Image-Build.md

Bootloader build instructions

Here are instructions on how to produce a final flashable image.

The idea is the following:

1. You build the containers that are necessary for building the bootloader and image-builder:

   ./scripts/setup_containers.sh

2. Now you can build the bootloader. The scripts mounts your current workspace, so changes to the files will be reflected in the build:

   ./scripts/build_bootloader.sh

   This will output the bootloader at bootloader.bin

3. Now we want to create an image using the image-builder. Let's say you have osiris.bin that you want to create an image from:

   ./scripts/build_image.sh write -b bootloader.bin -1 osiris.bin

   Here we specify only the first slot (the other slots will be filled with a copy of the exact same binary as well), but you can also add -2 and -3. Note that this is done in Docker by mounting your current directory, so use only relative paths or adjust the script.

4. Now a file with exactly 2MB was generated at output_image.bin. This is the file we can flash onto our chip:

   st-flash --reset write output_image.bin 0x8000000

If st-flash doesn't believe you that your chip actually has 2MB of flash storage, you can add the --flash=0x200000 flag to convince it.