powerpc: Move ppc64 boot wrapper code over to arch/powerpc

This also extends the code to handle 32-bit ELF vmlinux files as well
as 64-bit ones.  This is sufficient for booting on new-world 32-bit
powermacs (i.e. all recent machines).

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 59 insertions, 0 deletions

diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
new file mode 100644
index 00000000000..9cc44226393
--- /dev/null
+++ b/arch/powerpc/boot/crt0.S
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) Paul Mackerras 1997.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * NOTE: this code runs in 32 bit mode and is packaged as ELF32.
+ */
+
+#include "ppc_asm.h"
+
+        .text
+        .globl  _zimage_start
+_zimage_start:
+        bl      reloc_offset
+
+reloc_offset:
+        mflr    r0
+        lis     r9,reloc_offset@ha
+        addi    r9,r9,reloc_offset@l
+        subf.   r0,r9,r0
+        beq     clear_caches
+
+reloc_got2:
+        lis     r9,__got2_start@ha
+        addi    r9,r9,__got2_start@l
+        lis     r8,__got2_end@ha
+        addi    r8,r8,__got2_end@l
+        subf.   r8,r9,r8
+        beq     clear_caches
+        srwi.   r8,r8,2
+        mtctr   r8
+        add     r9,r0,r9
+reloc_got2_loop:
+        lwz     r8,0(r9)
+        add     r8,r8,r0
+        stw     r8,0(r9)
+        addi    r9,r9,4
+        bdnz    reloc_got2_loop
+
+clear_caches:
+        lis     r9,_start@h
+        add     r9,r0,r9
+        lis     r8,_etext@ha
+        addi    r8,r8,_etext@l
+        add     r8,r0,r8
+1:      dcbf    r0,r9
+        icbi    r0,r9
+        addi    r9,r9,0x20
+        cmplwi  0,r9,8
+        blt     1b
+        sync
+        isync
+
+        mr      r6,r1
+        b       start
+