MSM9112007: MASM Generates a _TEXT Segment in Far Code Models

ID Number: Q79285

6.00 6.00a | 6.00 6.00a

MS-DOS | OS/2

buglist6.00 buglist6.00a

Summary:

PROBLEM ID: MSM9112007

SYMPTOMS

When the assembly language module of a mixed-language program is

placed in an overlay, the program hangs at startup. If the assembly

module is placed in the root, the problem disappears. This problem

occurs only when using the .MODEL directive in the Microsoft Macro

Assembler (MASM) versions 6.0 and 6.0a.

CAUSE

MASM 6.0 generates a zero length _TEXT segment from source files

that specify .MODEL medium, .MODEL large, or .MODEL huge. The

startup code for Microsoft's high level languages is also declared

in the _TEXT segment. The linker combines segments with the same

name. If the assembly module is overlayed, the startup code is

pulled into the overlay because the _TEXT segments will be

combined. This means that the startup code is not available when

the program starts executing, which causes the program to crash.

RESOLUTION

Work around this problem by removing the .MODEL directive and using

full segment directives instead in any module that will be placed

in an overlay.

STATUS

Microsoft has confirmed this to be a problem in MASM version 6.0

and 6.0a. We are researching this problem and will post new

information here as it becomes available.

Additional reference words: 6.00