Quickly Try devicetree and Root Filesystem Changes from a Xilinx PetaLinux Built image.ub

This post shows how to get the Linux kernel, Flattened Device Tree blob, petalinux-user-image from an image.ub built by PetaLinux. Then it shows how to convert the Flattened Device Tree blob (DTB) into a DTS so that it can be edited and how to convert it back to a DTB. It then details how to extract the rootfilesystem and rebuild the rootfilesystem. It finishes by showing how to rebuild and use an image.ub with the updated components. This method is useful to try out quick changes to a device tree and a root filesystem.

Setup

Ubuntu 16.04.5

PetaLinux 2019.1 installed to ~/petalinux/2019.1/ using:

sudo apt-get update sudo apt-get -y install python3 dos2unix iproute2 gawk xvfb git make net-tools libncurses5-dev tftpd lib32z1 libssl-dev flex bison libselinux1 gnupg wget diffstat chrpath socat xterm autoconf libtool tar unzip texinfo zlib1g-dev gcc-multilib build-essential libsdl1.2-dev libglib2.0-dev libsdl-dev build-essential gcc-multilib glib2.0 automake screen pax gzip libtool-bin zlib1g:i386 mkdir -p $HOME/petalinux cd ~/Downloads ./petalinux-v2019.1-final-installer.run $HOME/petalinux/2019.1

ZCU102 BSP was built using:

# Download the 2019.1 ZCU102 BSP from:

https://www.xilinx.com/member/forms/download/xef.html?filename=xilinx-zcu102-v2019.1-final.bsp to ~/Downloads

# Step #2:

mkdir ~/plxbsps

cd ~/plxbsps

cp ~/Downloads/xilinx-zcu102-v2019.1-final.bsp .

md5sum xilinx-zcu102-v2019.1-final.bsp

# You should see:

# 2189911c4ac9c33f170cdced96472ba7 xilinx-zcu102-v2019.1-final.bsp

rm ~/Downloads/xilinx-zcu102-v2019.1-final.bsp

# Step #3:

mkdir ~/plxprjs

cd ~/plxprjs/

source ~/petalinux/2019.1/settings.sh

# You should see:

# PetaLinux environment set to '/home/demo/petalinux/2019.1'

# INFO: Checking free disk space

# INFO: Checking installed tools

# INFO: Checking installed development libraries

# INFO: Checking network and other services

# WARNING: No tftp server found - please refer to "PetaLinux SDK Installation Guide" for its impact and solution

petalinux-create -t project -s ~/plxbsps/xilinx-zcu102-v2019.1-final.bsp cd xilinx-zcu102-2019.1/

petalinux-build

Steps

# Get the Tools: dtc, dumpimage, mkimage

sudo apt-get install u-boot-tools

# Get the version of dtc

dtc -v

# Example output:

# Version: DTC 1.4.0

# Get the Version of dumpimage with

dumpimage -V

# Example output:

# dumpimage version 2016.01+dfsg1-2ubuntu5

# Get the Version of mkimage with:

mkimage -V

# Example output:

# mkimage version 2016.01+dfsg1-2ubuntu5

# List Contents of the FIT Image (aka list the contents of images/linux/image.ub)

cd ~/plxprjs/xilinx-zcu102-2019.1/

mkimage -l images/linux/image.ub

# Example output:

FIT description: U-Boot fitImage for PetaLinux/4.19-xilinx-v2019.1+gitAUTOINC+9811303824/zcu102-zynqmp

Created: Tue Oct 5 10:29:19 2021

Image 0 (kernel@1)

Description: Linux kernel

Created: Tue Oct 5 10:29:19 2021

Type: Kernel Image

Compression: uncompressed

Data Size: 18149888 Bytes = 17724.50 kB = 17.31 MB

Architecture: AArch64

OS: Linux

Load Address: 0x00080000

Entry Point: 0x00080000

Hash algo: sha1

Hash value: e4d410bcdce2a6869cb553b054d5fb31988a0cb1

Image 1 (fdt@system-top.dtb)

Description: Flattened Device Tree blob

Created: Tue Oct 5 10:29:19 2021

Type: Flat Device Tree

Compression: uncompressed

Data Size: 41288 Bytes = 40.32 kB = 0.04 MB

Architecture: AArch64

Hash algo: sha1

Hash value: 2062c3ae51659cc8ac7ab76bf3ae0dc311ca4b08

Image 2 (ramdisk@1)

Description: petalinux-user-image

Created: Tue Oct 5 10:29:19 2021

Type: RAMDisk Image

Compression: gzip compressed

Data Size: 6625387 Bytes = 6470.10 kB = 6.32 MB

Architecture: AArch64

OS: Linux

Load Address: unavailable

Entry Point: unavailable

Hash algo: sha1

Hash value: 74c7a71f25ef5f2ed8e74d0ccdc93e31306fb567

Default Configuration: 'conf@system-top.dtb'

Configuration 0 (conf@system-top.dtb)

Description: 1 Linux kernel, FDT blob, ramdisk

Kernel: kernel@1

Init Ramdisk: ramdisk@1

FDT: fdt@system-top.dtb

# Split Out the dtb from a FIT Image (aka extract the dtb from an image.ub)

cd ~/plxprjs/xilinx-zcu102-2019.1/

dumpimage -i images/linux/image.ub -T flat_dt -p 1 mysystems.dtb

# Example output:

Extracted:

Image 1 (fdt@system-top.dtb)

Description: Flattened Device Tree blob

Created: Tue Oct 5 10:29:19 2021

Type: Flat Device Tree

Compression: uncompressed

Data Size: 41288 Bytes = 40.32 kB = 0.04 MB

Architecture: AArch64

Hash algo: sha1

Hash value: 2062c3ae51659cc8ac7ab76bf3ae0dc311ca4b08

# Convert a DTB to a DTS (aka see what's in the DTB we're going boot)

dtc -I dtb -O dts mysystems.dtb > mysystems.dts

# Make the changes to mysystems.dts you want to try

# ...like disable power management:

vi mysystems.dts

bootargs = "earlycon console=ttyPS0,115200 clk_ignore_unused cpuidle.off=1";

# Convert a DTS to a DTB (aka get a DTB ready for a FIT image, aka put a new DTB in an image.ub)

dtc -I dts -O dtb mysystems.dts > new-mysystem.dtb

#..and back (to check):

dtc -I dtb -O dts new-mysystem.dtb > new-mysystem.dts

# Split Out the kernel from a FIT Image (aka extract the kernel from an image.ub)

dumpimage -i images/linux/image.ub -T flat_dt -p 0 myImage

# Example output:

Extracted:

Image 0 (kernel@1)

Description: Linux kernel

Created: Tue Oct 5 10:29:19 2021

Type: Kernel Image

Compression: uncompressed

Data Size: 18149888 Bytes = 17724.50 kB = 17.31 MB

Architecture: AArch64

OS: Linux

Load Address: 0x00080000

Entry Point: 0x00080000

Hash algo: sha1

Hash value: e4d410bcdce2a6869cb553b054d5fb31988a0cb1

# Split Out the rootfs from a FIT Image (aka get the rootfs from an image.ub)

dumpimage -i images/linux/image.ub -T flat_dt -p 2 myrootfs.cpio.gz

# Example output

Extracted:

Image 2 (ramdisk@1)

Description: petalinux-user-image

Created: Tue Oct 5 10:29:19 2021

Type: RAMDisk Image

Compression: gzip compressed

Data Size: 6625387 Bytes = 6470.10 kB = 6.32 MB

Architecture: AArch64

OS: Linux

Load Address: unavailable

Entry Point: unavailable

Hash algo: sha1

Hash value: 74c7a71f25ef5f2ed8e74d0ccdc93e31306fb567

# Expand, Get The Biggest Items, Make an Update, and Repack a rootfs (aka extract a rootfs.cpio.gz )

mkdir debugrootfs

pushd debugrootfs

gzip -cd ../myrootfs.cpio.gz | cpio -imd --quiet

du -a . | sort -n -r | head -n 20

touch test.txt

find . | cpio -H newc -o -R root:root > ../newmyrootfs.cpio

popd

cat newmyrootfs.cpio | gzip > newmyrootfs.cpio.gz

# Example output

demo@ubuntu:~/plxprjs/xilinx-zcu102-2019.1/debugrootfs$ gzip -cd ../myrootfs.cpio.gz | cpio -imd --quiet

demo@ubuntu:~/plxprjs/xilinx-zcu102-2019.1/debugrootfs$ du -a . | sort -n -r | head -n 20

18308 .

7548 ./usr

5972 ./lib

3056 ./usr/sbin

2072 ./usr/share

2000 ./bin

1920 ./sbin

1756 ./usr/share/licenses

1692 ./lib/modules

1688 ./lib/modules/4.19.0-xilinx-v2019.1

1584 ./lib/modules/4.19.0-xilinx-v2019.1/kernel

1380 ./lib/libc-2.28.so

1300 ./usr/lib

1124 ./bin/bash.bash

1008 ./lib/modules/4.19.0-xilinx-v2019.1/kernel/drivers

996 ./usr/bin

892 ./usr/lib/opkg

888 ./usr/lib/opkg/alternatives

876 ./usr/sbin/tcf-agent

772 ./etc

demo@ubuntu:~/plxprjs/xilinx-zcu102-2019.1/debugrootfs$ touch test.txt

demo@ubuntu:~/plxprjs/xilinx-zcu102-2019.1/debugrootfs$ find . | cpio -H newc -o -R root:root > ../newmyrootfs.cpio

31340 blocks

demo@ubuntu:~/plxprjs/xilinx-zcu102-2019.1/debugrootfs$ popd

~/plxprjs/xilinx-zcu102-2019.1

demo@ubuntu:~/plxprjs/xilinx-zcu102-2019.1$ cat newmyrootfs.cpio | gzip > newmyrootfs.cpio.gz

# Create an image.ub (aka repack a FIT image)

# Note: uses the new files created above:

# myImage, new-mysystem.dtb, newmyrootfs.cpio.gz

# Note: select everything from the "c" in cat to the "S" in IMAGEITS

# Note2: you can also create image.its with the contents starting with /dts-v1/; and ending with the }; before IMAGEITS

cat << "IMAGEITS" > image.its

/dts-v1/;

/ {

description = "U-Boot fitImage for plnx_aarch64 kernel";

#address-cells = <1>;

images {

kernel@0 {

description = "Linux Kernel";

data = /incbin/("./myImage");

type = "kernel";

arch = "arm64";

os = "linux";

compression = "none";

load = <0x80000>;

entry = <0x80000>;

hash@1 {

algo = "sha1";

};

};

fdt@0 {

description = "Flattened Device Tree blob";

data = /incbin/("./new-mysystem.dtb");

type = "flat_dt";

arch = "arm64";

compression = "none";

hash@1 {

algo = "sha1";

};

};

ramdisk@0 {

description = "ramdisk";

data = /incbin/("./newmyrootfs.cpio.gz");

type = "ramdisk";

arch = "arm64";

os = "linux";

compression = "gzip";

hash@1 {

algo = "sha1";

};

};

};

configurations {

default = "conf@1";

conf@1 {

description = "Boot Linux kernel with FDT blob + ramdisk";

kernel = "kernel@0";

fdt = "fdt@0";

ramdisk = "ramdisk@0";

hash@1 {

algo = "sha1";

};

};

};

};

IMAGEITS

mkimage -f image.its image.itb

# Example output:

FIT description: U-Boot fitImage for plnx_aarch64 kernel

Created: Sun Oct 10 11:15:23 2021

Image 0 (kernel@0)

Description: Linux Kernel

Created: Sun Oct 10 11:15:23 2021

Type: Kernel Image

Compression: uncompressed

Data Size: 18149888 Bytes = 17724.50 kB = 17.31 MB

Architecture: AArch64

OS: Linux

Load Address: 0x00080000

Entry Point: 0x00080000

Hash algo: sha1

Hash value: e4d410bcdce2a6869cb553b054d5fb31988a0cb1

Image 1 (fdt@0)

Description: Flattened Device Tree blob

Created: Sun Oct 10 11:15:23 2021

Type: Flat Device Tree

Compression: uncompressed

Data Size: 37064 Bytes = 36.20 kB = 0.04 MB

Architecture: AArch64

Hash algo: sha1

Hash value: 6acc0c305ed9b3c820ed981ed421e617d86f5d7b

Image 2 (ramdisk@0)

Description: ramdisk

Created: Sun Oct 10 11:15:23 2021

Type: RAMDisk Image

Compression: gzip compressed

Data Size: 6653833 Bytes = 6497.88 kB = 6.35 MB

Architecture: AArch64

OS: Linux

Load Address: unavailable

Entry Point: unavailable

Hash algo: sha1

Hash value: f59fd56ab1974d2e684131e86b447b0ec46f01fe

Default Configuration: 'conf@1'

Configuration 0 (conf@1)

Description: Boot Linux kernel with FDT blob + ramdisk

Kernel: kernel@0

Init Ramdisk: ramdisk@0

FDT: fdt@0

Test

# Switch the ZCU102 to PS JTAG mode

# See all the modes here:

https://www.centennialsoftwaresolutions.com/post/pictures-of-sw6-for-every-zcu102-zynq-ultrascale-mpsoc-boot-mode

# Turn on the ZCU102

# In one terminal

screen /dev/ttyUSB0 115200

# Use Ctrl-a x to scroll

# In another terminal

cd ~/plxprjs/xilinx-zcu102-2019.1

source ~/petalinux/2019.1/settings.sh

petalinux-boot --jtag --u-boot -v

# Stop U-Boot at: "Hit any key to stop autoboot: " ...in the other terminal

# In a third terminal

~/petalinux/2019.1/tools/xsct/bin/xsct

# In xsct

connect

# You should see: tcfchan#0

targets

targets -set -nocase -filter {name =~ "*A53*#0"} ;# or targets 10

dow -data ~/plxprjs/xilinx-zcu102-2019.1/image.itb 0x20000000

disco

# You should see:

# 100% 23MB 0.3MB/s 01:11

# Successfully downloaded /home/demo/plxprjs/xilinx-zcu102-2019.1/image.itb

# In the U-Boot terminal

bootm 0x20000000

# After boot:

ls /

# You'll see test.txt

# Example output from boot:

INIT: version 2.88 booting

PMU Firmware 2019.1 Sep 5 2021 21:05:51

PMU_ROM Version: xpbr-v7.2.0-1

Xilinx Zynq MP First Stage Boot Loader

Release 2019.1 Sep 5 2021 - 21:05:09

NOTICE: ATF running on XCZU9EG/silicon v3/RTL5.1 at 0xfffea000

NOTICE: BL31: Secure code at 0x60000000

NOTICE: BL31: Non secure code at 0x10080000

NOTICE: BL31: v2.0(release):xilinx-v2018.3-720-g80d1c790

NOTICE: BL31: Built : 16:26:05, Oct 5 2021

PMUFW: v1.1

U-Boot 2019.01 (Oct 05 2021 - 16:26:46 +0000)

Model: ZynqMP ZCU102 Rev1.0

Board: Xilinx ZynqMP

DRAM: 4 GiB

EL Level: EL2

Chip ID: zu9eg

MMC: mmc@ff170000: 0

Loading Environment from SPI Flash... SF: Detected n25q512a with page size 512 Bytes, erase size 128 KiB, total 128 MiB

*** Warning - bad CRC, using default environment

In: serial@ff000000

Out: serial@ff000000

Err: serial@ff000000

Model: ZynqMP ZCU102 Rev1.0

Board: Xilinx ZynqMP

Bootmode: JTAG_MODE

Reset reason: EXTERNAL

Net: ZYNQ GEM: ff0e0000, phyaddr c, interface rgmii-id

Warning: ethernet@ff0e0000 MAC addresses don't match:

Address in ROM is ff:ff:ff:ff:ff:ff

Address in environment is 00:0a:35:00:22:01

eth0: ethernet@ff0e0000

U-BOOT for xilinx-zcu102-2019_1

ethernet@ff0e0000 Waiting for PHY auto negotiation to complete......................................... TIMEOUT !

Hit any key to stop autoboot: 0

# Example output from petalinux-boot --jtag --u-boot -v

INFO: sourcing build tools

XSDB Script:

INFO: Launching XSDB for file download and boot.

INFO: This may take a few minutes, depending on the size of your image.

connect

targets -set -nocase -filter {name =~ "*PSU*"}

mask_write 0xFFCA0038 0x1C0 0x1C0

targets -set -nocase -filter {name =~ "*MicroBlaze PMU*"}

puts stderr "INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/pmufw.elf to the target."

dow "/home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/pmufw.elf"

after 2000

con

targets -set -nocase -filter {name =~ "*APU*"}

mwr 0xffff0000 0x14000000

mask_write 0xFD1A0104 0x501 0x0

targets -set -nocase -filter {name =~ "*A53*#0"}

source /home/demo/plxprjs/xilinx-zcu102-2019.1/project-spec/hw-description/psu_init.tcl

puts stderr "INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/zynqmp_fsbl.elf to the target."

dow "/home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/zynqmp_fsbl.elf"

after 2000

con

after 4000; stop; catch {stop}; psu_ps_pl_isolation_removal; psu_ps_pl_reset_config

targets -set -nocase -filter {name =~ "*A53*#0"}

puts stderr "INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/u-boot.elf to the target."

dow "/home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/u-boot.elf"

after 2000

targets -set -nocase -filter {name =~ "*A53*#0"}

puts stderr "INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/bl31.elf to the target."

dow "/home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/bl31.elf"

after 2000

con

exit

rlwrap: warning: your $TERM is 'xterm-256color' but rlwrap couldn't find it in the terminfo database. Expect some problems.: Inappropriate ioctl for device

INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/pmufw.elf to the target.

Downloading Program -- /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/pmufw.elf

section, .vectors.reset: 0xffdc0000 - 0xffdc0007

section, .vectors.sw_exception: 0xffdc0008 - 0xffdc000f

section, .vectors.interrupt: 0xffdc0010 - 0xffdc0017

section, .vectors.hw_exception: 0xffdc0020 - 0xffdc0027

section, .text: 0xffdc0050 - 0xffdd0dc7

section, .rodata: 0xffdd0dc8 - 0xffdd2edf

section, .data: 0xffdd2ee0 - 0xffdd71d7

section, .sdata2: 0xffdd71d8 - 0xffdd71d7

section, .sdata: 0xffdd71d8 - 0xffdd71d7

section, .sbss: 0xffdd71d8 - 0xffdd71d7

section, .bss: 0xffdd71e0 - 0xffddb20b

section, .srdata: 0xffddb20c - 0xffddbb2f

section, .stack: 0xffddbb30 - 0xffddcb2f

section, .xpbr_serv_ext_tbl: 0xffddf6e0 - 0xffddfadf

100% 0MB 0.2MB/s 00:00

Setting PC to Program Start Address 0xffdcffe0

Successfully downloaded /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/pmufw.elf

INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/zynqmp_fsbl.elf to the target.

Downloading Program -- /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/zynqmp_fsbl.elf

section, .text: 0xfffc0000 - 0xfffd410b

section, .init: 0xfffd4140 - 0xfffd4173

section, .fini: 0xfffd4180 - 0xfffd41b3

section, .note.gnu.build-id: 0xfffd41b4 - 0xfffd41d7

section, .rodata: 0xfffd4200 - 0xfffd474f

section, .sys_cfg_data: 0xfffd4780 - 0xfffd4f67

section, .mmu_tbl0: 0xfffd5000 - 0xfffd500f

section, .mmu_tbl1: 0xfffd6000 - 0xfffd7fff

section, .mmu_tbl2: 0xfffd8000 - 0xfffdbfff

section, .data: 0xfffdc000 - 0xfffdd3b7

section, .sbss: 0xfffdd3b8 - 0xfffdd3bf

section, .bss: 0xfffdd3c0 - 0xfffdf5bf

section, .heap: 0xfffdf5c0 - 0xfffdf9bf

section, .stack: 0xfffdf9c0 - 0xfffe19bf

section, .dup_data: 0xfffe19c0 - 0xfffe2d77

section, .handoff_params: 0xfffe9e00 - 0xfffe9e87

section, .bitstream_buffer: 0xffff0040 - 0xfffffc3f

100% 0MB 0.2MB/s 00:00

Setting PC to Program Start Address 0xfffc0000

Successfully downloaded /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/zynqmp_fsbl.elf

INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/u-boot.elf to the target.

Downloading Program -- /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/u-boot.elf

section, .data: 0x10080000 - 0x1014c51f

100% 0MB 0.2MB/s 00:04

Setting PC to Program Start Address 0x10080000

Successfully downloaded /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/u-boot.elf

INFO: Downloading ELF file: /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/bl31.elf to the target.

Downloading Program -- /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/bl31.elf

section, .text: 0xfffea000 - 0xffff1fff

section, .rodata: 0xffff2000 - 0xffff2fff

section, .data: 0xffff3000 - 0xffff6777

section, stacks: 0xffff6780 - 0xffff787f

section, .bss: 0xffff7880 - 0xffff8613

section, xlat_table: 0xffff9000 - 0xffffdfff

section, coherent_ram: 0xffffe000 - 0xffffefff

100% 0MB 0.1MB/s 00:00

Setting PC to Program Start Address 0xfffea000

Successfully downloaded /home/demo/plxprjs/xilinx-zcu102-2019.1/images/linux/bl31.elf

References

• https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842374/U-Boot+Images

• The Xilinx graphic is from [link]