Arch Linux

Avg-Joe

Member

Registered: 2021-02-27

Posts: 6

Manually compiled linux kernel, kernel log not showing during boot

I'm asking the exact opposite of what normally people as, I want to see the kernel boot log instead of hiding it, unfortunately it's not showing, I don't if it's a kernel issue or a grub issue.

I just compiled linux-5.15.0 using the default x86_64_defconfig. I updated grub to ad the entry, here is my kernel command-line,

root=/dev/sda2 rw loglevel=5

Needless to say nothing is being shown, the kernel successfully loads and starts systemd but there is no log of it showing. I induced a kernel panic by not specifying a root partition, even then no output, the system locks up in a black screen, no error message saying "kernel panic, not syncing, unable to mount....yada yada"

Here is the kernel config https://pastebin.com/mCnTTFPi

What am I doing wrong? How do I fix this?

PS : I booted the kernel in qemu using the same arguments, here it shows the kernel log properly. I have the filesystem drivers within the kernel.

Last edited by Avg-Joe (2021-12-17 06:52:36)

loqs

Member

Registered: 2014-03-06

Posts: 18,900

Re: Manually compiled linux kernel, kernel log not showing during boot

https://git.kernel.org/pub/scm/linux/ke … ig?h=v5.15
You disabled all framebuffer support?

# CONFIG_FB is not set

Avg-Joe

Member

Registered: 2021-02-27

Posts: 6

Re: Manually compiled linux kernel, kernel log not showing during boot

I thought that would be the default, I'll recompile and update the details.

loqs

Member

Registered: 2014-03-06

Posts: 18,900

Re: Manually compiled linux kernel, kernel log not showing during boot

I thought that would be the default

Edit:
Should CONFIG_FB=y be present in arch/x86/configs/x86_64_defconfig ?

Last edited by loqs (2021-12-17 07:22:46)