I want to write a BIOS debugger.Can you give me some advice?

Jeremy Jackson jerj at coplanar.net
Tue Nov 5 13:14:00 CET 2002

I think this is an excellent idea.  I have thought thought about this
myself also.

I was looking at taking kgdb kernel debugger stub and moving it
from the Linux kernel into LinuxBIOS.  It would have the advantage that
it could trap some hardware events that cause a reset, which are currently
overwritten or cleared by the PC BIOS upon reset.  A LinuxBIOS debugger
could save some extra machine state and send it out the debug (serial) port.
This functionality is related to implementing power management in
LinuxBIOS -
things like STR (suspend to ram) require a reset vector handler that is
more intelligent.

A BIOS debugger could also make use of the hardware Break/SMI button to
up the debugger, even if keyboard and serial port are not responding.

I would find such a system useful.  I would encourage you to use existing
if possible (kgdb, or kdb) since the source level debuggers already exist
for these
(ie emacs) and the project could be completed sooner.



----- Original Message -----
From: "王海明" <whm_buaa at sina.com>
To: <linuxbios at clustermatic.org>
Sent: Tuesday, October 29, 2002 11:51 AM
Subject: I want to write a BIOS debugger.Can you give me some advice?

> hi , all,
>       I am a postgraduate student of Beijing University of Aeronautics and
Astronautics ( in china , Beijing).
> I want to write a BIOS debugger as my graduation article.
> My plan are as follow:
>       1. firstly I want to write a debug stub which is INDEPENDENT of
specific Mainchips,
> and  small enough. The stub can set up a basic environment ( such as  RAM
>         initialization, uart initialization). It can also communicate with
the develop PC
>         through Serial port,and excute the debug command transfered by the
develp PC.
> 2. write a source debugger .
>                                                      ---------
>                                                     |         |
>      --------------------------       serial port   | develop |
>      | BIOS       |debug stub | ----<---->--------- |   pc    |
>    --------------------------                     -----------
>                                                        | |
>                                                 ------------------
>                 the system figure
>     I appreciate some advice about the possibility of my plan .
>       best regards!
>             yours Haiming Wang
>                               王海明
>               whm_buaa at sina.com
>                  2002-10-30
> _______________________________________________
> Linuxbios mailing list
> Linuxbios at clustermatic.org
> http://www.clustermatic.org/mailman/listinfo/linuxbios

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