[vladvasiliu]

> You can use `dmesg --boot` to analyze the boot of the Linux kernel.

What kind of information does this give?

On my machine it doesn't work.

    ~ » dmesg --boot
    dmesg: unrecognized option '--boot'
    
    ~ » dmesg -V
    dmesg from util-linux 2.38
    
    ~ » uname -r
    5.18.14-zen1-1-zen

[anyfoo]

I strongly suspect it would give you the content of the kernel log ring buffer (what "dmesg" alone gives you), but up until the time that userspace comes up, probably.

A lot of distributions have something very similar in /var/log/dmesg or /var/log/boot or similar. They do this by just doing something like "dmesg > /var/log/dmesg" early at boot so that the boot messages are (hopefully) still in the ring buffer.