Serial over LAN

Tim Small tim at
Fri May 21 04:17:53 CDT 2010

Jefferson Ogata wrote:
> Hmm, my impression was that "Redirection After Boot" only affects comms 
> up to the point of getting a bootloader running, but I'm not 100% sure.

I believe (but again, I could be wrong), that with redirection after
boot enabled, the BIOS polls the VGA character buffers using a timer
interrupt. This mechanism continues to work until Linux switches the CPU
to protected mode very early in the kernel boot process - i.e. it works
in DOS and the boot loader - and (as has been mentioned already) it
relies on things like the boot loader NOT being configured to
communicate with the serial port directly themselves.

Personally, I normally enable redirection after boot, and disable the
native serial coms in grub.


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