Ref:

1. https://nuttx.apache.org/docs/latest/guides/cpp_cmake.html
2. apache/nuttx#5530

Build:

1. How to build Nutxx

$ git clone https://github.com/huanglilong/stm32h7_fmu

$ git submodule update --init --recursive

$ cmake -B build;cmake --build build

2. How to update firmware

$ st-flash write ./build/fmu_nuttx.bin 0x8000000

3. Testing with nsh

$ reset MCU

$ screen /dev/ttyACM0 115200 8N1

![nsh testing](figs/nsh.png)