BL602 serial flasher
blflash is written in rust. It requires the latest environment of rust, which you can get via running 'rustup update'. You can build blflash by running 'cargo build'.
Inspired by https://github.com/esp-rs/espflash, https://github.com/bouffalolab/BLOpenFlasher
ISP documentation: https://github.com/bouffalolab/bl_docs/tree/main/BL602_ISP