Kria SOM has some ease-of-use designs for application developers. It provides software-like development experience on FPGA and SoC, such as real time reloading applications without rebooting the system. In order to allow updating PL design without rebooting Linux, it boots Linux from Arm® Cortex®-A53 and loads the FPGA bitstream using Linux. To ensure the board can always boot successfully and prevent the board get into brick status by accidental mistakes, the Kria SOM boot flow forces to boot Linux from QSPI mode and the boot firmware in QSPI is read-only. Linux will mount rootfs in the SD card. You can update the rootfs in the SD Card.
Vitis platform and application development can be divided into these parts:
Platform hardware creation in the AMD Vivado™ Design Suite. It exports an XSA file with clock, reset, AXI interface, and interrupt signals and properties.
Platform software preparation with common image or using PetaLinux tool, including Linux kernel, rootfs, device tree, and boot components.
Platform creation in the Vitis to combine all hardware and software components and generate XPFM description.
Create applications in Vitis against the platform. Vitis generates host application, xclbin and
sd_card.img.Write the
sd_card.imgto SD card or update host application and xclbin to an existing SD card.
Because the Kria SOM Starter Kit provides an off-the-shelf boot image and has its enhanced boot sequence, Vitis platform developers and application developers can skip some steps above. Here is a summary for what needs to be done by Kria platform and acceleration application developers.
| Procedure | Required Actions | Output | Skipped Actions |
|---|---|---|---|
| Platform Hardware | Same as step 1 | XSA | N/A |
| Platform Creation | Same as step 2; generate the device tree overlay for platform programmable logic (PL) of XSA; create Vitis platform | pl.dtbo, sysroot and XPFM | Skip adding the boot components |
| Application Creation | Same as step 3; Create application | Host App, XCLBIN | skip generating the sd_card.img |
| Transfer files and run | Use scp to copy generated files to Linux partition on SD card | skip writing sd_card.img |
NOTE: In step 2, after extracting the common image there are a lot of output components, the only valuable output product in this case is sysroot. It is used for host application cross-compilation. Because the boot images of KV260 Starter Kit is fixed, you do not need to generate any boot components, e.g., FSBL, etc.
NOTE: In this case, we assume you start to do this experiment after you have already had your board booted up successfully. If you do not, refer to kv260 getting started page.
The following chapters will explain the details about these steps.