supermin

He briefly mentions dietlibc ("not evolving anymore") and ulibc. I think he'd be better off contributing to those projects (or musl). You might start off thinking you only need system calls, but at some point you'll want to print something, and even a basic 'printf' will be very handy. FWIW I have built a program that needs a tiny initramfs[1] and we've found that dietlibc and musl worked really well producing very tiny binaries. glibc is terrible - it links huge amounts of code into even the smallest program. [1] https://github.com/libguestfs/supermin/blob/86fd6f3e86ab99d5...

I used dietlibc as a replacement for glibc in supermin, when making an initramfs. As background the size of the initramfs is key for boot performance since qemu takes quite some time (where "some time" means milliseconds) to load a large initramfs; and the binaries in the initramfs are usually statically linked. The final size of the init binary was about 1/40th as big as when using glibc: https://github.com/libguestfs/supermin/blob/c97b3917068597a0...

Looks good. The reason I know a bit about this is I had the same "bin2o" hacky script that used objcopy. It broke every time someone found a new architecture or platform (ie. having to choose the correct -O and -B flags is non-trivial if you want to support every architecture). The solution (which is not really much better than yours) is a script that creates some assembler and assembles it: https://github.com/libguestfs/supermin/blob/master/src/bin2s... I think it's bad that such a simple thing is so hard to do. Edit: In fact looking at the script now I can see we really should be using .rodata instead of .data. That bug has survived for at least 4 years. Patch posted: https://www.redhat.com/archives/libguestfs/2015-December/msg...

Supermin is actively developed. The last commit was 2 days ago. https://github.com/libguestfs/supermin/commits/master Having said that, it's not relevant to what the OP wants to do. libguestfs, however, is very relevant.