hexdumping /dev/mem

[Matías Perret Cantoni]

Hello!

I'm trying to read a 32 bit register of the System Level Control
Registers of the ZedBoard (Zynq-7000 SoC) from a running FreeBSD. I
thought that I could simply do it with hexdump(1) to avoid writing a
driver since I only need to read it once. I've tried:


#hexdump -s 0xF8000910 -n 4 /dev/mem


and I get this message:

hexdump: /dev/mem: Invalid argument


Reading some archives in this mailing list I've found that "the arm
version of /dev/mem is not functionally equivalent to that of amd64 or
i386.  Arm disallows access to non-DRAM addresses through /dev/mem".

Is there any other way of doing this? Maybe the whole idea of using
hexdump for this isn't really good.



Thanks in advance.
Regards,
Matias.