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authorUlrich Drepper <drepper@redhat.com>1998-09-01 14:31:49 +0000
committerUlrich Drepper <drepper@redhat.com>1998-09-01 14:31:49 +0000
commit052b6a6c94cc330dfbc09ff7b5f03c943deb7ca2 (patch)
tree0ef4d2730e6e20141e3b669b8a3614193200f3fc /sysdeps/powerpc/dl-start.S
parent85c165befc61d049abe3cc443c275a210c569338 (diff)
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Update.
1998-08-09  Geoff Keating  <geoffk@ozemail.com.au>

	* sysdeps/powerpc/Makefile [subdir=elf]: Add new files split out of
	dl-machine.h.
	* sysdeps/powerpc/dl-machine.c: New file.
	* sysdeps/powerpc/dl-machine.h: Move much stuff into separate
	files.  Revise ELF_PREFERRED_ADDRESS to take account of
	the new mapping information (fixes bug involving huge bloated
	web browser).  Set ELF_MACHINE_PLTREL_OVERLAP.
	* sysdeps/powerpc/dl-start.S: New file.

	* elf/dl-load.c (_dl_map_object_from_fd): Initialise l_map_start,
	l_map_end.
	* elf/do-rel.h: Call elf_machine_rel only once (to save space).
	* elf/dynamic-link.h: Allow PLT relocs to be in the middle of the
	others.  Call elf_dynamic_do_##reloc only once (to save even more
	space).
	* elf/link.h: Add new members l_map_start and l_map_end to keep
	track of the memory map.
	* elf/rtld.c (_dl_start): Initialise l_map_start for ld.so and
	the executable.

1998-09-01 11:53  Ulrich Drepper  <drepper@cygnus.com>

	* debug/Makefile (catchsegv): We need not rewrite SOVER anymore.
	Reported by Andreas Jaeger.

	* posix/glob.h: Use __size_t instead of size_t in definitions and
	make sure this is defined.

	* manual/locale.texi: Almost complete rewrite.  Document more functions
Diffstat (limited to 'sysdeps/powerpc/dl-start.S')
-rw-r--r--sysdeps/powerpc/dl-start.S111
1 files changed, 111 insertions, 0 deletions
diff --git a/sysdeps/powerpc/dl-start.S b/sysdeps/powerpc/dl-start.S
new file mode 100644
index 0000000000..91c0896a8f
--- /dev/null
+++ b/sysdeps/powerpc/dl-start.S
@@ -0,0 +1,111 @@
+/* Machine-dependent ELF startup code.  PowerPC version.
+   Copyright (C) 1995, 1996, 1997, 1998 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sysdep.h>
+
+/* Initial entry point code for the dynamic linker.
+   The C function `_dl_start' is the real entry point;
+   its return value is the user program's entry point.	*/
+ENTRY(_start)
+/* We start with the following on the stack, from top:
+   argc (4 bytes);
+   arguments for program (terminated by NULL);
+   environment variables (terminated by NULL);
+   arguments for the program loader. */
+
+/* Call _dl_start with one parameter pointing at argc */
+	mr	%r3,%r1
+/* (we have to frob the stack pointer a bit to allow room for
+   _dl_start to save the link register).  */
+	li	%r4,0
+	addi	%r1,%r1,-16
+	stw	%r4,0(%r1)
+	bl	_dl_start@local
+
+/* Now, we do our main work of calling initialisation procedures.
+   The ELF ABI doesn't say anything about parameters for these,
+   so we just pass argc, argv, and the environment.
+   Changing these is strongly discouraged (not least because argc is
+   passed by value!).  */
+
+/*  Put our GOT pointer in r31, */
+	bl	_GLOBAL_OFFSET_TABLE_-4@local
+	mflr	%r31
+/*  the address of _start in r30, */
+	mr	%r30,%r3
+/*  &_dl_argc in 29, &_dl_argv in 27, and _dl_default_scope in 28.  */
+	lwz	%r28,_dl_default_scope@got(%r31)
+	lwz	%r29,_dl_argc@got(%r31)
+	lwz	%r27,_dl_argv@got(%r31)
+0:
+/*  Set initfunc = _dl_init_next(_dl_default_scope[2]) */
+	lwz	%r3,8(%r28)
+	bl	_dl_init_next@plt
+/* If initfunc is NULL, we exit the loop; otherwise, */
+	cmpwi	%r3,0
+	beq	1f
+/* call initfunc(_dl_argc, _dl_argv, _dl_argv+_dl_argc+1) */
+	mtlr	%r3
+	lwz	%r3,0(%r29)
+	lwz	%r4,0(%r27)
+	slwi	%r5,%r3,2
+	add	%r5,%r4,%r5
+	addi	%r5,%r5,4
+	blrl
+/* and loop.  */
+	b	0b
+1:
+/* Now, to conform to the ELF ABI, we have to: */
+/* Pass argc (actually _dl_argc) in r3; */
+	lwz	%r3,0(%r29)
+/* pass argv (actually _dl_argv) in r4; */
+	lwz	%r4,0(%r27)
+/* pass envp (actually _dl_argv+_dl_argc+1) in r5; */
+	slwi	%r5,%r3,2
+	add	%r6,%r4,%r5
+	addi	%r5,%r6,4
+/* pass the auxilary vector in r6. This is passed to us just after _envp.  */
+2:	lwzu	%r0,4(%r6)
+	cmpwi	%r0,0
+	bne	2b
+	addi	%r6,%r6,4
+/* Pass a termination function pointer (in this case _dl_fini) in r7.  */
+	lwz	%r7,_dl_fini@got(%r31)
+/* Now, call the start function in r30... */
+	mtctr	%r30
+	lwz	%r26,_dl_starting_up@got(%r31)
+/* Pass the stack pointer in r1 (so far so good), pointing to a NULL value.
+   (This lets our startup code distinguish between a program linked statically,
+   which linux will call with argc on top of the stack which will hopefully
+   never be zero, and a dynamically linked program which will always have
+   a NULL on the top of the stack).
+   Take the opportunity to clear LR, so anyone who accidentally returns
+   from _start gets SEGV.  Also clear the next few words of the stack.  */
+
+	li	%r31,0
+	stw	%r31,0(%r1)
+	mtlr	%r31
+	stw	%r31,4(%r1)
+	stw	%r31,8(%r1)
+	stw	%r31,12(%r1)
+/* Clear _dl_starting_up.  */
+	stw	%r31,0(%r26)
+/* Go do it!  */
+	bctr
+END(_start)