ARM assembly language is considered moderately difficult to learn and use compared to other assembly languages. While it has some complex features, ARM assembly also simplifies certain aspects of programming that can make it more approachable than other low-level languages.
The Learning Curve
For programmers with experience in C and other high-level languages, ARM assembly will definitely present a steep learning curve at first. Assembly language requires dealing with computer architecture concepts like registers, memory addresses, and machine code that high-level languages normally abstract away. You’ll need to learn the ARM instruction set and understand how to map C constructs to assembly instructions.
That said, ARM assembly has a smaller and more regular instruction set than x86 assembly. Programs also follow a simple linear sequence of instructions without complex branching logic. These aspects make ARM a bit easier to get started with compared to other assembly languages.
Coding in ARM Assembly
Writing ARM assembly code itself has some tricky aspects but can be mastered with practice. You’ll need to track register usage, allocate stack space correctly, adhere to ARM syntax rules, and optimize performance through careful instruction ordering. Managing continuity and branching between code sections takes care as well.
However, ARM assembly does avoid a few pitfalls of other low-level languages. Memory access is simplified with a regular addressing mode. Code density is improved through powerful 16-bit and 32-bit instructions. The unified syntax also means you don’t have to write different assembly code for ARM’s 16-bit Thumb and 32-bit ARM instruction sets.
Debugging and Testing
Debugging assembly code can be challenging without the help of variables, function calls, and other high-level language features. But ARM assembly at least avoids dealing with x86 assembly’s complex segmented memory. The consistency of the ARM architecture also lends itself better to instruction tracing and simulation techniques.
ARM’s wide availability across devices means you aren’t tied to a specific development environment for testing. You can apply ARM code written on a desktop machine to embedded systems like ARM boards readily. Unit testing frameworks and methods used for C code can often be adapted for testing ARM assembly as well.
Use of ARM Assembly Today
For most application development today, ARM assembly isn’t commonly used, as high-level languages provide greater programmer productivity and portability. But assembly still has niche use cases in time-critical code sections, OS kernels, bootloaders, device drivers, and other low-level systems programming where ultimate performance or control is needed.
ARM assembly skills remain valued alongside C for working on constrained and embedded devices. Specific product areas like mobile chips and microcontrollers may require assembly knowledge. Having assembly fluency can also aid overall learning for both software and hardware engineers working across the stack.
Resources for Learning
While challenging overall, ARM assembly can be learned systematically like any language. Many online courses, tutorials, and books are available covering ARM syntax, registers, instructions, stack use, branching, optimization, and more. Start by studying the basics before attempting practical programming projects.
Reference documentation for ARM instruction sets is freely provided by Arm. Example code and open source ARM projects can accelerate learning as well. Joining online forums and communities provides support and advice from fellow programmers. With dedication, ARM assembly skills can be obtained like any skill.
ARM assembly requires significant initial effort to learn coming from a high-level language background. But its streamlined RISC architecture, consistent syntax, and accessible tooling provide some advantages over working in other low-level languages. With practice, ARM assembly’s complexity can be managed, making it feasible to use where C alone is insufficient.