Assembly code typically needs assembler directives as well as the instructions themselves. The operation of all the directives are described in the subsections of Assembler Directives. Common directives required are mentioned below.
All assembly code must be placed in a psect (section) so it can be manipulated as a whole by the linker and placed in memory. See Compiler-Generated Psects for general information on psects; see Psect Directive for information on the directive used to create and specify psects.
The other commonly used directive is GLOBAL, defined in
Global Directive which is used to
make symbols accessible across multiple source files.