PetaLinux Design Flow

0. Environment set up

• PetaLinux relies on Python 2.7. It would ease the process by creating a Conda environment with Python 2.7 enabled and doing PetaLinux work in it.
• Sometime you should source the following file to run PetaLinux smoothly
  $PetaLinux/components/yocto/source/arm/environment-setup-cortexa9t2hf-neon-xilinx-linux-gnueabi

1. Create a new project

petalinux-create -t project --template zynq -n $(project_name)

or

petalinux-create -t project -s $(bsp_file)

2. Import hardware information and configure

Refer to the directory where the .hdf file is instead of the path to the .hdf file.

petalinux-config --get-hw-description=$(path_to_hdf)

The following is a list of requirements for a Zynq hardware project to boot Linux (UG980):

1. One Triple Timer Counter (TTC) (Required)
   IMPORTANT:
   If multiple TTCs are enabled, the Zynq Linux kernel uses the first TTC block from the device tree.
   Please make sure the TTC is not used by others.
2. External memory controller with at least 32MB of memory (Required)
3. UART for serial console (Required)
   IMPORTANT: If soft IP is used, ensure the interrupt signal is connected
4. Non-volatile memory (Optional) e.g. QSPI Flash, SD/MMC
5. Ethernet (Optional, essential for network access)
   IMPORTANT: If soft IP is used, ensure the interrupt signal is connected

HDF文件是一个zip文件，可以直接使用7zip解压；也可以把后缀改为zip，使用其它工具解压。解压后可以得到文件design_1.hwh, design_1_bd.tcl, design_1_wrapper.bit, psu_init.c, psu_init.h, psu_init.html, psu_init.tcl, psu_init_gpl.c, psu_init_gpl.h, sysdef.xml。

• psu_init.c, psu_init.h是Vivado根据工程师配置的硬件信息，产生的C代码，会被编译进FSBL，用于初始化MPSoC的MIO，DDR等。
• design_1_bd.tcl是一个TCL脚本，Vivado可以执行这个脚本恢复整个Vivado工程。
• sysdef.xml，design_1_bd.tcl都含有工具版本信息，可以查看Vivado的版本。

2.1 Ethernet configuration

Subsystem AUTO Hardware Settings Ethernet Settings

2.2 tftp server configuration

u-boot Configuration TFTP server IP address

Image Packaging Configuration tftpboot directory

2.3 Firmware information

Firmware Version Configuration

2.4 Change to boot from SD card

Image Packaging Configuration Root filesystem type SD card

3. Create a new application/module

petalinux-create -t apps -n $(app_name)

petalinux-create -t modules -n $(module_name)

The PL device tree is located at:
./components/plnx_workspace/device-tree/device-tree/pl.dtsi

4. Configure kernel

petalinux-config -c kernel

For DMA, may need to disable DMAS engine:
Device Drivers DMA Engine support Xilinx AXI DMAS Engine. Uncheck the option. (per https://lauri.vosandi.com/hdl/zynq/xilinx-dma.html)

5. Configure rootfs

petalinux-config -c rootfs

Select modules/apps to be enabled:

apps

6. Build

petalinux-build

7. Create BOOT.bin

petalinux-package --boot --fsbl images/linux/zynq_fsbl.elf --fpga images/linux/system.bit --u-boot --force

or

create a file, e.g., boot.bif (UG1283)

image : {
        [bootloader] images/linux/zynq_fsbl.elf
        images/linux/system.bit
        images/linux/u-boot.elf
}

And then, run command:

bootgen -image boot.bif -o i BOOT.BIN -w on

8. Boot file system from SD card

a) Change configuration if using standalone rootfs

When reading hardware configuration (petalinux-config --get-hw-description=xxx)

Select Image Packaging Configuration Root filesystem type SD card

Or when configuring:

petalinux-config

Select Image Packaging Configuration Root filesystem type SD card

If using default rootfs, keep this option unchanged:
Image Packaging Configuration Root filesystem type INITRAMFS

b) Generate images

petalinux-build
petalinux-package --boot --fsbl images/linux/zynq_fsbl.elf --fpga images/linux/system.bit --u-boot --force

c) Prepare SD card

cp /tftpboot/BOOT.BIN /media/$(username)/BOOT/.
cp /tftpboot/image.ub /media/$(username)/BOOT/.
cp /tftpboot/boot.scr /media/$(username)/BOOT/.

PetaLinux 2020.1 changed uboot so that it requires boot.scr also in the BOOT partition of the SD card.

If use rootfs images created by PetaLinux:

cp images/linux/rootfs.cpio /media/$(username)/rootfs

If use standalone rootfs:

sudo cp -a /path-to-compiled-rootfs/* /media/$(username)/rootfs/.

Then

petalinux-util --update-sdcard -d /media/$(username)/BOOT

Unmount and eject the SD card.

Reference

• UG980
• UG1144
• UG1157
• UG1283