[PATCH v3 4/9] doc: Add a note about how to produce 'md' output using hexdump

[Pratyush Yadav]

On 04/02/21 10:55AM, Simon Glass wrote:
> Comparing a hex dump on the U-Boot command line with the contents of a
> file on the host system is fairly easy and convenient to do manually if
> it is small. But the format used hexdump by default differs from that
> shown by U-Boot. Add a note about how to make them the same.
> 
> (For large dumps, writing the data to the network with tftpput, or to a
> USB stick with ext4save is easiest.)
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
> Changes in v3:
> - Add this to the docs for the md command
> 
>  doc/usage/md.rst | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/doc/usage/md.rst b/doc/usage/md.rst
> index 3951b0d58f5..e9ea798f5fc 100644
> --- a/doc/usage/md.rst
> +++ b/doc/usage/md.rst
> @@ -39,6 +39,10 @@ length
>      number of values to dump. Defaults to 40 (0d64). Note that this is not
>      the same as the number of bytes, unless .b is used.
>  
> +Note that the format of 'md' can be emulated from linux with::

s/md/md.b/

It won't emulate the output for md.w or md.l or md.q.

> +
> +    hexdump -v -e '"%08.8_ax: " 16/1 "%02x " "    "' -e '16/1 "%_p" "\n" ' <f>

This does not produce the _exact_ output. md.b sets offsets based on the 
memory address being read from. For example, if I read from 0x80000000, 
it will output something like:

  80000000: 00 00 00 00 00 ...

Hexdump obviously does not know this address so it will produce 
something like:

  00000000: 00 00 00 00 00 ...

Dunno what to do about this though. Just figured I'd point it out.

> +
>  
>  Example
>  -------

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.