[PATCH] arm/linux-crt0.c: New file

[Shaun Jackman]

This patch replaces the arm/linux-crt0 assembler source file with a C
source file. Some inline assembler is used to switch to Thumb mode.
The purpose of this patch is to allow the compiler to generate the
correct relocation for environ when compiling PIC code. As a bonus,
the C source file is also shorter and easier to read. Alright to
commit?

Cheers,
Shaun

2006-06-29  Shaun Jackman  <sjackman@gmail.com>

	* arm/linux-crt0.S: Remove file.
	* arm/linux-crt0.c: New file. Supports PIC code.

--- /dev/null	2006-06-25 13:04:47.285393520 -0600
+++ arm/linux-crt0.c	2006-06-29 11:43:50.000000000 -0600
@@ -0,0 +1,39 @@
+/** Linux startup code for the ARM processor.
+ * Written by Shaun Jackman <sjackman@gmail.com>.
+ * Copyright 2006 Pathway Connectivity
+ *
+ * Permission to use, copy, modify, and distribute this software
+ * is freely granted, provided that this notice is preserved.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+
+static int _main(int argc, char *argv[]) __attribute__((noreturn));
+
+#if __thumb__
+asm("\n"
+	".code 32\n"
+	".global _start\n"
+	".type _start, %function\n"
+	"_start:\n"
+	"\tadr r0, _start_thumb+1\n"
+	"\tbx r0\n"
+	".size _start, .-_start\n");
+
+__attribute__((naked, used))
+static void _start_thumb(void)
+#else
+__attribute__((naked))
+void _start(void)
+#endif
+{
+	register int *sp asm("sp");
+	_main(*sp, (char **)(sp + 1));
+}
+
+static int _main(int argc, char *argv[])
+{
+	environ = argv + argc + 1;
+	exit(main(argc, argv, environ));
+}