forked from ariadne/libucontext
109 lines
2.5 KiB
ArmAsm
109 lines
2.5 KiB
ArmAsm
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/*
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* Copyright (c) 2021 Peng Fan <fanpeng@loongson.cn>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* This software is provided 'as is' and without any warranty, express or
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* implied. In no event shall the authors be liable for any damages arising
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* from the use of this software.
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*/
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#include "defs.h"
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#define LOCALSZ (6)
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#define A3_OFF (FRAMESZ - (5 * REG_SZ))
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#define A4_OFF (FRAMESZ - (4 * REG_SZ))
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#define A5_OFF (FRAMESZ - (3 * REG_SZ))
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#define A6_OFF (FRAMESZ - (2 * REG_SZ))
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#define A7_OFF (FRAMESZ - (1 * REG_SZ))
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ALIAS(makecontext, libucontext_makecontext)
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FUNC(libucontext_makecontext)
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PUSH_FRAME(libucontext_makecontext)
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move $t5, $a0
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move $t4, $a1
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/* store $a3 through $a7 to the stack frame. */
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st.d $a3, $sp, A3_OFF
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st.d $a4, $sp, A4_OFF
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st.d $a5, $sp, A5_OFF
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st.d $a6, $sp, A6_OFF
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st.d $a7, $sp, A7_OFF
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/* set $zero in the mcontext to 1. */
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addi.d $v0, $zero, 1
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st.d $v0, $t5, REG_OFFSET(0)
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/* ensure the stack is aligned on a quad-word boundary. */
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ld.d $t0, $t5, UCONTEXT_STACK_PTR
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ld.d $t2, $t5, UCONTEXT_STACK_SIZE
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/* the third argument(from zero), that's the first argument of func() */
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addi.d $t1, $sp, A3_OFF
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add.d $t0, $t0, $t2
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addi.d $t7, $zero, ALMASK
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and $t0, $t0, $t7
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/* number of args */
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beq $a2, $zero, no_more_arguments
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bltu $a2, $zero, no_more_arguments
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/* store register arguments. */
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addi.d $t2, $t5, MCONTEXT_GREGS + (4 * REG_SZ)
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move $t3, $zero
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store_register_arg:
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addi.d $t3, $t3, 1
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ld.d $v1, $t1, 0
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addi.d $t1, $t1, REG_SZ
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st.d $v1, $t2, 0
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addi.d $t2, $t2, REG_SZ
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addi.d $t6, $zero, 8
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bltu $t3, $t6, store_register_arg
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bgeu $t3, $a2, no_more_arguments
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/* make room for stack arguments. */
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sub.d $t2, $a2, $t3
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addi.d $t6, $zero, 3
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sll.d $t2, $t2, $t6
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sub.d $t0, $t0, $t2
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addi.d $t6, $zero, ALMASK
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and $t0, $t0, $t6
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/* store stack arguments. */
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move $t2, $t0
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store_stack_arg:
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addi.d $t3, $t3, 1
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ld.d $v1, $t1, 0
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addi.d $t1, $t1, REG_SZ
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st.d $v1, $t2, 0
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addi.d $t2, $t2, REG_SZ
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bltu $t3, $a2, store_stack_arg
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no_more_arguments:
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/* trampoline setup. */
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la.got $t8, libucontext_trampoline
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ld.d $v1, $t5, UCONTEXT_UC_LINK
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st.d $v1, $t5, REG_OFFSET(23)
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st.d $t0, $t5, REG_OFFSET(3)
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st.d $t8, $t5, REG_OFFSET(1)
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st.d $t4, $t5, MCONTEXT_PC
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POP_FRAME(libucontext_makecontext)
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jr $ra
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END(libucontext_makecontext)
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