After reset, the Kryo Silver core 0 comes out of reset and then executes PBL On Kryo Silver core 0, applications PBL initializes hardware (clocks, and so on), CPU caches and MMU, and detects the boot device as per the boot option configuration:  Default boot option: UFS > SD > USB  Default boot option: overridden by EDL cookie or Force USB GPIO 2a. Loads and authenticates XBL-SEC (region #0) from the boot device to OCIMEM 2b. Loads and authenticates XBL-Loader (region #1) from the boot device to Boot IMEM 2c. Loads and authenticates XBL-Debug (region #2) from the boot device to OCIMEM Jumps to XBL-SEC 3. XBL-SEC runs the security configuration in EL3 mode, and then executes the XBL-Loader in EL1 mode XBL-Loader initializes hardware and firmware images, CPU caches, MMU, boot device, XBLConfig, PMIC driver, and DDR. It performs DDR training if applicable, executes an SCM call to XBL-SEC to initialize PIMEM, and initializes clocks and configures the clock frequencies as per clock plan 4a. Loads and authenticates applications debug policy (APDP) image from the boot device 4b. If, DLOAD cookie is set, loads, and authenticates XBL-RAM dump and jumps to XBL-RAM dump to collect crash dump 4c. Initializes SMEM (shared memory) and fills platform ID and RAM partition table 4d. Loads and authenticates AOP image from the boot device and then bring AOP out of reset 4e. Loads and authenticates DEVCFG (TZ device configuration) image from the boot device 4f. Loads SEC.dat (fuse blowing data) image from the boot storage if exists 4g. Loads and authenticates QTEE image from the boot device 4h. Loads and authenticates QHEE image from the boot device 4i. Loads and authenticates ABL image from the boot device 4j. Executes an SCM call to XBL-SEC to jump to QTEE cold boot是什么意思

这段话是描述了一个系统启动的过程，包括初始化硬件、加载和验证引导程序，以及执行一系列的初始化和配置操作。其中，XBL-SEC 和 XBL-Loader 是引导程序的两个主要组成部分，它们负责初始化硬件和固件镜像，执行 DDR 训练等操作。在引导程序的执行过程中，还会加载和验证其他的固件镜像，例如 AOP、DEVCFG、SEC.dat、QTEE、QHEE 和 ABL 等。最后，系统会执行一个 SCM 调用，以启动 QTEE 冷启动。