md5sum arguments

[Sascha Hauer]

On Tue, Jul 01, 2014 at 09:14:47PM +0400, Antony Pavlov wrote:
> Hi All!
> 
> Current 'md5sum' command gets FILE|AREA argument, e.g.
> 
> 
>   barebox:/ help md5sum 
> 
>   md5sum - calculate MD5 checksum
> 
>   Usage: md5sum FILE|AREA...
> 
>   Calculate a MD5 digest over a FILE or a memory area.
> 
> The *nix 'md5sum' gets [FILE]... argument.
> This behavour can be misleading. E.g. today I have tryed this command sequence on
> my qemu-malta machine:
> 
>   barebox:/ memcpy -s /dev/zero -d 1M 0 0 0x100000
>   barebox:/ md5sum 1M
> 
> md5sum just hangs!

This is beacuse size is initialized with ~0 and thus the command will
create a md5sum over the whole memory space.

This works:

md5sum 1M+0x100000

> But this command sequence works fine:
> 
>   barebox:/ memcpy -s /dev/zero -d zeros 0 0 0x100000
>   barebox:/ md5sum zeros                             
>   b6d81b360a5672d80c27430f39153e2c  zeros 0x00000000 ... 0xffffffffffffffff
> 
> 
> Do we really need this?

Personally I don't need this, but since we have this feature and it's
not really expensive, why should we remove it?

Sascha

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