Relationship of assembler to operating system
High Level Assembler operates under the z/OS® operating
system, the CMS component of the z/VM® operating system, the
z/VSE® operating system, and Linux® on IBM Z®. These operating systems
provide the assembler with services for:
- Assembling a source module
- Running the assembled object module as a program
z/OS provides
the following services:
- For assembling the source module:
- A control program
- Sequential data sets to contain source code
- Libraries to contain source code and macro definitions
- Utilities
- For preparing for the execution of the assembler program as represented
by the object module:
- A control program
- Storage allocation
- Input and output facilities
- Binder
- Loader
CMS provides the following services:
- For assembling the source module:
- An interactive control program
- Files to contain source code
- Libraries to contain source code and macro definitions
- Utilities
- For preparing for the execution of the assembler program as represented
by the object modules:
- An interactive control program
- Storage allocation
- Input and output facilities
- Linker
- A loader
z/VSE provides the following services:
- For assembling the source module:
- A control program
- Sequential data sets to contain source code
- Libraries to contain source code and macro definitions
- Utilities
- For preparing for the execution of the assembler program as represented
by the object module:
- A control program
- Storage allocation
- Input and output facilities
- Linker
Linux on IBM Z provides the
following services:
- For assembling the source module:
- An interactive control program
- Files to contain source code
- Utilities
- For preparing for the execution of the assembler program as represented by the object modules:
- An interactive control program
- Storage allocation
- Input and output facilities
- Linker
- A loader
In writing a source module, you must include instructions that request required service functions not provided by the operating system, for example obtaining and freeing storage.