Add ARM support

libgloss/arm/redboot-crt0.S

@@ -0,0 +1,79 @@
+
+	
+    .file   "crt0.S"
+	
+#define XGLUE(a,b) a##b
+#define GLUE(a,b) XGLUE(a,b)
+	
+#ifdef __USER_LABEL_PREFIX__
+#define SYM_NAME( name ) GLUE (__USER_LABEL_PREFIX__, name)
+#else
+#error __USER_LABEL_PREFIX is not defined
+#endif
+
+    .text
+     /*
+      * Setup the assembly entry point.
+      */
+    .code 32
+    .globl SYM_NAME(start)
+    .globl SYM_NAME(_start)
+SYM_NAME(start):
+SYM_NAME(_start):
+	mov	fp, #0	/* Null frame pointer */
+	mov	r7, #0	/* Null frame pointer for Thumb */
+
+	/* enable interrupts for gdb debugging */
+	mrs    r0, cpsr
+	bic    r0, r0, #0xC0
+	msr    cpsr, r0
+	
+	mov 	a2, #0			/* Second arg: fill value */
+	ldr	a1, .LC1		/* First arg: start of memory block */
+	ldr	a3, .LC2	
+	sub	a3, a3, a1		/* Third arg: length of block */
+
+#ifdef __thumb__		/* Enter Thumb mode.... */
+	add	a4, pc, #1	/* Get the address of the Thumb block */
+	bx	a4		/* Go there and start Thumb decoding  */
+
+	.code 16
+	.global __change_mode
+	.thumb_func
+__change_mode:	
+#endif
+
+	bl	SYM_NAME(memset)
+	
+	mov 	a1, #0
+	ldr	a2, .LC3
+	mov	a3, a2
+	bl	SYM_NAME(main)
+    1:	bl	SYM_NAME(exit)
+	b	1b
+.LC1:
+	.word	__bss_start__
+.LC2:
+	.word	__bss_end__
+.LC3:
+	.word	0
+	
+#if 0
+#ifdef __thumb__
+	.code 16
+#endif
+	.global SYM_NAME(__syscall)
+#ifdef __thumb__
+        .thumb_func
+#else
+	.align  4
+#endif
+SYM_NAME(__syscall):
+	mov	r12, lr
+#ifdef __thumb__
+	swi	0x18
+#else
+	swi	0x180001
+#endif
+	mov	pc, r12
+#endif