Boot Flags

This little section here is a short explainer on some of the more commonly useful boot flags used for getting your GPU working. Do note, most of these boot-flags are from WhateverGreen (opens new window) so refer to their FAQ (opens new window) for a complete list of boot flags. And for a list of all shikigva boot arguments, see here (opens new window) and DRM boot-flags can be found here: WhateverGreen's DRM chart (opens new window)

AMD Boot Arguments

• shikigva=40 + shiki-id=Mac-7BA5B2D9E42DDD94
  • Swaps boardID with iMacPro1,1
  • Allows for Polaris, Vega and Navi GPUs to handle all types of rendering, useful for SMBIOS which expect an iGPU
  • See here for more info: Fixing DRM (opens new window)
• radpg=15
  • Fixes initialization for HD 7730/7750/7770/R7 250/R7 250X
• -raddvi
  • Fixes DVI connector-type for 290X, 370, etc
• -radvesa
  • Forces GPU into VESA mode(no GPU acceleration), useful for troubleshooting
  • Apple's built in version of this flag is -amd_no_dgpu_accel
• agdpmod=vit9696
  • Disables board-id check, may be needed for when screen turns black after finishing booting
• agdpmod=pikera
  • Renames board-id to board-ix effectively disabling boardID checks, this is based off of Pike.R.A's work here (opens new window)
  • This is also required for all Navi GPUs due to the difference in framework with the x6000 drivers

Nvidia Boot Arguments

• nvda_drv=1
  • A boot flag that refuses to die, STOP USING IT. Used for enabling Nvidia's WebDrivers pre-macOS Sierra but no longer works as it was moved to an NVRAM variable instead.
    • For Clover, use NvidiaWeb under System Parameters in your config.plist.
    • For OpenCore, use NVRAM -> Add -> 7C436110-AB2A-4BBB-A880-FE41995C9F82 -> nvda_drv: <31> in your config.plist.
  • The WebDrivers in Sierra and High Sierra also support another boot argument called nvda_drv_vrl=1, this will actually do the same thing as nvda_drv=1 did in previous versions
• nv_disable=1
  • Forces GPU into VESA mode(no GPU acceleration), useful for troubleshooting and when having issues installing Nvidia's WebDrivers. This is a macOS flag so WEG is not needed.
• shikigva=40
  • Swaps boardID with iMac14,2
  • Useful for SMBIOS that don't expect a Nvidia GPU, however WhateverGreen should handle patching by itself
• shikigva=1
  • Needed when you're wanting to use your iGPU's display out along with the dGPU, allows the iGPU to handle hardware decoding even when not using a connector-less framebuffer
• shikigva=4
  • Needed to support hardware accelerated video decoding on systems that are newer than Haswell, may need to be used with shikigva=12 to patch the needed processes
• agdpmod=vit9696
  • Disables board-id check, may be needed for when screen turns black after finishing booting
• agdpmod=pikera
  • Swaps board-id for board-ix, needed for disabling string comparison which is useful for non-iMac13,2/iMac14,2 SMBIOS

Intel Boot Arguments

• -wegnoegpu
  • disables all GPUs excluding the iGPU, most relevant for users with Nvidia wanting to run Mojave+
• -igfxnohdmi
  • Disables DisplayPort to HDMI Audio Conversion
• -cdfon
  • Performs numerous patches required for enabling HDMI 2.0 support
• -igfxvesa
  • Forces GPU into VESA mode(no GPU acceleration), useful for troubleshooting
• igfxonln=1
  • Forces all displays online, useful for resolving screen wake issues in 10.15.4+ on Coffee and Comet Lake
• igfxfw=2
  • Enables loading Apple's GUC firmware for iGPUs, requires a 9th Gen chipset or newer(ie Z390)
  • See here for more info: Fixing DRM (opens new window)