Private bug reported: With "Above 4G MMIO" enabled in BIOS, EFI FB driver cannot get 64-bit FB address on Raven1 platform. Then fail to initialize EFI FB driver.
That results in black-screen for console mode or installing Ubuntu system. e.g. if the FB address is 0x7fc80000000, EFI FB could only get the low 32-bit FB address. [ 0.992990] efifb: probing for efifb [ 0.992995] efifb: cannot reserve video memory at 0x80000000 [ 0.992999] ioremap on RAM at 0x0000000080000000 - 0x00000000808cffff As my investigation, it looks Ubuntu efi boot stub cannot get 64-bit address by GOP. 1) create a EFI shell app to get the fb address, it’s 64-bit 2) Build bzImage.efi to load 4.13 custom kernel, efifb driver also could get 64-bit address. ** Affects: amd Importance: High Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1736862 Title: [Raven1] EFI FB driver cannot get 64-bit FB address with "Above 4G MMIO" enabled in Ubuntu16.04.3 To manage notifications about this bug go to: https://bugs.launchpad.net/amd/+bug/1736862/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs