Does it have to be a disk? The Walnut has a similar setup to what you are describing and allows you to define a device, /dev/nvram, that functions as a disk-like object (you can open it, seek it, read and write it).
-- David Wright, InfiniSwitch Corp. > -----Original Message----- > From: Mike Moleschi [mailto:moleschi at rmsweldingsystems.com] > Sent: Tuesday, November 12, 2002 1:29 PM > To: linuxppc-embedded at lists.linuxppc.org > Subject: Accessing nvram rom the linux users space > > > > I am using a PPC board running a version of Hard Hat linux, and > currently using version of the 2.4.20 kernel. On the board there > are several places for storage: 32MB of SRAM, 4MB of flash-EPROM, > 32kB of NVRAM, and 16k-bit serial EEPROM. The SRAM, flash and NVRAM > are memory mapped. The NVRAM is actually battery backed up RAM > that includes a RTC in the last 8 bytes of addressed memory. Right > now there is nothing stored in the NVRAM (PPC Boot is stored in > part of the flash, and the PPC environment variable are in the > serial EEPROM.) NVRAM is mapped from 0xF0200000 to 0xF0207FFF. > > I would like to be able to uses the NVRAM from the linux users > space. Ideally it would just be an extention of my filesystem, > where I could place one or two small files on it. This would > let me store information that needs to be kept through a loss of > power. > > So basically I think what I am trying to figure out, is how do I > mount the NVRAM as a disk. > > > > > -- > > > Mike Moleschi > moleschi at rmsweldingsystems.com > RMS Welding Systems > 1409 - 4th Street, Nisku, Alberta CANADA T9E 7M9 > Tel: (780)955-3907 Fax: (780)955-3996 > > ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
