Boot and Configuration

The purpose of this chapter is to show how to integrate and load boot loaders, bare-metal applications (For APU/RPU), and the Linux Operating System for a Versal™ ACAP. This chapter discusses the following topics:

  • System software: PLM, Arm® trusted firmware (ATF), U-Boot

  • Steps to generate boot image for standalone application.

  • Boot sequences for SD-boot, and QSPI and OSPI boot modes.

You can achieve these configurations using the Vitis™ software platform and the PetaLinux tool flow. While Versal ACAP CIPS and NoC (DDR) IP Core Configuration focused only on creating software blocks for each processing unit in the PS, this chapter explains how these blocks can be loaded as a part of a bigger system.

System Software

The following system software blocks cover most of the boot and configuration for this chapter.

Platform Loader and Manager

The platform loader and manager (PLM) is the software that runs on one of the dedicated processors in the Platform Management Controller (PMC) block of the Versal ACAP. It is responsible for boot and run time management, including platform management, error management, partial reconfiguration, and subsystem restart of the device. The PLM can reload images, and load partial PDIs and service interrupts. The PLM reads the programmable device image from the boot source and configures the components of the system including the NoC initialization, DDR memory initialization, programmable logic, and processing system, and then completes the device boot.

U-Boot

U-Boot acts as a secondary boot loader. After the PLM handoff, U-Boot loads Linux onto the Arm A72 APU and configures the rest of the peripherals in the processing system based on the board configuration. U-Boot can fetch images from different memory sources like eMMC, SATA, TFTP, SD, and QSPI. U-Boot can be configured and built using the PetaLinux tool flow.

Arm Trusted Firmware

The Arm Trusted Firmware (ATF) is a transparent bare-metal application layer executed in Exception Level 3 (EL3) on the APU. The ATF includes a Secure Monitor layer for switching between the secure and the non-secure world. The Secure Monitor calls and implementation of Trusted Board Boot Requirements (TBBR) makes the ATF layer a mandatory requirement to load Linux on the APU on Versal ACAP. The PLM loads the ATF to be executed by the APU, which keeps running in EL3 awaiting a service request. The PLM also loads U-Boot into DDR to be executed by the APU, which loads Linux OS in SMP mode on the APU. The ATF (bl31.elf) is built by default in PetaLinux and can be found in the PetaLinux Project images directory.

Generating Boot Image for Standalone Application

The Vitis software platform does not support automatic boot image creation for Versal architecture. To generate a bootable image, use Bootgen, which is a command line utility which is part of the Vitis software platform package. The principle function of Bootgen is to integrate the various partitions of the bootable image. Bootgen uses a Bootgen Image Format (BIF) file as an input and generates a single file image in binary BIN or PDI format. It outputs a single file image which can be loaded into non-volatile memory (NVM) (QSPI or SD Card). Use the following steps to generate a PDI/BIN file:

  1. Open the XSCT Console view in the Vitis IDE, if not already open, by clicking on Window → Show View. Type xsct console within the search bar of the Show View wizard. Click Open to open the console.

    ../../../../_images/image49.png

  2. Create a folder where you want to generate the boot image by typing the following command in the XSCT Console:

    mkdir bootimages
cd bootimages/

  3. Copy the sd_boot.bif file present within the <design-package>/<board-name>/ready_to_test/qspi_images/standalone/<cips or cips_noc>/<apu or rpu>/ directory, the PDI file present within <Vitis platform project>/hw/<.pdi-file>, and the application elf files present within the <Vitis application-project>/Debug folder to the folder created in step 2.

    Note

    If needed, open the sd_boot.bif file in a text editor of your choice and modify the name of the PDI or elfs as per your Vitis projects.

  4. Run the following command in the XSCT Console view.

    `bootgen -image <bif filename>.bif -arch versal -o BOOT.BIN`

    The following log is displayed in the XSCT Console view.

    ../../../../_images/image51.jpeg

Boot Sequence for SD-Boot Mode

The following steps demonstrate the boot sequence for the SD-boot mode.

  1. To verify the image, copy the required images to the SD card:

    • For standalone, copy the BOOT.BIN to the SD card.

    • For Linux images, navigate to the <plnx-proj-root>/images/linux and copy BOOT.BIN, Image, rootfs.cpio.gz.uboot, boot.scr to the SD card.

    Note

    You can either boot the VCK190/VMK180 board using the ready-to-test images as part of the released package path, <design-package>/<vck190 or vmk180>/ready_to_test/qspi_images/linux/, or refer to Example Project: Creating Linux Images Using PetaLinux to build your own set of Linux images using the PetaLinux tool.

  2. Load the SD card into the VMK180/VCK190 board, in the J302 connector.

  3. Connect the Micro USB cable into the VMK180/VCK190 Board Micro USB port (J207), and the other end into an open USB port on the host machine.

  4. Configure the board to boot in SD-Boot mode by setting switch SW1 as shown in the following figure.

    ../../../../_images/sd_boot_mode.JPG

  5. Connect 12V power to the VMK180/VCK190 6-Pin Molex connector.

  6. Start a terminal session, using Tera Term or Minicom depending on the host machine being used. Set the COM port and baud rate for your system, as shown in the following figure.

    ../../../../_images/image46.png

  7. For port settings, verify COM Port in the device manager and select the com port with interface-0.

  8. Turn on the VMK180/VCK190 board using the power switch (SW13).

    Note

    For standalone images, the respective logs are displayed on the terminal. For Linux images, you can log in using user: root and pw: root after the boot-up sequence on the terminal. After that, run gpiotest on the terminal. You will see logs as shown in the following figure.

    ../../../../_images/led_example_console_prints.PNG

Boot Sequence for QSPI Boot Mode

This section demonstrates the boot sequence for the QSPI boot mode. For this, you need to connect a QSPI daughter card (part number: X_EBM-01, REV_A01) as shown in the following figure:

Figure 2: Daughter Card on VCK190

../../../../_images/image54.jpeg

Note

For standalone, copy the BOOT.BIN to the SD card. For Linux images, you can either boot the VCK190/VMK180 board using the ready-to-test images as part of the released package path, <design-package>/<vck190 or vmk180>/ready_to_test/qspi_images/linux/, or refer to Example Project: Creating Linux Images Using PetaLinux to build your own set of Linux images using the PetaLinux tool.

You need to flash the images to the daughter card, using the following steps: .. note:: The following steps use the SD boot mode initially to load an image to indirectly program the QSPI Flash.

  1. With the card powered off, install the QSPI daughter card.

  2. Set the boot mode switch SW1 to ON-OFF-OFF-OFF to SD Boot mode as shown in the following figure.

    ../../../../_images/sd_boot_mode.JPG

  3. Insert the SD card in the SD card slot on the board, as follows:

    ../../../../_images/image56.jpeg

  4. Power on the board. At the U-Boot stage, when the message “Hit any key to stop autoboot:” appears, hit any key, then run the following commands to flash the images on the QSPI daughter card:

    sf probe 0 0 0
sf erase 0x0 0x10000000
fatload mmc 0 0x80000 BOOT.BIN
sf write 0x80000 0x0 <BOOT.BIN_filesize_in_hex>
fatload mmc 0 0x80000 Image
sf write 0x80000 0xF00000 <Image_filesize_in_hex>
fatload mmc 0 0x80000 rootfs.cpio.gz.u-boot
sf write 0x80000 0x2E00000 <rootfs.cpio.gz.u-boot_filesize_in_hex>
fatload mmc 0 0x80000 boot.scr
sf write 0x80000 0x7F80000  <boot.scr_filesize_in_hex>

  5. After flashing the images, turn off the power switch on the board, and change the SW1 boot mode pin settings to QSPI boot mode, that is ON-OFF-ON-ON as follows:

    ../../../../_images/image52.png

  6. Power cycle the board. The board now boots up using the images in the QSPI flash.

Boot Sequence for OSPI Boot Mode

To configure the design for the OSPI boot mode, see OSPI Boot Mode Configuration. This section demonstrates the boot sequence for the OSPI boot mode. For this, you need to connect a OSPI daughter card (part number X-EBM-03 REV_A02) as shown in the following figure:

../../../../_images/X-EBM-03_OSPI_Daughter_card.jpg

Note

For standalone, copy the BOOT.BIN to the SD card. For Linux images, you can either boot the VCK190 or VMK180 board using the ready-to-test images as part of the released package path, <design-package>/<vck190 or vmk180>/ready_to_test/ospi_images/linux, or refer to Example Project: Creating Linux Images Using PetaLinux to build your own set of Linux images using the PetaLinux tool.

To flash the images to the daughter card, use the following steps:

Note

The following steps use the SD boot mode initially to load an image to indirectly program the OSPI Flash.

  1. With the card powered off, install the OSPI daughter card.

  2. Set the boot mode switch SW1 to ON-OFF-OFF-OFF to SD boot mode as shown in the following figure.

    ../../../../_images/sd_boot_mode.JPG

  3. Insert the SD card in the SD card slot on the board, as follows:

    ../../../../_images/image56.jpeg

  4. Power on the board. At the U-Boot stage, when the message “Hit any key to stop autoboot:” appears, hit any key, then run the following commands to flash the images on the OSPI daughter card:

    sf probe 0 0 0
sf erase 0x0 0x10000000
fatload mmc 0 0x80000 BOOT.BIN
sf write 0x80000 0x0 <BOOT.BIN_filesize_in_hex>
fatload mmc 0 0x80000 Image
sf write 0x80000 0xF00000 <Image_filesize_in_hex>
fatload mmc 0 0x80000 rootfs.cpio.gz.u-boot
sf write 0x80000 0x2E00000 <rootfs.cpio.gz.u-bootfilesize_in_hex>
fatload mmc 0 0x80000 boot.scr
sf write 0x80000 0x7F80000  <boot.scr_filesize_in_hex>

  5. After flashing the images, turn off the power switch on the board.

  6. Change the SW1 boot mode pin settings to OSPI boot mode, that is ON-OFF-OFF-OFF.

  7. Power cycle the board. The board now boots up using the images in the OSPI flash.

Note

For VMK180 Production board, OSPI images are not provided as part of design package. Only VCK190 OSPI images are shared under design package.

Boot Sequence for eMMC Boot Mode

To configure the design for the eMMC boot mode, see eMMC Boot Mode Configuration. This section demonstrates the boot sequence for the emmc boot mode. For this, you need to connect a eMMC daughter card (part number X-EBM-02, REV_A02) as shown in the following figure:

../../../../_images/X-EBM-02_emmc_Daughter_card.jpg

Note

For standalone, copy the BOOT.BIN to the SD card. For Linux images, you can either boot the VCK190 or vmk180 board using the ready-to-test images as part of the released package path, <designpackage>/<vck190 or YAML_DT_BOARD_FLAGS_vmk180>/ready_to_test/emmc_images/linux, or refer to Example Project: Creating Linux Images Using PetaLinux to build your own set of Linux images using the PetaLinux tool.

To format the eMMC flash on Versal board for the first time, use the following steps:

  1. With the card powered off, install the eMMC daughter card.

  2. Set the boot mode switch SW1 to ON-ON-ON-ON JTAG Boot mode, as shown in the following figure.

    ../../../../_images/vck190_jtag_boot_mode_sw1_settings.png

    This example uses the XSCT console to download a BOOT image file (BOOT.BIN). It uses the U-Boot console to load Linux images to format the eMMC flash.

  3. Ensure that the Ethernet cable is connected from the host to the board. Set up dhcp and tftpb server on the host.

  4. Copy the Linux images BOOT.BIN, Image, rootfs.cpio.gz.u-boot, and boot.scr to host tftp home directory.

  5. In the XSCT console, connect to the target over JTAG using the connect command:

    xsct% connect

    The connect command returns the channel ID of the connection.

  6. Run the target command to list the available targets and to select a target using its ID. The targets are assigned IDs as they are discovered on the JTAG chain, so the IDs can change from session to session.

    xsct% targets

  7. Download the BOOT.BIN on the VCK190 board using the following commands to get the U-Boot console.

    xsct% targets 1
xsct% rst
xsct% device program BOOT.BIN

    After executing this command, you can see the PLM and U-Boot boot logs on the serial console.

  8. At the U-Boot stage, when the message “Hit any key to stop autoboot:” appears, hit any key, then run the following commands to flash the images on the eMMC daughter card:

    dhcp
tftpboot 0x80000 Image
tftpboot 0x2000000 rootfs.cpio.gz.u-boot
booti 0x80000 0x2000000 0x1000

    After executing above U-Boot commands, Linux starts booting and stops at Linux console prompt waiting for user input commands.

  9. Run the following commands from the Linux console prompt to create the eMMC Linux bootable partition and format the eMMC with FAT32 filesystem.

    root@xilinx-vmk180-2021_1:~# fdisk /dev/mmcblk0
The number of cylinders for this disk is set to 233472.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): m
Command Action
a       toggle a bootable flag
b       edit bsd disklabel
c       toggle the dos compatibility flag
d       delete a partition
l       list known partition types
n       add a new partition
o       create a new empty DOS partition table
p       print the partition table
q       quit without saving changes
s       create a new empty Sun disklabel
t       change a partition's system id
u       change display/entry units
v       verify the partition table
w       write table to disk and exit

Command (m for help): n
Partition type
p   primary partition (1-4)
e   extended
p
Partition number (1-4): 1
First sector (16-14942207, default 16):
Using default value 16
Last sector or +size{,K,M,G,T} (16-14942207, default 14942207):
Using default value 14942207

Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table
fdisk: WARNING: rereading partition table failed, kernel still uses old table: Device or resource busy

root@xilinx-vmk180-2021_1:~# mkfs.vfat -F 32 -n boot /dev/mmcblk0p1

    eMMC flash is formatted with the FAT32 filesystem.

To flash the Linux images to the eMMC Flash, use the following steps:

  1. With the card powered off, install the eMMC daughter card.

  2. Set the boot mode switch SW1 to ON-ON-ON-ON JTAG Boot mode, as shown in the following figure.

    ../../../../_images/vck190_jtag_boot_mode_sw1_settings.png

    This example uses the XSCT console to download a BOOT image file (BOOT.BIN). It uses the U-Boot console to load the Linux images to EMMC flash.

  3. Ensure that the Ethernet cable is connected to the board. Setup dhcp and tftpb server on the host.

  4. Copy the Linux images BOOT.BIN, Image, rootfs.cpio.gz.u-boot, and boot.scr to the host tftp home directory. Also, ensure that the eMMC card is formatted with FAT32 filesystem as explained in the previous section, before copying the images from the U-Boot for the first time.

  5. In the XSCT console, connect to the target over JTAG using the connect command:

    xsct% connect

    The connect command returns the channel ID of the connection.

  6. Run the targets command to list the available targets. Select a target using its ID. The targets are assigned IDs as they are discovered on the JTAG chain, so the IDs can change from session to session.

    xsct% targets

  7. Download the BOOT.BIN on the VCK190 board using the following commands to get the U-Boot console.

    xsct% targets 1
xsct% rst
xsct% device program BOOT.BIN

    After executing this command, you can see the PLM and U-Boot boot logs on the serial console.

  8. At the U-Boot stage, when the message “Hit any key to stop autoboot:” appears, hit any key, then run the following commands to flash the images on the eMMC daughter card:

    fatls mmc 0  // to check emmc is formatted or not.
dhcp
tftpb 0x80000 BOOT.BIN
fatwrite mmc 0 0x80000 BOOT.BIN $filesize
tftpb 0x80000  Image
fatwrite mmc 0 0x80000 Image $filesize
tftpb 0x80000  rootfs.cpio.gz.u-boot
fatwrite mmc 0 0x80000 rootfs.cpio.gz.u-boot $filesize
tftpb 0x80000  boot.scr
fatwrite mmc 0 0x80000 boot.scr $filesize

  9. After flashing the images, turn off the power switch on the board, and change the SW1 boot mode pin settings to eMMC boot mode, that is OFF-ON-ON-OFF.

  10. Power cycle the board. The board now boots up using the images in the eMMC flash.