Back up and Restore System Image on NRU-220S _ JetPack 5.x

Prerequisites

• A host computer with L4T environment, e.g., JetPack 5.1.1

• The latest NRU-220S tarball (e.g., ....), which could be downloaded from NRU NAS.

• Untar the tarball in L4T folder.

The backup procedure of AGX Orin is slightly different from AGX Xavier.

Prepare a Clone-able NRU-220S

• Before flashing NRU-220S, make sure the APP partition of $L4T/bootloader/t186ref/cfg/flash_t234_qspi_sdmmc.xml is as the below, especially the <size> 62090379264 </size> and <allocation_attribute> 0x8 </allocation_attribute>

<partition name="APP" id="1" type="data">
    <allocation_policy> sequential </allocation_policy>
    <filesystem_type> basic </filesystem_type>
    <size> 62090379264 </size>
    <file_system_attribute> 0 </file_system_attribute>
    <allocation_attribute> 0x8 </allocation_attribute>
    <align_boundary> 16384 </align_boundary>
    <percent_reserved> 0 </percent_reserved>
    <unique_guid> APPUUID </unique_guid>
    <filename> APPFILE </filename>
    <description> **Required.** Contains the rootfs. This partition must be assigned
    the "1" for id as it is physically put to the end of the device, so that it
    can be accessed as the fixed known special device `/dev/mmcblk0p1`. </description>
</partition>

• After NRU-220S is flashed, you may also check the APP partition size by the following command

sudo blockdev --getsize64 /dev/mmcblk0p1
# 62090379264 <- Good! Dividable by 4096 to for sparse image building
# 62091116032 <- Not dividable by 4096. Can't make sparse image

Backup the System Image

• Turn on NRU-220S, boot into OS, and make sure the NRU-220S is connected to the same local Ethernet with the host computer.

• On NRU-220S, enter the following command

sudo su

# update below parameters
export HOST_IP=192.168.1.99
export SYS_IMG_RAW=NRU220_20230511_J511
echo u > /proc/sysrq-trigger

# low level backup the whole APP partition (/dev/mmcblk0p1) of AGX Orin
dd if=/dev/mmcblk0p1 | ssh nvidia@$HOST_IP dd of=$SYS_IMG_RAW.raw status=progress

# After this procedure, you will have a $SYS_IMG_RAW.raw on the root folder(/) host computer

Restore a System Image

• Shutdown NRU-220S, boot NRU-220S into recovery mode, connect the host and NRU-220S with a USB Type A to Type C cable.

• On the host computer, enter the following command

sudo -s

L4T=/e_nvme/JP511_220/Linux_for_Tegra
SYS_IMG_RAW=NRU220_20230511_J511

cd $L4T/bootloader
mv /$SYS_IMG_RAW.raw .
./mksparse -v --fillpattern=0 $SYS_IMG_RAW.raw $SYS_IMG_RAW.img
sudo cp $SYS_IMG_RAW.img system.img

cd $L4T
sudo ./flash.sh -r nru220_32GB mmcblk0p1

Modify System Image

If a system.img has already been generated and you need to customize it, follow the steps below

#install tools
sudo apt-get update
sudo apt-get install android-sdk-libsparse-utils

#Modify system.img
simg2img system.img system.img.raw
sudo mkdir /media/po/sysTest/
sudo losetup -d /dev/loop0  # if it has already been used
sudo losetup -fP system.img.raw
sudo mount /dev/loop0 /media/po/sysTest/
cd /media/po/sysTest/

#flashing system.img
sudo umount /media/po/sysTest/
mv system.img.raw $L4T/bootloader/
cd $L4T/bootloader/
./mksparse -v --fillpattern=0 system.img.raw system.img
sudo ./flash.sh -r nru220_32GB mmcblk0p1