| OPENPROM(4) | Device Drivers Manual (sparc) | OPENPROM(4) | 
openprom —
#include <machine/openpromio.h>
/dev/openprom is an interface to the SPARC
  OPENPROM, including the EEPROM area. This interface is highly stylized; ioctls
  are used for all operations. These ioctls refer to “nodes”,
  which are simply “magic” integer values describing data areas.
  Occasionally the number 0 may be used or returned instead, as described below.
  A special distinguished “options” node holds the EEPROM
  settings.
The calls that take and/or return a node use a pointer to an
    int variable for this purpose; others use a pointer
    to an struct opiocdesc descriptor, which contains a
    node and two counted strings. The first string comprises the fields
    op_namelen (an int) and
    op_name (a char *), giving
    the name of a field. The second string comprises the fields
    op_buflen and op_buf, used
    analogously. These two counted strings work in a
    “value-result” fashion. At entry to the ioctl, the counts are
    expected to reflect the buffer size; on return, the counts are updated to
    reflect the buffer contents.
The following ioctls are supported:
OPIOCGETOPTNODEOPIOCGETCHILDOPIOCGETNEXT.OPIOCGETOPIOCSETEINVAL is returned.OPIOCNEXTPROPOPIOCGETNEXT, the next name after the
      empty string is the first name.EINVAL]EBADF]open().ENAMETOOLONG]openprom itself, these
  functions run at elevated priority and may adversely affect system
  performance.
The Sun openprom is what became the Open
    Firmware (IEEE 1275) standard for processor and system independent boot
    firmware.
| June 5, 1993 | NetBSD 10.1 |