Updated: 11 December 1998

OpenVMS System Services Reference Manual

On Alpha systems, initializes system process alignment fault reporting.

This service accepts 64-bit addresses.

Format

SYS$INIT_SYS_ALIGN_FAULT_REPORT match_table ,buffer_size ,flags

C Prototype

int sys$init_sys_align_fault_report void *match_table, int buffer_size, unsigned int flags

;)

Arguments

match_table

OpenVMS usage:	address
type:	longword (unsigned)
access:	read
mechanism:	by 32-bit or 64-bit reference

Describes the system fault match table. The match_table argument is the 32-bit or 64-bit virtual address of an array of longwords describing the system fault match table. The first longword is the number of match entries; the remaining longwords are the match entries.

The match table is used to restrict the number of alignment faults reported. Each entry in the table is a bit mask divided into three groups: mode bits, program counter (PC) space bits, and virtual address (VA) space bits.

The following table lists the symbols that can be used to define these bits.

Bit Type	Symbols
Mode bits	AME$M_KERNEL_MODE	Kernel mode
	AME$M_EXEC_MODE	Executive mode
	AME$M_SUPER_MODE	Supervisor mode
	AME$M_USER_MODE	User mode
Program counter bits	AME$M_USER_PC	PC in User space
	AME$M_SYSTEM_PC	PC in System space
Virtual address bits	AME$M_SYSTEM_VA	VA in System space
	AME$M_USER_VA_P0	VA in User P0 space
	AME$M_USER_VA_P1	VA in User P1 space
	AME$M_USER_VA_P2	VA in User P2 space

The following diagram illustrates the data structure of the match table.

When an alignment fault occurs, a fault bit mask is created with one bit set in each group. The alignment fault handler then compares this fault bit mask against each entry in the match table. If the fault bit mask is a subset of an entry in the match table, the fault is reported.

buffer_size

flags

If the flags argument is 0, data items of size AFR$K_VMS_LENGTH will be returned. If the flags argument is AFR$M_USER_INFO, the user name and image name are added to each data item and they are returned in a buffer of length AFR$K_EXTENDED_LENGTH. If the user name and image name are not available, an empty string is returned in the data item.

Description

The Initialize System Alignment Fault Reporting service initializes system alignment fault reporting.

System alignment faults must be written to a buffer. The following diagram illustrates the format in which system alignment fault data is saved in the buffer.

Only one user on a system can initialize system alignment fault reporting at any time. Subsequent calls will return SS$_AFR_ENABLED.

System alignment fault reporting is disabled when the program that called the service completes.

Required Access or Privileges

CMKRNL privilege is required.

Required Quota

None

Related Services

$GET_ALIGN_FAULT_DATA, $GET_SYS_ALIGN_FAULT_DATA, $PERM_DIS_ALIGN_FAULT_REPORT, $PERM_REPORT_ALIGN_FAULT, $START_ALIGN_FAULT_REPORT, $STOP_ALIGN_FAULT_REPORT, $STOP_SYS_ALIGN_FAULT_REPORT

Condition Values Returned

SS$_NORMAL	The service completed successfully.
SS$_ACCVIO	The match table is not read accessible.
SS$_AFR_ENABLED	The service was already called.
SS$_BADPARAM	The buffer_size argument is less than the minimum size required. If the flags argument is 0, AFR$K_VMS_LENGTH + 32 is required. If the flags argument is 1, AFR$K_EXTENDED_LENGTH + 32 is required.
SS$_NOPRIV	The caller does not have CMKRNL privilege.

Formats a disk or magnetic tape volume and writes a label on the volume. At the end of initialization, the disk is empty except for the system files containing the structure information. All former contents of the volume are lost.

Format

SYS$INIT_VOL devnam, volnam [,itmlst]

C Prototype

int sys$init_vol (void *devnam, void *volnam, void *itmlst);

Arguments

devnam

OpenVMS usage:	char_string
type:	character string
access:	read only
mechanism:	by descriptor

Name of the device on which the volume is physically mounted. The descriptor must point to the device name, a character string of 1 to 64 characters. The device name can be a physical device name or a logical name; if it is a logical name, it must translate to a physical name.

The device does not have to be currently allocated; however, allocating the device before initializing it is recommended.

volnam

OpenVMS usage:	char_string
type:	character string
access:	read only
mechanism:	by descriptor

Identification to be encoded on the volume. The descriptor must point to the volume name, a character string of 1 to 12 characters. For a disk volume name, you can specify a maximum of 12 ANSI characters; for a magnetic tape volume name, you can specify a maximum of 6 ANSI "a" characters. Any valid ANSI "a" characters can be used; these include numbers, uppercase letters, and any one of the following nonalphanumeric characters:

! " % ' ( ) * + , - . / : ; < = >

Compaq strongly recommends that a disk volume name consist of only alphanumeric characters, dollar signs ($), underscores (_), and hyphens (-).

itmlst

OpenVMS usage:	item_list_3
type:	longword (unsigned)
access:	read only
mechanism:	by reference

Item list specifying options that can be used when initializing the volume. The itmlst argument is the address of a list of item descriptors, each of which describes one option. The list of item descriptors is terminated by a longword of 0.

The following diagram depicts the format of a single item descriptor.

The following table defines the item descriptor fields.

Descriptor Field	Definition
Buffer length	A word specifying the length (in bytes) of the buffer that supplies the information $INIT_VOL needs to process the specific item code. The length of the buffer needed depends on the item code specified in the item descriptor.
Item code	A word containing an option for the initialize operation. These codes are defined by the $INITDEF macro. There are three types of item codes:
	Boolean item code Boolean item codes specify a true or false value. The form INIT$_ code specifies a true value and the form INIT$_NO_ code specifies a false value. For Boolean item codes, the buffer length and buffer address fields of the item descriptor must be 0. Symbolic value item code Symbolic value item codes specify one of a specified range of possible choices. The buffer length and buffer address fields of the item descriptor must be 0. Input value item code Input value item codes specify a value to be used by $INIT_VOL. The buffer length and buffer address fields of the item descriptor must be nonzero.
Buffer address	A longword containing the address of the buffer that supplies information to $INIT_VOL.
Return length address	This field is not used.

Item Codes

INIT$_ACCESSED

An input item code that specifies the number of directories allowed in system space on the volume.

You must specify an integer between 0 and 255 in the input buffer. The default value is 3.

The INIT$_ACCESSED item code applies only to Files-11 On-Disk Structure Level 1 disks.

INIT$_BADBLOCKS_LBN

An input item code that enables $INIT_VOL to mark bad blocks on the volume; no data is written to those faulty areas. INIT$_BADBLOCKS_LBN specifies faulty areas on the volume by logical block number and block count.

The buffer from which $INIT_VOL reads the option information contains an array of quadwords containing information in the following format.

The following table describes the information to be specified for INIT$_BADBLOCKS_LBN.

Field	Symbol Name	Description
Logical block number	INIT$L_BADBLOCKS_LBN	Specifies the logical block number of the first block to be marked as allocated.
Count	INIT$L_BADBLOCKS_COUNT	Specifies the number of blocks to be allocated. This range begins with the first block, as specified in INIT$L_BADBLOCKS_LBN.

For example, if the input buffer contains the values 5 and 3, INIT_VOL starts at logical block number 5 and allocates 3 blocks.

The number of entries in the buffer is determined by the buffer length field in the item descriptor.

All media supplied by Compaq and supported on the operating system, except disks and TU58 cartridges, are factory formatted and contain bad block data. The Bad Block Locator utility (BAD) or the diagnostic formatter EVRAC can be used to refresh the bad block data or to construct it for the disks and TU58 cartridges. The INIT$_BADBLOCKS_LBN item code is necessary only to enter bad blocks that are not identified in the volume's bad block data. For more information, see the OpenVMS Bad Block Locator Utility Manual.

The INIT$_BADBLOCKS_LBN item code applies only to disks.

INIT$_BADBLOCKS_SEC

The input buffer must contain an array of octawords containing information in the following format.

The following table describes the information to be specified for INIT$_BADBLOCKS_SEC.

Field	Symbol Name	Description
Sector	INIT$L_BADBLOCKS_SECTOR	Specifies the sector number of the first block to be marked as allocated.
Count	INIT$L_BADBLOCKS_COUNT	Specifies the number of blocks to be allocated.
Track	INIT$L_BADBLOCKS_TRACK	Specifies the track number of the first block to be marked as allocated.
Cylinder	INIT$L_BADBLOCKS_CYLINDER	Specifies the cylinder number of the first block to be marked as allocated.

For example, if the input buffer contains the values 12, 3, 1, and 2, INIT_VOL starts at sector 12, track 1, cylinder 2, and allocates 3 blocks.

The number of entries in the buffer is determined by the buffer length field in the item descriptor.

All media supplied by Compaq and supported on the operating system, except disks and TU58 cartridges, are factory formatted and contain bad block data. The Bad Block Locator utility (BAD) or the diagnostic formatter EVRAC can be used to refresh the bad block data or to construct it for the disks and TU58 cartridges. The INIT$_BADBLOCKS_SEC item code is necessary only to enter bad blocks that are not identified in the volume's bad block data. For more information, see the OpenVMS Bad Block Locator Utility Manual.

The INIT$_BADBLOCKS_SEC item code applies only to disks.

INIT$_CLUSTERSIZE

volume size in blocks/(255 * 4096)

The INIT$_CLUSTERSIZE item code applies only to Files-11 On-Disk Structure Level 2 disks (for Files-11 On-Disk Structure Level 1 disks, the cluster size is 1). For Files-11 On-Disk Structure Level 2 disks, the cluster size default depends on the disk capacity.

• Disks that are 50,000 blocks or larger have a default cluster size of 3.
• Disks smaller than 50,000 blocks have a default value of 1.

INIT$_COMPACTION

INIT$_NO_COMPACTION---Default

The INIT$_COMPACTION item code applies only to TA90 drives.

INIT$_DENSITY

For magnetic tape volumes, the INIT$_DENSITY item code specifies the density in bytes per inch (bpi) at which the magnetic tape is written. Possible symbolic values for tapes are as follows:

• INIT$K_DENSITY_800_BPI
• INIT$K_DENSITY_1600_BPI
• INIT$K_DENSITY_6250_BPI

The specified density value must be supported by the drive. If you do not specify a density item code for a blank magnetic tape, the system uses a default density of the highest value allowed by the tape drive. If the drive allows 6250, 1600, and 800 bpi operation, the default density is 6250. If the drive allows only 1600 and 800 bpi operation, the default density is 1600. If you do not specify a density item code for a magnetic tape that has been previously written, the system uses the previously set volume density.

For diskettes, the INIT$_DENSITY item code specifies how the diskette is to be formatted. Possible symbolic values for diskettes are as follows:

• INIT$K_DENSITY_SINGLE_DISK
• INIT$K_DENSITY_DOUBLE_DISK
• INIT$K_DENSITY_DD_DISK
• INIT$K_DENSITY_HD_DISK

For disk volumes that are to be initialized on RX02, RX23, or RX33 diskette drives, the following values specify how the disk is to be formatted:

• INIT$K_DENSITY_SINGLE_DISK
• INIT$K_DENSITY_DOUBLE_DISK
• INIT$K_DENSITY_DD_DISK
• INIT$K_DENSITY_HD_DISK

Diskettes are initialized as follows:

• RX23 diskettes---DD or HD density
• RX33 diskettes---double density only
• RX02 dual-density diskette drives---single or double density

If you do not specify a density item code for a disk, the system leaves the volume at the density at which it was last formatted. RX02 disks purchased from Compaq are formatted in single density.

INIT$_DIRECTORIES

The INIT$_DIRECTORIES item code applies only to disks.

INIT$_ERASE

INIT$_NO_ERASE---Default

• ODS--2 disk volumes
• ANSI magnetic tape volumes on magnetic tape devices that support the hardware erase function, for example, TU78 and MSCP magnetic tapes

For disk devices, this item code sets the ERASE volume attribute, causing each file on the volume to be erased when it is deleted.

INIT$_EXTENSION

The default extension set by this item code is used only if the following conditions are in effect:

• No default extension for the file has been set.
• No default extension for the process has been set using the SET RMS command.

INIT$_FPROT

The INIT$_FPROT item code applies only to Files-11 On-Disk Structure Level 1 disks and is ignored if it is used on an OpenVMS system. OpenVMS systems use the default file extension set by the DCL command SET PROTECTION/DEFAULT.

INIT$_HEADERS

The INIT$_HEADERS item code applies only to disks.

INIT$_HIGHWATER---Default

INIT$_NO_HIGHWATER

INIT$_NO_HIGHWATER disables FHM for a volume.

The INIT$_HIGHWATER and INIT$_NO_HIGHWATER item codes apply only to Files-11 On-Disk Structure Level 2 disks.

INIT$_HOMEBLOCKS

• INIT$K_HOMEBLOCKS_GEOMETRY
  Causes the homeblocks to be placed at separate locations on disk, to protect against failure of a disk block. Placement depends on the reported geometry of the disk.
• INIT$K_HOMEBLOCKS_FIXED
  Causes the homeblocks to be placed at separate fixed locations on the disk; this is the default. Placement is independent of the reported geometry of the disk. This caters for disks that report different geometries according to the type of controller to which they are attached.
• INIT$K_HOMEBLOCKS_CONTIGUOUS
  Causes the homeblocks to be placed contiguously at the start of the disk. This allows container file systems to maximize the amount of contiguous space on the disk, when used with the INIT$_INDEX_BEGINNING item code.

INIT$_INDEX_BEGINNING

When issuing calls to $INIT_VOL, using this item code in conjunction with INIT$_INDEX_BLOCK results in an error. If you specify both item codes from DCL, INIT$_INDEX_BLOCK takes precedence.

This item code applies only to disks.

INIT$_INDEX_BLOCK

When issuing calls to $INIT_VOL, using this item code with INIT$_INDEX_BEGINNING, INIT$_INDEX_MIDDLE, or INIT$_INDEX_END results in an error. From DCL, if you specify INIT$_INDEX_BLOCK with INIT$_INDEX_BEGINNING, INIT$_INDEX_MIDDLE, or INIT$_INDEX_END, then INIT$_INDEX_BLOCK takes precedence.

The INIT$_INDEX_BLOCK item code applies only to disks.

INIT$_INDEX_END

When issuing calls to $INIT_VOL, using this item code with INIT$_INDEX_BLOCK results in an error. If you specify both item codes from DCL, INIT$_INDEX_BLOCK takes precedence.

This item code applies only to disks.

INIT$_INDEX_MIDDLE

When issuing calls to $INIT_VOL, using this item code with INIT$_INDEX_BLOCK results in an error. If you specify both item codes from DCL, INIT$_INDEX_BLOCK takes precedence.

This item code applies only to disks.

INIT$_INTERCHANGE

For more information about the INIT$_INTERCHANGE item code and about magnetic tape labeling and tape interchange, see the OpenVMS System Manager's Manual: Essentials.

INIT$_LABEL_ACCESS

! " % ' ( ) * + , - . / : ; < = >

By default, the operating system provides a routine SYS$MTACCESS that checks this field in the following manner:

• If the magnetic tape was created on a version of the operating system that conforms to Version 3 of ANSI, this item code is used to override any character except an ASCII space.
• If the magnetic tape conforms to an ANSI standard that is later than Version 3, this item code is used to override any character except an ASCII 1 character.

INIT$_LABEL_VOLO

INIT$_MAXFILES

volume size in blocks/cluster factor + 1

Once initialized, the maximum number of files can be increased only by reinitializing the volume.

The default maximum number of files is calculated as follows:

volume size in blocks/(cluster factor + 1) * 2

The INIT$_MAXFILES item code applies only to disks.

INIT$_OVR_ACCESS

INIT$_NO_OVR_ACCESS---Default

To specify INIT$_OVR_ACCESS, the caller must either own the volume or have VOLPRO privilege.

INIT$_OVR_EXP

INIT$_NO_OVR_EXP---Default

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