Move arm from ports to libc.

I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply

git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm

and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc.  There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.

Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).

	* sysdeps/arm: Move directory from ports/sysdeps/arm.
	* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
	* sysdeps/unix/sysv/linux/arm: Move directory from
	ports/sysdeps/unix/sysv/linux/arm.
	* README: Update listing for arm-*-linux-gnueabi.

ports/ChangeLog.arm:
	* sysdeps/arm: Move directory to ../sysdeps/arm.
	* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
	* sysdeps/unix/sysv/linux/arm: Move directory to
	../sysdeps/unix/sysv/linux/arm.

1 files changed, 117 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/arm/sigrestorer.S b/sysdeps/unix/sysv/linux/arm/sigrestorer.S
new file mode 100644
index 0000000000..566c04aed0
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/sigrestorer.S
@@ -0,0 +1,117 @@
+/* Copyright (C) 1999-2014 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>
+
+/* If no SA_RESTORER function was specified by the application we use
+   one of these.  This avoids the need for the kernel to synthesise a return
+   instruction on the stack, which would involve expensive cache flushes.
+
+   Nowadays (2.6 series, and somewhat earlier) the kernel uses a high page
+   for signal trampolines, so the cache flushes are not an issue.  But since
+   we do not have a vDSO, continue to use these so that we can provide
+   unwind information.
+
+   Start the unwind tables at least one instruction before the signal
+   trampoline, because the unwinder will assume we are returning after
+   a call site.
+
+   Because the signal frame layout changed in 2.6.18, we provide two
+   copies of these functions with different unwind information.  */
+
+/* Used in ENTRY.  */
+#undef cfi_startproc
+#define cfi_startproc \
+	.cfi_startproc simple; \
+	.cfi_signal_frame
+
+/* The CFA is not computed / used correctly here; this is neither trivial to
+   do, nor is it needed.  */
+#define CFI \
+	cfi_def_cfa (sp, 0); \
+	cfi_offset (r0, OFFSET + 0 * 4); \
+	cfi_offset (r1, OFFSET + 1 * 4); \
+	cfi_offset (r2, OFFSET + 2 * 4); \
+	cfi_offset (r3, OFFSET + 3 * 4); \
+	cfi_offset (r4, OFFSET + 4 * 4); \
+	cfi_offset (r5, OFFSET + 5 * 4); \
+	cfi_offset (r6, OFFSET + 6 * 4); \
+	cfi_offset (r7, OFFSET + 7 * 4); \
+	cfi_offset (r8, OFFSET + 8 * 4); \
+	cfi_offset (r9, OFFSET + 9 * 4); \
+	cfi_offset (r10, OFFSET + 10 * 4); \
+	cfi_offset (r11, OFFSET + 11 * 4); \
+	cfi_offset (r12, OFFSET + 12 * 4); \
+	cfi_offset (r13, OFFSET + 13 * 4); \
+	cfi_offset (r14, OFFSET + 14 * 4); \
+	cfi_offset (r15, OFFSET + 15 * 4)
+
+#ifndef __ASSUME_SIGFRAME_V2
+#define OFFSET 12
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_sa_restorer_v1)
+	CFI
+	mov	r7, $SYS_ify(sigreturn)
+	swi	0x0
+	.fnend
+END(__default_sa_restorer_v1)
+#undef OFFSET
+#endif /* __ASSUME_SIGFRAME_V2 */
+
+#define OFFSET 32
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_sa_restorer_v2)
+	CFI
+	mov	r7, $SYS_ify(sigreturn)
+	swi	0x0
+	.fnend
+END(__default_sa_restorer_v2)
+#undef OFFSET
+
+#ifndef __ASSUME_SIGFRAME_V2
+#define OFFSET 168
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_rt_sa_restorer_v1)
+	CFI
+	mov	r7, $SYS_ify(rt_sigreturn)
+	swi	0x0
+	.fnend
+END(__default_rt_sa_restorer_v1)
+#undef OFFSET
+#endif /* __ASSUME_SIGFRAME_V2 */
+
+#define OFFSET 160
+	.fnstart
+	.save {r0-r15}
+	.pad #OFFSET
+	nop
+ENTRY(__default_rt_sa_restorer_v2)
+	CFI
+	mov	r7, $SYS_ify(rt_sigreturn)
+	swi	0x0
+	.fnend
+END(__default_rt_sa_restorer_v2)
+#undef OFFSET