Looking at the current 2.6 tree, there's an issue when one tries to boot a
zImage image (with or without an attached initrd). This is present in the -benh
tree as well.
In ~/arch/ppc/boot/simple/relocate.S the following snip is present:
..
li r9,0xc
mtlr r9
#ifdef CONFIG_PPC_MULTIPLATFORM
/* tell kernel we're prep, by putting 0xdeadc0de at KERNELLOAD,
* and tell the kernel to start on the 4th instruction since we
* overwrite the first 3 sometimes (which are 'nop').
*/
lis r10,0xdeadc0de@h
ori r10,r10,0xdeadc0de@l
li r9,0
stw r10,0(r9)
#endif
blr
We jump to the 4th instruction, but for the 40x class of cpu's this inst being
taken into account anymore. 3 nop's are missing from head_4xx.S:
.text
_GLOBAL(_stext)
_GLOBAL(_start)
/* Save parameters we are passed.
*/
mr r31,r3
mr r30,r4
...
...
The requirements of the 3 nops is silly anyway, but the relocation code needs
to be fixed. I haven't done the patch as I'm not sure if any other code will
overwrite the first 3 instructions. I hit this bug on an IBM 405EP dev
platform.
Torben
-
On Fri, Apr 02, 2004 at 02:07:12PM +0200, Torben Mathiasen wrote:
> Looking at the current 2.6 tree, there's an issue when one tries to boot a
> zImage image (with or without an attached initrd). This is present in the -benh
> tree as well.
>
> In ~/arch/ppc/boot/simple/relocate.S the following snip is present:
Tom and I discussed this yesterday since it was breaking ppc44x as
well. He already has a relocate.S patch in akpm's queue to fix
the issue.
-Matt