R&D mode

You can enable R&D mode by passing the --enable-rd-mode flag to the flasher.

Note: This flag does not need to be passed to the EMMC image if you are flashing that as well.

You must use a Linux or a Mac OS X computer to enable R&D Mode, as the Windows update wizard will not allow you to enable/disable R&D Mode. Although, the Windows flasher will disable R&D Mode if you use it to reflash a device that has R&D Mode already enabled.

To switch back to production mode, use --disable-rd-mode.

[edit] What R&D mode does

  • sudo gainroot in the console can be used, without installing anything extra, to gain a root shell.
  • The power button turns on the tablet with a shortpress press as opposed to the longpress normally required.
  • N900: The keyboard backlight behind the left and right side of the keyboard flickers in response to system activity.

[edit] R&D mode flags

You can enable some R&D mode flags (flasher-3.5 --set-rd-flags=<flag>) for various features:

  • no-omap-wd - Disables the watchdog on the OMAP processor.
  • no-retu-wd - Disables the watchdog on retu.
  • no-lifeguard-reset - Disables the lifeguard process (lifeguard reboots the device when an important system process crashes).
  • serial-console - Enables the serial console (the serial port pins are next to the battery) and causes a shorter battery life.
  • no-usb-timeout - Unknown
  • sti-console - Unknown
  • no-charging - Disables charging via the USB port. bme will still be running in the background.
  • force-power-key - Omap bootreason will be always pwr_key. Maemo system will not see any reboots or watchdog resets. Instead Maemo will think that device was started by power key.

running the command without parameters gives a list of available modes: flasher-3.5 --set-rd-flags

maemo_flasher-3.5_2.4.5.3_beta/flasher-3.5 --set-rd-flag
flasher v2.4.5 (Jun 25 2009)

Possible R&D flags:

It seems enabling of R&D mode is causing device (N900) to power up on battery insert and USB-connect.