I'm trying to get LinuxBIOS booting on a custom board with a Socket AM2 Athlon and an MCP55. There is no SuperIO; instead, we're using the MCP55's internal serial UART. A couple of the MCP55's GPIO pins are hooked up to LEDs.
I have had no luck getting either the serial port or the LEDs to work, though. My cache_as_ram_main() sets up the serial port by:
- enabling the serial port and configuring the IO address and IRQ in register 0x78 on PCI device 1:0 - NOT redirecting IO address 0x3f8 to the LPC bus in register 0xa0 on PCI device 1:0 (as is done when the serial port is on a SuperIO) - setting GPIO pins 11, 12, 13 and 14 to their "normal" (non-GPIO) mode, which I hope is RX, TX, DTR and DSR
It also tries to turn on an LED on GPIO pin 1 by setting it to GPIO output mode, drive low.
Has anyone tried tried this with an MCP55-based board? Any ideas for other ways to communicate with the outside world when the serial port doesn't work?
--Ed