# Debug

The universal asynchronous receiver/transmitter (UART) logs enable you
to monitor and debug data exchanged using a UART interface between the
Qualcomm Linux software and a device.

The sample UART logs can help you identify the various stages of system
bootup. In the event of a crash, you can use these logs to do the
following:

- Determine the stage at which the crash occurred
- Gain a high-level understanding of the execution process

- [PBL/XBL log](https://docs.qualcomm.com/doc/80-70017-4/topic/bootloader-logs.html)
The sample primary boot loader/eXtensible boot loader (PBL/XBL) log
indicates the start and end of the PBL and XBL.
- [UEFI log](https://docs.qualcomm.com/doc/80-70017-4/topic/uefi-log.html)
The UEFI log provides information about the start and end of UEFI.
- [Linux log](https://docs.qualcomm.com/doc/80-70017-4/topic/hlos-logging.html)
The sample log signifies the start of the Linux boot process.
- [Capsule update logs](https://docs.qualcomm.com/doc/80-70017-4/topic/capsule-update-logs.html)
The capsule update log provides information about the start and end of the capsule update.

Last Published: Dec 30, 2024

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