[openbeos] Re: Getting debug output without a serial port

  • From: "François Revol" <revol@xxxxxxx>
  • To: openbeos@xxxxxxxxxxxxx
  • Date: Sat, 14 Apr 2007 20:51:12 +0200 CEST

> More and more computers do not include serial port anymore. This is 
> the 
> case of my laptop.

Yes... was the same here when I got that laptop that wouldn't boot from 
yellowTAB (because of a bug in the ATI IXP chipset) :)

> As far as i know, infra-red ports could act as a serial device in 
> Serial 
> IR mode (compatibility mode) without requiring an IRDA stack. But, it 
> seems it does not work "out of the box" : nothing is send through the 
> port (checked with a webcam !). Maybe my configuration is wrong. 
> Maybe 
> this mode need more initialization.
> 
> Is there other solutions to get debug output during boot like 
> parallel 
> or infra-red ports ?

For IR ports... IrDA is a full protocol stack (the network socket way), 
so it's a no go, but maybe there is a simpler protocol you can use on 
top of it, dunno...

As for parallel port, I wrote a parallel debug output for Zeta that 
made use of a laplink cable, and a minimal tty driver for the other end 
running on BeOS.
(no, it wasn't asked for by yT if anyone of you care, so I own it. 
Actually my contract had enough provision so I own back all I wrote 
now. Besides ... oh well I know you wouldn't believe me anyway).

Like this one: 
http://www.hardwarebook.info/LapLink/InterLink_Parallel

I was meaning to contribute it anyway.

(btw Axel: maybe it's time to modularize those or at least provide a 
framework for debug outputs, to stuff bochs hacks and others... oh, 
there is also the USB kernel debugging extention someone has to write 
(stupid USB people (M$) thought it was so great they forced 
manufacturers to abandon serial ports... then later found they couldn't 
debug WinNT anymore... so they came up with a standard for USB 2.0 
controllers that makes it mandatory to have a kernel debugging mode 
accessible, but with expensive on-purpose cables)).

François.

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