Issue #315 has been reported by Master Geek.
---------------------------------------- Bug #315: Xorg/Wayland show black screen when system memory is 4GB or higher https://ticket.coreboot.org/issues/315
* Author: Master Geek * Status: New * Priority: Normal * Assignee: * Category: * Target version: ---------------------------------------- Board: ASROCK G41M-VS3 R2.0 CB Revision: coreboot-4.14-1258-gfbc46a3bfb
When this board has one memory stick with 2GB of ram, or two memory sticks with 1GB and 2GB (3GB total) there's no issue with display; Xorg and wayland (using weston) work as expected. But when there's 4GB or maybe more (two 2GB sticks only available, haven't tried a single 4GB stick) the system works as expected up to just before starting Xorg or wayland, the screen goes black and nothing else happens. Returning to a tty by means of Ctrl-Alt-# 'ing to some other tty doesn't bring display back, neither does exitting/killing Xorg or wayland. Not even forcefully removing and reloading the relevant kernel modules (i915, drm) does anything to bring the display back, display will only comeback with a reboot.
When the screen goes black there's no system freeze of any kind, and the kernel complains with a single line: "i915 0000:00:02.0: [drm] *ERROR* CPU pipe A FIFO underrun" that isn't very helpful for debugging imo.
Attached dmesg loglevel=9 logs of stock bios, coreboot with 4GB (coreboot_bad) and with 2GB (coreboot_good), cbmem console log of coreboot with 2GB (cbmem_good).
---Files-------------------------------- cb_config.txt (16.3 KB) cbmem_good.log (31.3 KB) dmesg_coreboot_bad.log (443 KB) dmesg_coreboot_good.log (457 KB) dmesg_stock_bios.log (315 KB)