Date: Mon, 8 Jan 2018 22:17:51 +0400 From: Roman Bogorodskiy <novel@FreeBSD.org> To: freebsd-ppc@freebsd.org Subject: Booting an alternate kernel Message-ID: <20180108181749.GA3689@kloomba>
index | next in thread | raw e-mail
[-- Attachment #1 --] Hi, Recently I upgraded FreeBSD -CURRENT as of mid-2016 to a fresh one (Jan 6-7 -CURRENT). Of course I didn't read UPDATING and missed 20171125 entry so it failed to find root. However, when I manually set root to 'ufs:/dev/ada0s3', it failed to boot because init segfaulted (I did installkernel but not installworld). I decided to boot kernel.old. There's a note here: https://www.freebsd.org/platforms/ppc.html#issues that tells how to boot a custom kernel, e.g. doing 0 > boot hd:loader hd:0 It doesn't work for me. I figured out that I can proceed to normal boot from the OpenFirmware shell using 0 > boot hd:\ppc\boot1.elf But I don't quite understand how to specify invalid partition? I tried things like "boot hd:\ppc\boot1.elf hd:4" but it appears to treat "hd:4" as a loader. As far as I understand, boot1.elf source code is: https://github.com/freebsd/freebsd/blob/master/stand/powerpc/boot1.chrp/boot1.c From what I can see: https://github.com/freebsd/freebsd/blob/master/stand/powerpc/boot1.chrp/boot1.c#L414 it only allows to define 'path' which is PATH_LOADER "/boot/loader" by default; and bootpath is set from /chosen bootpath property. Would appreciate if somebody could help with the follow: * How do I force invalid 'bootpath' so it drops into loader without loading kernel (or other ways to load kernel.old)? * Hints how to debug init segfault issue Thanks, Roman Bogorodskiy [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJaU7XNAAoJEMltX/4IwiJqDscH/A3HYtTm0vZWdBqpBqaIGNz5 153XbSVRk8tAMXYeWcSzeKEagjjnyEHH89UuYKsII4jovVv9WyOP+Hvsmo2hw2fg J0n+eVw53lqp7XEufEYPYLBEHKLkWbojohjRErsamXMQw129zLqNxFpNNEO91BTM olf9yWr50HOK3YnU9XsNZ7MvGnuFMm2Wa7aoJwaLp89bhYHtw2XVUpwcmbN5vQdM 03sGUkxpyDPRaOrIdMLFcofG3eipw/o6biHyLm62ZSYxm7s1WVXCya+ErMYwM55C BXxzvJ9Fwr6dxMnruH3LcyOD9uAt5ai1jEw3PszAxnb8QQnQIZ7th5hoyEh8nJk= =RiJB -----END PGP SIGNATURE-----home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20180108181749.GA3689>