How to access physical ISA-memory from kernel space

[+BigNose <bignose@xxxxxxxxxx>]

Hello,

I installed a ISA memory card which has 8K memory at the address E0000.
(embedded system)
But how can I access it?

I read in a book that it should work like that:

#define FRAM_ADDRESS 0xE0000
typedef struct
{
  int Data[2048];
} t_FRAM;
static t_FRAM *fram;

In the init of the kernel space module i then do the following:

int temp_var;

  fram= (t_FRAM *) FRAM_ADDRESS;
  temp_var=fram->Data[0];

But when i load the module the kernel traps and outputs the following
error:

Unable to handle kernel paging request at virtual address 000e0000

And the memory region is not occupied by some other device!
BTW it's the same when I try to read other memory regions, e.g. like
the Video Bios (c0000 on my EMBEDDED PC).

So how can I access these memory regions within kernel modules?

Thanks for any answer.

                                 Greetz
                                   Ramon


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                          mailto:bignose@xxxxxxxxxx


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