Vivek Goyal <[EMAIL PROTECTED]> writes: > On Wed, Jun 14, 2006 at 11:13:27AM -0600, Eric W. Biederman wrote: > > Somehow my previous mail did not make to the mailing list. Trying it > again. > >> >> > Other than that, I think that yes you should be able to use kexec to >> > bootstrap into any kind of kernel (or code running in real mode). >> > Certainly linux->xen is possible (and with patches I have posted >> > to xen-devel, xen->xen and xen->linux, though thats not really relevant), >> > so its not restricted to booting linux. >> >> Correct. >> >> Most BIOS's get confused after the kernel has run so after 16bit BIOS >> calls can be a problem. I have a test image called kexec_test from >> when I was really trying to get the 16bit mode with BIOS calls to >> work. >> > > Eric, I got a little unrelated question. Does that mean that we can not > use BIOS services at during transition to the new kernel. I was thinking > of using "Int 10" for setting the video mode during transition.
We can't do that reliably in the normal kexec case, and definitely not in the kdump case. > Currently no messages appear on the console if we are in X or using some > frame buffer driver and this becomes a problem in kdump as while second > kernel is booting no messages are displayed and if there is a problem > at customer site, one would never know where did kdump fail. Someone sent me a patch that makes the frame-buffer case work. I just haven't had a chance to follow up on that. > Any thoughts upon how this problem can potentially be handled, would > be helpful. If it is the normal kexec case we can execute an order shutdown and everything is good. If it is the kdump case we probably should not count on manual intervention. >> It uses the serial port to report how far it has gotten. >> Depending on how ambitious you are I have a fairly good clue on >> what needs to happen to make things work even when the BIOS would >> muck things up. >> >> I have a vague memory that the --real-mode switch had a bug in >> some version so that may be the problem rather than the bios. >> In any event kexec_test will report how far it gets and be a useful >> starting place for further debugging. >> > > I had found one bug in --real-mode entry long back. I could dig out the > patch I had used that time. Attaching the patch with the mail for the > people who might be interested in using real mode entry on i386. Thanks. I keep intending to find time to integrate the new patches, but something always comes when I think I am going to have time :( Eric _______________________________________________ fastboot mailing list [email protected] https://lists.osdl.org/mailman/listinfo/fastboot
