See this blog entry for the start of the series and background for this code.

• SDCC Compiler
• Meson Build System
• STC89C52RC development kit or bootstrap circuits explained here

meson build
ninja -v -C ./build

These examples use stcgal as flashing tool. Flashing for particular versions of the firmware can be done via ninja. My BSL version of the chip was not supported by the mainline stcgal, nrifes version seemed to work better.

# Power target off
ninja -v -C ./build flash_<hexname>
# Power target on
# Power-cycle target to see new firmware running

This demo is a simple hello world application that toggles a LED on pin P2.0.

# Flash using ...
ninja -v -C ./build flash_00_hello
# Adjust the meson.build file to point to the COM port your serial flasher enumerates to.

Manual boostrap of this example without a dev-kit should be doable as follows.

Drawing source.

(C) 2022 Thomas Reidemeister