This is a small tool that runs an ELF executable on Bouffalo Lab SoCs without
touching the flash contents. It communicates with the boot ROM over UART. It is
mostly focused on BL808, but it uses the unmodified image header definitions
from bflb-mcu-tool, so it should be easy to extend to other SoCs.
Run loader.py. Its inputs are the firmware file and a configuration file. The
configuration file sets fields in the boot header, such as clock and CPU setup.
Default files are provided for BL602 and BL808, but they may need to be
adjusted if your MCU has some eFuses set. Fields such as the load and entry
addresses are automatically updated from the ELF file.
The tool uses a safe, slow baud rate by default, but larger values of at least 2 Mbaud are known to work.
See below or run python3 loader.py --help for the full help text.
usage: loader [-h] [-b BAUD] [-C CFG] [-c {bl602,bl808}] [-p PORT] firmware
Load an ELF to the MCU's RAM and execute it.
positional arguments:
firmware ELF executable file path
options:
-h, --help show this help message and exit
-b BAUD, --baud BAUD Serial port baud rate
-C CFG, --cfg CFG Config file with values for boot header fields
-c {bl602,bl808}, --chip {bl602,bl808}
MCU variant connected to the serial port
-p PORT, --port PORT Serial port device path
This repository also contains demo applications for testing the loader. They do nothing useful on their own. See the Makefile for more details. The loader itself is pure Python, and does not require compiling the demo applications.