67 lines
1.2 KiB
ArmAsm
67 lines
1.2 KiB
ArmAsm
.globl switch
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switch:
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# Load task page table
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mov (%rdi), %rax
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mov %rax, %cr3
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# First load the task stack
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mov 64(%rdi), %rsp
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# Prepare for iret
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push 96(%rdi) # ds
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push 64(%rdi) # rsp
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push 128(%rdi) # Flags
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pop %rax
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or $0x200, %rax # Enable interrupt
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mov $0xffffffffbfff, %rbx # NT flag
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and %rbx, %rax
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push %rax # Apply flags changes
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push 40(%rdi) # cs
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push 48(%rdi) # rip
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# Prepare to restore general registers
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push 8(%rdi) # rax
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push 16(%rdi) # rbx
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push 24(%rdi) # rcx
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push 32(%rdi) # rdx
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push 72(%rdi) # rbp
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push 80(%rdi) # rsi
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push 88(%rdi) # rdi
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push 144(%rdi) # r8
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push 152(%rdi) # r9
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push 160(%rdi) # r10
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push 160(%rdi) # r11
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push 176(%rdi) # r12
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push 184(%rdi) # r13
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push 192(%rdi) # r14
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push 200(%rdi) # r15
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# ds
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mov 96(%rdi), %ax
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mov %ax, %ds
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mov %ax, %gs
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mov %ax, %fs
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mov %ax, %es
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# Restore general registers
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pop %r15
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pop %r14
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pop %r13
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pop %r12
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pop %r11
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pop %r10
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pop %r9
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pop %r8
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pop %rdi
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pop %rsi
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pop %rbp
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pop %rdx
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pop %rcx
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pop %rbx
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pop %rax
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# Perform task switching
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iretq
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