Create an image for a partitioned medium, such as a hard drive, SD card, or MMC


diskimage -c configfile -o imgfile 
         [-b bootstrapfile] 
         [-m] [-M] 
         [-p] [-s number] [-v]

Runs on:

Windows, Linux


-b bootstrapfile
Use the specified bootstrap file to write to the master boot record (MBR).
-c configfile
Use the specified configuration file.
Display a help message showing diskimage usage information.
Don't modify Power-Safe (fs-qnx6.so) filesystems. The default is to patch all bootable Power-Safe filesystem partitions.
Modify all Power-Safe filesystems, including non-bootable partitions.
-o imgfile
Write to the specified image file.
Don't pad the image to the full disk size.
-s number
Read and write up to the specified number of bytes at a time. The default size is 4096.
Increase the verbosity.


The diskimage utility creates an image for a partitioned medium. The partitioned medium image can contain any number of filesystem images. For example, Power-Safe filesystems that were created using mkqnx6fsimg or mkqnx6fs. After an image is successfully created, it can be copied to a hard drive, SD, or MMC. Options are available to adjust Power-Safe filesystems in the image so that they are bootable. With this command, you can also specify the IPL file to write into the master boot record (MBR).

You must use a configuration file to specify the disk image content and layout. The configuration file consists of a description for the disk and any number of optional descriptions about the partitions. There are three types of partitions you can use: primary, extended, and logical. The following constraints apply when you use diskimage:
  • The disk can have up to four primary partitions or up to three primary and one extended partition. That extended partition can be used as a container for any number of logical partitions.
  • Any logical partitions on the disk require the existence of an extended partition. When logical partitions are used, you're not required to explicitly specify the extended partition. Regardless of whether you do this, there can be only three primary partitions if you define logical partitions. If no extended partition is defined but logical partitions are defined, an extended partition is automatically created. You can't specify more than one extended partition in the configuration file.
  • The extended partition must be explicitly defined when a specific partition index must be assigned to it or the required space exceeds the defined logical partitions. For information about calculating the size of the extended partition, see "Using extended and logical partitions".
  • The combined size of all logical partitions (including any overhead) should be equal to and must not exceed the size of the extended partition.
  • Filesystem images are copied to the disk image in blocks of up to 4096 bytes. You can override this default setting using the -s option.

Overview of configuration file syntax

The configuration file uses a specific structure, syntax, and grammar. For an explanation of the configuration structure (or contents), see "Configuration file structure". For a full description of the grammar, see "Summary of configuration file syntax". The configuration file can have these special characters:
  • Whitespaces used in double quotes ("") of a string literal are interpreted as part of that string. Whitespaces aren't allowed within numeric literals (including the suffix).
  • Line breaks and spaces can occur anywhere, except in literals or tokens.
  • A line feed (LF) character indicates the end of a line. Carriage return characters (CR) are silently ignored and aren't interpreted as the end of line.
  • A hash (#) character indicates the beginning of a comment. Comments can begin anywhere and always extend to the end of the line.
  • Numeric values can be specified as decimal, octal, or hexadecimal. Optionally, numeric values can use these suffix values to indicate a factor:
    • k or K to represent kilo (1024)
    • m or M to represent mega (10242)
    • g or G to represent giga (10243)

Configuration file structure

The configuration file structure has two parts:
  • disk configuration― (Required) A description of disk-wide parameters.
  • partition definitions― (Optional) Any number of partition descriptions. The partition descriptions specify the partitions to create, as well as the contents and characteristics (attributes) of each partition.

The disk configuration is required in each configuration file. The configuration file defines a number of disk attributes that mainly describe the disk's geometry. All disk attribute definitions must be enclosed in square brackets ([]). A single pair of brackets can contain one or more attribute definitions; multiple attribute definitions within a pair of brackets must be separated by a whitespace.

Disk attributes

The diskimage command supports the following disk attributes:
(Required) Specifies the number of cylinders on the disk. The value must be in the range of 1–4294967295 (232-1).
(Required) Specifies the number of heads on the disk. The value must be in the range of 1–255.
(Required) Specifies the number of sectors on each track. The value must be in the range of 1–63.
(Optional) Specifies the number of bytes per sector. The value must be in the range of 1–4294967295 (232-1). If not specified, a default value of 512 is used.
(Optional) Specifies the cylinder at which the first partition shall begin. The value must be in the range of 0–4294967294 (232-2). The default is zero.
Note: The first track is always reserved for the MBR. Because of this, a partition beginning at cylinder zero has sectors_per_track x (heads-1) sectors available in the first cylinder.
The partition definitions are optional and you can specify as many as you require. You can define primary, extended, and logical partitions using the following syntax where:
A unique value in the range of 1–4.
The pathname of the file containing the filesystem image for the partition. The pathname must be enclosed in double quotes (""), and can't exceed the host's maximum pathname length. The file size must not exceed the partition size. For filesystems that are not Power-Safe filesystems, the image file can be smaller than the partition (although a warning is issued).
  • Primary partition:
    [partition=partn_idx boot=true|false
                       num_sectors=number] partn_file
    # Power-Safe filesystem, > 2GB, bootable
    [partition=2 boot=true type=179 num_sectors=4273290] "../fsi/qnx6-1.fsi"
  • Extended partition:
    [extended=partn_idx num_sectors=number] 
    [extended=2 num_sectors=8256]
  • Logical partitions:
    [logical type=number
             ebr_sectors=number] partn_file 
    # Power-Safe filesystem (~500MB)
    [logical type=178 num_sectors=1060290] "../fsi/qnx6-2.fsi"

Partition Attributes

The following partition attributes are supported by diskimage:
(Optional) Specifies whether the partition should be marked as bootable. A boolean value is used, where true indicates that the partition is bootable and false indicates that it isn't. The default value is false.
(Required) Specifies the partition type. The value must be in the range of one to 255 and should match the type of the filesystem in the partition image file. Frequently used types include 11/12 (DOS FAT32) and 177/178/179 (Power-Safe filesystem). For more information about partitions and a list of partition IDs, refer to http://en.wikipedia.org/wiki/Partition_type.
(Optional) Specifies the number of sectors to allocate for the partition. The value must be in the range of 1–4294967295 (232-1). If this attribute isn't specified, it's set to the smallest number of sectors required for the partition’s filesystem image.
(Optional) Specifies the number of sectors to be reserved in front of the logical partition. At least one sector is required for the EBR (Extended Boot Record) associated with the partition. The value must be in the range of 1–4294967295 (232-1). If this attribute isn't specified, exactly one track is reserved. For more information, see the sectors_per_track disk attribute.

Using extended and logical partitions

When logical partitions are used, an extended partition is required as well. It can be defined explicitly or created automatically by diskimage. The extended partition acts as a primary partition and serves as a container for the logical partitions. Within the extended partition, the logical partitions are laid out in the order in which they appear in the config file.

The total combined size of all logical partitions (including any overhead) must be less than or equal to the size of the extended partition. To determine the space required for the extended partition, include the following items in your calculation:
  • the size of each logical partition
  • each logical partition's ebr_sectors
By default, the ebr_sectors option is set to the disk's number of sectors per track. The size of the ebr_sectors option includes the EBR and any optional padding. It's recommended that the default of one track is used.
Attention: Even though the EBR requires one sector, the entire track is allocated for it.
Figure 1. Extended boot record, padding, and logical partition
To illustrate the calculation, consider the following example:
Note: In the following example, the specified partitions intentionally don't add up to fill the disk.
Target disk geometry
16 cylinders
32 heads
32 sectors per track
One primary type 11 (DOS FAT32), bootable, 4096 sectors
One extended partition with:
  • 1 logical type 179 (Power-Safe filesystem), 2048 sectors
  • 1 logical type 178 (Power-Safe filesystem), 6144 sectors
To calculate the extended partition, use the following formula:
  <sectors_per_track>	/* First logical EBR  */
+ <logical-type-179>	 /* First logical data */
+ <sectors_per_track>	/* Second logical EBR  */
+ <logical-type-178>	 /* Second logical data */
= ext_sectors
Therefore, for the example, these are the values to use in the formula:
    32    /* sectors_per_track */
+ 2048    /* First logical data */
+   32    /* sectors_per_track  */
+ 6144    /* Second logical data */
= 8256    /* size of extended partition sectors */
To define the configuration specified in the previous example, the configuration file would be:
[cylinders=16 heads=32 sectors_per_track=32]
[partition=1 boot=true  type= 11 num_sectors=4096] "fat.img"
[extended=2                      num_sectors=8256]
[logical     boot=false type=179 num_sectors=2048] "qnx-179.img"
[logical     boot=false type=178 num_sectors=6144] "qnx-178.img"
However, if you wanted to presume that the three filesystem images are full-sized, you can use a more simplified syntax:
[cylinders=16 heads=32 sectors_per_track=32]
[partition=1 boot=true type=11] "fat.img"
[logical type=179] "qnx-179.img"
[logical type=178] "qnx-178.img"

Summary of configuration file syntax

The following excerpt explains the configuration file grammar:
# Configuration file
config_file : disk_cfg+ partn_def*

# Disk configuration
disk_cfg : '[' disk_attr+ ']'

# Disk attributes
disk_attr : 'cylinders' '=' uint
          | 'heads' '=' uint
          | 'sectors_per_track' '=' uint
          | 'sector_size' '=' uint
          | 'start_at_cylinder' '=' uint
# Partition definition            
partn_def : primary_partn_def
          | extended_partn_def
          | logical_partn_def
# Primary partition definition            
primary_partn_def : 
      '[' 'partition' '=' partn_idx ppartn_attr* ']' 

# Extended partition definition  
extended_partn_def : 
     '[' 'extended' '=' partn_idx epartn_attr* ']'

# Logical partition definition  
logical_partn_def : 
     '[' 'logical' lpartn_attr* ']'  partn_file
# Partition index  
partn_idx : uint

# The primary partition attributes  
ppartn_attr : boot_attr
            | type_attr
            | nsec_attr

# The extended partition attributes  
epartn_attr : nsec_attr

# The logical partition attributes  
lpartn_attr : boot_attr
            | type_attr
            | nsec_attr
            | esec_attr

# The boot attribute
boot_attr : 'boot' '=' bool

# The type attribute
type_attr : 'type' '=' uint

# The num_sectors attribute
nsec_attr : 'num_sectors' '=' uint

# The ebr_sectors attribute
esec_attr : 'ebr_sectors' '=' uint

# Partition file
partn_file : string

# The boolean definition
bool : 'true'
     | 'false'

# Unsigned integer 
uint : '0' [0-7]+ sfx?
            | '0x' [0-9a-fA-F]+ sfx?
            | [1-9][0-9]* sfx?
# Factors that can be used to with integers. 
sfx : [kKmMgG]
# string values must be enclosed within double quotes ("")            
string : '"' [^"]* '"'


Create an image
diskimage –c mydisk.cfg –o mydisk.img
Create an image and specify a primary boot loader (IPL)
diskimage -c mydisk.cfg 
          -b C:\qnx660\target\qnx6\x86\boot\sys\ipl-diskpc1 
          -o mydiskipl.img

Configuration file for three primary partitions

An example for a disk with three primary partitions, one DOS FAT32 and two Power-Safe filesystems. It's targeted at a disk geometry of 974/255/63 (cylinders/heads/sectors). The configuration file expects the filesystem images to reside in the directory ../fsi.

] "../fsi/fat32.fsi"

# First Power-Safe filesystem, >2GB, bootable
] "../fsi/qnx6-1.fsi"

# Second Power-Safe filesystem
] "../fsi/qnx6-2.fsi"

Configuration file for two primary and two logical partitions

An example for a disk with two primary and two logical partitions. The primary partitions are DOS FAT32 and Power-Safe filesystems. Both logical partitions are Power-Safe filesystems. The extended partition uses slot 3 in the MBR. The resulting image is intended for a disk geometry of 4096/64/32 (cylinders/heads/sectors), which can represent an eMMC. The configuration file expects the filesystem images to reside in the directory ../fsi.
[cylinders=4096 heads=64 sectors_per_track=32]

# DOS FAT32 (~480MB)
] "../fsi/fat32.fsi"

# Primary Power-Safe filesystem, >2GB, bootable
] "../fsi/qnx6-1.fsi"


# Power-Safe filesystem (~500MB)
] "../fsi/qnx6-2.fsi"

# Power-Safe filesystem (~500MB)
] "../fsi/qnx6-3.fsi"

Exit status:

Zero is returned when the command completes without errors.
One is returned when an error occurs while running the command. Possible errors include but aren't limited to:
  • the configuration file wasn't specified
  • the configuration file couldn't be read
  • there were syntax errors in the configuration file