IBM VERSION 5 SY44-5902-05 - Manual (Page 232)

Table 43. Methods to perform IPL (continued)
Methods Description
F03 Attention: No system shutdown is performed before the IPL. The use of this function can
cause loss of data.
Control panel Function 03 starts a Load IPL. This differs from a POR IPL because no power
off and power on sequence is done. This means a system shutdown is not performed and
not all hardware diagnostics are performed during the IPL. Input-output processors (IOP)
are reset using a software POR equivalent.
Programmed IPL
without parameters This IPL is started by the operating system. A PWRDWNSYS command with RESTART
(*YES) will initiate this IPL.
Remote power on An unattended IPL is started from a remote location (using a modem). Normal mode must
be selected, the system power must be turned off, and the user must set specific indicators
(see the system operation information).
Automatic restart An unattended IPL is started automatically after a power failure. Normal mode must be
selected and the user must set specific indicators (see the system operation information).
Power on by
date/time This IPL is started by an internal clock. Normal mode must be selected and the user must
set specific indicators (see the system operation information).
Alternate installation IPL
To enable an alternate installation IPL, select the dedicated service tool (DST)
option to Work with alternate installation device; see “Work with Dedicated Service
Tools environment” on page 23 or “Work with alternate installation device” on
page 27. This option is available in DST from control panel function 21 or a type D
IPL. For more information about defining and enabling the alternate installation
device, see Software Installation, SC41-5120-06.
IPL sequence
The IPL consists of the following steps:
1.
Service processor’s performing power-on tests and loading the system
processor
2. Licensed Internal Code (system) initialization
3. Installing or starting the operating system program
For information on IPL status SRCs, see “IPL status SRCs” on page 201.
Service processor initialization
Functions performed
The following list is a high-level description of the functions the service processor
performs during an IPL:
1.
The service processor starts by running the hardware diagnostic routines to
verify the service processor’s own hardware.
2. The service processor obtains the necessary code (software) from the load
source (disk or tape) to load itself and control the remainder of the IPL.
3. The service processor runs hardware diagnostic routines on the system
processor.
4. The service processor loads the run-time Licensed Internal Code (system).
What is initialized
The following data areas are initialized by the service processor during an IPL:
v Bus 1 I/O configuration table
218 Service Functions V5R2