IRISC: An ARMv7 assembly interpreter and computer architecture simulator | Hacker News Reader

IRISC: An ARMv7 assembly interpreter and computer architecture simulator

polysoftit.co.uk

50 pointsrtybanana4 comments

This is a little web app I developed a good while ago now to help people start learning ARMv7 assembly language and to understand how the computer hardware interprets and executes instructions of low level languages.

The tutorial section should have enough content to get people started. Only a minimal understanding of comp sci concepts are required, so whether you're completely new to programming or are experienced with high level languages and want to understand more about what goes on lower down, this tool is for you! I hope you enjoy it or learn something from it. I certainly enjoyed making it.

Unfortunately, mobile is not supported since the simulator has a lot of moving parts which describe the state of the simulated computer hardware. I recommend a laptop or larger for the optimal experience :).

I played around with it, and it's very neat. This is the first time I've seen an assembly REPL and I wish I had something like this that ran native for playing with unfamiliar instructions.

I did find a couple minor issues with the simulator: MVN is supposed to be a bitwise NOT but the simulator does a two's-complement negation instead (https://github.com/rtybanana/irisc-web/blob/main/src/interpr...), and it seems negative immediate offsets aren't supported, e.g.

  ldr r0, [r1, #-4]

Thanks for the bug reports, if you like you can open some issues for those and I’ll look into them ASAP.

Interesting about the bitwise NOT, I’ll need to dig up the manual on this I must have missed that.

This is a great tool to learn ARM Assembly, and also to play around on downtime at work.

Congratulations on the work.

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