[U-Boot] [PATCH 1/4] Add option -r to env import to allow import of text files with CRLF as line endings

Alexander Holler holler at ahsoftware.de
Thu Aug 14 23:05:36 CEST 2014


Am 14.08.2014 22:53, schrieb Tom Rini:
> On Thu, Aug 14, 2014 at 01:50:31PM -0600, Stephen Warren wrote:
>
> [snip]
>> uenv.txt is the opposite; it's very U-Boot specific, and more about
>> internal implementation details of U-Boot. In particular, I only see
>> a use-case for uenv.txt on systems that have nowhere to store the
>> U-Boot environment other than in some filesystem. That's the reason
>> the RPi port loads uenv.txt, so the environment can be modified
>> somehow. Perhaps there's an ENV_IS_IN_FAT that could be used instead
>> on the Pi? For example, none of the Tegra boards use uEnv.txt since
>> "saveenv" to flash works there.
>
> Even with ENV_IS_IN_FAT you need to be in U-Boot to modify the
> environment (fw_setenv/printenv should be adaptable easily enough I
> would hope, but aren't today).  uEnv.txt is the way for a user to pop
> the SD card into their PC, tweak the env as needed (or fiddle some
> bits), eject the card and boot their target.

Yes, many "developers" today (those which do buy development boards) are 
having problems to use a serial which most of the time is needed to 
access the u-boot command line. The reasons are various, most devices 
people do use don't have a serial anymore, the voltage of the serial 
changes every few years (12, 5, 3.3 and now 1.8 Volt), sometimes a 
nullmodem (just 3 wires) is needed, ...

Whatever the reason is, sometimes it can be very hard to access the 
u-boot command line. But most are able to modifying or create a file on 
disk. ;)

Regards,

Alexander Holler


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