lkml.org 
[lkml]   [2001]   [Dec]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: AMD SC410 boot problems with recent kernels
Date
From
hpa wrote:
>> If the board is really _broken_ I have no problem with the fact that in
>> the future the manufacturer has either to supply a correct BIOS or a
>> workaround patch has to be used. If it's only uggly that there's no BIOS
>> routine it would IMHO be better to find a way to make it work again. There
>> are fixes for other uggly architectures in the code as well, see the
>> Toshiba Laptop reference. If the board may be PC compatible, Linux should
>> IMHO boot without further changes.

It is an embedded board with a _mostly_ PC compatible CPU, but it
has a few strange bugs/features that have to be worked around. For
example look a the fix for the timer and serial port in:

http://www.uwsg.iu.edu/hypermail/linux/kernel/0004.2/0667.html

Especially the serial fix is (IMHO) too ugly to live in the standard
kernel.

I'd also suggest that you change the whole gate A20-mess to:

inb $0xee, %al

this will enable A20 propagation on the SC410 and always works,
the disadvantage is that it won't work on a normal PC anymore.

>The weird part about your board is that the code clearly *works*, or
>your kernel wouldn't boot at all. It somehow poisons the system,
>though, and that's utterly bizarre.
>
>I don't think this is debuggable without access to hardware (and maybe
>not even then.)

It has been a few years since I was working on an Elan SC400 board, but
if I remember correctly, the Elan CPU has some configuration registers
located at some I/O ports that on a normal PC are either "safe" or used
for something else.

Additionally, since there normally isn't a keyboard controller on the
SC410, accesss to port 0x60 and 0x64 trap into SMI mode, doing I/O to
those ports could mess up a badly written BIOS.

My belief is that the SC410 based boards are so strange that one has
to have a custom kernel anyways, so asking why it isn't 100% PC
compatible and trying to fix that is rather pointless.

/Christer

--
"Just how much can I get away with and still go to heaven?"
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:14    [W:1.010 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site