[clug] Rescuing old motherboards the hard way
Paul Wayper
paulway at mabula.net
Thu Jun 24 06:18:42 MDT 2010
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 06/24/2010 05:05 PM, Daniel Pittman wrote:
> Can you attach a VGA output, or a regular or USB keyboard for input? That
> might be more robust than trying to talk over the usually insanely quirky
> serial console support. :/
Haven't tried the USB keyboard, but the VGA output is actually unsoldered
jumpers and unpopulated chip fanouts on the board. So I don't think I'll be
getting actual display from it. A pity, as having to put up with the Phoenix
BIOS's emulation of a screen display over 9600 baud terminal is painful.
> That should be pretty much the last stage of BIOS before it does hand-over to
> the boot loader, so ... maybe it doesn't like your boot loader?
That's the theory.
> Er, and make sure you have a partition flagged as bootable, since some BIOS
> implementations hate not having one. Maybe even try pretending it is an MSDOS
> partition of some sort in the BIOS type flag?
I took one of the disks, put it in a different machine, installed Linux on it,
and then put the disk back where it came from. No boot.
> Failing anything else, extract the MBR from the original image, disassemble
> it, and see what the heck it is doing differently? They code at that level is
> pretty much straight forward. You can even inject little BIOS interactions
> easily enough if you want to try and debug it printf style.
It's been long enough since I have hacked 8086 assembler that I don't really
look forward to the prospect. And this is somewhat of a low priority.
> I have had a few implementations that recognize ESC-A for control-A in the
> serial console ... and more than a few controller extension BIOS
> implementations that bypass the BIOS bits that the serial console hooks, look
> directly at hardware, and just don't work with the serial console at all.
Definitely an indication that plugging a USB keyboard in might help.
Have fun,
Paul
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.14 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/
iEYEARECAAYFAkwjTSIACgkQu7W0U8VsXYI+7gCfc8ckEGMpnQc5zOLGvLkgSkzS
5U8AniNw/uxnX7v5kHH+y+nL7ps2HGhu
=z9Vz
-----END PGP SIGNATURE-----
More information about the linux
mailing list