OSIBK Back to Index page
 
Prolog 
Control Block Contents 
   OSIBK DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  OSIBK Prolog Top of page
 
 NAME       : HCPOSIBK
 DESCRIPTION: OS Info
 DSECT      : OSIBK
 FUNCTION   : The OSIBK describes the contents of the OS Info data area
              which is a data interface to stand-alone dump. This is a
              singleton data structure.
 LOCATED BY : HCPDMOSI - allocated in nucleus. IPL sets the location.
              PFXOSIAD - in each PFXPG as well as absolute page 0. The
              absolute page 0 location is the one used by
              stand-alone dump to locate the data area.
              For SAPL, located in a page of storage within HCPSAL.
              For DDR, located in a page of storage within HCPDDR.
 CREATED BY : Allocated in CP nucleus and initialized in stages during
              CP initialization. Never changed after IPL. See HCPDMO
              for details of data area initialization.
              For SAPL, the OSIBK is located in a page of storage
              within HCPSAL and initialized early during its
              processing.  In most cases, the OSIBK is overlaid by
              the module being loaded during the end of SAPL's
              processing.  Whether the overlay occurs depends on the
              load origin that was requested.
              For DDR, the OSIBK located in a page of storage within
              HCPDDR and initialized early during its processing if
              DDR is running stand-alone.  It is never changed after
              being initialized.
 DELETED BY : Never deleted.
 REFERENCES : None
 SERIALIZED : CP initialization (uni-processor).
              SAPL and DDR run entirely in uni-processor mode.
 RELOCATION CONSIDERATIONS : None
 COMPATIBILITY AND MIGRATION CONCERNS : - The format and content of the OS Info is determined by
              the level of the stand-alone dump function supported by
              the VM release.
              - The level of the stand-alone dump support is determined
              by the level of VLP distributed with VM.
              - The OSIVERMJ and OSIVERMN fields document the version
              and thus the format and content of the OS Info area.
              OSIVERMJ (version_major) -
              - For incompatible interface changes, for example when
              new mandatory fields are introduced to the OS Info
              structure, the major version will be increased.  When
              the stand-alone dump utility finds an OS info structure
              that has a higher version number, stand-alone dump will
              stop with a disabled wait PSW.  Therefore when a major
              version update is done, VM users have to prepare their
              dump disks with the new version of the stand-alone dump
              utility.
              OSIVERMN (version_minor) -
              - For compatible interface changes, for example when new
              optional fields are introduced to the OS info
              structure, the minor version will be increased.  When
              the stand-alone dump utility finds an OS info structure
              that has a higher version number, stand-alone dump will
              ignore the new optional features and will do everything
              that was defined for its own lower version number.
              - version_minor resets to 1 when version_major increases
 NOTES      : - Must be allocated on a page boundary.
              - Must be 4K in length.
              - Refer to the design document "RAS1211 Support for
              stand-alone kdump" from IBM LTC.  That document defines
              the format and content of OS Info.
 
 
  OSIBK Control Block Content Top of page
 

 OSIBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure OSIBK OS Info Now define the OSIBK. 0000 0 Bitstring 8 OSIMAGIC Magic number for OS Info. Contains ascii string of 'OSINFOSZ' 0008 8 Signed 4 OSICSUM Checksum for OS Info structure calculated for OS Info starting at OSIVERMJ to the end of the page. 000C 12 Signed 2 OSIVERMJ Version_major - see prolog. 000E 14 Signed 2 OSIVERMN Version_minor - see prolog. 0010 16 Address 8 OSICKADD Crashkernel_addr - absolute addr of crashkernel memory which must have megabyte alignment. See HCPDMO for a description of its usage. Limit the requirement for RSMBK reference to HCPDMO. 0018 24 Address 8 OSICKSIZ Crashkernel_size - bytes of crashkernel memory. Size must be a multiple of whole megabytes. Don't reference HCPDMOVC when not part of CP nucleus. 0020 32 Address 8 OSIVCADD Absolute address of vmcoreinfo. 0028 40 Signed 8 OSIVCSIZ Size in bytes of vmcoreinfo. Vmcoreinfo must not have a terminating zero. 0030 48 Signed 4 OSIVCCSM Checksum of vmcoreinfo structure. next 2 fields are not dword aligned by design. 0034 52 Bitstring 8 OSIRBADD Absolute address of Diag x'308' re-IPL block. (unused) 003C 60 Bitstring 8 OSIRBSIZ Size of Diag x'308' re-IPL block. (unused) 0044 68 Signed 4 OSIRBCSM Checksum of Diag x'308' re-IPL block. (unused) HCPOSIBK is 4K in length. 0048 72 Bitstring 1 OSIRESRV (4024) Reserved for IBM use 00000FF4 OSICSUML *-OSIVERMJ Length of area the OSICSUM value is calculated for. 00000200 OSISIZE (*-OSIBK+7)/8 Size in double words 00001000 OSIBSIZE OSISIZE*8 Size in bytes
 
 
  OSIBK Storage Layout Top of page
 
          
*** OSIBK - OS Info
*
*     +-------------------------------------------------------+
*   0 |                       OSIMAGIC                        |
*     +---------------------------+-------------+-------------+
*   8 |         OSICSUM           |  OSIVERMJ   |  OSIVERMN   |
*     +---------------------------+-------------+-------------+
*  10 |                       OSICKADD                        |
*     +-------------------------------------------------------+
*  18 |                       OSICKSIZ                        |
*     +-------------------------------------------------------+
*  20 |                       OSIVCADD                        |
*     +-------------------------------------------------------+
*  28 |                       OSIVCSIZ                        |
*     +---------------------------+---------------------------+
*  30 |         OSIVCCSM          |        OSIRBADD-          |
*     +---------------------------+---------------------------+
*  38 |          -(034)           |        OSIRBSIZ-          |
*     +---------------------------+---------------------------+
*  40 |          -(03C)           |         OSIRBCSM          |
*     +---------------------------+---------------------------+
*  48 |                                                       |
*     =                       OSIRESRV                        =
*     |                                                       |
*     +-------------------------------------------------------+
*1000
*
*** OSIBK - OS Info
 
 
  OSIBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
OSIBSIZE       0048 00001000
OSICKADD       0010
OSICKSIZ       0018
OSICSUM        0008
OSICSUML       0048 00000FF4
OSIMAGIC       0000
OSIRBADD       0034
OSIRBCSM       0044
OSIRBSIZ       003C
OSIRESRV       0048
OSISIZE        0048 00000200
OSIVCADD       0020
OSIVCCSM       0030
OSIVCSIZ       0028
OSIVERMJ       000C
OSIVERMN       000E
 
This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:29:27 EDT.
Copyright IBM Corporation, 1990, 2020