On Mon, Jun 16, 2008 at 04:19:44PM +0000, Sean Young wrote:
On Mon, Jun 16, 2008 at 06:37:12AM -0700, Jeremy Fitzhardinge wrote:
Rusty Russell wrote:Reverting only head_32.S makes the problem go away. I didn't try any other
On Monday 16 June 2008 22:11:39 Sean Young wrote:And the arch/x86/boot/compressed/misc_32.c change too, just in case...
The symptons are either a crash or reboot on booting the kernel. NoHi Sean,
printk's have occurred yet -- even with early printk on.
2.6.15 worked on this board however current does not. I've bisected it to:
commit a24e785111a32ccb7cebafd24b1b1cb474ea8e5d
Author: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Date: Sun Oct 21 16:41:35 2007 -0700
i386: paravirt boot sequence
Thanks for tracking this down. Can we try reverting this in pieces to see exactly what the cause was?
1) Revert arch/x86/boot/compressed/head_32.S
2) If that doesn't fix it, Try removing the 8 lines which were added to arch/x86/kernel/head_32.S
changes.
Looking at the beginning of startup_32, it seems ds is used before it is set:
startup_32:
cld
/* test KEEP_SEGMENTS flag to see if the bootloader is asking
* us to not reload segments */
testb $(1<<6), BP_loadflags(%esi)
jnz 1f
cli
movl $(__BOOT_DS),%eax
movl %eax,%ds
movl %eax,%es
movl %eax,%fs
movl %eax,%gs
movl %eax,%ss
1:
Since the testb instruction is a dereference, ds is implicitly used. If
I move the testb to after "movl %eax,%ds" it seems to work (not that it
would make any sense there, but just to prove the point).
1) Am I barking up the wrong tree?
2) If I'm right I have no idea what the correct solution is; it seems that
a chicken & egg issue is introduced.
Please advise. I am very new to all of this.