Going to be a hacky program for doing dynamic DNS with Cloudflare's API, on my home router, which is an old MIPS machine.
Initial work is just on getting Rust working on it.
I created a bind mount with a matching path to the project directory
from my real root, inside the mipsel chroot, to the project directory,
so we can feed linker commands into the chroot's gcc without fixing argument paths.
sudo mkdir -p mipsel/path/to/project/ddns
sudo mount --bind /path/to/project/ddns mipsel/path/to/project/ddns
This leads to needing to enter your sudo password at the link step. Do that.
I wrote a little C wrapper (lmips.c) to perform the chroot invocation and replace -lutil
in the linker flags with -lc, since the Rust tooling tries to link against a library
called libutil.so whose functions are part of libc.so on the target system.
(i.e., at least puts and exit are in there.)
This wrapper is itself wrapped by a shell program that performs the sudo invocation
necessary for using chroot.