@@ -18,7 +18,7 @@ EnableGop version (OpenCore version)
*Note 1*: This should provide faster GOP rendering on all EnableGopDirect systems; and rendering at least at
the same speed as before, and on some systems noticeably faster than before, on almost all EnableGop systems.
*Note 2*: The compressed driver for version 1.2 is 1KB larger than for version 1.1, so for AMD vBIOSes which are
*Note 2*: The compressed driver for version 1.2 is 1KB larger than for version 1.1, so for AMD GPU firmware which is
tight on space version 1.1 may be used instead to avoid the need for VGA stripping to make additional space.
### 1.1 (0.9.0)
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@@ -36,22 +36,23 @@ with several different GPUs, and on several MacPro4,1/5,1 machines with several
case (and still possible) scenario, an incompatible or incorrectly installed driver
in firmware may brick your hardware.
*In all cases take a backup of the main firmware or vBIOS firmware which you are modifying, and confirm that
*In all cases take a backup of the main firmware or GPU firmware which you are modifying, and confirm that
you can successfully restore from this, before starting.*
## Recovery from bricked hardware
- If attempting firmware insertion on a MacPro4,1/5,1, for recovery from a bricked device you will either
- If attempting main firmware insertion on a MacPro4,1/5,1, for recovery from a bricked device you will either
need a Matt card (which may breach intellectual property laws in some jurisdictions) or the ability to
desolder and reprogram your own NVRAM chip.
- If testing via firmware insertion on an iMac, you will need the ability to disassemble your iMac and
reprogram its NVRAM chip using a SOIC clip attached to a CH341A controller running on another computer.
- If testing via vBIOS insertion (iMac or Mac Pro), you will need the ability to disassemble your system,
likely remove the heat sink from the graphics card, and then reprogram its NVRAM chip using a SOIC
desolder and reprogram your own SPI flash chip.
- If testing via main firmware insertion on an iMac, you will need the ability to disassemble your iMac and
reprogram its SPI flash chip using a SOIC clip attached to a CH341A controller running on another computer.
- If testing via GPU firmware insertion (iMac or Mac Pro), you will need the ability to disassemble your system,
likely remove the heat sink from the graphics card, and then reprogram its SPI flash chip using a SOIC
clip attached to a CH341A controller running on another computer.
- If testing via vBIOS insertion, in some cases it may also be possible
to use physical electrical connection to your GPU NVRAM chip in order to boot with no graphics, then connect
to your machine with `ssh` (which must have been enabled beforehand) and reprogram the GPU NVRAM. Advice on
this is not provided here, but may be found for instance on the iMac GPU related forum threads listed below.
- If testing via GPU firmware insertion, in some cases it may also be possible
to use physical electrical connection to your GPU in order to enable booting with no graphics even though the GPU
is present, then connect to your machine with `ssh` (which must have been enabled beforehand) and reprogram the GPU
firmware. Advice on this headless boot approach is not provided here, but may be found for instance on the iMac GPU
related forum threads listed below.
*If you are not familiar with the above procedures, you are strongly recommended to wait for further testing by
users who are. No further help can be provided here, and you proceed entirely at your own risk.*
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@@ -62,16 +63,17 @@ OpenCore needed for pre-boot graphics support with non-natively supported GPUs.
The requirements for using this driver are:
- EFI-era (~2009-2012) MacPro4,1/5,1 or iMac with most recent firmware.
- EFI-era (~2009-2012) MacPro4,1/5,1 or iMac with most recent main firmware.
- A GPU which does not produce native pre-boot graphics (such as native picker when pressing ALT key during boot)
before OpenCore starts (otherwise, you do not need it).
- A GPU which produces graphics when using OpenCore (this must include successfully showing the native Apple boot
picker when started via the latest version of OpenCore tool `BootKicker.efi`) (otherwise, the driver will not work).
-*Note*: If your OpenCore installation includes a required GOP driver for your graphics card (this is added
automatically on some systems by recent versions of OpenCore Legacy Patcher, as a way to enable OpenCore menu
in cards such as ex-mining GPUs), then you would also need to burn that driver to the vBIOS of your graphics
card in order to obtain pre-OpenCore graphics; instructions for this are outside the scope of this tutorial,
although the procedures required for modifying vBIOS are similar to what is covered here.
-*Note*: If your OpenCore installation includes a required GOP driver for your graphics card, then you would
also need to burn that driver to the firmware of your graphics card in order to obtain pre-OpenCore graphics;
instructions for this are outside the scope of this tutorial, although the procedures required for modifying
GPU firmware are similar to what is covered here.
Note that such a driver is added by the OCLP **Enable AMD GOP** option, which is enabled automatically on some
systems by recent versions of OpenCore Legacy Patcher, as a way to enable the OpenCore menu in cards such as ex-mining GPUs.
When installed, the driver should enable:
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@@ -87,9 +89,9 @@ directory of the OpenCore release package.
For GPUs needing `DirectGopRendering` in OpenCore configuration, use `EnableGopDirect.efi`, otherwise use `EnableGop.efi`
as it renders faster on most other systems.
The driver may be installed to vBIOS or to main firmware. It is expected that most Mac Pro users will use firmware insertion
and most iMac users will chose vBIOS insertion, however both techniques work on both systems (but it is harder to modify the
iMac firmware, since there is no simple way to enable writing to it).
The driver may be installed to GPU or main motherboard firmware. It is expected that most Mac Pro users will use main firmware insertion
and most iMac users will chose GPU firmware insertion, however both techniques work on both systems (but it is harder to modify the
iMac main firmware, since there is no simple way to enable writing to it).
Further discussion and community support for this driver is available at:
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@@ -97,14 +99,14 @@ Further discussion and community support for this driver is available at:
## Usage
## Install to firmware
## Install to main firmware
For reading and writing to firmware on the Mac Pro, @Macschrauber's [Rom Dump](https://youtu.be/yHnZeht_isU) works
For reading and writing to main firmware on the Mac Pro, @Macschrauber's [Rom Dump](https://youtu.be/yHnZeht_isU) works
well. Alternatively the kexts and executables which this uses can be sourced individually (or extracted from the Rom Dump app) and
run from the command line.
The firmware on the iMac cannot be updated without an initial hardware flash (SOIC clip plus CH341A controller), therefore
the recommended approach on iMac systems is [vBIOS injection](#install-to-vBIOS). However, the below instructions for firmware
The main firmware on the iMac cannot be updated without an initial hardware flash (SOIC clip plus CH341A controller), therefore
the recommended approach on iMac systems is [GPU firmware injection](#install-to-gpu-firmware). However, the below instructions for firmware
injection do work, if you are willing to do a hardware flash of the resulting firmware file, or if you have already
[unprotected your iMac firmware](https://forums.macrumors.com/threads/imac-2011-see-more-uefi-firmware-mod.2257435/page-3?post=31087001#post-31087001) -
which reduces security, and is only recommended for those actively developing firmware modifications.
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@@ -142,9 +144,9 @@ The end result, after saving and re-loading, should look like this:
<imgsrc="UEFITool_Inserted_Screenshot.png">
## Install to vBIOS
## Install to GPU firmware
Instructions and a script for inserting the driver into Nvidia or AMD vBIOS are provided.
Instructions and a script for inserting the driver into Nvidia or AMD GPU firmware (aka VBIOS) are provided.
Please note all the cautions already given above about the difficulty of recovering, unless you are familiar with
the procedures necessary, if this process fails.
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@@ -152,23 +154,23 @@ the procedures necessary, if this process fails.
To use the provided `vBiosInsert.sh` script:
- Locate an appropriate version of the `nvflash` tool (Nvidia) or `amdvbflash` tool (AMD) (both are available for
Linux and Windows), which can be used to read from and write to the GPU vBIOS.
- Use that tool to read a copy of the vBIOS.
Linux and Windows), which can be used to read from and write to the GPU firmware.
- Use that tool to read a copy of the GPU firmware.
- Run `./vBiosInsertEfi.sh [-a|-n] {original}.rom EnableGop.efi {modified}.rom`, with `-a` for AMD and `-n` for Nvidia.
- The new file `{modified}.rom` may be burnt to the vBIOS firmware.
- The new file `{modified}.rom` may be burnt to the GPU firmware.
In the case of AMD, considerably less space is normally available, due to a strict limit of 128k for legacy and EFI
parts of the larger ROM image. If there is not enough space (i.e. script reports
data would be truncated) then it is necessary to [strip some legacy VGA parts of the
vBIOS](https://github.com/Ausdauersportler/IMAC-EFI-BOOT-SCREEN/wiki/Deleting-the-VGA). This is beyond the scope
GPU firmware](https://github.com/Ausdauersportler/IMAC-EFI-BOOT-SCREEN/wiki/Deleting-the-VGA). This is beyond the scope
of these instructions.
If required to manually detect the GOP offset (this should normally be autodetected):
> Using a hex editor, search in the vBIOS for the byte sequence `F1 0E 00 00` with the byte sequence `55 AA` coming
> Using a hex editor, search in the GPU firmware dump for the byte sequence `F1 0E 00 00` with the byte sequence `55 AA` coming
close before it; the start address of the `55 AA` is the GOP offset value needed.
For further information on vBIOS modification, see:
For further information on GPU firmware modification, see:
