Re: [Xenomai-help] Read TSC results in bus error (ARM iMX25)

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Henri Roosen wrote:
> Hi,
> 
> I'm trying to bringup Xenomai 2.4.9.1 on a freescale iMX25 board and
> linux kernel 2.6.28. Until now all was straightforward by following
> the ArmPorting page on the Xenomai website and because the iMX25 is
> very similar to the already supported iMX3. The kernel boots and the
> xenomai timer is running.
> 
> However the testsuite apps (latency) are not working because the
> rt_timer_tsc() call results in a Bus error: 'Unhandled fault: external
> abort on non-linefetch (0x008) at 0x4001f024)'.
> 
> I verified at the xeno_arm_features_check() call the physical address
> of the GPT1 counter register is correct (0x53f90024 which matches the
> datasheet). The mmap call succeeds and the virtual address is at
> 0x4001f024. However, when de-referencing that pointer in the
> __xn_rdtsc() call the bus error occurs.
> 
> Anyone have an idea what I am missing?

Ok. I have already heard about that, and have not yet had time to
investigate it. However, I have seen in the kernel configuration which
restricts the access to /dev/mem, would you have such an option enabled?

Could you send me your .config ?

-- 
                                          Gilles