Fix arm so it actually works.

1 files changed, 82 insertions, 40 deletions

diff --git a/libc/sysdeps/linux/arm/crt0.S b/libc/sysdeps/linux/arm/crt0.S
index 90478fa59..115650f98 100644
--- a/libc/sysdeps/linux/arm/crt0.S
+++ b/libc/sysdeps/linux/arm/crt0.S
@@ -1,61 +1,103 @@
-/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
+/* When we enter this piece of code, the program stack looks like this:
+        argc            argument counter (integer)
+        argv[0]         program name (pointer)
+        argv[1...N]     program args (pointers)
+        argv[argc-1]    end of args (integer)
+        env[0...N]      environment variables (pointers)
+        NULL
+
+This file now uses the register naming from the ARM Procedure Calling Standard
+
+    Name    Number      APCS Role
+
+    a1      0           argument 1 / integer result / scratch register / argc
+    a2      1           argument 2 / scratch register / argv
+    a3      2           argument 3 / scratch register / envp
+    a4      3           argument 4 / scratch register
+    v1      4           register variable
+    v2      5           register variable
+    v3      6           register variable
+    v4      7           register variable
+    v5      8           register variable
+    sb/v6   9           static base / register variable
+    sl/v7   10          stack limit / stack chunk handle / reg. variable
+    fp      11          frame pointer
+    ip      12          scratch register / new-sb in inter-link-unit calls
+    sp      13          lower end of current stack frame
+    lr      14          link address / scratch register
+    pc      15          program counter
+*/
 
-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.
+.text
+	.align 2
+	.global __environ
+	.global _start
+	.global exit
+	.global main
+	.global __libc_init
+	.global __init_stdio
+	.global __stdio_close_all
+	.global _void_void_null_func
+
+	.type   _start,%function
+	.type   exit,%function
+	.type   main,%function
+	.type   __libc_init,%function
+	.type   __init_stdio,%function
+	.type   __stdio_close_all,%function
+	.type   _void_void_null_func,%function
 
-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., 675 Mass Ave,
-Cambridge, MA 02139, USA.  */
+.text
+_start:
 
+	/* clear the frame pointer */
+	mov     fp, #0
 
-#define BASEREG r9
+	/* Load argc into a1 -- its final resting place */
+	ldr     a1, [sp], #4
 
-@ r0 = argc
-@ r1 = argv
-@ r2 = envp
-@ sl = data segment
+	/* Load argv into a2 -- which its final resting place */
+	mov     a2, sp
 
+	/* Set up environ,  skip to the end of argv, and put 
+	 * a pointer to whatever we find there (hopefully the
+	 environment) in a3 */
+	ldr     a4, .L3
+	add     a3, a2, a1, lsl #2
+	add     a3, a3, #4
+	str     a3, [a4, #0]
 
+	/* Tell libc to initialize whatever it needs */
+        bl __libc_init		    
+        bl __init_stdio
+	bl      main
+	bl      exit
 
-	.text
-	.align 2
-	.global _start, exit, main
-	.type _start,%function
+_void_void_null_func:
+	nop
 
-.text
-_start:
-    @ adjust the data sgement base pointer
-	ldr r3,=__data_start
-	sub sl,sl,r3
-	mov	BASEREG,sl
+.weak __libc_init
+__libc_init = _void_void_null_func
 
-	ldr	r3, .L3
-	str r2,[BASEREG,r3]
-	ldr r0,[sp, #0]
-	ldr r1,[sp, #4]
-	ldr r2,[sp, #8]
-	bl  main
-	ldr r0,=0
-	bl  exit
+.weak __init_stdio
+__init_stdio = _void_void_null_func
 
+.weak __stdio_close_all
+__stdio_close_all = _void_void_null_func
 
-.L3:  .word environ
+.align 2
+.L3:
+	.word environ
 
 
-	.data
+.data
 	.align 2
 	.global __environ
 	
-__environ:  .long 0
+__environ:  
+	.long 0
+
 .weak environ
 environ = __environ