ReBarUEFI: Z97 board can't allocate above 4G even with above 4g decoding enable in BIOS
System
- Motherboard: Asus Z97i-Plus
- BIOS Version: 2704
- GPU: Intel Arc A750 LE (supports up to 8GB BAR)
- Above 4G decoding is enabled in BIOS
- CSM is disabled
- Applied PciBus | Remove <16GB BAR size limit patch
- replaced NvramSmi module from an older BIOS(version 2103) to allow new uefi variable creation
Description I modded the BIOS to enable rebar using your instructions but the maximum working BAR size is 1GB. At 2GB the system gets stuck during post, at 4GB and 8GB it boots into the OS(Windows 10 and Ubuntu 20.04) but video output works only from the iGPU.
This is dmesg after booting with 8GB
[ 0.194347] pci_bus 0000:00: root bus resource [bus 00-3e]
[ 0.194349] pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window]
[ 0.194350] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window]
[ 0.194352] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000dffff window]
[ 0.194353] pci_bus 0000:00: root bus resource [mem 0xdf200000-0xfeafffff window]
[ 0.194354] pci_bus 0000:00: root bus resource [mem 0x800000000-0xfbfffffff window]
[ 0.197052] pci 0000:00:01.0: PCI bridge to [bus 01-04]
[ 0.197055] pci 0000:00:01.0: bridge window [mem 0xf7c00000-0xf7cfffff]
[ 0.197058] pci 0000:00:01.0: bridge window [mem 0xf0000000-0xf07fffff 64bit pref]
[ 0.197408] pci 0000:01:00.0: PCI bridge to [bus 02-04]
[ 0.197413] pci 0000:01:00.0: bridge window [mem 0xf7c00000-0xf7cfffff]
[ 0.197453] pci 0000:03:00.0: [8086:56a1] type 00 class 0x030000
[ 0.197468] pci 0000:03:00.0: reg 0x10: [mem 0x00000000-0x00ffffff 64bit]
[ 0.197477] pci 0000:03:00.0: reg 0x18: [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.197491] pci 0000:03:00.0: reg 0x30: [mem 0x00000000-0x001fffff pref]
[ 0.197563] pci 0000:03:00.0: PME# supported from D0 D3hot
[ 0.209169] pnp 00:00: disabling [mem 0xfed40000-0xfed44fff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209785] pnp 00:06: disabling [mem 0xfed1c000-0xfed1ffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209788] pnp 00:06: disabling [mem 0xfed10000-0xfed17fff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209790] pnp 00:06: disabling [mem 0xfed18000-0xfed18fff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209791] pnp 00:06: disabling [mem 0xfed19000-0xfed19fff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209793] pnp 00:06: disabling [mem 0xf8000000-0xfbffffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209794] pnp 00:06: disabling [mem 0xfed20000-0xfed3ffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209796] pnp 00:06: disabling [mem 0xfed90000-0xfed93fff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209797] pnp 00:06: disabling [mem 0xfed45000-0xfed8ffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209798] pnp 00:06: disabling [mem 0xff000000-0xffffffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209800] pnp 00:06: disabling [mem 0xfee00000-0xfeefffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209801] pnp 00:06: disabling [mem 0xf7fe0000-0xf7feffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.209803] pnp 00:06: disabling [mem 0xf7ff0000-0xf7ffffff] because it overlaps 0000:03:00.0 BAR 2 [mem 0x00000000-0x1ffffffff 64bit pref]
[ 0.217718] pci 0000:01:00.0: BAR 15: no space for [mem size 0x200000000 64bit pref]
[ 0.217720] pci 0000:01:00.0: BAR 15: failed to assign [mem size 0x200000000 64bit pref]
[ 0.217723] pci 0000:02:01.0: BAR 15: no space for [mem size 0x200000000 64bit pref]
[ 0.217724] pci 0000:02:01.0: BAR 15: failed to assign [mem size 0x200000000 64bit pref]
[ 0.217725] pci 0000:02:01.0: BAR 14: no space for [mem size 0x01800000]
[ 0.217726] pci 0000:02:01.0: BAR 14: failed to assign [mem size 0x01800000]
[ 0.217727] pci 0000:03:00.0: BAR 2: no space for [mem size 0x200000000 64bit pref]
[ 0.217729] pci 0000:03:00.0: BAR 2: failed to assign [mem size 0x200000000 64bit pref]
[ 0.217730] pci 0000:03:00.0: BAR 0: no space for [mem size 0x01000000 64bit]
[ 0.217731] pci 0000:03:00.0: BAR 0: failed to assign [mem size 0x01000000 64bit]
[ 0.217732] pci 0000:03:00.0: BAR 6: no space for [mem size 0x00200000 pref]
[ 0.217733] pci 0000:03:00.0: BAR 6: failed to assign [mem size 0x00200000 pref]
[ 0.217734] pci 0000:02:01.0: PCI bridge to [bus 03]
[ 0.217744] pci 0000:02:04.0: PCI bridge to [bus 04]
[ 0.217748] pci 0000:02:04.0: bridge window [mem 0xf7c00000-0xf7cfffff]
[ 0.217756] pci 0000:01:00.0: PCI bridge to [bus 02-04]
[ 0.217759] pci 0000:01:00.0: bridge window [mem 0xf7c00000-0xf7cfffff]
[ 0.217764] pci 0000:00:01.0: PCI bridge to [bus 01-04]
[ 0.217766] pci 0000:00:01.0: bridge window [mem 0xf7c00000-0xf7cfffff]
[ 0.217768] pci 0000:00:01.0: bridge window [mem 0xf0000000-0xf07fffff 64bit pref]
[ 0.217771] pci 0000:00:1c.0: PCI bridge to [bus 05]
[ 0.217779] pci_bus 0000:00: Some PCI device resources are unassigned, try booting with pci=realloc
[ 0.217780] pci_bus 0000:00: resource 4 [io 0x0000-0x0cf7 window]
[ 0.217782] pci_bus 0000:00: resource 5 [io 0x0d00-0xffff window]
[ 0.217783] pci_bus 0000:00: resource 6 [mem 0x000a0000-0x000dffff window]
[ 0.217784] pci_bus 0000:00: resource 7 [mem 0xdf200000-0xfeafffff window]
[ 0.217785] pci_bus 0000:00: resource 8 [mem 0x800000000-0xfbfffffff window]
[ 0.217786] pci_bus 0000:01: resource 1 [mem 0xf7c00000-0xf7cfffff]
[ 0.217787] pci_bus 0000:01: resource 2 [mem 0xf0000000-0xf07fffff 64bit pref]
[ 0.217788] pci_bus 0000:02: resource 1 [mem 0xf7c00000-0xf7cfffff]
[ 0.217789] pci_bus 0000:04: resource 1 [mem 0xf7c00000-0xf7cfffff]
00:00.0 Host bridge: Intel Corporation 4th Gen Core Processor DRAM Controller (rev 06)
03:00.0 VGA compatible controller: Intel Corporation Device 56a1 (rev 08)
06:00.0 Network controller: Broadcom Inc. and subsidiaries BCM4352 802.11ac Wireless Network Adapter (rev 03)
and /proc/iomem
f0000000-f07fffff : PCI Bus 0000:01
f0000000-f07fffff : 0000:01:00.0
f7400000-f77fffff : 0000:00:02.0
f7800000-f7afffff : PCI Bus 0000:06
f7800000-f79fffff : 0000:06:00.0
f7a00000-f7a07fff : 0000:06:00.0
f7b00000-f7bfffff : PCI Bus 0000:01
f7b00000-f7bfffff : PCI Bus 0000:02
f7b00000-f7bfffff : PCI Bus 0000:04
f7b00000-f7b03fff : 0000:04:00.0
...
100000000-41fdfffff : System RAM
179e00000-17ae025c7 : Kernel code
17b000000-17ba87fff : Kernel rodata
17bc00000-17c0455ff : Kernel data
17c393000-17c9fffff : Kernel bss
41fe00000-41fffffff : RAM buffer
About this issue
- Original URL
- State: closed
- Created 2 years ago
- Comments: 84 (27 by maintainers)
i think i found the problem. PciBus driver is downgrading 64-bit resources to 32-bit ones automatically on Z97 it seems.
Asus Z97(bad)
Asus Z77 (good)
@DawgNewb you only need the UEFIPatch
The thing of replacing module with old one was used before the patch was discovered
@DawgNewb apply all the patches not just the ones you listed. There’s one for nvram module fixes this issue. And don’t forget to check for and fix pad file issue
All ASUS 100/200 motherboards which I can find BIOS on ASUS website have the 64-bit downgrade problem(latest BIOS), except Z270-WS and need BIOS version 0602(included) or later. I guess ASUS fix this problem because someone reported it, which Z270-WS offer quad PCIE x16 via PLX chip so users may have more probability installing lots of high-end GPU on it and found this problem.
@xCuri0 I was about to retract my statement. I couldn’t get into safe mode to use DDU (I think it’s related to the DRAM refresh failure. Keyboard was not detected), so I uninstalled the drivers normally and reinstalled it.
I’ll put a the 1104 firmware up for those who have 16gb and want to use it 😃