[coreboot] Kontron 986LCD-M support

Petr Cvek petrcvekcz at gmail.com
Wed Nov 14 21:37:39 CET 2018


I was trying to upgrade my Kontron 986LCD-M setup to AMD Radeon RX460
and I've found the vendor BIOS lack support for the video BIOS (RX460
requires UEFI). This incompatibility leads to x16 PCIe slot disable and
no graphics in linux at all.

I was able to re-enable the PCIe slot until now when I tried to upgrade
to 2+2 GiB DDR2 modules (little more MB and dual channel). The RAM space
is shared with PCI space and limited by 32bit so the top part of RAM is
eaten by the regions of PCI devices. Problem is when vendor BIOS
disables the card's slot it doesn't leave a hole for my GPU and it sets
the TOLUD register (top of used RAM). This causes kernel to crash in GPU

There is probably no way to fix TOLUD (and ACPI tables, SMI and other
stuff) or force vendor's BIOS to reserve region for GPU, so I'm
considering to switch to coreboot.

My question is: does anybody know advanced information about TPM and SPI
connectors? In the Kontron 986LCD-M datasheet (sections 4.16 and 4.17)
there are only pin names and caption "unsupported". I understand these
signals are likely buses from chipset, but it would be nice to know more
details. Namely if the default LPC flash chip needs to be disconnected
when using these busses and which pins of the chipset are connected to
SPI pins BOOT0 and BOOT1 (I suppose they are LPC/SPI/PCI priority?).

Thanks for any help.

Petr Cvek

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