m68knommu: add uboot commandline argument passing support

This patch adds m68knommu support for getting the kernel command line
arguments from uboot, including the passing of an initrd image from uboot.

We use this on a 5270/5271 based board, and have used it on the 5271evb
development board.  It is based on a patch found in the linux-2.6-denx
git tree, although that tree seems to have had lots of other changes
since which are not in the main Linus kernel.  I believe this will work
on all coldfires, although other m68knommu might be missing the _init_sp
stuff in head.S as far as I can tell.  I only have the coldfire to
test on.

Signed-off-by: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/m68knommu/platform/coldfire/head.S b/arch/m68knommu/platform/coldfire/head.S
index 2b0d73c0cc32..4b91aa24eb00 100644
--- a/arch/m68knommu/platform/coldfire/head.S
+++ b/arch/m68knommu/platform/coldfire/head.S
@@ -106,6 +106,9 @@
 .global _ramvec
 .global _ramstart
 .global _ramend
+#if defined(CONFIG_UBOOT)
+.global _init_sp
+#endif
 
 /*****************************************************************************/
 
@@ -124,6 +127,10 @@ _ramstart:
 .long   0
 _ramend:
 .long   0
+#if defined(CONFIG_UBOOT)
+_init_sp:
+.long   0
+#endif
 
 /*****************************************************************************/
 
@@ -137,6 +144,9 @@ __HEAD
 _start:
         nop                                     /* filler */
         movew   #0x2700, %sr                    /* no interrupts */
+#if defined(CONFIG_UBOOT)
+        movel   %sp,_init_sp                    /* save initial stack pointer */
+#endif
 
         /*
          *      Do any platform or board specific setup now. Most boards