45 lines
760 B
ArmAsm
45 lines
760 B
ArmAsm
.intel_syntax noprefix
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.section .text
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.global switch_to_task
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switch_to_task:
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push ebx
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push ebp
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push edi
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push esi
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// save the current stack pointer to the old stack
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mov [current_task+0], esp
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mov edi, [esp_backup] // get eip
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mov [current_task+16], edi // save instruction before Interrupt
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// stack pointer + the 4 regs pushed
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// and + 1 to get the argument (next task)
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mov esi, [esp+(4+1)*4]
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mov [current_task], esi
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mov esp, [current_task] // esp
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mov eax, [current_task+4] // esp0
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mov ebx, [current_task+8] // cr3
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mov [TSS+4], eax // tss.esp0
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mov ecx, cr3
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// if cr3 hasn't change, do nothing
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cmp ecx, ebx
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je .END
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// mov cr3, ebx
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.END:
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mov edi, [current_task+16]
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mov [esp_backup], edi
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pop esi
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pop edi
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pop ebp
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pop ebx
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ret
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