In my quest to get POST codes to show on my Asus P8Z77-M, and fixing sb/bd82x6x [1] along the way, I'm still not quite getting them.
I have a ISA/PCI POST card, but it isn't giving me anything. I bought a little "Debug Card Expert" off Amazon that looks like a mini-PCI/mini-PCIe cross, but in today's testing I found out that it isn't wired properly (i.e. isn't going to work) for PCIe at all, but I did get it to show POST codes over LPC via the TPM header. I have another of this same little PoS that broke in half on arrival. Now that I know it only really works over LPC and only 9 signals, I'll attempt to repair the broken traces and glue it together.
My board has a PCI-PCI bridge on bus:device.func 3:0.0 (so bus 3, this will be important) that services the PCI slot. After applying [1] to have the PCH send port 80 data to PCI as I specified in Kconfig, I still don't get any POST code... and not over LPC either, so I know my patch works.
Now I think I may need to enable CONFIG_EARLY_PCI_BRIDGE. Problem is the bridge has to be a device on bus 0.
How can I enable this PCI bridge on bus 3 early so a POST card sitting on it can get codes?
Thanks Keith