The programs are in general installed on the ` mobiles' by means of a CAB file. These CAB files (Cabinet File) were developed by Microsoft as archive files for installation.
It should be noted that the "Today Themes" are neither more nor less than files of installation CAB whose extension is "TSK".
A specific format of these files CAB is used for Windows CE. On the mobile the installation is carried out by the program WCELOAD.EXE which reads the file, installs it by copying the files in the defined repertories, writes the entries in the registry...
In these files CAB are stored the files to be transferred on the ` mobile'. The names of these files use convention "MS-DOS 8.3", i.e. 8 characters for the name followed of the point (`.') and 3 characters for the extension. The extensions for Windows CE are in fact of the numbers from 000 to 999. No file in a CAB can have the same numerical extension as another.
For example the file Theme "Cafe.tsk", provided by Microsoft includesthe files :
· Cafe_4~1.000 The file tdywater.001 is the image "Today", the file 0stwater.002 is the image "Start".
As for the Cafe_4~1.000 file, it is in fact the file giving all the instructions to install this theme : To install the two images in the directory "\Windows", to define the contents of 22 keys in the registry which are in fact here the definition of the colors for the theme for the ` mobile'.
The file whose extension is "000" is always that providing all information of installation.
This file "000" is defined as follows :
· A header with fixed length100 bytes.
· Application Name(APPNAME).
· Provider Name(PROVIDER).
· Section of unsupported platforms Windows CE non supportées (UNSUPPORTED multi string).
· Section of strings (STRINGS) used to build the names of the folders, files, registry keys and shortcut for application.
· Section of Dirs (DIRS) of installation of the files.
· Section of Files (FILES) defining all the files to be transferred on the mobile in the folders enumerated in the preceding section.
· Section of Hives (REGHIVES) for which values will be defined or modified.
· Section of the values for these registry keys (REGKEYS) .
· Section of the shortcuts (LINKS) being used for the application.
All these precise details concerning the files of installation Windows CE (CAB) were collected on Internet in the page : http://docs.vernstok.nl/cabextract/wince_cab_format.html .
To note on this page a small error concerning the section FILES: the third word of 2 bytes is indicated as the extension on 3 digits of the file concerned (it rather represents the order of treatment in the list of the files). Only the first word of 2 bytes is useful like identification of the extension of the file concerned.
Another error relates to the shortcuts: the second word of 2 bytes is announced like unknown, but corresponds in fact to the repertory of destination of the shortcut if the value is different from 0.