Binder Manual (G06.27+, H06.04+, J06.03+)

Object File Structure

Binder Manual—528613-004

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Header

The object file header is a block at offset zero containing pointers and descriptive

information for other regions in the object file.

Code Region

The code region consists of consecutive pages of disk space, starting on a page

boundary, in the object file. Binder output statistics give the exact number of pages to

be allocated for the code area at run time.

Code region contents, in order, are:

1. PEP table

2. Global read-only arrays (TAL only)

3. Resident code blocks (TAL only)

4. Nonresident code blocks

5. XEP table

You can define the order of blocks that Binder uses to build the code region. In building

the file, Binder separates resident code blocks from nonresident code blocks for you.

In the completed target file, nonresident code can come before resident code if

compression of the target file requires it. Binder compresses the file contents by

moving nonresident blocks that fit in the gap at 32K even if resident code blocks are

placed above the 32K boundary. The SELECT COMPACT OFF command prevents

Binder from performing any compression or filling the gap.

Multiple-Code-Segment Files

For small programs, Binder builds single-code-segment files. But if a program exceeds

64K words of code or 512 entry points, Binder builds its object file with multiple code

segments. You can also create multiple-code-segment files explicitly by using the ADD

SPACE command or the MOVE entry-list IN NEW SPACE command.

Note. This figure shows a single code segment in the code region. Normally, many more code

segments would appear.

Note. The object file format may change. New versions of Binder will accept all existing Binder

object file formats; however, old versions of Binder will not accept new object file formats.