2.9.1. About the baremetal setup
This setup does not use the Linux kernel nor Buildroot at all: it just runs your very own minimal OS.
x86_64 is not currently supported, only arm and aarch64: I had made some x86 bare metal examples at: https://github.com/cirosantilli/x86-bare-metal-examples but I’m lazy to port them here now. Pull requests are welcome.
The main reason this setup is included in this project, despite the word "Linux" being on the project name, is that a lot of the emulator boilerplate can be reused for both use cases.
This setup allows you to make a tiny OS and that runs just a few instructions, use it to fully control the CPU to better understand the simulators for example, or develop your own OS if you are into that.
You can also use C and a subset of the C standard library because we enable Newlib by default. See also:
Our C bare-metal compiler is built with crosstool-NG. If you have already built Buildroot previously, you will end up with two GCCs installed. Unfortunately I don’t see a solution for this, since we need separate toolchains for Newlib on baremetal and glibc on Linux: https://stackoverflow.com/questions/38956680/difference-between-arm-none-eabi-and-arm-linux-gnueabi/38989869#38989869