:
push dword [active_task]
call delete_task
call make_sure_tasks
mov dword [esp], yield_isr.return_to_task
jmp advance_active_task
yield_isr:
mov eax, dword [active_task]
mov dword [eax + 8], ebx
mov dword [eax + 12], ecx
mov dword [eax + 16], edx
mov dword [eax + 20], esi
mov dword [eax + 24], edi
mov dword [eax + 28], ebp
mov edx, dword [esp]
mov dword [eax], edx
mov edx, cr3
mov dword [eax + 4], edx
mov edx, dword [esp + 12]
mov dword [eax + 32], edx
call advance_active_task
.return_to_task:
mov eax, dword [active_task]
mov edx, dword [eax]
mov dword [esp], edx
mov edx, dword [eax + 4]
mov cr3, edx
mov edx, dword [eax + 32]
mov dword [esp + 12], edx
mov ebx, dword [eax + 8]
mov ecx, dword [eax + 12]
mov edx, dword [eax + 16]
mov esi, dword [eax + 20]
mov edi, dword [eax + 24]
mov ebp, dword [eax + 28]
._before_return:
iret
_start_user_mode:
mov ax, 0x2b
mov ds, ax
mov es, ax
push dword 0x2b
sub esp, 4
push dword 0x00000200;interrupt flag
push dword 0x23
sub esp, 4
jmp yield_isr.return_to_task
kbd_isr:
push eax
push ecx
push edx
call on_kbd_isr
test eax, eax
jz .no_debug
push ebx
push esi
push edi
push eax
call dump
add esp, 16
.no_debug:
mov al, 0x20
out 0x0020, al
pop edx
pop ecx
pop eax
iret
udf_isr:
push 0
push udid
jmp exception
dfa_isr:
push dfid
jmp exception
tsf_isr:
push tsid
jmp exception
npf_isr:
push npid
jmp exception
ssf_isr:
push ssid
jmp exception
gpf_isr:
push gpid
jmp exception
pff_isr:
push eax
push ecx
push edx
mov eax, cr2
push eax
call pf_check_stack
add esp, 4
pop edx
pop ecx
test eax, eax
jz .not_stack
pop eax
add esp, 4
iret
.not_stack:
pop eax
push pfid
jmp exception
exception:
push edi
push esi
push edx
push ecx
push ebx
push eax
call exception_halt
section .rodata
udid db "UD", 0
dfid db "DF", 0
tsid db "TS", 0
npid db "NP", 0
ssid db "SS", 0
gpid db "GP", 0
pfid db "PF", 0
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