IPARM Back to Index page
 
Prolog 
Control Block Contents 
   IPARM DSECT
   IPAX DSECT
   IPASECD DSECT
   IPAMETS DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This page documents intended Programming Interfaces that
allow the customer to write programs to obtain the services of z/VM.


  IPARM Prolog Top of page
 
 NAME       : HCPIPARM
 DESCRIPTION: IPL parameters
 DSECT      : IPARM
 FUNCTION   : IPARM maps the parameters passed in general
              registers 0 through 15 to CP when it is loaded
              from a module.
 LOCATED BY : In R0-R15 at entry to HCPLODNC and saved at
              HCPLODPM thereafter.
 CREATED BY : HCPSAL, HCPBOU
 DELETED BY : N/A
  ENERAL CONSIDERATIONS
              Only compatible changes should be made to DSECTs in
              HCPIPARM because these data areas are passed from SAPL
              or HCPBOU and they may be at different releases than
              what the running CP is.
 
 
  IPARM Control Block Content Top of page
 

 IPARM DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IPARM IPL parameters 0000 0 Character 32 IPARMS IPL parameters 0020 32 Bitstring 1 * (4) Reserved for Future IBM Use 0024 36 Address 4 IPAEPARM Pointer to extended IPL parm area 0028 40 Bitstring 6 IPADATE Module date/time (YYMMDDHHMMSS) 002E 46 Bitstring 1 IPAINITL Save for SYSINITL field 002F 47 Bitstring 1 IPARFIFL Flag bits (also in HCPIPARX) 1... .... IPACRTST X'80' IPACRTST Certificate store facilty is available 0030 48 Bitstring 1 * (4) reserved for future use Note: This word does not survive a bounce (it contains HCPLOD's base). 0034 52 Signed 4 IPAOFFST Offset to parm disk 0038 56 Character 8 IPANAME Name of CP module 00000040 IPASIZEB (*-IPARM) Size in bytes 00000008 IPASIZED (*-IPARM+7)/8 Size in d-words Function : IPAX maps the extended IPL Parameter area registers 0 through 15 to CP when it is loaded from a module. Located by : Created in HCPSAL's and HCPBOU's work page. - IPAEPARM at entry to HCPLODNC and saved at HCPLODPM thereafter. Created by : HCPSAL, HCPBOU Deleted by : N/A GENERAL CONSIDERATIONS Only compatible changes should be made to DSECTs in HCPIPARM because these data areas are passed from SAPL or HCPBOU and they may be at different releases than what the running CP is.
 IPAX DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IPAX IPL parameters 0000 0 Character 240 IPAXIPRM IPL Parameter buffer 1111 .... IPAXIPRL 240 IPAXIPRL Length of IPL Parameter buffer 00F0 240 Address 4 IPAXPSIB Pointer to PSIBK. Zero if SAPL. 00F4 244 Signed 4 IPAXDEVS IPL Device Subchannel ID. If IPL'ed from FCP, this is FCP Device SubChannel ID 00F8 248 Signed 4 IPAXDEVN (0) IPL Device number 00F8 248 Bitstring 1 * (2) Device number high-order 00FA 250 Bitstring 2 IPAXDEVA IPL Device Number low-order If IPL'ed from FCP, this is FCP Device Number. 00FC 252 Bitstring 8 IPAXWWPN WWPN if IPL'ed from FCP Device 0104 260 Bitstring 8 IPAXLUN LUN if IPL'ed from FCP Device 010C 268 Address 4 IPAXSECD Ptr to first IPASECD (SAPL) 0110 272 Address 4 IPAXSEC2 Ptr to second IPASECD (CPLOAD) 0114 276 Bitstring 2 IPAXVERS IPAX version number 0116 278 Bitstring 2 IPAXLEN IPAX length in bytes 0118 280 Character 32 IPAXRSVD Reserved for IBM use Notes : If IPL from FCP, IPL Parameter PDVOL=<rdev> must b specified and IPL Device (where SAPL is) must = SYSRES device (where module is) and must = PARM DISK device (where config file is). 00000138 IPAXSIZB (*-IPAX) Size in bytes 00000027 IPAXSIZD (*-IPAX+7)/8 Size in d-words Function : IPASECD maps the security data that is needed for a secure IPL of CP and to satisfy a security audit. Located by : Created in HCPSAL's and HCPBOU's work page. - IPAXSECD at entry to HCPLODNC and saved at storage pointed to by HCPSYSIS. Created by : HCPSAL, HCPBOU Deleted by : N/A GENERAL CONSIDERATIONS Only compatible changes should be made to DSECTs in HCPIPARM because these data areas are passed from SAPL or HCPBOU and they may be at different releases than what the running CP is. This DSECT has a version number which can possibly be used to handle changes to the DSECT in the future if care is taken.
 IPASECD DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IPASECD IPL parameters 0000 0 Character 8 IPASEYEC Eye catcher: 'IPASECD ' 0008 8 Bitstring 2 IPASVRSN Version number .... ...1 IPASVERS 1 IPASVERS Current version number 000A 10 Bitstring 2 IPASLENG Length of IPASECD (bytes) 000C 12 Bitstring 1 IPASFLG1 Flag byte 1... .... IPASIPL X'80' IPASIPL This was a secure IPL .1.. .... IPASIGND x'40' IPASIGND Loaded object was signed 000D 13 Bitstring 1 IPASDCF IPL Device Component Flags 1... .... IPASSC X'80' IPASSC Component is signed .1.. .... IPASCSV X'40' IPASCSV Component Signature Verified 000E 14 Bitstring 2 IPASCNDX Matching certificate index 0010 16 Bitstring 4 IPASCEI Component Error Indicators 0014 20 Bitstring 4 * Reserved 0018 24 Character 8 IPASCREA Name of IPASECD block creator (SAPL, HCPBOU, or CPNUC) 0020 32 Character 16 IPASLDTM Date/time of loaded part in printable EBCDIC format (YYMMDDHHMMSS) 0030 48 Bitstring 6 IPASCRVR Version of IPASECD creator 0036 54 Bitstring 6 * Reserved 003C 60 Bitstring 4 IPASTKN Cert store token 0040 64 Character 8 IPASLDED Name of what was loaded (SAPL or cpload module) 0048 72 Signed 8 IPASTODV TOD when verification was done 0050 80 Character 64 IPASCRTNM Name of certificate used for verification 0090 144 Signed 8 IPASCRTVTM Cert validity start (first 8 bytes of STCKE TOD format) 0098 152 Signed 8 IPASCRTXTM Cert validity expiration (first 8 bytes of STCKE TOD format) 00A0 160 Character 16 IPASMSGS (0) Room for 4 message identifiers of MSmmmmnn form from HCPMXRBK to pass to the cpload module to display during initialization 00A0 160 Signed 4 IPASMSG1 First message to display by CP 00A4 164 Signed 4 IPASMSG2 Second message to display 00A8 168 Signed 4 IPASMSG3 Third message to display 00AC 172 Signed 4 IPASMSG4 Fourth message to display 00B0 176 Bitstring 4 IPASRCS (0) Room for four reason codes related to IPASMSGS items. 00B0 176 Bitstring 1 IPASRC1 Reason Code for IPASMSG1 00B1 177 Bitstring 1 IPASRC2 Reason Code for IPASMSG2 00B2 178 Bitstring 1 IPASRC3 Reason Code for IPASMSG3 00B3 179 Bitstring 1 IPASRC4 Reason Code for IPASMSG4 00B4 180 Character 4 IPAS8525RC Reason code for msg 8525 00B8 184 Signed 2 IPASHCDSP Displacement from start of IPASECD to the hash value calculated during IPL 00BA 186 Signed 2 IPASHCLEN Length of calculated hash 00BC 188 Signed 2 IPASHSDSP Displacement from start of IPASECD to the hash value used for signature creation and obtained from the module 00BE 190 Signed 2 IPASHSLEN Length of the hash value used for signature creation 00C0 192 Signed 2 IPASVCHDS Displacement from start of the IPASECD to the VC hash from the VC extract of the certificate used for verification 00C2 194 Signed 2 IPASVCHLN Length of the VC hash from the VC extract of the certificate used for verification 00C4 196 Signed 2 IPASMEDSP Displacement from start of IPASECD to the metadata from the cpload module 00C6 198 Signed 2 IPASMELEN Length of the metadata from the cpload module 00C8 200 Bitstring 1 IPASHSTYP Hash type 00000001 IPASHST1 1 IPASHST1 SHA2-256 hash type code from certificate store architecture Same codes as those defined for IPASHSTYP 00C9 201 Bitstring 1 IPASVCHT VC Hash type 00CA 202 Bitstring 2 * Reserved for IBM use 00CC 204 Signed 2 IPASMETSD Displacement from start of IPASECD to the metadata from the signing server 00CE 206 Signed 2 IPASMETSL Length of the metadata from the signing server 00D0 208 Signed 2 IPASRVXC Remaining verification extract count (for debug purposes if HCPBOS can't get all of the extracts in one diagnose) 00D2 210 Character 50 * Reserved for IBM use Below here are fields whose lengths might not always be the same. Therefore any fields defined below this point should be accessed using their displacement within the IPASECD and length which are available in fixed location fields above. The hash values are all hardcoded as 32 bytes because today the only hash algorithm allowed in the architecture is SHA2-256. 0104 260 Character 32 IPASHSHC HASH used for verification and is calculated during the IPL 0124 292 Character 32 IPASHSHS HASH passed in the module and is the one used to create the signature 0144 324 Character 32 IPASVCHS VC Hash from the VC extract entry of the certificate used for verification 0164 356 Character 512 IPASMETA PLace for the CPSIGN metadata record read in from the cpload module 0364 868 Character 512 IPASGNMET PLace for Signing Server metadata rec read in from the cpload module 00000564 IPASECDB (*-IPASECD) Size in bytes 000000AD IPASECDD (*-IPASECD+7)/8 Size in d-words Function : IPAMETS maps METadata from Signing server Located by : Created by the signing server when the salipl $EXTRACT or cpload hash is signed and passed back with the generated signature. - Pointed to by IPASMETSD field in IPASECD. Created by : Signing server, HCPSAL, HCPBOU. Deleted by : N/A GENERAL CONSIDERATIONS Only compatible changes should be made to DSECTs in HCPIPARM because these data areas are passed from SAPL or HCPBOU and they may be at different releases than what the running CP is. This DSECT has a version number which can possibly be used to handle changes to the DSECT in the future if care is taken.
 IPAMETS DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IPAMETS IPL parameters 0000 0 Character 8 IPAMEYEC Eye catcher: 'IPAMETS ' 0008 8 Character 8 IPAMVRSN Version number CL8'1.1.0.0 ' Current version number 0010 16 Character 8 IPAMLENG Length of IPAMETS (bytes in hex) CL8'0000000 ' Current length 0018 24 Character 10 * Reserved for IBM use 0022 34 Character 6 IPAMZNID Time zone of IPAMSDAT sample data: "GMT " 0028 40 Character 20 IPAMSDAT Signature timestamp sample data: "20xx-12-12 22:49:35 " 003C 60 Character 20 IPAMHALG Hash Algorithm sample data: "SHA2-256 " 0050 80 Character 32 IPAMSALG Signature Algorithm sample data: "ECDSA - NIST Curve P521 " | + .1 .+ .2 .+ .3 .+ .4 0070 112 Character 72 IPAMHASH Module hash sample data: "4A8AA33D 54968872 754AEC57 12E6B722 " "60D32406 D460F20B 21033252 9921D4AE " 00B8 184 Character 4 IPAMSEP1 Field separator sample data: ">>> " 00BC 188 Character 72 IPAMFING Certificate Fingerprint sample data: "4A8AA33D 54968872 754AEC57 12E6B722 " "60D32406 D460F20B 21033252 9921D4AE " 0104 260 Character 4 IPAMSEP2 Field separator sample data: ">>> " 0108 264 Character 220 * Reserved 000001E4 IPAMETSB (*-IPAMETS) Size in bytes 0000003D IPAMETSD (*-IPAMETS+7)/8 Size in d-words
 
 
  IPARM Storage Layout Top of page
 
          
*** IPARM - IPL parameters
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                        IPARMS                         =
*     |                                                       |
*     +---------------------------+---------------------------+
*  20 |///////////////////////////|         IPAEPARM          |
*     +---------------------------+-------------+------+------+
*  28 |                IPADATE                  |:INITL|:RFIFL|
*     +---------------------------+-------------+------+------+
*  30 |///////////////////////////|         IPAOFFST          |
*     +---------------------------+---------------------------+
*  38 |                       IPANAME                         |
*     +-------------------------------------------------------+
*  40
*
*** IPARM - IPL parameters
          
*** IPAX - IPL parameters
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       IPAXIPRM                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  F0 |         IPAXPSIB          |         IPAXDEVS          |
*     +-------------+-------------+---------------------------+
*  F8 |/////////////|  IPAXDEVA   |        IPAXWWPN-          |
*     +-------------+-------------+---------------------------+
* 100 |          -(0FC)           |         IPAXLUN-          |
*     +---------------------------+---------------------------+
* 108 |          -(104)           |         IPAXSECD          |
*     +---------------------------+-------------+-------------+
* 110 |         IPAXSEC2          |  IPAXVERS   |  IPAXLEN    |
*     +---------------------------+-------------+-------------+
* 118 |                                                       |
*     =                       IPAXRSVD                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 138
*
*** IPAX - IPL parameters
          
*** IPASECD - IPL parameters
*
*     +-------------------------------------------------------+
*   0 |                       IPASEYEC                        |
*     +-------------+-------------+------+------+-------------+
*   8 |  IPASVRSN   |  IPASLENG   |:SFLG1|:SDCF |  IPASCNDX   |
*     +-------------+-------------+------+------+-------------+
*  10 |         IPASCEI           |///////////////////////////|
*     +---------------------------+---------------------------+
*  18 |                       IPASCREA                        |
*     +-------------------------------------------------------+
*  20 |                       IPASLDTM                        |
*     |                                                       |
*     +-----------------------------------------+-------------+
*  30 |                IPASCRVR                 |/////////////|
*     +---------------------------+-------------+-------------+
*  38 |///////////////////////////|         IPASTKN           |
*     +---------------------------+---------------------------+
*  40 |                       IPASLDED                        |
*     +-------------------------------------------------------+
*  48 |                       IPASTODV                        |
*     +-------------------------------------------------------+
*  50 |                                                       |
*     =                      IPASCRTNM                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  90 |                      IPASCRTVTM                       |
*     +-------------------------------------------------------+
*  98 |                      IPASCRTXTM                       |
*     +---------------------------+---------------------------+
*  A0 |         IPASMSG1          |         IPASMSG2          |
*     +---------------------------+---------------------------+
*  A8 |         IPASMSG3          |         IPASMSG4          |
*     +------+------+------+------+---------------------------+
*  B0 |:SRC1 |:SRC2 |:SRC3 |:SRC4 |        IPAS8525RC         |
*     +------+------+------+------+-------------+-------------+
*  B8 | IPASHCDSP   | IPASHCLEN   | IPASHSDSP   | IPASHSLEN   |
*     +-------------+-------------+-------------+-------------+
*  C0 | IPASVCHDS   | IPASVCHLN   | IPASMEDSP   | IPASMELEN   |
*     +------+------+-------------+-------------+-------------+
*  C8 |(0C8) |:SVCHT|/////////////| IPASMETSD   | IPASMETSL   |
*     +------+------+-------------+-------------+-------------+
*  D0 |  IPASRVXC   |/////////////////////////////////////////|
*     +-------------+/////////////////////////////////////////|
*  D8 |///////////////////////////////////////////////////////|
*     =///////////////////////////////////////////////////////=
*     |///////////////////////////+---------------------------+
*     |///////////////////////////|                           |
*     +---------------------------+                           |
* 108 |                                                       |
*     =                       IPASHSHC                        =
*     |                           +---------------------------+
*     |                           |                           |
*     +---------------------------+                           |
* 128 |                                                       |
*     =                       IPASHSHS                        =
*     |                           +---------------------------+
*     |                           |                           |
*     +---------------------------+                           |
* 148 |                                                       |
*     =                       IPASVCHS                        =
*     |                           +---------------------------+
*     |                           |                           |
*     +---------------------------+                           |
* 168 |                                                       |
*     =                       IPASMETA                        =
*     |                           +---------------------------+
*     |                           |                           |
*     +---------------------------+                           |
* 368 |                                                       |
*     =                      IPASGNMET                        =
*     |                           +---------------------------+
*     |                           | 564
*     +---------------------------+
*
*** IPASECD - IPL parameters
          
*** IPAMETS - IPL parameters
*
*     +-------------------------------------------------------+
*   0 |                       IPAMEYEC                        |
*     +-------------------------------------------------------+
*   8 |                       IPAMVRSN                        |
*     +-------------------------------------------------------+
*  10 |                       IPAMLENG                        |
*     +-------------------------------------------------------+
*  18 |///////////////////////////////////////////////////////|
*     |/////////////+-----------------------------------------+
*  20 |/////////////|                IPAMZNID                 |
*     +-------------+-----------------------------------------+
*  28 |                                                       |
*     =                       IPAMSDAT                        =
*     |                           +---------------------------+
*  38 |                           |                           |
*     +---------------------------+                           |
*     |                       IPAMHALG                        |
*     |                                                       |
*     +-------------------------------------------------------+
*  50 |                                                       |
*     =                       IPAMSALG                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  70 |                                                       |
*     =                       IPAMHASH                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  B8 |         IPAMSEP1          |                           |
*     +---------------------------+                           |
*  C0 |                                                       |
*     =                       IPAMFING                        =
*     |                           +---------------------------+
* 100 |                           |         IPAMSEP2          |
*     +---------------------------+---------------------------+
* 108 |///////////////////////////////////////////////////////|
*     =///////////////////////////////////////////////////////=
*     |///////////////////////////+---------------------------+
*     |///////////////////////////| 1E4
*     +---------------------------+
*
*** IPAMETS - IPL parameters
 
 
  IPARM Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
IPACRTST       002F 80
IPADATE        0028
IPAEPARM       0024
IPAINITL       002E
IPAMETSB       0108 000001E4
IPAMETSD       0108 0000003D
IPAMEYEC       0000
IPAMFING       00BC
IPAMHALG       003C
IPAMHASH       0070
IPAMLENG       0010
IPAMSALG       0050
IPAMSDAT       0028
IPAMSEP1       00B8
IPAMSEP2       0104
IPAMVRSN       0008
IPAMZNID       0022
IPANAME        0038
IPAOFFST       0034
IPARFIFL       002F
IPARMS         0000
IPASCEI        0010
IPASCNDX       000E
IPASCREA       0018
IPASCRTNM      0050
IPASCRTVTM     0090
IPASCRTXTM     0098
IPASCRVR       0030
IPASCSV        000D 40
IPASDCF        000D
IPASECDB       0364 00000564
IPASECDD       0364 000000AD
IPASEYEC       0000
IPASFLG1       000C
IPASGNMET      0364
IPASHCDSP      00B8
IPASHCLEN      00BA
IPASHSDSP      00BC
IPASHSHC       0104
IPASHSHS       0124
IPASHSLEN      00BE
IPASHSTYP      00C8
IPASHST1       00C8 00000001
IPASIGND       000C 40
IPASIPL        000C 80
IPASIZEB       0038 00000040
IPASIZED       0038 00000008
IPASLDED       0040
IPASLDTM       0020
IPASLENG       000A
IPASMEDSP      00C4
IPASMELEN      00C6
IPASMETA       0164
IPASMETSD      00CC
IPASMETSL      00CE
IPASMSGS       00A0
IPASMSG1       00A0
IPASMSG2       00A4
IPASMSG3       00A8
IPASMSG4       00AC
IPASRCS        00B0
IPASRC1        00B0
IPASRC2        00B1
IPASRC3        00B2
IPASRC4        00B3
IPASRVXC       00D0
IPASSC         000D 80
IPASTKN        003C
IPASTODV       0048
IPASVCHDS      00C0
IPASVCHLN      00C2
IPASVCHS       0144
IPASVCHT       00C9
IPASVERS       0008 01
IPASVRSN       0008
IPAS8525RC     00B4
IPAXDEVA       00FA
IPAXDEVN       00F8
IPAXDEVS       00F4
IPAXIPRL       0000 F0
IPAXIPRM       0000
IPAXLEN        0116
IPAXLUN        0104
IPAXPSIB       00F0
IPAXRSVD       0118
IPAXSECD       010C
IPAXSEC2       0110
IPAXSIZB       0118 00000138
IPAXSIZD       0118 00000027
IPAXVERS       0114
IPAXWWPN       00FC
 
This information is based on z/VM 7.5.0 Last updated on 22 Jun 2026 at 11:13:50 EDT.
Copyright IBM Corporation, 1990, 2026