FreeBSD kernel crashes, what to do
Paraphrased from a recent discussion, saving this off in case it is useful to myself or anyone else looking.
If the FreeBSD kernel crashes pretty reliably, ie if you boot with hardware it doesn’t like, you can try and catch the function pointer address where the panic happens. From there, you can cross reference it back to what function in the kernel it is, using these ideas, in order from worst to best:
- Use a released generic kernel, post asking for help, include uname -a output.
- nm /boot/kernel/kernel and search for a function symbol close to the address you crashed at
- objdump -d /boot/kernel/kernel and search..
- Best is to break to debugger if possible, and get a stack trace, check the freebsd handbook.