Application Header; Magic Number; Internal Application Name; Table 7.2: Application Header Format - Texas Instruments TI-89 Developer's Manual

Chapter 7: Flash Application Layout
7.1.3.

Application Header

The OS keeps track of apps through the application header. The application
header contains information about the application itself. The header contains the
internal name of the application, flags, the length of the application's data
segment, an offset to the beginning of application code, an offset to the
beginning of initial data, and the length of initial data.
Lengths and offsets are stored most significant byte first — the convention used
in the Motorola 68000 microprocessor.
This header is created by the MKAPPLET utility.
The following fields may be accessed through the AppHdr structure.
Offset
(bytes)
0
4
12
36
38
42
46
50
54
58
7.1.3.1.

Magic Number

The magic number marks the beginning of the app header.
7.1.3.2.

Internal Application Name

Every application has a unique internal name.
Note: This field must match the internal application name in the Flash header. The internal
TI-89 / TI-92 Plus Developer Guide
Length
(bytes) Contents
4 magic number (0x167B533D)
8 internal application name (padded with trailing zeros to eight
bytes)
24 reserved (fill with zeros)
2 flags
4 length of data segment
4 byte offset to code segment
4 byte offset to initial data table
4 length of initial data table
4 length of optional header — additional information can be stored
just after the application header.
n
optional header — this information is ignored by the OS.

Table 7.2: Application Header Format

application names in the app header and Flash header are case sensitive and must be
identical.
Not for Distribution
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Beta Version January 26, 2001