On Sun, 2011-03-27 at 20:00 +0200, Philipp Ittershagen wrote:

On 03/25/2011 09:50 AM, Guillaume Dargaud wrote:

quoted

Hello all,
what can you do when the kernel you try to run stops before printing anything on the console ?

http://elinux.org/Kernel_Debugging_Tips#Debugging_early_boot_problems

Basically it means connecting a debugger to the running kernel (using
XMD, for example) and then reading the printk log buffer, which contains
the last lines printed.

It actually mostly depends on the platform. There's various powerpc
specific early debug mechanisms that are more/less robust/functional
depending on the CPU type, the platform, etc...

Look in udbg.c, there's a list of early debug hacks in there controlled
by various config options.

Cheers,
Ben.