cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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efifb.rst (2302B)

      1==============
      2What is efifb?
      3==============
      4
      5This is a generic EFI platform driver for systems with UEFI firmware. The
      6system must be booted via the EFI stub for this to be usable. efifb supports
      7both firmware with Graphics Output Protocol (GOP) displays as well as older
      8systems with only Universal Graphics Adapter (UGA) displays.
      9
     10Supported Hardware
     11==================
     12
     13- iMac 17"/20"
     14- Macbook
     15- Macbook Pro 15"/17"
     16- MacMini
     17- ARM/ARM64/X86 systems with UEFI firmware
     18
     19How to use it?
     20==============
     21
     22For UGA displays, efifb does not have any kind of autodetection of your
     23machine.
     24
     25You have to add the following kernel parameters in your elilo.conf::
     26
     27	Macbook :
     28		video=efifb:macbook
     29	MacMini :
     30		video=efifb:mini
     31	Macbook Pro 15", iMac 17" :
     32		video=efifb:i17
     33	Macbook Pro 17", iMac 20" :
     34		video=efifb:i20
     35
     36For GOP displays, efifb can autodetect the display's resolution and framebuffer
     37address, so these should work out of the box without any special parameters.
     38
     39Accepted options:
     40
     41======= ===========================================================
     42nowc	Don't map the framebuffer write combined. This can be used
     43	to workaround side-effects and slowdowns on other CPU cores
     44	when large amounts of console data are written.
     45======= ===========================================================
     46
     47Options for GOP displays:
     48
     49mode=n
     50        The EFI stub will set the mode of the display to mode number n if
     51        possible.
     52
     53<xres>x<yres>[-(rgb|bgr|<bpp>)]
     54        The EFI stub will search for a display mode that matches the specified
     55        horizontal and vertical resolution, and optionally bit depth, and set
     56        the mode of the display to it if one is found. The bit depth can either
     57        "rgb" or "bgr" to match specifically those pixel formats, or a number
     58        for a mode with matching bits per pixel.
     59
     60auto
     61        The EFI stub will choose the mode with the highest resolution (product
     62        of horizontal and vertical resolution). If there are multiple modes
     63        with the highest resolution, it will choose one with the highest color
     64        depth.
     65
     66list
     67        The EFI stub will list out all the display modes that are available. A
     68        specific mode can then be chosen using one of the above options for the
     69        next boot.
     70
     71Edgar Hucek <gimli@dark-green.com>