[coreboot] X120e AGESA hangs

[Łukasz Dobrowolski]

Hi!
I'm porting ThinkPad X120e(I based my work on asrock/e350m1).
Sometimes it boots, other times it hangs on src/vendorcode/amd/cimx/sb800/SBPort.c:294
    RWMEM (ACPI_MMIO_BASE + PMIO_BASE + SB_PMIOA_REGC8, AccWidthUint8, 0xEF, 0x10);
I've used post_code() to find the offending line. It happens before EHCI debug starts so I have only postcodes to work with.
I've tried searching in the documentation on developer.amd.com but I can't figure out what that code is doing.
Should I just try to comment out the offending line? Any hints?

The chipset is Hudson-M1 (A50M).
Side note: The southbridge gets very hot quickly(it's cool on stock bios). I installed a radiator until I'll find out what's wrong.