62 lines
1.5 KiB
NASM
62 lines
1.5 KiB
NASM
struc PCB
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.PID resd 1 ; Offset: 0
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.STATE resd 1 ; Offset: 4
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.KSTACK resd 1 ; Offset: 8
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.CONTEXT resd 1 ; Offset: 12
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.TF resd 1 ; Offset: 16
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.FLAGS resd 1 ; Offset: 20
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.NEXT resd 1 ; Offset: 24
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.PAGE_DIRECTORY resd 1 ; Offset: 28
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endstruc
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; void switchProcess(Process* next)
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section .text
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global switchProcess
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extern current
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extern trapret
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; void switchProcess(Process* next_process_ptr)
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switchProcess:
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mov edx, [esp + 4] ; edx = next_process_ptr (получаем аргумент СРАЗУ)
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cli ; Запретить прерывания
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push ebp
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push ebx
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push esi
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push edi
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mov eax, [current]
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mov [eax + 4], esp ; current->kesp = esp
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; edx уже содержит next_process_ptr
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mov esp, [edx + 4] ; esp = next_process_ptr->kesp
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mov [current], edx ; current = next_process_ptr
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mov eax, [edx + 40]
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mov cr3, eax
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pop edi
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pop esi
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pop ebx
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pop ebp
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ret
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trapret:
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; Восстанавливаем общие регистры из trap frame
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;popal ; edi, esi, ebp, oesp, ebx, edx, ecx, eax
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; Восстанавливаем сегментные регистры
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pop gs
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pop fs
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pop es
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pop ds
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popad
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; Пропускаем trapno и err
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add esp, 8 ; trapno (4 байта) + err (4 байта)
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; Теперь ESP указывает на eip, cs, eflags, esp, ss
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iret |