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From: "Mark Chambers" <markc@mail.com>
To: "Vijay Padiyar" <vijay_padiyar@hotmail.com>,
	"LinuxPPC Support" <linuxppc-embedded@ozlabs.org>
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Date: Fri, 11 Feb 2005 08:27:47 -0500
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Subject: Re: problem with accessing memory mapped area
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> 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?