VeriFone DUET Vx810, Reference Manual

Page: 96 / 162

P
ERFORMING
D
OWNLOADS
Support for Multiple Applications
96
V X 810 R
EFERENCE
G
UIDE
•
Partial OS downloads are performed mainly by VeriFone for development
purposes and are rarely performed in the field.
•
Partial downloads are routinely performed by many applications. This
procedure, which can be automated by an application running on a remote
host computer, permits the host application to update data files and device
configuration settings in a V
x
810 and return control to the main application.
•
Full downloads restart the device; partial downloads return control to system
mode or the issuing application. OS and application downloads can be
combined. The file authentication module is not invoked until the device is
restarted following the download procedure.
Support for
Multiple
Applications
The V
x
810 architecture supports multiple applications. This means that more than
one application can reside in device’s memory, and that more than one application
can run (execute) on the device.
The application memory of the V
x
810 uses a system of file groups to store and
manage multiple applications, as well as operating system files. This system of file
groups are used in such a way that the data integrity of each application is
ensured and applications do not interfere with each other (see
File Groups ).
How the File System
Supports Multiple
Applications
The application memory partition of the V
x
810 is divided into 15 logically-defined
sub-partitions called file groups or GIDs (for example, Group 1, Group 2, and so
on through GID15).
Another partition of the device’s memory area, called Group 0, is reserved for the
operating system and is logically separated from the application memory area. So,
including Group 0, there is a total of 16 file groups.
An application must be downloaded onto a specific file group, along with any
related files. Select the target file group for the download using system mode
menu options and by entering a file group password.
Usually, one application is stored in one file group. An application can, however,
consist of more than one executable program file, and any number of executables
(*.out or *.lib) can be stored in a given group. In most implementations, there is a
main application, one or more related programs or secondary applications, and
one or more libraries.
The main application, or the application to execute set in the *GO CONFIG.SYS
variable, must always be stored in the Group 1 sub-partition. Related programs or
secondary applications can be stored in GIDs 2–14. GID15 is available to all other
groups.