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

Timur Tabi timur at freescale.com
Tue Mar 15 16:52:28 CET 2011


Wolfgang Denk wrote:
>> 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

> Don't try to be more clever than the user.  Instead of helping, you
> restrict him. That's bad.

I'm not being more clever.  The code is setting a variable (diubootargs) that is
guaranteed to be the same video mode that U-Boot is running.  If you want to
ensure that Linux set to the same video mode, then use the variable.  Otherwise,
don't use the variable and set the command line manually.

>> > 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

> NAK, NAK, NAK.  All such automatic and unconditional editing is bad
> and should strictly be avoided.

You didn't understand my post.  I was saying that I tried to implement it, but
gave up because it got too complicated.

> Leave the decision which device to use as console to the user.

That's what the 'monitor' environment variable is for.

>> > There are three things that need to be done:
>> > 
>> > 1) The video mode needs to be configured
> ACK.
> 
>> > 2) The video display needs to be enabled and the U-Boot console needs to be
>> > routed to it
> NAK.
> 
> Wether the U-Boot console is attached to the serial port or the video
> console or netconsole or anything else should be left to the user.

Again, that's what the variable is for.  What's the point of configuring the
video display if you're not going to enable it?

> A default setting is OK, but the user must be able to set anything he
> likes.

Are we speaking the same language?  It doesn't appear that you're understanding
anything I'm saying.

>> > 3) The kernel command line needs to be set
> ACK.  Again, the user must have free choice of options.
> 
>> > For #1, we use video-mode.  How do you want #2 and #3 handled?
> See above.

I still don't understand what you actually want.

-- 
Timur Tabi
Linux kernel developer at Freescale



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