EPIA-M "Magic Potion"?

Dave Ashley linuxbios at xdr.com
Sat Mar 27 23:30:00 CET 2004

I really should check this list more often. However I've been really busy...

I think I gathered that the VGA isn't showing up in the lspci. I
looked at the latest CVS and found my earlysetup.inc isn't getting included
in the Config in src/mainboard/via/epia-m. Actually the earlysetup.inc isn't
even there.

Here's what I have. This can go after
mainboardinit southbridge/via/vt8235/setup_misc.inc
// enable VGA device
        movl    $CONFIG_ADDR(0, 0x00, 0xe1), %eax
        movb    $0xbd, %dl // enable vga with 8 megs

// The stupid firewire device (undocumented) steps on IO 0+ on reset
        movl    $CONFIG_ADDR(0, 0x0d*8, 0x15), %eax
        movb    $0x1c, %dl

Both of the above are *required*.

The following is optional but works well for me. Our application has a pci
card in the slot that can impose an interrupt even after a cpu reset, so
this can cause a lockup. I got around this by doing a single hard pci bus
reset. In order to know if I've already done the reset once, I store a flag
in the CMOS memory. I think this is a good idea but my choice of where in
the CMOS to store the flag is probably not kosher.

// use CMOS byte 0x0e as marker so we only reboot once
        movb    $0x0e, %al
        mov     $0x70, %dx
        outb    %al, %dx
        inc     %dx
        inb     %dx, %al
        cmpb    $0xda, %al
        je      1f

        movl    $0x100000, %ecx
        movw    $0x70,%dx
        mov     $0x0e,%al
        outb    %al, %dx
        inc     %dx
        movb    $0xda, %al
        outb    %al, %dx
        inb     %dx, %al
        cmpb    $0xda, %al
        je      4f
        dec     %ecx
        jne     0b


        movl    $CONFIG_ADDR(0, 0x88, 0x4f), %eax
        movb    $0x09, %dl

        jmp     2b

        sub     %al,%al
        outb    %al, %dx

Finally, I implemented the SMBUS io for being able to access the serial
eeprom on the DDR module. I had it print out the contents of the serial
eeprom on bootup. I had hoped Ron or Eric or cwlinux would run with this and
implement the auto ddr memory config but that didn't happen.

Anyway after the topmost fix the VGA will probably appear in lspci.


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