Re: Loading splash ok -> <reset>, how to debug?
Date: Sun, 08 Jun 2025 17:46:29 UTC
On Sun, 8 Jun 2025, Warner Losh wrote: > On Sun, Jun 8, 2025, 10:08 AM Tomek CEDRO <tomek@cedro.info> wrote: > >> On Sun, Jun 8, 2025 at 5:10 PM Bjoern A. Zeeb >> <bzeeb-lists@lists.zabbadoz.net> wrote: >>> Hi, >>> is there any good way to debug early kernel kabooms (or maybe efi loader >>> handover) without JTAG in place? >>> I have a SoC using U-Boot and often after a cold start it goes like >>> this: >>> ------------------------------------------------------------------------ >>> Hit [Enter] to boot immediately, or any other key for command prompt. >>> Booting [/boot/kernel/kernel]... >>> Using DTB provided by EFI at 0x3e6c3000. >>> Loading splash ok >>> <reset> >>> ------------------------------------------------------------------------ >>> Once it's been looping for a few iterations eventually it starts >>> booting. >>> Given there is zero output of the error, is there aything one could try >>> to do to debug this (remotely)? >>> I can netboot it and change laoder/kernel. >> >> DDB? >> https://docs.freebsd.org/en/books/developers-handbook/kerneldebug/#kerneldebug-online-ddb >> >> KGDB? >> https://docs.freebsd.org/en/books/developers-handbook/kerneldebug/#kerneldebug-online-gdb >> >> over the Serial Port? :-) >> > > I think he's not even getting to the handoff. Best to toss out all hmm.. > graphical things that are configured and see if that gets us to the handoff > point... get rid of the splash screen first of all.. How? I do not have boot_mute="YES" set. I tried setting console to just efi manually; that didn't help. Also on first attempt I got an error, typing it again worked (but I didn't re-validate). I have the following in loader.conf and I tried various combinations without success to see ... I also tried to fdt ls to make sure fdt is all right and there... ---------------------------------------- boot_verbose="-v" debug.kdb.alt_break_to_debugger=1 beastie_disable="YES" ---------------------------------------- Do we have a way to validate in loader if a kernel loaded into memory is correct? I was wondering if the kernel was corrupted... -- Bjoern A. Zeeb r15:7