Device node - How does kernel know about it

Jon Smirl jonsmirl at
Thu Dec 27 13:55:51 EST 2007

On 12/26/07, Siva Prasad <sprasad at> wrote:
> Hi,
> I am really interested in finding out how kernel knows about device
> nodes and how the whole thing work. This is as part of my debugging
> effort on 8641D based PowerPC board.
> * It all started with the problem of "not printing" any thing that comes
> from ramdisk (echo and printf statements), while kernel printk's work
> perfectly fine.
> * Ramdisk is also executing fine, just that prints are not coming out of
> serial. I can see the execution of various user programs with a printk
> in sys_execve() routine. Ramdisk has all the required files like
> /dev/console, /dev/ttyS0, etc.

Does adding console=ttyS0,baud to the kernel boot command line fix it?

Jon Smirl
jonsmirl at

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