hexdumping /dev/mem

[Matías Perret Cantoni]

2015-03-17 13:04 GMT-03:00 Ian Lepore <ian at freebsd.org>:
> On Mon, 2015-03-16 at 16:41 -0700, Stanislav Sedov wrote:
>> > On Mar 16, 2015, at 3:58 PM, Matas Perret Cantoni <perretcantonim at gmail.com> wrote:
>> >
>> > I couldn't find any man page for "kdb" or "db", and the help command
>> > of db didn't help much.
>>
>> The only relevant manual pages are ddb(4) and ddb(8), I’m afraid.
>> But they have plenty of information.  Nothing on devmap though.
>>
>
> show devmap and show physmem are arm-specific commands I added a while
> back, but didn't document anywhere except in the builtin help display.
>
> Accessing device registers from ddb is possible because the access is
> all within the kernel (unlike with /dev/[k]mem where the pages have to
> be mapped into user space, which can't be done safely on arm).  But you
> still have to be careful about what other device drivers might be doing
> with the same registers (if there are drivers attached for that
> hardware).
>
> -- Ian
>
>
Thank you everyone. All this is very helpful.

Matias.-