Simple framebuffer support

[musv]

Hi there,

today I made a kernel update and found:

Mark VGA/VBE/EFI FB as generic system framebuffer (X86_SYSFB)

CONFIG_X86_SYSFB:

Firmwares often provide initial graphics framebuffers so the BIOS,
bootloader or kernel can show basic video-output during boot for
user-guidance and debugging. Historically, x86 used the VESA BIOS
Extensions and EFI-framebuffers for this, which are mostly limited
to x86.
This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
framebuffers so the new generic system-framebuffer drivers can be
used on x86. If the framebuffer is not compatible with the generic
modes, it is adverticed as fallback platform framebuffer so legacy
drivers like efifb, vesafb and uvesafb can pick it up.
If this option is not selected, all system framebuffers are always
marked as fallback platform framebuffers as usual.

Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
not be able to pick up generic system framebuffers if this option
is selected. You are highly encouraged to enable simplefb as
replacement if you select this option. simplefb can correctly deal
with generic system framebuffers. But you should still keep vesafb
and others enabled as fallback if a system framebuffer is
incompatible with simplefb.

If unsure, say Y.



Simple framebuffer support (FB_SIMPLE)

CONFIG_FB_SIMPLE:

Say Y if you want support for a simple frame-buffer.

This driver assumes that the display hardware has been initialized
before the kernel boots, and the kernel will simply render to the
pre-allocated frame buffer surface.

Configuration re: surface address, size, and format must be provided
through device tree, or plain old platform data.

Didn't find any documentation, how to use that thing. Does anybody know more about it?

[666threesixes666]

hi here is the documentation you request.

https://wiki.gentoo.org/wiki/Framebuffer

basically its a high resolution console for booting. makes it so you can actually see some stuff going on. looking at that wikipedia link of the subject gives a bunch of information on frame buffers.

if you want support i suggest posting information from 3.4 collection section of this page. https://wiki.gentoo.org/wiki/Troubleshooting

[musv]

Sorry, but maybe I was something misunderstood. I didn't ask for framebuffer generally. The above described options are new in the kernel and I didn't find a documentation how to use the simple fb driver, e.g. to specify the resolution via boot commandline.

[666threesixes666]

https://www.kernel.org/doc/Documentatio ... buffer.txt

yeah that documentations pretty useless.

[mimosinnet]

I am also upgrading the kernel and I am not sure what to do with this option. I set it as 'y', as it suggests.

[s4e8]

simplefb is dev side's code change, provide no adavantage over vesafb/efifb, and increase kernel size. Always disable it if possible.

[mimosinnet]

Thanks!

[VoidMage]

simplefb is dev side's code change, provide no adavantage over vesafb/efifb, and increase kernel size. Always disable it if possible.

Well, I don't know. That "move console completely into userspace" goal, while wacky, does have a few potential benefits for average users.

[Aquous]

simplefb is dev side's code change, provide no adavantage over vesafb/efifb, and increase kernel size. Always disable it if possible.

You couldn't be more wrong. simplefb is a replacement for vesafb that retains the fb resolution set by grub2, hence, if you use proprietary AMD/NVIDIA GPU drivers enabling simplefb will give you a native-resolution console rather than the ugly 80x25 one (assuming you use grub2, have set it to use a native resolution framebuffer, and are booting with GFXPAYLOAD=keep).

[TomWij]

Thank you for sharing this; I'll try it soon as it seems promising, but I'm not getting my hopes up.