[LinuxBIOS] 440BX progress.

Uwe Hermann uwe at hermann-uwe.de
Sun Nov 26 17:52:58 CET 2006


I have now reached a state in my 440BX code where the RAM init _could_ work
(maybe). The current code I have is mostly a very ugly hack and I won't
post any patches until I cleaned up the mess. Also, I'm currently
hard-coding some stuff from known-good 'lspci -xxx 0:0.0' values, so
that's not really useful for anybody with a different configuration, anyway.

Here's what I'm able to get over serial right now:

Testing DRAM : 10000000-02000000
DRAM fill: 10000000-02000000
DRAM filled                   
DRAM verify: 10000000-02000000
DRAM range verified.
Copying LinuxBIOS to ram.
Jumping to LinuxBIOS.  

I'm basically using this code in auto.c (based on bitworks/ims stuff):

  sdram_initialize(sizeof(cpu)/sizeof(cpu[0]), cpu);
  ram_check(0x10000000, 0x2000000);

Is that the canonical way to test whether RAM init works? The above
serial output _looks_ fine, but nothing happens after the
"Jumping to LinuxBIOS." anymore (but that may have other reasons).

I tried using different payloads (filo, memtest) but with no success.
What else do I have to configure for a payload to be able to start?
I added 
  default CONFIG_PCI_ROM_RUN=1
to Options.lb in the hope to get VGA output, but no luck. Also, I tried
adding some stuff to Config.lb; still no luck. I guess this needs some
more work later, but I don't want to fix all of that right now.

What's the absolute minimum config I need to get _something_ to boot, so
that I can verify that RAM init works?

Can someone provide a known-good memtest payload with serial support I
could use? Is that supposed to work if the ram_check() succeeds?

http://www.hermann-uwe.de  | http://www.holsham-traders.de
http://www.crazy-hacks.org | http://www.unmaintained-free-software.org
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