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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.
HCPFMUSG when the full track cache address space
is created.
HCPHDTMA when an address space is expanded.
HCPHDTNL 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' STDSWEM Isolate
space-switch-event bit
000STDES STDSTOM X'7FFFF000' STDSTOM Isolate
segment-table origin
000STDES STDPSM X'00000100' STDPSM Isolate
private-space bit
1... .... STDSAEM X'00000080' STDSAEM Isolate
storage-alteration-event bit.
.111 1111 STDSTLM X'0000007F' STDSTLM Isolate
segment-table length
.1.. .... STDSTUNT 64 STDSTUNT 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' STDSTL01 2 64-byte blocks
(to address 32M)
..11 1111 STDSTL3F X'3F' STDSTL3F 64 64-byte blocks
(to address 1024M).
.1.. .... STDSTL40 X'40' STDSTL40 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' STDSTL7F 128 64-byte blocks
(to address 2048M).
.... .11. STDSTUNS 6 STDSTUNS 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 STDSXSTL 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 STDSXDWS 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 STDDWSTL Bits to shift to
convert between STL units and
segment table length in
doublewords.
.... .11. STDBYSTL 6 STDBYSTL Bits to shift to
convert between STL units and
segment table length in bytes.
...1 ..1. STDSXDSP 20-2 STDSXDSP 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' STDSWE 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' STDSSGRP Subspace-Group
bit. When set, indicates that the
address space specified by the
STD is part of a subspace group.
.... ...1 STDPRIVS X'01' STDPRIVS 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' STDSAE
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, 2007