umps3-mkdev – The umps3-mkdev device creation utility
umps3-mkdev -d DISKFILE [DISKOPTIONS]
umps3-mkdev -f FLASHFILE FILE
[FLASHOPTIONS]
The command-line umps3-mkdev utility is used to create the files
that represent disk and flash devices.
- DISKS:
- Disks in uMPS3 are “direct access” nonvolatile read/write
devices. The umps3-mkdev utility allows one to create an empty disk only;
this way an OS developer may elect any desired disk data
organization.
- The created DISKFILE represents the entire disk contents, even when
empty. Hence this file may be very large. It is recommended to create
small disks which can be used to represent a little portion of an
otherwise very large disk unit.
- As with real disks, differing performance statistics result in differing
simulated drive performance. E.g. a faster rotation speed results in less
latency delay and a smaller sector data occupancy percentage results in
shorter read/write times.
- The default values for all these parameters are shown when entering the
umps3-mkdev alone without any parameters.
- FLASH DEVICES:
- Flash devices in uMPS3 are “random access” nonvolatile
read/write devices. A uMPS3 flash device is essentially equivalent to a
seek-free one-dimensional disk drive. The umps3-mkdev utility allows one
to create both slow flash devices (e.g. USB stick) or fast flash
devices (e.g. SSDs). Furthermore, the utility allows one to create
both empty flash devices as well as ones preloaded with a specific
file.
- The created FLASHFILE represents the entire device contents, even
when empty. Hence this file may be very large. It is recommended to create
small flash devices which can be used to represent a little portion of an
otherwise very large device.
- uMPS3 caps the maximum block size for flash devices at 2^24. This
translates to a maximum device size of 64GB.
- As with real flash devices, read operations are faster than write
operations. The read speed for uMPS3 flash devices is fixed at 75% of the
device write time in microseconds.
- The default values for all these parameters are shown when entering the
umps3-mkdev alone without any parameters.
- -d
- instructs the utility to build a disk file image.
- -f
- instructs the utility to build a flash device file image.
- DISKFILE
- is the name of the disk file image to be created.
- FLASHFILE
- is the name of the flash device file image to be created.
- FILE
- is the name of the file to be preloaded onto the device beginning with
block 0. If one wishes to create an empty flash device but still specify
some of the additional parameters, use /dev/null as the FILE
argument. To load a flash device with a collection of files, it is
recommended to initially create a single .tar file from the collection and
then use this single .tar file for this parameter. We recommend the .tar
file format due to its simple structure.
[CYL [HEAD [SECT [RPM [SEEKT
[DATAS]]]]]]
- CYL:
- Number of cylinders: [1..65535], default = 32
- HEAD:
- Number of heads/surfaces: [1..255], default = 2
- SECT:
- Number of 4KB sectors/tracks: [1..255], default = 8
- RPM:
- Disk rotations per minute: [360..10800], default = 3600
- SEEKT:
- Average cylinder to cylinder seek time in microseconds: [1..10000],
default = 100
- DATAS:
- Sector data occupation %: [10%..90%], default = 80%
[BLOCKS [WT]]
- BLOCKS:
- Number of blocks: [1..0xFFFFFF], default = 512
- WT:
- Average write time in microseconds: [1..10000], default = 1000
Mauro Morsiani
Mattia Biondi mattiabiondi1@gmail.com
Contributors can be listed on GitHub.
Report issues on GitHub:
https://github.com/virtualsquare/umps3
2004, Mauro Morsiani
2020, Mattia Biondi mattiabiondi1@gmail.com