This section describes the boot and configuration sequence for Zynq®-7000 SoC. See the Zynq-7000 SoC Technical Reference Manual (UG585) for more details on the available first stage boot loader (FSBL) structures.
BootROM on Zynq-7000 SoC
The BootROM is the first software to run in the application processing unit (APU). BootROM executes on the first Cortex® processor, A9-0, while the second processor, Cortex, A9-1, executes the wait for event (WFE) instruction. The main tasks of the BootROM are to configure the system, copy the FSBL from the boot device to the on-chip memory (OCM), and then branch the code execution to the OCM.
Optionally, you can execute the FSBL directly from a Quad-SPI or NOR device in a non-secure environment. The master boot device holds one or more boot images. A boot image is made up of the boot header and the first stage boot loader (FSBL). Additionally, a boot image can have programmable logic (PL), a second stage boot loader (SSBL), and an embedded operating system and applications; however, these are not accessed by the BootROM. The BootROM execution flow is affected by the boot mode pin strap settings, the boot header, and what it discovers about the system. The BootROM can execute in a secure environment with encrypted FSBL, or a non-secure environment. The supported boot modes are:
- JTAG mode is primarily used for development and debug.
- NAND, parallel NOR, Serial NOR (Quad-SPI), and Secure Digital (SD) flash memories are used for booting the device. The Zynq-7000 SoC Technical Reference Manual (UG585) provides the details of these boot modes. See Zynq-7000 Boot and Configuration AR#52538 for answers to common boot and configuration questions.