linux-mips
[Top] [All Lists]

Accessing DDR DCR registers in init_mem - PMC RM9000

To: linux-mips@linux-mips.org
Subject: Accessing DDR DCR registers in init_mem - PMC RM9000
From: Sean Parker <seaneparker@yahoo.com>
Date: Mon, 14 Jul 2008 06:23:49 -0700 (PDT)
Cc: supinlick@yahoo.com
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Received:X-Mailer:Date:From:Reply-To:Subject:To:Cc:MIME-Version:Content-Type:Message-ID; b=6dwEJ38aAislPWoGGRQBJixW5o3QZwHmTEF6sx8EkTEPhqeE/MbCdon/et+G8KbDNJcFXiCvT/3IjLS6Ar5rUPfLc/iQoEZuJv5X3+d6+y0EvxdjqmVeodcELLcqgrNCT6F1QK37iUPV49zV4YDYxzStzGtFLqWQai5QrOd4LHM=;
Original-recipient: rfc822;linux-mips@linux-mips.org
Reply-to: seaneparker@yahoo.com
Sender: linux-mips-bounce@linux-mips.org
Hello - 

  We're trying to determine dynamically the DDR DCR register values from within 
setup.c, init_mem(), so that we can remove the hard-coded 256MB RAM size (and 
not rely on cmd-line args) From documentation I've read (not evry clear for a 
MIPS newbie) it appears I need to setup a TLB entry to access phys mem above 
0x80000000. (PMON already sets up a range for Compact Flash)

  I setup a TLB entry for that region ( 0xFF080000, making 3 total entries 
setup in PMON) but I still get an exception in setup.c when I try to read the 
DCR reg.

  Is it as simple as setting up a TLB entry? I can't find examples for how to 
access registeres in various segments of physical memory (in kernel mode) does 
anyone know of a good resource for that kind of stuff?

  Any suggestions?

  Thanks
    Sean



      

<Prev in Thread] Current Thread [Next in Thread>