Host Firmware Notes

Some notes about the Linux host firmware (see this GitHub repo).

• UARTs don't work in DMA mode
  • All UARTs (including the high speed RF TTY/serial spew) can only operate in interrupt driven mode. This is pretty inefficient
• GPIO IRQs don't work
  • Kernel drivers (such as buttons) fail to get external interrupts
  • Buttons need to be operated in polling mode