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Diffstat (limited to 'Documentation/fb/efifb.rst')
| -rw-r--r-- | Documentation/fb/efifb.rst | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/Documentation/fb/efifb.rst b/Documentation/fb/efifb.rst index 04840331a00e..6badff64756f 100644 --- a/Documentation/fb/efifb.rst +++ b/Documentation/fb/efifb.rst @@ -2,8 +2,10 @@ What is efifb? ============== -This is a generic EFI platform driver for Intel based Apple computers. -efifb is only for EFI booted Intel Macs. +This is a generic EFI platform driver for systems with UEFI firmware. The +system must be booted via the EFI stub for this to be usable. efifb supports +both firmware with Graphics Output Protocol (GOP) displays as well as older +systems with only Universal Graphics Adapter (UGA) displays. Supported Hardware ================== @@ -12,11 +14,14 @@ Supported Hardware - Macbook - Macbook Pro 15"/17" - MacMini +- ARM/ARM64/X86 systems with UEFI firmware How to use it? ============== -efifb does not have any kind of autodetection of your machine. +For UGA displays, efifb does not have any kind of autodetection of your +machine. + You have to add the following kernel parameters in your elilo.conf:: Macbook : @@ -28,6 +33,9 @@ You have to add the following kernel parameters in your elilo.conf:: Macbook Pro 17", iMac 20" : video=efifb:i20 +For GOP displays, efifb can autodetect the display's resolution and framebuffer +address, so these should work out of the box without any special parameters. + Accepted options: ======= =========================================================== @@ -36,4 +44,28 @@ nowc Don't map the framebuffer write combined. This can be used when large amounts of console data are written. ======= =========================================================== +Options for GOP displays: + +mode=n + The EFI stub will set the mode of the display to mode number n if + possible. + +<xres>x<yres>[-(rgb|bgr|<bpp>)] + The EFI stub will search for a display mode that matches the specified + horizontal and vertical resolution, and optionally bit depth, and set + the mode of the display to it if one is found. The bit depth can either + "rgb" or "bgr" to match specifically those pixel formats, or a number + for a mode with matching bits per pixel. + +auto + The EFI stub will choose the mode with the highest resolution (product + of horizontal and vertical resolution). If there are multiple modes + with the highest resolution, it will choose one with the highest color + depth. + +list + The EFI stub will list out all the display modes that are available. A + specific mode can then be chosen using one of the above options for the + next boot. + Edgar Hucek <gimli@dark-green.com> |