[U-Boot] [PATCH] [v2] powerpc: 'monitor' environment variable contains full video configuration

Timur Tabi
2011-03-15T15:21:16Z

Wolfgang Denk wrote:
>> > because the kernel also needs to see "console=tty0" on the command line only if
> This may or may not be the case. Frequently we still use a serial
> console even when booting with a graphics display enabled.
>
> This is a different option, and does not belong into that setting.
>
>> > video is supposed to be enabled. I want to make video mode completely dynamic,
>> > so that if the 'video-mode' variable is set, then the console is switched to the
>> > video device, and the kernel is told to do the same. Otherwise, all output will
>> > go to the serial port.

> NAK. video-mode settings and console settings are two separate things
> and must not be mangled into a single variable.

Well, that's why I have two variables. My patch has the ability to set the
kernel command line appropriately if the video display is configured and enabled
in U-Boot. The second variable is used to assist in setting the actual kernel
command-line, because that's the easiest and safest way to do it. An
alternative that I tried to implement is to have do_bootm_linux() edit the
kernel command line directly, removing any existing video= option and putting a
new one in, but I found that to be too intrusive, especially since we don't have
any good string editing functions already in U-Boot.

There are three things that need to be done:

1) The video mode needs to be configured
2) The video display needs to be enabled and the U-Boot console needs to be
routed to it
3) The kernel command line needs to be set

For #1, we use video-mode. How do you want #2 and #3 handled?

--
Timur Tabi
Linux kernel developer at Freescale