Dear community, I'm trying to bring up custom motherboard with Apollo Lake e3950 SoC. The first thing I've tried is flashed UP Squared-based BIOS compiled using this instructions: https://doc.coreboot.org/mainboard/up/squared/index.html After I run the motherboard it showed this uart0 output:
coreboot-4.12-4087-g6aaf7db719-dirty Tue Nov 17 09:50:24 UTC 2020 bootblock starting (log level: 7)... No FMAP found at 300000 offset. No FMAP found at 300000 offset. POST: 0xe0 Couldn't load romstage.
After some time spent trying to figure out the reason of such problem I found out that bootblock cannot load FMAP into RAM. I printed out some parts of ram where romstage and FMAP should be and there where only 0xff values. Looks like bootblock can't map SPI flash data to RAM although flash image has romstage and FMAP regions. The strange thing is that bootblock is loaded ok but any further load (FMAP) fails. Any ideas what can be the cause of this and how can I debug this thing?
PS I tried flashing another BIOS (from AMI) and it passes CAR stage, FSP stage, it even successfully initializes/trains DDR and so on. But coreboot BIOS somehow fails on the very early stages.
Best Regards, Anatolii Vorobev