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Programming Interface Information:
This page documents intended Programming Interfaces that allow the customer to write programs to obtain the services of z/VM. |
STD
Control Block Contents
STD DSECT
Cross Reference (Contains links to field and bit definitions)
STD Prolog
Name : HCPSTD
Description: Architected version of the ESA/390
segment-table designation.
DSECT : STD
Function : This DSECT maps the ESA/390 segment-table
designation. The format of a segment-table
designation is architected, and described in the
Principles of Operation.
Located by : CR1 is the STD for the primary address space.
CR7 is the STD for the secondary address space.
CR13 is the STD for the home address space.
ASTSTD in an ASTE.
VMDPSTD is the STD for a virtual CPU's current
primary address space.
PFXSXSTD is the STD for the system-execution space.
Created by : HCPASMCR when an address space is created.
HCPSSMCR when the system-execution address space is
created.
HCPFTUSG when the full track cache address space
is created.
HCPBPBRN when an address space is expanded.
HCPRPBSN when an address space is compressed.
Deleted by : HCPASMDS when the address space is destroyed.
STD Control Block Content
STD DSECT
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure STD Architected version of the
ESA/390
ESA/390 mode STD - 4 bytes, 32 bits
0000 0 Signed 4 STDES (0) Entire STD
.... .... STDSWEM X'80000000' Isolate
space-switch-event bit
000STDES STDSTOM X'7FFFF000' Isolate segment-table
origin
000STDES STDPSM X'00000100' Isolate private-space
bit
1... .... STDSAEM X'00000080' Isolate
storage-alteration-event bit.
.111 1111 STDSTLM X'0000007F' Isolate segment-table
length
.1.. .... STDSTUNT 64 Number of bytes in a "segment-
table unit", the number of bytes
in the smallest variation of the
size of a segment table.
.... ...1 STDSTL01 X'01' 2 64-byte blocks (to
address 32M)
..11 1111 STDSTL3F X'3F' 64 64-byte blocks (to
address 1024M).
.1.. .... STDSTL40 X'40' 65 64-byte blocks (to
address 1040M), also, the number
of 64-byte blocks in one 4K page
of segment table entries.
.111 1111 STDSTL7F X'7F' 128 64-byte blocks (to
address 2048M).
.... .11. STDSTUNS 6 Number of bits to shift left in
order to multiply by STDSTUNT.
Also, number of bits to shift to
convert between STE offset and
corresponding STL value.
...1 1... STDSXSTL 20+4 Bits to shift to convert
between an isolated segment index
and the corresponding segment-
table length. Also used to
convert between STL units and
addressable bytes.
...1 .1.1 STDSXDWS STDSXSTL-3 Bits to shift to
convert between an isolated
segment index (or number of
addressable bytes) and
doublewords of segment table
space required.
.... ..11 STDDWSTL 3 Bits to shift to convert
between STL units and segment
table length in doublewords.
.... .11. STDBYSTL 6 Bits to shift to convert
between STL units and segment
table length in bytes.
...1 ..1. STDSXDSP 20-2 Bits to shift right an
isolated segment index to obtain
the displacement into the segment
table of the applicable STE.
0000 0 Bitstring 1 STD0 STD, byte 0
1... .... STDSWE X'80' Space-switch event bit.
When set, space-switch event
program interruptions are
recognized when space switches
occur.
0001 1 Bitstring 1 STD1 STD, byte 1
0002 2 Bitstring 1 STD2 STD, byte 2
.... ..1. STDSSGRP X'02' Subspace-Group bit. When
set, indicates that the address
space specified by the STD is
part of a subspace group.
.... ...1 STDPRIVS X'01' Private-space bit. When
set, prefixing, low-address
protection, and fetch- protection
override to not apply to DAT
references.
0003 3 Bitstring 1 STD3 STD, byte 3
1... .... STDSAE X'80' Storage-alteration-event
bit. When set, storage-alteration
PER events in this address space
are enabled via the
storage-alteration-space control
bit of CR9.
00000004 STDSLEN *-STDES Length in bytes of a STD.
00000001 STDSSIZE (STDSLEN+7)/8 Size in doublewords
of a STD.
The following maps the segment-table designation in the System/370
architecture.
.... .... STD3STLM X'FF000000' Isolate segment-table
length
00FFFFC0 STD3STOM X'00FFFFC0' Isolate segment-table
origin
.... ...1 STD3SWEM X'00000001' Isolate
space-switch-event bit
STD Storage Layout
*** STD - Architected version of the ESA/390
*
* +------+------+------+------+
* 0 |STD0 |STD1 |STD2 |STD3 | 4
* +------+------+------+------+
*
*** STD - Architected version of the ESA/390
STD Cross Reference
Symbol Dspl Value -------------- ---- ----- STDBYSTL 0000 06 STDDWSTL 0000 03 STDES 0000 STDPRIVS 0002 01 STDPSM 0000 000STDES STDSAE 0003 80 STDSAEM 0000 80 STDSLEN 0003 00000004 STDSSGRP 0002 02 STDSSIZE 0003 00000001 STDSTLM 0000 7F STDSTL01 0000 01 STDSTL3F 0000 3F STDSTL40 0000 40 STDSTL7F 0000 7F STDSTOM 0000 000STDES STDSTUNS 0000 06 STDSTUNT 0000 40 STDSWE 0000 80 STDSWEM 0000 00 STDSXDSP 0000 12 STDSXDWS 0000 15 STDSXSTL 0000 18 STD0 0000 STD1 0001 STD2 0002 STD3 0003 STD3STLM 0003 00 STD3STOM 0003 00FFFFC0 STD3SWEM 0003 01
Copyright IBM Corporation, 1990, 2001