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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
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Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+==============
+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>