Hardware reference guide

Chapter 3: The Software
User Interface
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• by pressing the OFF key-combination Blue + Enter.
If the unit is running on battery power, and the remaining battery power drops to
critical levels as reported by the battery pack, the system will transition gracefully to
the Suspend state, and no data will be lost.
If the unit is running on external power without a battery installed, and external
power is removed, the system will make a ‘non-graceful’ transition to the Suspend
state. The object store is preserved, the file system in flash is intact, but registry
changes that have not been stored in the registry files in flash are lost, running appli-
cations are lost, unsaved data is lost. Restart from this state is a cold boot.
3.2.3.2 Resume
During a Resume transition from the Suspend state, the boot process starts in the
same way as a cold boot. When going into Suspend, the main operating system
writes a value into the Power Management Scratch Pad register. This value can be
“run the main operating system on resume” or “run the boot loader on resume”.
When a value is read from this register on resume that corresponds to the value for
“run the main operating system on resume”, the bootloader jumps to the OS image
in RAM, and the boot continues. If the value read corresponds to the value “run the
boot loader on resume”, the bootloader continues to run, giving the user a command
prompt.
The user can go to the bootloader’s command prompt manually by:
• pressing and holding the Scan, Blue, and Enter keys simultaneously
for 6 seconds
• selecting Blue + 0 to get the start menu, then selecting Shut Down,
Bootloader.
3.2.4 User Interface
During the boot process, indicators let the user know what is happening:
• When the user presses the ON button, the four LEDs turn on momentarily
to confirm the button press.
• When the bootloader is loaded and running on the main processor, a
message is displayed on the terminal’s screen and on the console port.