[Soekris] net4501: pxelinux hangs if serial not connected

[Brian Candler]

On Thu, Nov 15, 2007 at 12:17:39PM -0500, Bob Keyes wrote:
> I hope that you are OK with me taking your post (with attribution, of 
> course) and putting it on our internal Wiki here at the Harvard CitySense 
> project.

No problem. I wrote it while I was debugging the problem, so it might make
sense to reorganise it so the solution is first, followed by the analysis
for anyone who's interested.

I still can't think of a good reason why outputting via the BIOS int10h
would stop after a number of characters (for both pxelinux and grub), and
why sticking a signal on the RD line would make it start again. Possibly an
interrupt is getting lost somewhere. At least it's entirely repeatable.

Regards,

Brian.