Rewrite powerpc crt0.S for proper ctor/dtor handling

1 files changed, 58 insertions, 36 deletions

diff --git a/libc/sysdeps/linux/powerpc/crt0.S b/libc/sysdeps/linux/powerpc/crt0.S
index 11738ad5b..ec3fbd4ae 100644
--- a/libc/sysdeps/linux/powerpc/crt0.S
+++ b/libc/sysdeps/linux/powerpc/crt0.S
@@ -1,9 +1,5 @@
 /*
- * uC-libc/sysdeps/linux/powerpc/crt0.S
- * process init code for powerpc
- *
- * Copyright (C) 2001 by Lineo, Inc.
- * Author: David A. Schleef <ds@schleef.org>
+ * Copyright (C) 2003 by Erik Andersen
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU Library General Public License as published by
@@ -18,46 +14,72 @@
  * You should have received a copy of the GNU Library General Public License
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- */
-
-/*
-   _start is called with the following registers initialized:
-
-     r1  null stack frame
-     r3  argc
-     r4  argv
-     r5  envp
-     r6  auxiliary vector.  ignored.
-     r7  function pointer to jump to when main() exits.  If
-         this is non-zero, it should be registered with atexit().
-	 Linux always (?) sets r7 to NULL, so it is not implemented
-	 here.
  */
 
+/* Integer registers.  */
+#define r0      0
+#define r1      1
+#define r2      2
+#define r3      3
+#define r4      4
+#define r5      5
+#define r6      6
+#define r7      7
+#define r8      8
+#define r9      9
+#define r13     13
+#define r31     31
 
-.text
-	.global	_start
-	.global	__uClibc_main
+#include <features.h>
 
-	.type	_start,%function
+	.section ".text"
+	.globl	_start
+	.type	main,%function
+#if defined L_crt0 || ! defined __UCLIBC_CTOR_DTOR__
 	.type	__uClibc_main,%function
+#else
+	.weak	_init
+	.weak	_fini
+	.type	__uClibc_start_main,%function
+#endif
+/* Stick in a dummy reference to main(), so that if an application
+ * is linking when the main() function is in a static library (.a)
+ * we can be sure that main() actually gets linked in */
+	.type	_start,@function
 
 _start:
-	/* create 2 empty stack frames */
-	stwu	1,-32(1)
+	/* Save the stack pointer, in case we're statically linked under Linux.  */
+	mr	r9,r1
+	/* Set up an initial stack frame, and clear the LR.  */
+	clrrwi	r1,r1,4
+	li	r0,0
+	stwu	r1,-16(r1)
+	mtlr	r0
+	stw	r0,0(r1)
 
-	lwz	3,32(1)
-	addi	4,1,36
-	addi	5,1,40
-	rlwinm	0,3,2,0,29
-	add	5,5,0
+	/* find argc from the stack pointer */
+	lwz	r3,0(r9)
+	/* find argv one word offset from the stack pointer */
+	addi	r4,r9,4
+	/* find environment pointer (argv+argc+1) */
+	lwz	r5,0(r9)
+	addi	r5,r5,1
+	rlwinm	r5,r5,2,0,29
+	add	r5,r5,r4
 
+	/* Ok, now run uClibc's main() -- shouldn't return */
+#if defined L_crt0 || ! defined __UCLIBC_CTOR_DTOR__
 	bl	__uClibc_main
+#else
+	lis     r6,_init@ha	# load top 16 bits
+	addi    r6,r6,_init@l	# load bottom 16 bits
+	lis     r7,_fini@ha	# load top 16 bits of &msg
+	addi    r7,r7,_fini@l	# load bottom 16 bits
+	bl	__uClibc_start_main
+#endif
+.size _start,.-_start
 
-/* Stick in a dummy reference to main(), so that if an application
- * is linking when the main() function is in a static library (.a)
- * we can be sure that main() actually gets linked in */
-L_dummy_main_reference:
-	.long	main
+	.section ".data"
+	.globl  __data_start
+__data_start: