VisUAL: A highly visual ARM emulator | Hacker News Reader

VisUAL: A highly visual ARM emulator

salmanarif.bitbucket.io

132 pointsingve10 comments

The one thing that immediately caught my eye is the lack of fixed-width-ness (for lack of a better term) in the value displays. IMHO besides being somewhat annoying to read it can be rather misleading, which is bad especially for something "designed specifically to use as a teaching tool". It's misleading because it doesn't show that the storage for the values is fixed-width. For example, this clearly shows that the registers are 32 bits and never anything but:

    R0 0000BEEF
    R1 000BEEF0
    R2 000000BE
    R3 00000001
    R4 BEEF0000
    R5 00005F77
    R6 00000000
    R7 00000000
    ...

I've taught Asm before and seen so many students get this wrong that it's worth calling out. In fact the right example under the "Error Correction Suggestions" section gets this wrong too --- that's an assembly/syntax error, not a runtime error. (ARM's immediate value encoding is also worth looking at if you haven't seen it before, since it's not just a single 32-bit value either: https://alisdair.mcdiarmid.org/arm-immediate-value-encoding/ )

The other thing that I'd suggest as an improvement is a 16-byte-hexdump mode with ASCII on the right for "View Memory Contents". Other than that, with perhaps the exception of "infinite loop detection", the other features look useful.

Is there a video we can see this in action? I wouldnt ever use a tool like this because my work doesn't require it, but this stuff still fascinates me and I'd like to watch someone use it.

This simulator since it is based on the unicorn,keystone,capstone framework, has a lot more instruction support(and architecture support): https://github.com/hugsy/cemu .

Its front was just thrown together though, and it has a few issues. It would be nice if it ever develops into having a rich front end and progresses towards what VisUAL has.

I like this project, and really appreciate that there's a Linux version. Looks very polished, friendly and inviting, so kudos.

Maybe some code samples could be a good addition.

I used a similar program to learn assembly, GNUSim8085, targeting the Intel 8085 architecture and is packaged for most distros.

To be able to use VisUAL, your system must be compatible with the Java 8 Runtime Environment

Theoretically it should run on any platform with a JVM, although the lack of a JAR download (as well as 32-bit Windows) is a little odd.

Edit: I can confirm that the 64-bit Windows download consists of mostly a 64-bit JRE (56MB) and a JAR (<5MB), the latter of which works on 32-bit Windows too.

Yes, I realized after a while that it was in fact a Java application since context menus have the default Java look and feel.

If anyone wants to learn ARM assembly, a program called ARMsim and the pdf documentation you can find is a pretty good way to do it. You can step through, set break points and follow tutorials to learn with a gradual buildup in difficulty.

This was posted here some time ago; in that thread there are links to other tools that you may find interesting: https://news.ycombinator.com/item?id=10787226

What is the license of this program? I couldn't find it on the website.

It seems very good project. Because I am using fedora I couldn't use it though, I wish there were a rpm package too. or at least linux .run package would be great.

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