Janneke Nieuwenhuizen <jann...@gnu.org> writes: > Sergey Bugaev writes: > > Hello Sergey, > >> On Wed, May 17, 2023 at 9:25 PM Janneke Nieuwenhuizen <jann...@gnu.org> >> wrote: > >> I've recently been doing this kind of debugging early boot-up process >> *a lot*, so maybe I could provide some tips indeed. For getting more >> lines of output, try console=com0 on gnumach cmdline, and run qemu >> with -nographic -serial stdio or something like that. > > Now that was really a great help, thanks! It helped me (e)diff many > different qemu runs: plain debian, debian+guix/pci-arbiter, > debian+guix/pci-arbiter+guix/rumpdisk, plain guix, > guix+debian/pci-arbiter, guix+debian/pci-arbiter+debian/rumpdisk... > > It was immediately obvious that the messages from rumpdisk were (nearly) > identical. As the boot went silent at the end I assumed a crash or a > hang in rumpdisk. After inspecting the diffs and seeing nothing really > different, I noticed that I used -m 4096 for debian and -m 1024 for guix > on the qemu command line. Do'h, turns out rumpdisk needs at least > 1200MB... > > With > > https://gitlab.com/janneke/guix/-/tree/wip-hurd > > I've now succesfully been doing > > --8<---------------cut here---------------start------------->8--- > ./pre-inst-env guix system image -t hurd-raw > gnu/system/examples/bare-hurd.tmpl > cp /gnu/store/r5dpblnfsj08jh3hdmn8s6l9xaczwn65-disk-image guix.img > sudo losetup -o $((512*2048)) /dev/loop0 guix.img > sudo mount /dev/loop0 /mnt > edit /mnt/boot/grub/grub.cfg, adding console=com0 > sudo umount /mnt > --8<---------------cut here---------------end--------------->8--- > > > and then > > --8<---------------cut here---------------start------------->8--- > guix shell qemu -- qemu-system-i386 \ > -m 4096 \ > --enable-kvm \ > --device rtl8139,netdev=net0 \ > --netdev user,id=net0,hostfwd=tcp:0.0.0.0:11022-:2222 \ > --snapshot \ > --no-reboot \ > --device virtio-serial-pci \ > --nographic \ > --serial mon:stdio \ > --hda r5dpblnfsj08jh3hdmn8s6l9xaczwn65-disk-image+CONSOLE=COM0 > --8<---------------cut here---------------end--------------->8--- > > Just for fun, find the succesful log attached. > > Is there a way to pass the "console=com0" argument from the QEMU command > line? That would be nice! > >> Other than that, just attach gdb and see what it crashes on? Like this: >> >> $ gdb /path/to/gnumach >> (gdb) tar rem :1234 >> (gdb) b i386_exception >> (gdb) b task_terminate >> (gdb) b Panic >> (gdb) add-symbol-file /path/to/rumpdisk.static >> blah-blah (y/n?) y >> (gdb) c > > [..] > > Ah, I had no idea; this is so helpful. Maybe a good idea to have this > on the website/wiki, right?
Yes it will be. I will send a patch for it soon. Adding it for my todo list. > > Greetings, > Janneke -- Joshua Branson Sent from the Hurd
