GNU-style Arm Assembly syntax Guide (very detailed) 4

Conversion from: GNU-style Arm Assembly syntax Guide (very detailed) 4

4. GNU assembly language definition entry point

The default entry for assembler is_ StartLabel,You can also use the entry mark in the connection script file to specify other entry points..

Example: Define the entry point

. Section. Data

<Initialized data here>

. Section. BSS

<Uninitialized data here>

. Section. Text

. Globl _ start

_ Start:

<Instruction code goes here>

 

5. macro definition in GNU Assembler

The format is as follows:

. Macro macro name parameter name list @ pseudodirective. Macro defines a macro

Macro

. Endm @. endm indicates that the macro ends.

If a macro uses a parameter, the prefix is added when the macro uses this parameter."\". Default values can also be used for macro-defined parameters. You can use the. exitm pseudo command to exit the macro.

For example, macro definition

. Macro shiftleft a, B

. If \ B <0

Mov \ A, \ A, ASR #-\ B

. Exitm

. Endif

Mov \ A, \ A, LSL # \ B

. Endm