sermon.txt

The serial monitor can be located at any location. The default is $E00.

By default, it uses a 9600 bps serial line on a 4MHz quartz. You can
easily change those values, to use for example 115200 bps with a 20MHz
oscillator.

Each time the serial monitor is ready to get a command, it prints ">".
Commands are one character, and acked by "!" when all the paramters have
been read or "?" if the command is unknown.

8 bits values are transmitted as two hexa digits.
16 bits values are transmitted as four hexa digits. Case is insensitive.

Protocol: (spaces do not belong to the protocol, -> indicates the answer)
  f NNNN -> XXXX     Read content of flash memory word NNNN
  F NNNN XXXX        Write content of flash memory word NNNN (14 bits)
  e NN -> XX         Read content of eeprom memory byte NN
  E NN XX            Write content of eeprom memory byte NN
  m NN -> XX         Read content of memory (low bank) byte NN
  M NN XX            Write content of memory (low bank) byte NN
  X NNNN             Jump to an arbitrary address
  O                  Jump to firmware (see below)
  o -> NNNN          Get offset for firmware installation

If you want to keep your bootloader running when you start your device,
you should have your loader read the offset returned by the "o" command
and add this to all the flash addresses between 0 and 2.

For example, if the boot loader is installed at address $E00, the offset
return by the "o" command will be $E03. The firmware command "O" will
jump to this address.