This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / avr32 / boot / u-boot / head.S

diff --git a/arch/avr32/boot/u-boot/head.S b/arch/avr32/boot/u-boot/head.S
new file mode 100644 (file)
index 0000000..4488fa2
--- /dev/null
+++ b/arch/avr32/boot/u-boot/head.S
@@ -0,0 +1,60 @@
+/*
+ * Startup code for use with the u-boot bootloader.
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <asm/setup.h>
+
+       /*
+        * The kernel is loaded where we want it to be and all caches
+        * have just been flushed. We get two parameters from u-boot:
+        *
+        * r12 contains a magic number (ATAG_MAGIC)
+        * r11 points to a tag table providing information about
+        *     the system.
+        */
+       .section .init.text,"ax"
+       .global _start
+_start:
+       /* Check if the boot loader actually provided a tag table */
+       lddpc   r0, magic_number
+       cp.w    r12, r0
+       brne    no_tag_table
+
+       /* Initialize .bss */
+       lddpc   r2, bss_start_addr
+       lddpc   r3, end_addr
+       mov     r0, 0
+       mov     r1, 0
+1:      st.d    r2++, r0
+       cp      r2, r3
+       brlo    1b
+
+       /*
+        * Save the tag table address for later use. This must be done
+        * _after_ .bss has been initialized...
+        */
+       lddpc   r0, tag_table_addr
+       st.w    r0[0], r11
+
+       /* Jump to loader-independent setup code */
+       rjmp    kernel_entry
+
+       .align  2
+magic_number:
+       .long   ATAG_MAGIC
+tag_table_addr:
+       .long   bootloader_tags
+bss_start_addr:
+       .long   __bss_start
+end_addr:
+       .long   _end
+
+no_tag_table:
+       sub     r12, pc, (. - 2f)
+       bral    panic
+2:     .asciz  "Boot loader didn't provide correct magic number\n"