ARM VERSION 1.2 - Manual (Page 228)

Thumb Instruction Reference
5-34 Copyright © 2000, 2001 ARM Limited. All rights reserved. ARM DUI 0068B
5.4.2 BL
Long branch with Link.
Syntax
BL label
where:
label is a program-relative expression. See Register-relative and
program-relative expressions on page 3-23 for more information.
Usage
The BL instruction copies the address of the next instruction into r14 (lr, the link
register), and causes a branch to label .
The machine-level instruction cannot branch to an address outside
±4Mb of the current
instruction. When necessary, the ARM linker inserts code (a veneer) to allow longer
branches (see The ARM linker chapter in ADS Linker and Utilities Guide).
Architectures
This instruction is available in all T variants of the ARM architecture.
Example
BL extract