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, 148 insertions, 0 deletions

diff --git a/sysdeps/arm/start.S b/sysdeps/arm/start.S
new file mode 100644
index 0000000000..adf6531892
--- /dev/null
+++ b/sysdeps/arm/start.S
@@ -0,0 +1,148 @@
+/* Startup code for ARM & ELF
+   Copyright (C) 1995-2014 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.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file with other
+   programs, and to distribute those programs without any restriction
+   coming from the use of this file. (The GNU Lesser General Public
+   License restrictions do apply in other respects; for example, they
+   cover modification of the file, and distribution when not linked
+   into another program.)
+
+   Note that people who make modified versions of this file are not
+   obligated to grant this special exception for their modified
+   versions; it is their choice whether to do so. The GNU Lesser
+   General Public License gives permission to release a modified
+   version without this exception; this exception also makes it
+   possible to release a modified version which carries forward this
+   exception.
+
+   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/>.  */
+
+/* This is the canonical entry point, usually the first thing in the text
+   segment.
+
+	Note that the code in the .init section has already been run.
+	This includes _init and _libc_init
+
+
+	At this entry point, most registers' values are unspecified, except:
+
+   a1		Contains a function pointer to be registered with `atexit'.
+		This is how the dynamic linker arranges to have DT_FINI
+		functions called for shared libraries that have been loaded
+		before this code runs.
+
+   sp		The stack contains the arguments and environment:
+		0(sp)			argc
+		4(sp)			argv[0]
+		...
+		(4*argc)(sp)		NULL
+		(4*(argc+1))(sp)	envp[0]
+		...
+					NULL
+*/
+
+/* Tag_ABI_align8_preserved: This code preserves 8-byte
+   alignment in any callee.  */
+	.eabi_attribute 25, 1
+/* Tag_ABI_align8_needed: This code may require 8-byte alignment from
+   the caller.  */
+	.eabi_attribute 24, 1
+
+#if defined(__thumb2__)
+	.thumb
+	.syntax unified
+#endif
+
+	.text
+	.globl _start
+	.type _start,#function
+_start:
+       /* Protect against unhandled exceptions.  */
+       .fnstart
+	/* Clear the frame pointer and link register since this is the outermost frame. */
+	mov fp, #0
+	mov lr, #0
+
+	/* Pop argc off the stack and save a pointer to argv */
+	pop { a2 }
+	mov a3, sp
+
+	/* Push stack limit */
+	push { a3 }
+
+	/* Push rtld_fini */
+	push { a1 }
+
+#ifdef SHARED
+	ldr sl, .L_GOT
+	adr a4, .L_GOT
+	add sl, sl, a4
+
+	ldr ip, .L_GOT+4	/* __libc_csu_fini */
+	ldr ip, [sl, ip]
+
+	push { ip }		/* Push __libc_csu_fini */
+
+	ldr a4, .L_GOT+8	/* __libc_csu_init */
+	ldr a4, [sl, a4]
+
+	ldr a1, .L_GOT+12	/* main */
+	ldr a1, [sl, a1]
+
+	/* __libc_start_main (main, argc, argv, init, fini, rtld_fini, stack_end) */
+	/* Let the libc call main and exit with its return code.  */
+	bl __libc_start_main(PLT)
+#else
+	/* Fetch address of __libc_csu_fini */
+	ldr ip, =__libc_csu_fini
+
+	/* Push __libc_csu_fini */
+	push { ip }
+
+	/* Set up the other arguments in registers */
+	ldr a1, =main
+	ldr a4, =__libc_csu_init
+
+	/* __libc_start_main (main, argc, argv, init, fini, rtld_fini, stack_end) */
+	/* Let the libc call main and exit with its return code.  */
+	bl __libc_start_main
+#endif
+
+	/* should never get here....*/
+	bl abort
+
+#ifdef SHARED
+	.align 2
+.L_GOT:
+	.word _GLOBAL_OFFSET_TABLE_ - .L_GOT
+	.word __libc_csu_fini(GOT)
+	.word __libc_csu_init(GOT)
+	.word main(GOT)
+#endif
+
+       .cantunwind
+       .fnend
+
+/* Define a symbol for the first piece of initialized data.  */
+	.data
+	.globl __data_start
+__data_start:
+	.long 0
+	.weak data_start
+	data_start = __data_start