[U-Boot] Antw: Re: U-Boot doesn't silent the output

[Frank Ihle]

>>>> Wolfgang Denk  18.03.14 10.05 Uhr >>>
>Dear Frank,
>
>In message <532816E0020000460004BEFA at gwia2.rz.hs-offenburg.de> you wrote:
>>
>> Anyway I wonder why the "setenv verify n" worked with the
>> BOOTCOMMAND but the "silent" didn't. Should I shift all the commands
>> from CONFIG_BOOTCOMMAND to CONFIG_EXTRA_ENV_SETTINGS to be sure all
>> the commands are really executed?
>
>I think you should try to get a deeper understanding of what is what.
>first, it is important to remember that there are two different sets
>of environment variables.  With all the CONFIG_ settings you define
>only the _default_ environment, which gets used as a default (hence
>the name) only when the normale environment does not exist or is not
>valid (like corrupted checksum).  So as long as you have a valid
>environment stored somewhere on your system, installing a new U-Boot
>with different settings of the default environment will have zero
>effect.

Thanks for the advise, I'll have a closer look ASAP. The way I got into this U-Boot 2010.06 was: I used an already existing board header file (that was not a standard U-Boot board header file) and that's how it was implemented there.

>Second, CONFIG_BOOTCOMMAND defines exactly one environment variable,
>"bootcmd".  As documented, the values of this variable is apssed to
>the Linux kernel as boot argument - and this is the only function of
>this variable.  You can add random things to it, even U-Boot commands,
>but this will never have any effect on the operation of U-Boot - it
>might only consfuse the Linux kernel.

Well the variables I pass to the kernel command line are stored not in the CONFIG_BOOTCOMMAND, but in the CONFIG_BOOTARGS. When checking the kernel command line during boot, it is the same like the one defined in the BOOTARGS. 

In that mentioned header file, with what I started U-Boot, there are commands in the CONFIG_BOOTCOMMAND like "nand write, tftp, setenv ipaddr" etc. - since those are the commands from the U-Boot menu on target, I thought enqueuing the BOOTCOMMAND with "silent", or "verify" would work too, though "verify" worked this way (a recognizable boot time was decreased). 

>> I really don't know the reason why Linux keeps talking during boot
>> when using "console=", whereas "quiet" and changing the loglevel is
>> working. I already asked in some forums about this, but it was as

>What exactly did you pass in the kernel command line - just
>"console=", i. e. without a value?  Did you try passing a valid device
>name instead, like "console=null"?

Yes I tried with "console=" and "console=null".

>Also, are you sure early debug output is disabled in your kernel
>configuration?  Otherwise this will get printed even before the Linux
>kernel's console driver has been started.

If you mean the "early printk" then yes, otherwise I need more information what is meant by early debug output.

Kind Regards,

Frank