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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-01 13:35:27 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-01 13:35:27 -0700 |
commit | 58ff3b7604a461a766a84348e620834dce9834a9 (patch) | |
tree | 55aa2f96f7d342ceeaa377a0095f1c1cfe00b6ad /Documentation | |
parent | a7092c82042b4ba3000cf7b369d1032161c5d4c9 (diff) | |
parent | e9524fb97ab5b41b85e1d3408f8e513433798f3c (diff) | |
download | linux-58ff3b7604a461a766a84348e620834dce9834a9.tar.bz2 |
Merge tag 'efi-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:
"The EFI changes for this cycle are:
- preliminary changes for RISC-V
- Add support for setting the resolution on the EFI framebuffer
- Simplify kernel image loading for arm64
- Move .bss into .data via the linker script instead of relying on
symbol annotations.
- Get rid of __pure getters to access global variables
- Clean up the config table matching arrays
- Rename pr_efi/pr_efi_err to efi_info/efi_err, and use them
consistently
- Simplify and unify initrd loading
- Parse the builtin command line on x86 (if provided)
- Implement printk() support, including support for wide character
strings
- Simplify GDT handling in early mixed mode thunking code
- Some other minor fixes and cleanups"
* tag 'efi-core-2020-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (79 commits)
efi/x86: Don't blow away existing initrd
efi/x86: Drop the special GDT for the EFI thunk
efi/libstub: Add missing prototype for PE/COFF entry point
efi/efivars: Add missing kobject_put() in sysfs entry creation error path
efi/libstub: Use pool allocation for the command line
efi/libstub: Don't parse overlong command lines
efi/libstub: Use snprintf with %ls to convert the command line
efi/libstub: Get the exact UTF-8 length
efi/libstub: Use %ls for filename
efi/libstub: Add UTF-8 decoding to efi_puts
efi/printf: Add support for wchar_t (UTF-16)
efi/gop: Add an option to list out the available GOP modes
efi/libstub: Add definitions for console input and events
efi/libstub: Implement printk-style logging
efi/printf: Turn vsprintf into vsnprintf
efi/printf: Abort on invalid format
efi/printf: Refactor code to consolidate padding and output
efi/printf: Handle null string input
efi/printf: Factor out integer argument retrieval
efi/printf: Factor out width/precision parsing
...
Diffstat (limited to 'Documentation')
-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> |