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/* Copyright (C) 2012-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "ucontext_i.h"
.syntax unified
.text
/* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */
ENTRY(swapcontext)
/* Have getcontext() do most of the work then fix up
LR afterwards. Save R3 to keep the stack aligned. */
push {r0,r1,r3,r14}
cfi_adjust_cfa_offset (16)
cfi_rel_offset (r0,0)
cfi_rel_offset (r1,4)
cfi_rel_offset (r3,8)
cfi_rel_offset (r14,12)
bl __getcontext
mov r4, r0
pop {r0,r1,r3,r14}
cfi_adjust_cfa_offset (-16)
cfi_restore (r0)
cfi_restore (r1)
cfi_restore (r3)
cfi_restore (r14)
/* Exit if getcontext() failed. */
cmp r4, #0
itt ne
movne r0, r4
RETINSTR(ne, r14)
/* Fix up LR and the PC. */
str r13,[r0, #MCONTEXT_ARM_SP]
str r14,[r0, #MCONTEXT_ARM_LR]
str r14,[r0, #MCONTEXT_ARM_PC]
/* And swap using swapcontext(). */
mov r0, r1
b __setcontext
END(swapcontext)
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