I am thinking of making a custom board for a device that will only need flashed once, during production. I wanted to check to make sure I'm thinking correctly about the process, could anyone with knowledge on the subject correct anything they see wrong, please?

  1. I can do development with an actual teensy 4.1 and save the compiled .bin or .hex code produced to use for flashing the actual product.
  2. Since I don't need a bootloader running all the time I can omit the MKL02Z32VFG4. I would also omit the DP83825 since I wont be using ethernet, as well as omitting the optional PSRAM and Flash pads.
  3. The rest of the device would follow the 4.1 schematic, with additions for my actual product.
  4. I would flash the W25Q64JVXGIM with my previously compiled code using an AVR ISP programmer over SPI and a flash program like AVRdude or something similar.

Would this be the complete process for setting up my product firmware? Will I also need to flash the i.MX RT1062 to make it run the code flashed to the W25Q64JVXGIM?

Thanks for any advice!