rizin VS chibicc

Just for the record, for nicer inspection of files with such debug information, including compressed sections, and debuginfod support, Rizin[1] can be used, since starting from the 0.7.0 release[2] all of those were added.

[1] https://rizin.re

[2] https://github.com/rizinorg/rizin/releases/tag/v0.7.0

Rizin[1] is also able to uplift native code to the new RzIL, which is based on the BAP Core Theory[2] and is essentially an extension of SMT theories of bitvectors, bitvector-indexed arrays of bitvectors and effects[3].

[1] https://rizin.re/

[2] https://binaryanalysisplatform.github.io/bap/api/master/bap-...

[3] https://github.com/rizinorg/rizin/blob/dev/doc/rzil.md

Everything Hiew can do, Rizin[1] can do too, and is completely free and open source[2] under LGPL3 license. Moreover, it supports more architectures, platforms, and file formats, as well as GUI in Qt - Cutter[3][4]. If something is missing in Rizin but presented in Hiew, please let us know by opening the issue with details.

[1] https://rizin.re

[2] https://github.com/rizinorg/rizin

[3] https://cutter.re

[4] https://github.com/rizinorg/cutter

This is precisely what we are trying to do at Rizin[1][2]. Though the primary goal of the tool/framework is static analysis. All that portability across OSes, their versions, platforms and architectures, etc is definitely hard. If anyone is interested in these subjects, all contributions are welcome. For example, check out our "RzDebug" label, marking debugging issues[3].

[1] https://rizin.re

[2] https://github.com/rizinorg/rizin

[3] https://github.com/rizinorg/rizin/labels/RzDebug

Okay, so, your comment about a "Dasher + Guitar Hero music theory/improvisation practice program" just sent me down a huge rabbit hole...

Well, rabbit hole(s) plural, I guess, most not directly related. :D

Largely because I made the "mistake" of looking at your HN profile & discovering you're also in NZ & we seem to have somewhat overlapping interests (and an affinity for "bacon" in account names, apparently), so, some thoughts[0]... :)

# Topic 1: Nissan Leaf VSP hacking

After reading your recent posts (https://ianrrees.github.io//2023/07/03/vsp-hacking.html & https://ianrrees.github.io//2023/08/05/voltage-glitch-inject...) on this topic & noting your remark about wanting to try reverse engineering a firmware image, I found the following thesis PDF (via a brief google search for `"reverse engineer" "firmware" "Renesas"`):

* "AUTOMOTIVE FIRMWARE EXTRACTION AND ANALYSIS TECHNIQUES" by Jan Van den Herrewegen https://etheses.bham.ac.uk/id/eprint/11516/1/VandenHerrewege...

Not really what I was anticipating finding but seems relevant to your interests--I don't think it was already in your resource list.

While the thesis addresses the Renesas 78K0 rather than the Renesas 78K0R, from a brief look at the "Flash Protection" PDF Application Note in your resource list it seems there's a large overlap.

Perhaps most significantly the author presents "novel methods" that combine bootloader binary analysis with constraint-based power glitching in an effort to improve on the results described in "Shaping the Glitch".

While I haven't read the entire 186 pages :D they theorize that using their approach extracting 8kB firmware might only take ~10 hours.

And, most helpfully, they even published their source code under the GPL here: https://github.com/janvdherrewegen/bootl-attacks

So, an interesting adjacent read even if it turns out not to be directly applicable to your situation.

Given I have an interest in & a little experience with firmware reversing my original thought was to maybe provide some hopefully helpful references that more generically related to firmware reversing but more specific is good too, I guess. :)

In terms of reverse engineering tooling, I've used Rizin/Cutter/radare2 previously: https://rizin.re https://cutter.re

On the CAN tooling/info front, you might be interested in taking a look at my "Adequate CAN" list which I originally wrote-up for a client a couple years ago: https://gitlab.com/RancidBacon/adequate-can

Some other probably outdated reverse engineering tooling links of mine: https://web.archive.org/web/20200119074540/http://www.labrad...

In terms of how to approach RE, other than just "getting started & digging in" & learning by doing, I've sometimes found it informative to read other people's firmware reverse engineering write-ups to learn about potentially useful approaches/tools.

Anyway, hopefully some of this is helpful!

[0] I have a tendency to be a little... "verbose" and/or "thorough" (depending on one's POV :) ) so I'll probably split this over a couple of comments, in case I run out of steam while writing and for topic separation.

See our FAQ[1] on why we forked. As three years passed and both projects are actively developed, the divergence has grown a lot since. We aim for exposing the proper API instead of relying just commands, see e.g. our new Python bindings and rz-bindgen[2]. We have completely different concept of projects, new intermediate language - RzIL[3], and many other things. And under the new organization Cutter is a first-class citizen, not an afterthought as before.

[1] https://rizin.re/posts/faq/

[2] https://rizin.re/posts/gsoc-2022-rz-bindgen/

[3] https://github.com/rizinorg/rizin/blob/dev/doc/rzil.md

If a --k&r mode was to be reliable, wouldn't it need to get specified first? Otherwise people would start relying on some edge case.

If speed is not a requirement for the --k&r mode, you could just take the tis-interpreter and note that if it runs without UB, it is still much faster than an actual computer was when k&r were active.

Would it even be possible to specify a variant of C that contains no UB (e.g. would define exactly what happens on unaligned access), but can compile practical existing C89 programs? I wonder if it could be written such that it could actually specify the behaviour consistently across the language intersection supported by both of e.g. GCC 2.95 and Chibicc[0].

Or maybe there are so many bugs in GCC 2.95 that it would simply be infeasible? How much time would it take to specify?

[0]: https://github.com/rui314/chibicc

I was on the Eclipse Foundation call a few days ago regarding this topic and they said there was a well-established 3-part test for this in the EU courts. But I don't think I managed to take a screenshot, sorry.

Here is a snippet from the EU Blue Guide linked the from the Eclipse blog post:

"Commercial activity is understood as providing goods in a business related context. Non-profit organisations may be considered as carrying out commercial activities if they operate in such a context. This can only be appreciated on a case by case basis taking into account the regularity of the supplies, the characteristics of the product, the intentions of the supplier, etc. In principle, occasional supplies by charities or hobbyists should not be considered as taking place in a business related context."

I would consider GCC or React to fit this definition, while a hobby project like https://github.com/rui314/chibicc not to fit it.

chibicc

chibicc: https://github.com/rui314/chibicc (A reasonably digestible C implementation)

When you say a fork of LLVM, am I correct in assuming that you specifically mean a fork of Clang? I don't see how the compiler backend would affect support for language extensions, regardless of whether it's an exception to that such as Tcc, Cproc, the MIR C jitter, lacc, 8cc, 9cc, and chibicc. Most of those are not for production, excluding Cproc and Tcc (at least according to Suckless or Oasis).