Re: Memory access

Arnaldo Carvalho de Melo (acme@conectiva.com.br)
Tue, 3 Jul 2001 11:51:18 -0300


Em Tue, Jul 03, 2001 at 04:45:32PM +0200, Guillaume Lancelin escreveu:
> Writing a device driver for a IO card, I have the following message from
> the kernel:
> Unable to handle kernel paging request at virtual address 000d0804.
> [then it gives the register values]
> Segmentation fault."
>
> This address (0xd0804) is the location of a "mailbox" reserved by the IO
> card, and from which commands are passed to the card.
>
> My question: is the kernel using or protecting this area of the memory,
> and is there a way to deprotect it??? (how dangerous!)

are you accessing it directly? read Documentation/IO-mapping.txt

- Arnaldo
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