44 lines
963 B
ArmAsm
44 lines
963 B
ArmAsm
// Copyright (c) 2015, edef <edef@edef.eu>
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// See the LICENSE file included in this distribution.
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//! initialise a new context
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//! arguments:
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//! * rdi: stack pointer
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//! * rsi: function pointer
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//! * rdx: data pointer
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//! * rcx: stack limit
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//!
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//! return values:
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//! * rdi: new stack pointer
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// switch to the fresh stack
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xchg %rsp, %rdi
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// save the function pointer, data pointer, and stack limit, respectively
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pushq %rsi
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pushq %rdx
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pushq %rcx
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// save the return address, control flow continues at label 1
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call 1f
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// we arrive here once this context is reactivated (see swap.s)
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// restore the stack limit, data pointer, and function pointer, respectively
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popq %fs:0x70
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popq %rdi
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popq %rax
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// initialise the frame pointer
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movq $$0, %rbp
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// call the function pointer with the data pointer (rdi is the first argument)
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call *%rax
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// crash if it ever returns
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ud2
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1:
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// save our neatly-setup new stack
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xchg %rsp, %rdi
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// back into Rust-land we go
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