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authorFlorian Fainelli <florian@openwrt.org>2013-01-09 16:17:21 +0100
committerBernhard Reutner-Fischer <rep.dot.nop@gmail.com>2013-01-10 10:56:19 +0100
commita8dc90eaaa5e6474beac828558d969b1aafee4af (patch)
treeed22c27193dcc91697f6b8782da9a9abd08d42b1 /libc/sysdeps/linux/arm/setcontext.S
parentdf3a5fcc8d1c3402289375c92df705e978fab58d (diff)
libc: add {get,set,swap,make}context user context manipulation functions
Add the obsolescent SUSv3 family of user context manipulating functions for arm, i386, mips, x86_64. Signed-off-by: Timon ter Braak <timonterbraak@gmail.com> Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> Signed-off-by: Natanael Copa <ncopa@alpinelinux.org> Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
Diffstat (limited to 'libc/sysdeps/linux/arm/setcontext.S')
-rw-r--r--libc/sysdeps/linux/arm/setcontext.S76
1 files changed, 76 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/arm/setcontext.S b/libc/sysdeps/linux/arm/setcontext.S
new file mode 100644
index 000000000..a5c33a022
--- /dev/null
+++ b/libc/sysdeps/linux/arm/setcontext.S
@@ -0,0 +1,76 @@
+/* Copyright (C) 2012 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+ .syntax unified
+ .text
+
+/* int setcontext (const ucontext_t *ucp) */
+
+ENTRY(__setcontext)
+ mov r4, r0
+
+#if defined __UCLIBC_HAS_FLOATS__ && ! defined __UCLIBC_HAS_SOFT_FLOAT__
+# ifdef __VFP_FP__
+ /* Following instruction is vldmia r0!, {d8-d15}. */
+ ldc p11, cr8, [r0], #64
+ /* Restore the floating-point status register. */
+ ldr r1, [r0], #4
+ /* Following instruction is fmxr fpscr, r1. */
+ mcr p10, 7, r1, cr1, cr0, 0
+# endif
+#endif
+
+#ifdef __IWMMXT__
+ /* Restore the call-preserved iWMMXt registers. */
+ /* Following instructions are wldrd wr10, [r0], #8 (etc.) */
+ ldcl p1, cr10, [r0], #8
+ ldcl p1, cr11, [r0], #8
+ ldcl p1, cr12, [r0], #8
+ ldcl p1, cr13, [r0], #8
+ ldcl p1, cr14, [r0], #8
+ ldcl p1, cr15, [r0], #8
+#endif
+
+ /* Now bring back the signal status. */
+ mov r0, #SIG_SETMASK
+ add r1, r4, #UCONTEXT_SIGMASK
+ mov r2, #0
+ bl PLTJMP(sigprocmask)
+
+ /* Loading r0-r3 makes makecontext easier. */
+ add r14, r4, #MCONTEXT_ARM_R0
+ ldmia r14, {r0-r11}
+ ldr r13, [r14, #(MCONTEXT_ARM_SP - MCONTEXT_ARM_R0)]
+ add r14, r14, #(MCONTEXT_ARM_LR - MCONTEXT_ARM_R0)
+ ldmia r14, {r14, pc}
+
+END(setcontext)
+weak_alias(__setcontext, setcontext)
+
+ /* Called when a makecontext() context returns. Start the
+ context in R4 or fall through to exit(). */
+ENTRY(__startcontext)
+ movs r0, r4
+ bne PLTJMP(__setcontext)
+
+ @ New context was 0 - exit
+ b PLTJMP(_exit)
+END(__startcontext)