Length Of Initial Data Table; Optional Header; Relocation Map; Application Code - Texas Instruments TI-89 Developer's Manual

Chapter 7: Flash Application Layout
7.1.3.7.

Length of Initial Data Table

Number of bytes in initial data table.
7.1.3.8.

Optional Header

Additional header information may be included after the required header section.
The optional header length specifies how many bytes are in the header
extension.
7.1.4.

Relocation Map

The OS uses the relocation map to calculate absolute addresses when the
positions of the code and data segments are finally established. The relocation
map consists of a six-byte entry for each location which needs to be updated.
Offset
(bytes)
0
3
The hole offset specifies where in the application code or initial data table an
absolute address needs to be updated.
The value to store in the hole is calculated from the base and relative value. The
base is 00 for code-segment relative and 10 for data-segment relative. Base
values 01 and 11 are reserved for future implementations of AMS.
7.1.5.

Application Code

The code segment contains executable application code and constant data.
7.1.6.

Initial Data Table

When the OS installs an application, it allocates a data segment in RAM to hold
static and external variables. The initial data table provides their initial values.
Static/external variables which are not explicitly initialized are set to zero.
The application's data segment is initialized when the application is installed and
reinitialized every time the application is moved in Flash memory because of
garbage collection.
TI-89 / TI-92 Plus Developer Guide
Length
(bytes) Contents
3 hole offset
3 base (2 bits) and relative value to place in hole (22 bits)

Table 7.4: Relocation Map Format

Not for Distribution
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Beta Version January 26, 2001