Booting the PCMM2G Controller

This topic explains the boot sequence for the PCMM2G controller.

The PCMM2G controller contains these partitions: Active, Boot, Data, and Inactive.

Figure 1: PCMM and PCMM2G Partitions

Active Partition

The Active partition:
- Contains the entire operating system and the KAS Runtime.
- Is where the controller is currently booted from.
  - It contains the current version of the operating system and KAS Runtime.
  - When the user downloads a new version of firmware, it is loaded onto the Inactive partition.
  - When the loading is complete, the controller reboots to the Inactive partition, making it the new Active partition.
If the Active partition cannot boot up to an operable state, the controller can boot up a USB flash drive containing a recovery image.

The Boot partition contains the U-Boot, a universal bootloader.
- The bootloader initializes the hardware and loads the operating system.

The Data partition contains the:
- KAS application, user data, logs, and crash reports.
- EtherCAT and controller backup files.

The Inactive partition:
- Contains the entire operating system and the KAS Runtime.
- Serves as a fallback.
  - If booting up the Active partition fails, the controller attempts to boot up from the Inactive partition.
If the Inactive partition cannot boot up to an operable state, the controller can boot up from a USB flash drive containing a recovery image.
The user can force booting up from the inactive partition by holding the B3 button in while powering on the controller.
- This is one recourse to use if the controller does not become operational when booting off from the active partition.