ARM Thumb Assembly - Lesson 1

Hi guys! i need your help to understand what this arm instruction really does: 0x00010000: sub PC, PC, #1; (we are in Arm mode)

I would like to use cbz (thumb instruction) but my compiler shows an error message that this particular instruction not present in the Instruction.

ARM and Thumb instructions can be grouped by functional area. All ARM instructions are 32 bits long. Instructions are stored word-aligned, so the least ...

The ARM and Thumb modes are word-aligned and halfword-aligned. I understand this means that if it's in ARM mode, the start of addresses must be divisible by 32.

If you are on ARM, please check whether you are emulating a THUMB instruction. If so, please use UC_MODE_THUMB and make sure the starting address is odd.

ARM and THUMB modes are not mutually exclusive modes, it is very common for the mode to dynamically change during execution.

The ARMDisassembler changes allow changing between ARM and Thumb mode based on the MCSubtargetInfo, rather than the Target, which simplifies ...

You can certainly switch to thumb mode once entered no different than switching to thumb mode after a reset exception. The cortex-m3 has re- ...

The answers are in the ARM ARM (ARM Architectural Reference Manual). Look at BX both in the ARM instructions and Thumb instructions, ...

Interworking is the term used to describe the process of switching between ARM and Thumb modes. There are two main ways to do this: using branch ...