User:GNUtoo/Howto flash sgabios on an Nvidia video card

Howto flash sgabios on an Nvidia video card

Use case

• Servers often lack a screen.
• Some blind people also lack a way to see the startup of the computer until the braille tablet is running.

This Howto will help you transform your Nvidia video card in a something that send to a serial port what would have been displayed on the screen. The card will probably stop working as a graphic card due to the lack of VGA option rom tailored to the card.

The user is expected to see the output trough a serial console.

Howto

Here's an example on how to flash sgabios on an Nvidia video card:

• download flashrom
• apply that patch:

diff --git a/gfxnvidia.c b/gfxnvidia.c
index d0a9feb..35e4687 100644
--- a/gfxnvidia.c
+++ b/gfxnvidia.c
@@ -110,7 +110,7 @@ int gfxnvidia_init(void)
        rpci_write_long(dev, 0x50, reg32);
 
        /* Write/erase doesn't work. */
-       programmer_may_write = 0;
+       //programmer_may_write = 0;
        register_par_programmer(&par_programmer_gfxnvidia, BUS_PARALLEL);
 
        return 0;

• compile it
• download and build sgabios
• Identify your flash chip size by running:

flashrom -pgfxnvidia

• save the content of the chip with:

flashrom -pgfxnvidia -r original.rom

• pad sgabios to the size of your flashchip:

dd if=/dev/zero of=sgabios.rom bs=1 count=65536
dd if=10b79200.rom of=sgabios.rom conv=notrunc

• flash it(and retry in case of failure, it has a high failure rate)