minix/lib/libc/arch/arm/gen/swapcontext.S

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/* $NetBSD: swapcontext.S,v 1.14 2013/11/30 20:20:42 joerg Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Klaus Klein.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "SYS.h"
#include "assym.h"
#if defined(LIBC_SCCS) && !defined(lint)
RCSID("$NetBSD: swapcontext.S,v 1.14 2013/11/30 20:20:42 joerg Exp $")
#endif /* LIBC_SCCS && !lint */
ENTRY(swapcontext)
#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
.fnstart
.cfi_startproc
#endif
push {r0-r2, lr} /* Must save oucp, ucp, lr. */
#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
.save {r0-r2, lr}
.cfi_def_cfa_offset 16
.cfi_offset 14, -4
.cfi_offset 2, -8
.cfi_offset 1, -12
.cfi_offset 0, -16
#endif
bl PLT_SYM(_C_LABEL(_getcontext)) /* getcontext(oucp) */
cmp r0, #0
#if !defined(__thumb__)
pop {r0-r2, lr}
#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
.cfi_def_cfa_offset 0
#endif
RETc(ne)
#else
pop {r0-r3}
beq 1f
#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
.cfi_def_cfa_offset 0
.cfi_register 14, 3
#endif
RETr(r3)
1:
#endif
#if !defined(__thumb__)
str sp, [r0, #_UC_REGS_SP] /* Adjust saved SP. */
str lr, [r0, #_UC_REGS_PC] /* Adjust saved SP. */
#else
mov r2, sp
str r2, [r0, #_UC_REGS_SP] /* Adjust saved SP. */
str r3, [r0, #_UC_REGS_PC] /* Adjust saved PC. */
mov lr, r3
#endif
#ifdef SOFTFLOAT
/* Ahem. */
#endif
mov r0, r1
#if !defined(__thumb__) || defined(_ARM_ARCH_T2)
b PLT_SYM(_C_LABEL(setcontext))
#else
push {lr}
bl PLT_SYM(_C_LABEL(setcontext))
pop {pc}
#endif
#if defined(__ARM_EABI__) && defined(__UNWIND_TABLES__)
.cfi_endproc
.fnend
#endif
END(swapcontext)