I tried the xf86-video-vesa driver with xorg-server-1.18.1 and xorg-server-1.17.4, and got in both cases an error in Xorg.0.log: Cannot read int vect Cannot read BIOS Cannot load vbe By downgrading to xorg-server-1.16 I finally got a meaningfull error: (WW) xf86ReadBIOS: Failed to open /dev/mem (No such file or directory) (this bios call has been changed after 16.x, and the error message became less specific). Based on this error message I found out I needed to set CONFIG_DEVMEM in the kernel in order to get the vesa driver running. Given that it is not possible anymore to read the root cause from the Xorg log, I suggest to add a kernel check to the vesa driver and verify if the kernel option mentioned above is active.
Good idea. Fixed by: commit aafa644775d31150722aef2a6a68925a016aaa72 Author: Matt Turner <mattst88@gentoo.org> Date: Sat Jan 28 23:03:50 2017 -0800 x11-drivers/xf86-video-vesa: Check for CONFIG_DEVMEM.
