Flashing over USB
=================

This method allows updating the stock firmware on the keyboard.

Flashing tool ppkb-usb-flasher can be used to flash the firmware over USB.
You'll have to solder USB cable to the keyboard controller board to be able
to use this method.

For example to build and flash your own firmware you could run these
commands:

   # save the original firmware in case you want to restore it

   ./ppkb-usb-flasher info > saved-info.txt
   ./ppkb-usb-flasher --rom-out saved-rom.bin read

   # build the new firmware (you may need sdcc 4.1, older versions may
   # miscompile the firmware)

   (cd firmware && ./build.sh)

   # flash the new firmware

   ./ppkb-usb-flasher --rom-in firmware/build/fw-stock.bin write reset



Full help output
----------------

Usage: ppkb-usb-flasher [--rom-in <path>] [--rom-out <path>] [--verbose]
                        [--help] [<read|write|info|reset>...]

Options:
  -i, --rom-in <path>   Specify path to binary file you want to flash.
  -o, --rom-out <path>  Specify path where you want to store the contents
                        of code ROM read from the device.
  -s, --size <size>     Specify how many bytes of code rom to flash
                        starting from offset 0x2000 in the rom file.
  -v, --verbose         Show details of what's going on.
  -h, --help            This help.

Commands:
  info      Display information about the firmware.
  read      Read ROM from the device to --rom-out file.
  write     Flash ROM file to the device from --rom-in.
  reset     Perform software reset of the MCU.

Format of the ROM files is a flat binary. Only the part of it starting
from 0x2000 will be flashed. Use -s to specify how many bytes to write.


Flashing over I2C
=================

This method uses stock firmware's flashing interface to allow writing user's
own firmware to the keyboard, while keeping the stock firmware intact.

Stock firmware will remain present and available for future updates of the
users firmware.

You can use this method without having to disassemble the keyboard, or
solder anything.

You'll need to build the user firmware in a special way, so that it's placed
at address 0x4000 in code ROM. Interrupt vectors are forwarded with 0x4000
offset.


For example to build and flash your own firmware you could run these
commands:

   # build the new firmware (you may need sdcc 4.1, older versions may
   # miscompile the firmware)

   (cd firmware && ./build.sh)

   # flash the new firmware

   ./ppkb-i2c-flasher --rom-in firmware/build/fw-user.bin write reset

Depending on the user firmware, you may need to change stock firmware entry
method using -e option.


Full help output
----------------

Usage: ppkb-i2c-flasher [--rom-in <path>] [--rom-out <path>] [--verbose]
                        [--help] [<read|write|erase|info|reset>...]

Options:
  -i, --rom-in <path>   Specify path to binary file you want to flash.
  -o, --rom-out <path>  Specify path where you want to store the contents
                        of code ROM read from the device.
  -s, --size <size>     Specify how many bytes of code rom to flash
                        starting from offset 0x4000 in the rom file.
  -e, --entry <manual|i2c|none>
                        Specify how to enter the stock firmware:
                        - manual: Ask the user to power-cycle the keyboard
                        - i2c: Send I2C command to make supporting user
                        - none: Assume stock firmware is already running
  -v, --verbose         Show details of what's going on.
  -h, --help            This help.

Commands:
  info      Display information about the current firmware.
  read      Read ROM from the device to --rom-out file.
  write     Flash ROM file to the device from --rom-in.
  erase     Erase the user firmware.
  reset     Perform software reset of the MCU.

Format of the ROM files is a flat binary. Only the part of it starting
from 0x4000 will be flashed. Use -s to specify how many bytes to write.
The stock firmware between 0x2000 and 0x4000 will be preserved.