ARM VERSION 1.2 - Manual (Page 189)

ARM Instruction Reference
ARM DUI 0068B Copyright © 2000, 2001 ARM Limited. All rights reserved. 4-79
4.9.1 ADR ARM pseudo-instruction
Load a program-relative or register-relative address into a register.
Syntax
ADR{cond} register,expr
where:
cond is an optional condition code.
register is the register to load.
expr is a program-relative or register-relative expression that evaluates to:
• a non word-aligned address within
±255 bytes
• a word-aligned address within ±1020 bytes.
More distant addresses can be used if the alignment is 16 bytes or more.
The address can be either before or after the address of the instruction or
the base register (see Register-relative and program-relative expressions
on page 3-23).
Note
For program-relative expressions, the given range is relative to a point
two words after the address of the current instruction.
Usage
ADR always assembles to one instruction. The assembler attempts to produce a single ADD
or SUB instruction to load the address. If the address cannot be constructed in a single
instruction, an error is generated and the assembly fails.
ADR produces position-independent code, because the address is program-relative or
register-relative.
Use the ADRL pseudo-instruction to assemble a wider range of effective addresses.
If expr is program-relative, it must evaluate to an address in the same code section as the
ADR pseudo-instruction.
Example
start MOV r0,#10
ADR r4,start ; => SUB r4,pc,#0xc