Guardant Code / Code Time models allow the loading and execution of the source code inside the dongle. The source code (aka loadable code) needs to be preprepared (or written) specifically for this purpose.
GrdUtil.exe provides a convenient service for dealing with the loadable code, including its automatic conversion from BIN file into a format suitable for writing into dongle (GCEXE), and then for recording GCEXE into Flash memory.
Working with the Loadable Code field from within the application is handled using the special Guardant API functions: GrdCodeGetInfo, GrdCodeLoad, GrdCodeRun (see details in GrdAPI.chm).
The dialog of creating a field is made in the form of a wizard containing several pages:
- Adding Loadable Code Field
- Loadable Code Properties
- Time Dependencies of the Loadable Code (for Guardant Code Time)
- Loadable Code Settings
Click [Next] to move to the next page after completing the current dialog.
Adding the field
In order to create a Loadable Code field, select the Edit | Add new field command from the menu.
In the dialog box that appears, select Loadable Code and define the field’s name.
The Loadable Code protected item has a fixed size of 160 bytes.
Loadable Code Properties
A field of Loadable Code type is a special case of a protected item, i.e. it is protected with hardware locks from reading and writing. Its state can be programmed and later controlled from within the application.
Activation and deactivation services only are accessible to the loadable code, which control the state of the protected item and provide access to its contents from within the application. Operations with these services are identical to the operations with protected items and algorithms. See the section Hardware algorithm services for more information.
Time Dependencies of the Loadable Code
In Guardant Code Time dongle (Guardant Code Time contains a realtime clock) mask, the Loadable Code Properties page is followed by the Time dependencies page, on which are located the elements designed to limit the operating time of the protected application.
The notion of the time restriction technology is based upon the fact that the algorithm’s workability depends on the dongle’s built-in timer (RTC).
See Limiting the Application Operation’s Time chapter for information on the Time dependencies dialog.