From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> Subject: Re: [Fastboot] kexec - 2.6.14 - loads BIOS again To: "Prabhakar K." <krishkar99 at yahoo.com> Cc: "Kexec Mailing List" <kexec at lists.infradead.org>, fastboot at lists.linux-foundation.org Date: Tuesday, September 29, 2009, 6:11 AM "Prabhakar K." <krishkar99 at yahoo.com> writes: >> Hi - After my previous posting I was able to make some progress. >> >> When I do >> >> kexec -l vmlinux --append="init 1 root=/dev/hda2" --console-serial >> >> and? >> kexec -e, >> >> I get message: >> >> Starting new kernel >> I'm in purgatory >> >> And after that it still boots from BIOS (to the same first kernel). >> >> Whats the problem here? > > I would recommend instrumenting up purgatory and then your target kernel. > > It is quite possible the problem is in your backport. > >>>>> >? I have instrumented the purgatory code. when I run kexec -e, It hangs for a > while at? > sha256_starts(&ctx); in the function verify_sha256_digest(), and then reboots > to the first kernel (from BIOS). I have put debug prints in sha256_starts, but > none of those are executed. > > Interestingly, the same function sha256_starts is executed during kexec -l, > which is called as part of update_purgatory( )( when my_load( ) is called from > kexec.c). > so its surprise why the same function is giving problems when kexec -e is run. Do you by any chance have a watchdog you are not petting? >> Yes, we do have software watchdog and hardware watchdog. I disabled software watchdog and I think the reason for resetting to the first kernel can be explained due to hardware watchdog kicking in. To try out a different version of the kexec, I took kexec version 20080227 from?http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/and instrumented that code as well. With this, I was able to see the sha 256 verification done during kexec -e and also the post verification of purgatory code. And it hangs there (does not reboot to the first kernel). So, any conclusions based on these ? Please CC me in reply. Thanks !! Eric -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.infradead.org/pipermail/kexec/attachments/20090928/66467db3/attachment.htm>
