// HACKER NEWS — CYBERSECURITY
ReBarUEFI: Resizable BAR for almost any UEFI system
A UEFI DXE driver to enable Resizable BAR on systems which don't support it officially. This provides performance benefits and is even required for Intel Arc GPUs to function optimally.
Follow the wiki guide Adding FFS module and continue through the steps. It covers adding the module and the additional modifications needed if required.
Once running the modified firmware make sure that 4G decoding is enabled and CSM is off.
Next run ReBarState which can be found in Releases (if you're on Linux build with CMake) and set the Resizable BAR size. In most cases you should be able to use 32 (unlimited) without issues but you might need to use a smaller BAR size if 32 doesn't work
If Resizable BAR works for you reply to List of working motherboards so I can add it to the list. Most firmware will accept unsigned/patched modules with Secure Boot on so you won't have any problems running certain games.
If you have any issues after enabling Resizable BAR see Common Issues (and fixes)
The module is added to the UEFI firmware's DXE volume so it gets executed on every boot. The ReBarDxe module replaces the function PreprocessController of PciHostBridgeResourceAllocationProtocol with a function that checks for Resizable BAR capability and then sets it to the size from the ReBarState NVRAM variable after running the original function.
The new PreprocessController function later gets called during PCI enumeration by the PciBus module which will detect the new BAR size and allocate it accordingly.
Instructions for applying UEFIPatch not included as it isn't required for these X99 motherboards. You can follow them below.
Most UEFI firmwares have problems handling 64-bit BARs so several patches were created to fix these issues. You can use UEFIPatch to apply these patches located in the UEFIPatch folder. See wiki page Using UEFIPatch for more information on using UEFIPatch. Make sure to check that pad files aren't changed and if they are use the workaround