Add EM_RISCV constant

[nomadium]

Hi folks,

I was working with some RISC-V ELF binaries and I thought it would be convenient to have them properly recognised by this library so I'm submitting a small change to improve RISC-V architecture support.

Thanks.

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References:

• https://www.sco.com/developers/gabi/latest/ch4.eheader.html

• https://github.com/bminor/glibc/commit/94e73c95d9b5ac7d3b3f178e2ca03ef6b60e82aa

• https://www.google.com/search?q=EM_RISCV

[david942j]

Thanks for the PR! Only one feedback that I want the coverage be kept as 100%, please enhance the tests to cover the new line.

[nomadium]

Thanks for the feedback. Sure, no problem, I'll update the PR soon.

[nomadium]

@david942j it took me ages to add unit tests to this PR but hey, such is life.

My only concern at the moment it's that I added a binary (it's just a hello world) riscv64 file to the repo without a clear way how to build it.

I could update the Makefile to add a cross-compiler in similar way to what is done here:

https://github.com/popovicu/risc-v-bare-metal-fake-bios/blob/main/Makefile

But then this small library would be depending on the whole riscv64 toolchain and I don't think that's the right path.

[david942j]

How about adding a Dockerfile that could include all needed toolchain?

[nomadium]

I like that idea, do you have an example of another ruby gem shipping a Dockerfile?

[david942j]

You don't need a Ruby gem, just provide a Dockerfile under spec/files along with a README to describe the sequence of commands to generate the riscv binary (i.e. docker build; docker run... docker exec gcc ...). The Dockerfile can be based on the latest Ubuntu image and install required cross compiler.

As long as I can follow the README you provided to generate the same binary it's good enough :)