# Boot

Boot is the process where the system software is initiated using a set of predefined
    instructions from the ROM. The system loads and runs the operating system, and configures the
    devices after initializing the required software.

- **[Cold boot flow](https://docs.qualcomm.com/doc/80-88500-4/topic/9_Cold_boot_flow.html)**  

Cold boot is a process of starting the system from a power-off state. Cold boot begins with the execution of the primary boot loader (PBL).
- **[Configuration data table for boot loader](https://docs.qualcomm.com/doc/80-88500-4/topic/10_Boot_loader_configuration.html)**  

A configuration data table (CDT) is a data block that contains     platform/device-dependent data such as the hardware platform ID and DDR SDRAM configuration. The     CDT is available in storage (universal flash storage, embedded multimedia card, or     electronically erasable programmable read-only memory) or is linked with the eXtensible boot     loader (XBL).
- **[Boot configuration GPIOs](https://docs.qualcomm.com/doc/80-88500-4/topic/11_Boot_configuration_GPIOs.html)**  

The boot configuration control is implemented based on the input values of the     boot-related GPIOs.
- **[Force boot from USB 3.1](https://docs.qualcomm.com/doc/80-88500-4/topic/12_Force_boot_from_USB_3_1.html)**  

During development or factory production, a boot from the primary USB 3.1 port can be     forced by GPIO\_132.

**Parent Topic:** [System](https://docs.qualcomm.com/doc/80-88500-4/topic/7_System.html)

Last Published: Aug 18, 2023

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