User`s manual

siop_init()

SBCSCSI/D1 3-5

NOTES

❏ The Firmware needs to be initialized only once but may be initialized

many times as long as there are no outstanding command requests to the

Firmware when siop_init() is called. If a user calls the initialization

routine while commands are outstanding to the Firmware, then

unpredictable results will occur. However, a user may call this module

any number of times before calling the command entry module to

reinitialize the firmware.

❏ The siop data area (siopdata), pointed to by siopdatap, is for use by the

Firmware only and cannot be modified at any time by the caller.The value

of siopdatap passed to siop_init() establishes the value of siopdatap

passed on all subsequent calls to the SIOP other than siop_init(). Only

subsequent calls to siop_init() where a new value of siopdatap is passed

can change the current value. Successive calls to siop_init() with the same

siopdatap has no effect on the current value of siopdatap. The user is

responsible for clearing the siopdata area before calling siop_init() and

must ensure that the siopdata area is cache coherent.

❏ If initialization is called after a call to the command entry point

(siop_cmd()), then all synchronous data transfer information and tagged

command queuing information will be lost. Also refer to the section in

Chapter 5 on Use of the Firmware After Use by the SBC ROM Debugger for

more information.

❏ The user may change the SIOP interrupt level and SIOP SCSI address after

initialization through a CONFIG command to siop_cmd().

❏ The siop data area, pointed to by siopdatap, is for use by the firmware

only and cannot be modified at any time by the caller.

❏ The size of the siop data area pointed to by siopdatap must be of at least

sizeof(struct siopdata) bytes, and must be aligned to a four-byte

boundary.

❏ When using the Firmware Debug Log, the user must call the debug trace

initialization routine sdt_tinit() prior to initializing the firmware.