Power-On Sequence
At power-on, the flash boot block code initializes the hardware to a known state, then performs basic
power-on diagnostic tests to determine the integrity of the hardware. Initialization performs the
following functions:
1. Initializes CPU and memory controller.
2. Initializes and configures all PCI devices.
3. Initializes USB devices to a known state.
4. The unit boots the operating system.
Beep Codes
uBoot provides some feedback during startup according to the following table. If the system cannot
start up due to a catastrophic error (such as no RAM), no beep sounds; return the unit for service. If
the system can start up but encounters some other catastrophic error (such as the eMMC is
unreadable), 3 beeps are played; return the unit for service. In normal operation, 1 beep should
sound. If the system encounters a recoverable error such as the eMMC flash is corrupted, 2 beeps
sound to indicate the user should reflash the unit.
Number of Beeps Action
0 Return for service.
1 Normal operation.
2 Reflash the unit.
3 Return for service.
Power-On Sequence 5