42 lines
973 B
ArmAsm
42 lines
973 B
ArmAsm
/*
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* Copyright (C) 2019 Intel Corporation.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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/*
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* Function schedule() will finally call arch_switch_to here for x86 platform, which use
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* the pointer of previous & next thread_obj->host_sp as the input parameters (rdi & rsi).
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*
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* Function arch_switch_to will save rflags, rbx, rbp, r12~r15, and rdi in the previous
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* thread_obj's stack, then switch stack pointer(rsp) from previous to next thread_obj (saved
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* in thread_obj->host_sp) and restore above registers from next thread_obj's stack.
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* It make sure the execution context return to the same point of next thread_obj when it got
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* scheduled last time.
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*/
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.text
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.code64
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.align 8
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.global arch_switch_to
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arch_switch_to:
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pushf
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pushq %rbx
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pushq %rbp
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pushq %r12
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pushq %r13
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pushq %r14
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pushq %r15
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pushq %rdi
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movq %rsp, (%rdi)
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movq (%rsi), %rsp
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popq %rdi
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popq %r15
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popq %r14
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popq %r13
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popq %r12
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popq %rbp
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popq %rbx
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popf
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retq
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