OPENPROM(4) | Device Drivers Manual (sparc) | OPENPROM(4) |
openprom
— Sun
OPENPROM and EEPROM interface
#include
<machine/openpromio.h>
The file /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:
OPIOCGETOPTNODE
OPIOCGETCHILD
OPIOCGETNEXT
.OPIOCGET
OPIOCSET
EINVAL
is returned.OPIOCNEXTPROP
OPIOCGETNEXT
, the next name after the
empty string is the first name./dev/openprom
The following may result in rejection of an operation:
EINVAL
]EBADF
]open
().ENAMETOOLONG
]Due to limitations within the 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 10.99 |