gs_name_64
OpenVMS usage:section_name
type: character-coded text string
access: read only
mechanism: by 32- or 64-bit descriptor-fixed-length string
descriptor
Name of the global section. The gs_name_64 argument is the 32-
or 64-bit virtual address of a naturally aligned 32- or 64-bit
string descriptor pointing to this name string.
ident_64
OpenVMS usage:section_id
type: quadword (unsigned)
access: read only
mechanism: by 32- or 64-bit reference
Identification value specifying the version number of a global
section. The ident_64 argument is a quadword containing three
fields. The ident_64 argument is the 32- or 64-bit virtual
address of a naturally aligned quadword that contains the
identification value.
The first longword specifies the matching criteria in its low-
order 2 bits. The valid values, symbolic names by which they can
be specified, and their meanings are as follows:
Symbolic
Value Name Match Criteria
0 SEC$K_MATALL Match all versions of the section.
1 SEC$K_MATEQU Match only if major and minor
identifications match.
2 SEC$K_MATLEQ Match if the major identifications are
equal and the minor identification of the
mapper is less than or equal to the minor
identification of the global section.
When a section is mapped at creation time, the match control
field is ignored. If you specify the ident_64 argument as 0, the
version number and match control fields default to 0.
The version number is in the second longword. The version number
contains two fields: a minor identification in the low-order 24
bits and a major identification in the high-order 8 bits. You
can assign values for these fields by installation convention to
differentiate versions of global sections. If no version number
is specified when a section is created, processes that specify a
version number when mapping cannot access the global section.
prot
OpenVMS usage:file_protection
type: longword (unsigned)
access: read only
mechanism: by value
Protection to be applied to the global page file section. The
mask contains four 4-bit fields. Bits are read from right to left
in each field.
To view the mask diagram, see the VSI OpenVMS System Services
Reference Manual.
Cleared bits indicate that read, write, execute, and delete
access, in that order, are granted to the particular category
of user. Only read, write, and execute access are meaningful
for section protection. Delete access bits are ignored. Read
access also grants execute access for those situations where
execute access applies. If zero is specified, read access and
write access are granted to all users.
length_64
OpenVMS usage:byte count
type: quadword (unsigned)
access: read only
mechanism: by value
Length, in bytes, of the global page file section to be created.
The length specified must be a multiple of CPU-specific pages. A
length of 0 cannot be specified.
region_id_64
OpenVMS usage:region identifier
type: quadword (unsigned)
access: read only
mechanism: by 32- or 64-bit reference
The region ID associated with the region to map the global page
file section.
The file VADEF.H in SYS$STARLET_C.TLB and the $VADEF macro in
STARLET.MLB define a symbolic name for each of the three default
regions in P0, P1, and P2 space.
The following region IDs are defined:
Symbol Region
VA$C_P0 Program region
VA$C_P1 Control region
VA$C_P2 64-bit program region
Other region IDs, as returned by the $CREATE_REGION_64 service,
can be specified.
section_offset_64
OpenVMS usage:byte offset
type: quadword (unsigned)
access: read only
mechanism: by value
Offset into the global section to start mapping into the
process's virtual address space. The offset specified must be
a multiple of virtual disk blocks.
acmode
OpenVMS usage:access_mode
type: longword (unsigned)
access: read only
mechanism: by value
Access mode that is to be the owner of the pages created during
the mapping. The acmode argument is a longword containing the
access mode.
The $PSLDEF macro in STARLET.MLB and the file PSLDEF.H in
SYS$STARLET_C.TLB define the following symbols and their values
for the four access modes:
Value Symbolic Name Access Mode
0 PSL$C_KERNEL Kernel
1 PSL$C_EXEC Executive
2 PSL$C_SUPER Supervisor
3 PSL$C_USER User
The most privileged access mode used is the access mode of the
caller. The calling process can delete pages only if those pages
are owned by an access mode equal to or less privileged than the
access mode of the calling process.
Address space cannot be created within a region that has a create
mode associated with it that is more privileged than the caller's
mode. The condition value SS$_IVACMODE is returned if the caller
is less privileged than the create mode for the region.
flags
OpenVMS usage:mask_longword
type: longword (unsigned)
access: read only
mechanism: by value
Flag mask specifying the characteristics of the global section
to be created. The flags argument is a longword bit vector in
which each bit corresponds to a flag. The $SECDEF macro and the
SECDEF.H file define a symbolic name for each flag. You construct
the flags argument by performing a logical OR operation on the
symbol names for all desired flags.
The following table describes each flag that is valid for the
$CRMPSC_GPFILE_64 service:
Flag Description
SEC$M_DZRO Pages are demand-zero pages. By default, this flag
is always present in this service and cannot be
disabled.
SEC$M_EXPREG Pages are mapped into the first available space
at the current end of the specified region.
SEC$M_EXPREG cannot be specified with the
SEC$M_NO_OVERMAP flag.
SEC$M_GBL Pages form a global section. By default, this flag
is always present in this service and cannot be
disabled.
SEC$M_NO_ Pages cannot overmap existing address space. By
OVERMAP default, pages can overmap existing address space.
SEC$M_NO_OVERMAP cannot be specified with the
SEC$M_EXPREG flag.
SEC$M_PAGFIL Pages form a global page file section. By default,
this flag is always present in this service and
cannot be disabled.
SEC$M_PERM Global section is permanent. By default, global
sections are temporary.
SEC$M_SYSGBL Pages form a system global section. By default,
pages form a group global section.
SEC$M_WRT Pages form a read/write section. By default, this
flag is always present in this service and cannot
be disabled.
All other bits in the flags argument are reserved for future
use by VSI and should be specified as 0. The condition value
SS$_IVSECFLG is returned if any undefined bits are set or if
an invalid combination of flags is set.
return_va_64
OpenVMS usage:address
type: quadword address
access: write only
mechanism: by 32- or 64-bit reference
The lowest process virtual address into which the global page
file section was mapped. The return_va_64 argument is the 32- or
64-bit virtual address of a naturally aligned quadword into which
the service returns the virtual address.
return_length_64
OpenVMS usage:byte count
type: quadword (unsigned)
access: write only
mechanism: by 32- or 64-bit reference
The 32- or 64-bit virtual address of a naturally aligned quadword
into which the service returns the length of the virtual address
range mapped in bytes.
start_va_64
OpenVMS usage:address
type: quadword address
access: read only
mechanism: by value
The starting virtual address to map the global page file section.
The specified virtual address must be a CPU-specific page aligned
address. If the flag SEC$M_EXPREG is specified, the start_va_64
argument must not be specified or must be specified as 0. If
SEC$M_EXPREG is set and the start_va_64 argument is nonzero, the
condition value SS$_IVSECFLG is returned.
Always refer to the return_va_64 and return_length_64 arguments
to determine the range of virtual addresses mapped.
map_length_64
OpenVMS usage:byte count
type: quadword (unsigned)
access: read only
mechanism: by value
Length of the global page file section to be mapped. The length
specified must be a multiple of CPU-specific pages. If this
argument is not specified or is specified as zero, the global
file section is mapped up to and including the last page in that
section.