Observing the kernel boot process
At this point, you should have the kernel image files and the device tree blobs for the Raspberry Pi 4, BeaglePlay, and QEMU. Let’s start by looking at a kernel panic.
Kernel panic
While things started off well on QEMU, they ended badly:
[ 0.393978] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[ 0.394269] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.6.46 #2
[ 0.394443] Hardware name: linux,dummy-virt (DT)
<…>
[ 0.396719] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) ]---
This is a good example of a kernel panic. A panic occurs when the kernel encounters an unrecoverable error. By default, it will print out a message to the console and then halt. You can set the panic command-line parameter to allow a few seconds before reboots following a panic. In this case, the unrecoverable error is no root filesystem, illustrating that a...
