The ROM code creates the device list (order) based on information gathered from these locations:
- The first location is the sysboot[5:0] external configuration pins sensed in the device CTRL_CORE_BOOTSTRAP register. The sysboot[5:0] configuration pads have two main purposes: configure ROM code software in terms of interfaces and devices used for booting and configuring hardware after a POR or cold reset.
The SYSBOOT pins are used to index a booting device list from a table with possible booting scenarios. The order of examined booting devices is from the first to the third devices.
The following names are used in the tables:
- Memory types:
- Execute in place (XIP): NOR (CFI) flash memory or other XIP device
- NAND: NAND flash memories (non-XIP)
- SD: Removable SD card device
- eMMC: eMMC™ memory device
- QSPI_1: 1-bit SPI flash memories
- QSPI_4: 4-bit (Quad) SPI flash memories
- SATA: SATA-compatible devices such as solid state drives (SSDs) or hard-disk drives (HDDs)
- Peripheral interfaces:
- USB: HS USB 2.0 interface
- UART: UART interface
- Table 34-9 lists the permanent booting devices in bold typeface.
The above boot modes are described in detail in Section 34.3.5, Peripheral Booting and in Section 34.3.7, Memory Booting.