[U-Boot] U-boot VESA driver Initialization

[vinoth eswaran]

Hello Mr.Bin,
Hello Mr.George McCollister,

 I am working on an embedded project to optimize Linux boot up time. I have
a camera application, which I need to run as fast as possible after
powering up the board.

For this currently I am analyzing how can I optimize the U-boot. As of now,
u-boot takes around 3 to 4 seconds and most of the time is spent, around 2
secs in initializing the VESA display.

I have analyzed the sequence of VESA initialization flow and I have
identified that realmode_call under the function bios_run_on_x86() takes
more time -- around 1.7 Sec,

    realmode_call(addr + 0x0003, num_dev, 0xffff, 0x0000, 0xffff, 0x0,
              0x0);

Do you have any idea why this is happening?

I tried removing the VIDEO configuration from u-boot, though the boot up is
fast , the i915 driver from Linux is reporting an error -- 'i915
0000:00:02.0: Invalid ROM contents'
I understand that the Linux kernel expects the underlying boot loader to
setup some initialization which is missing in this case.

Do you know any methods by which I can speed up the video driver
initialization phase in u-boot. Please note that I don't need video support
during u-boot phase,I am not going to use any splash images.


Mit Freundlichen Grüßen
VinothKumar
+49 1798909072