# QCC730 boot flow Source: [https://docs.qualcomm.com/doc/80-Y8730-5/topic/qcc730_boot_flow.html](https://docs.qualcomm.com/doc/80-Y8730-5/topic/qcc730_boot_flow.html) QCC730 boot sequence can be divided into two relatively independent stages: - From PBL to SBL - From SBL to APP ## From PBL to SBL Source: [https://docs.qualcomm.com/doc/80-Y8730-5/topic/qcc730_boot_flow.html](https://docs.qualcomm.com/doc/80-Y8730-5/topic/qcc730_boot_flow.html) This is the first boot stage, which loads and executes the SBL. The PBL performs the following jobs after power-up: 1. Apply PBL patch if it exists 2. Initialize system resource 3. Check and handle boot reason 4. Read FDT to choose SBL image 5. Authenticate SBL image 6. Load image to RAM 7. Load PBL PATCH segment 8. Verify the hash of each image segment 9. Jump to SBL Note: In the above nine steps, - Step 5 is skipped if the boot is a warm boot. - Step 7 is skipped if this isn't an OTA new image. Figure : QCC730 boot sequence: PBL to SBL ## From SBL to APP Source: [https://docs.qualcomm.com/doc/80-Y8730-5/topic/qcc730_boot_flow.html](https://docs.qualcomm.com/doc/80-Y8730-5/topic/qcc730_boot_flow.html) Once SBL is loaded, the second boot stage starts. In this stage, SBL takes charge of the boot and performs the following jobs: 1. Read partition table/FDT from flash/RRAM to choose APP image 2. Authenticate selected APP image 3. Load RAM segments to RAM 4. Load RRAM segments to RRAM 5. Verify the hash for each segment 6. Jump to APP entry Note: Steps 2, 3, 4, 5 are skipped because the image is a BIN file. Figure : QCC730 boot sequence: SBL to APP Last Published: Apr 27, 2026 Previous Topic Configuration BIN binaries Next Topic Build and flash QCC730 images