problem with accessing memory mapped area

[Mark Chambers]

> In addition, in the address range 0x30000000-0x300000FF, I have a CPLD
> mapped.
>
> Now, I wish to access the registers of this CPLD. For this, I create a
> module and insert it into the kernel. Now, in my 'init_module' function, I
> map the address range 0x30000000-0x300000FF to cpld_mem:
>
> But when I execute this program on the target, it crashes after displaying
> "Writing to CPLD". Sometimes it says 'Bus error' and some other times I
get
> a 'Kernel panic' message and the system reboots.
>

If you are getting 'bus error' it sounds like the memory controller is not
set
up [correctly] for this address.  Do you know if the bootloader is
configuring
the CPLD chip select correctly?