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Programming Interface Information:
This information is NOT
intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only. |
STD
Cross Reference (Contains links to field and bit definitions)
STD Prolog
Name : HCPSTD
Description: Segment-Table Designation
DSECT : STD
Function : This DSECT maps an ESA/370 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 Segment-Table Designation 0000 0 Signed 4 STDES (0) Entire STD .... .... STDSWEM X'80000000' Isolate space-switch-event bit 00FFF000 STDSTOM X'7FFFF000' Isolate segment-table origin 00000100 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 00000040 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, fits in VMDBK VMDLSEG) ..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). 00000006 STDSTUNS 6 Number of bits to shift left in order to multiply by STDSTUNT. 00000018 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. 00000015 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. 00000003 STDDWSTL 3 Bits to shift to convert between STL units and segment table length in doublewords. 00000006 STDBYSTL 6 Bits to shift to convert between STL units and segment table length in bytes. 00000012 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 - Segment-Table Designation * * +------+------+------+------+ * 0 |STD0 |STD1 |STD2 |STD3 | 4 * +------+------+------+------+ * *** STD - Segment-Table Designation
STD Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----STDBYSTL 0000 00000006
STDDWSTL 0000 00000003
STDES 0000
STDPRIVS 0002 01
STDPSM 0000 00000100
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 00FFF000
STDSTUNS 0000 00000006
STDSTUNT 0000 00000040
STDSWE 0000 80
STDSWEM 0000 00
STDSXDSP 0000 00000012
STDSXDWS 0000 00000015
STDSXSTL 0000 00000018
STD0 0000
STD1 0001
STD2 0002
STD3 0003
STD3STLM 0003 00
STD3STOM 0003 00FFFFC0
STD3SWEM 0003 01
Last updated on 3 Aug 1999 at 12:36:48 EDT.
Copyright IBM Corporation, 1990, 1999