055

Explanation
The initial program load (IPL) program was unable
to locate a necessary member in the SYS1.NUCLEUS data set.
The
right-most four bytes of the program status word (PSW) have the following
format: xrr00www
 where: x
Irrelevant information.
rr
A hexadecimal reason code indicating the reason for the failure.
www
The wait state code.

 The reason code (rr) is one of the
following: 01
IPL could not find a DAT-off nucleus module. (DAT is the acronym
for dynamic address translation.)
02
IPL could not find a DAT-on nucleus module.
04
IPL could not find one or more required module list tables (MLT)
in SYS1.NUCLEUS.
05
IPL could not find a module required for IPL processing. This
reason code indicates that MVS™ is
not properly installed.
06
IPL could not find a DAT-on nucleus module.

System action
For reason codes X'01' through X'04',
IPL writes one or more IEA086W messages in the IPL WTO buffer. The
system enters a non-restartable wait state.
For reason code X'06',
IPL writes one or more IEA086W messages in the IPL WTO buffer. The
system enters a restartable wait state.

Operator response
For reason code X'01', if you selected
an alternate I/O configuration ensure that you correctly entered the
alternate I/O configuration identifier (xx) through
the console frame or at storage location 9-10.  ReIPL the system.
 If the error persists, notify the system programmer.
For reason
codes X'02' and X'06', make sure that the load parameter
fifth and sixth digits are correct.
For reason code X'01', X'02', X'04',
and X'06', do the following to find the WTO buffer and locate
message IEA086W in the buffer: Using the hardware Alter/Display facility, read the real address
in central storage at X'14'. This address points to the IPL
diagnostic area.  
Add X'28' to the address in X'14', and also
read this as a real address in central storage. The result is the
31-bit virtual address of the IPL vector table (IVT). Henceforth,
all addresses are 31-bit virtual and you must switch to displaying
Primary Virtual Storage to display remaining storage locations.
Add X'E0' to the IVT address. The result is the 31-bit
address of the IVTMQHP field. IVTMQHP contains the address of the
message queue header (MQH).
MQH+X'0' contains the address of the oldest message queue
element (MQE) available.  The message text for the oldest MQE begins
at MQE+X'08'.
Use MQE+X'0' of the oldest MQE to find the MQE of the
next oldest message.  Again, the message text for this MQE begins
at MQE+ X'08'.
Repeat this sequence (using MQE+X'0' of the current MQE
to locate the next MQE), until the message text for the appropriate
message is displayed.

 For all reason codes, notify the system programmer. For reason
codes X'01' through X'04' and X'06', provide
the text of message IEA086W. If the system programmer requests it,
obtain a stand-alone dump.

System programmer response
For reason codes X'01' through X'04' and X'06',
get the text of message IEA086W from the IPL WTO buffer and translate
it from hexadecimal into EBCDIC. The translated message text will
show which module or member was not found in SYS1.NUCLEUS: If memname is IEANUC0x, IEANUC1x, or IEANUC2x,
make sure that x is the correct identifier for the nucleus you need.
Specifically, if memname is IEANUC1x or IEANUC2x,
make sure both that x refers to the correct IEANUC0x and that the
corresponding IEANUC1x or IEANUC2x exists. For example, if x is 5
(you are defining an alternate nucleus named IEANUC05), you also need
to create the corresponding IEANUC15 and IEANUC25 members. If x
is incorrect, ask the operator to reIPL the system and specify the
correct identifier for the nucleus on the SYSCTL frame load parameter.

 If memname is a member name other than IEANUC0x, IEANUC1x, and
IEANUC2x, reason code X'04' identifies the module as an MLT,
and reason code X'02' or X'06' indicates either
a nucleus device support module, a  nucleus extension module, or a
module specified on an INCLUDE statement in a NUCLSTxx member (identified
on the NUCLST statement in  the LOADxx member).                  

  If the member is a module specified on an INCLUDE statement,
verify that the module was specified correctly.
 If the member
is an MLT or a nucleus device support module, find the MLT name and
the corresponding user information module (UIM) name in the MVS device report from HCD. If the
UIM was installation-provided: Verify that the UIM logic is correct and that the UIM provided
the correct MLT name.
Make sure the SYS1.NUCLEUS directory contains a directory entry
for the MLT.

 If the UIM was not installation-provided, determine which product
contains the member and why the member was not installed in SYS1.NUCLEUS.

If the reason code is X'05' or if you cannot
solve the problem, search problem reporting databases for a fix for
the problem. If no fix exists, contact the IBM® Support Center. Provide the text of accompanying
message IEA086W if issued.

Source
Initial program load (IPL)