On Mon, Mar 29, 2021 at 02:02:58PM -0600, Chris Murphy wrote: > On Mon, Mar 29, 2021 at 1:55 AM Richard W.M. Jones <rjones@xxxxxxxxxx> wrote: > > > > > > I have a weird problem on an old Asus Zenbook UX305C where new kernels > > cannot be installed by grub. Specifically what happens is they appear > > in the boot menu fine, but if you try to boot them then the machine > > hangs hard with a completely black screen. > > > > Oddly the kernel installed by Anaconda can boot, but obviously this > > makes upgrading the kernel RPM impossible. > > > > My real question is how on earth do I start debugging this? > > > > I edited the kernel command line, removed “rhgb quiet”, added > > “loglevel=9 nomodeset” but still no output at all is visible before > > the hang. The machine doesn't have a serial port. > > > > Any ideas? Does grub have debugging that can be enabled somehow? > > With rhgb and quiet removed, you should immediately get a boot scroll > from the kernel and a panic if that's what's happening. If not then > this is somewhere in between the hand off. When GRUB has a problem > loading kernel or initramfs, it complains and goes back to GRUB. So > this sounds like the kernel and initramfs did load, and boot command > is executed and something fails at that point or right in the kernel > at the earliest stage. > > I'd ask in #fedora-kernel to be sure of a better idea. But my idea is > edit the failing grub menu entry (in GRUB) and after the initrd line > add two more lines > > set pager=1 > set debug=all > > Then F10 or Ctrl-X to boot that edited entry. You should get maybe > just 4 lines of cryptic grub debug code (in my working case it doesn't > mean anything to me) and then it goes black then i get kernel boot > scroll. Thanks! Yes, cryptic indeed. This is transcribed from a photograph so hopefully I didn't make a mistake: script/lexer.c:336: token 259 text [ ] script/lexer.c:336: token 0 text [] script/lexer.c:336: token 259 text [ ] script/lexer.c:336: token 0 text [] loader/efi/linux.c:95: kernel_addr: 0x1000000 handover_offset: 0x190 params: 0x7f050000 loader/efi/linux.c:98: handover_func() = 0x1000390 _ With the final "_" meaning the cursor (not blinking). At this point the machine appears to be hung -- capslock key no longer toggles the capslock indicator light, keys do nothing. It seems to be a kind of well-known bug caused apparently by either faulty firmware or microcode. See eg: https://bugzilla.redhat.com/show_bug.cgi?id=1724262 https://bugzilla.redhat.com/show_bug.cgi?id=1790115 https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/1 I guess I'll need to find a BIOS update for this laptop somewhere on Asus's terrible website :-( Rich. > If you get a ton of errors, probably failure in grub. If you don't, > probably already handed off to the kernel and it faceplanted during > its very early bootstrapping sequence before we even usually see > anything. > > > > -- > Chris Murphy > _______________________________________________ > users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx > To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/ _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
