[coreboot] [PATCH] Free VGA BIOS for K8M890

Rudolf Marek r.marek at assembler.cz
Fri May 1 23:42:17 CEST 2009

Hash: SHA1

Hi again,

I'm attaching a rewritten version from VGA ROM, which mimics the BIOS init.

Sadly enough it is still not hitting the all required regs to make powernow
working as it is with orig bios.

The rest register spill is the captured IO as it was. The top of the file is
what bios is doing during the init. Just before it calls ax=0003 and exits the rom.

There is also one interresting place:

<------>write_cr((read_cr(0x36) & ~0x30) | (0x3 << 4), 0x36);
<------>write_cr((read_cr(0x30) & ~0x4), 0x30);

<------>/* just read, hope compiler won't optimize that out */
<------>tmp = inb(0x3da);
<------>tmp = inb(0x3ba);

<------>outb(0x0, 0x3c0);

/* original bios has it but if I compile it in I get blank screen */
//<---->tmp = inb(0x3da);
<------>tmp = inb(0x3ba);

The bios is doing it exactly like this. But if I enable the inb(0x3da) I get no
picture but monitors seems to have some signal. It works fine without those
inbs. Any idea what is doing the code?


Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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