30 lines
574 B
ArmAsm
30 lines
574 B
ArmAsm
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# Context switch
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#
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# void swtch(struct context **old, struct context *new);
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#
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# Save the current registers on the stack, creating
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# a struct context, and save its address in *old.
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# Switch stacks to new and pop previously-saved registers.
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.globl swtch
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swtch:
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movl 4(%esp), %eax
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movl 8(%esp), %edx
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# Save old callee-saved registers
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pushl %ebp
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pushl %ebx
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pushl %esi
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pushl %edi
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# Switch stacks
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movl %esp, (%eax)
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movl %edx, %esp
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# Load new callee-saved registers
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popl %edi
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popl %esi
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popl %ebx
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popl %ebp
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ret
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