NAME

nvram − general non-volatile RAM driver for SYSTEM V

DESCRIPTION

The nvram driver provides an interface from SYSTEM V to the non-volatile RAM device and to character devices. 

The non-volatile RAM is a collection of eight slices.  Each slice is associated with a minor device number and a size.  The nvram slice sizes are static and cannot be changed by the user.  The following tables show the 2 KB and 8 KB slice configurations for nvram. 

Superuser privileges are required to write nvram slices having a minor device number greater than 0.  Read access on slices 1 through 7 (inclusive) and read/write access on slice 0 are defined by the file permissions on the associated device file. 

NVRAM BASE ADDRESS

MVME187 - 0xfffc0000
MVME167 - 0xfffc0000
MVME188 - 0xfff80000
MVME197 - 0xfffc0000

ERRORS

If failure occurs, the NVRAM driver generates the following error messages:

ENXIO invalid device minor number

EPERM invalid access permission

EFAULT data transfer failed or an illegal accesss to memory occurred

EINVAL boundary violation

FILES

/dev/nvr/bug
/dev/nvr/config
/dev/nvr/net
/dev/nvr/nvr
/dev/nvr/os
/dev/nvr/user

SEE ALSO

close(2), lseek(2), open(2), read(2), and write(2)