forked from luck/tmp_suning_uos_patched
14c574f35c
Add video=efifb:list option to list the modes that are available. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200518190716.751506-20-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
72 lines
2.2 KiB
ReStructuredText
72 lines
2.2 KiB
ReStructuredText
==============
|
|
What is efifb?
|
|
==============
|
|
|
|
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
|
|
==================
|
|
|
|
- iMac 17"/20"
|
|
- Macbook
|
|
- Macbook Pro 15"/17"
|
|
- MacMini
|
|
- ARM/ARM64/X86 systems with UEFI firmware
|
|
|
|
How to use it?
|
|
==============
|
|
|
|
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 :
|
|
video=efifb:macbook
|
|
MacMini :
|
|
video=efifb:mini
|
|
Macbook Pro 15", iMac 17" :
|
|
video=efifb:i17
|
|
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:
|
|
|
|
======= ===========================================================
|
|
nowc Don't map the framebuffer write combined. This can be used
|
|
to workaround side-effects and slowdowns on other CPU cores
|
|
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>
|