I am not working much on embedded at the moment, however that's because I am still waiting for upstream Arduino support (AVR-Rust).
For the best Rust documentation, check out the official homepage, they have a section about embedded.
j already summarized the situation pretty well. There are a lot of C Kernels you can use, and you can either write your own wrapper, or use a more common Kernel, like Linux, which has a target in rustc. If you pack the low-level knowledge, you can write software directly on hardware, so anything is possible.
However, there are also Kernels in pure Rust! For example Tock will enable you to write applications on ARM Cortex M processors easily.
Keep in mind, though, that the Rust ecosystem is still young and most crates are still in beta. That might be a problem for your company and you will have to consider the risks vs the benefits.
Nicolas Bouhours
Software engineer