User guide

7: Host/ICP Interface
DC 900-1338I 135
in the
snode field. For a read, the node number is generally not specified on request
(
snode is not used), and on completion, the s_node field identifies the node number
from which the data was received.
Note that
inode and i_node are two separate fields in the host request header, as are snode
and s_node.
The number of bytes actually transferred to or from the host is returned in the
s_dlen
field. This value is never greater than the number requested (dlen), but might be less,
depending on the data length requested by the corresponding application program.
7.3 Reserved System Resources: XIO Interface
XIO reserves the following system resources:
For proper operation of XIO, ICP-resident SPS tasks added to the system must not use
conflicting system resources.
7.4 Executive Input/Output
Executive Input/Output (XIO) consists of three functions which are described in the
following sections:
s_initxio, s_nodec and s_xio.
0 = Good completion
1 = The queue to which the host request queue element was posted
is defined for a node number other than the one specified in
the inode field of the host request header
3 = The host request queue element was posted to a host read
request queue but contains a write function code, or was
posted to a host write request queue but contains a read func-
tion code
Queue IDs 1 and 2 (ID 1 = node declaration queue)
Vector numbers 25 and 26 (hexadecimal offsets 64 and 68)
GST entries gs_unused [0] (task entry point)
gs_unused [1] (panic code)