ARM VERSION 1.2 2.1 Introduction

Writing ARM and Thumb Assembly Language

2.1 Introduction

This chapter gives a basic, practical understanding of how to write ARM and Thumb

assembly language modules. It also gives information on the facilities provided by the

ARM assembler (armasm).

This chapter does not provide a detailed description of the ARM, Thumb, or VFP

instruction sets. This information can be found in Chapter4 ARM Instruction

Reference, Chapter 5 Thumb Instruction Reference, and Chapter6 Ve ct o r

Floating-point Programming. Further information can be found in ARM Architecture

Reference Manual.

2.1.1 Code examples

There are a number of code exam ples in this chapter. Many of them a re supplied in the

examples\asm

directory of the ADS.

Follow these steps to build, link, and execute an assembly language file:

1. Type

armasm -g filename.s

at the command prompt to assemble the file and

generate debug tables.

2. Type

armlink filename.o -o filename

to link the object file and generate an ELF

executable image.

3. Type

armsd filename

to load the image file into the debugger.

4. Type

at the

armsd:

prompt to execute it.

5. Type

quit

at the

armsd:

prompt to return to the command line.

To see how the assembler converts the source code, enter:

fromelf -text/c filename.o

or run the module in AXD with interleaving on.

See:

•AXD and armsd Debuggers Guide for details on armsd, and AXD.

•ADS Linker and Utilities Guide for details on

armlink

and

fromelf