How to create Debian 10 SD card image

Host Prerequisites

Debian 10 rootfs tarball

The environment variable ,ROOTFS, must be set properly. (Ref. keep the rootfs for future use)

Yocto Linux SD card image

SDIMAGE=5720A1AIM20LIV90100_iMX8M_2020-04-03.img # i.MX8 ROM-5720
SDIMAGE=3430A1LIV8940_DualQuad_2019-04-29.img # i.MX6 RSB-3430

backup modules and firmware

BACKUPDIR=~/${SDIMAGE%%_*}
mkdir $BACKUPDIR
MNT=~/mnt
mkdir -p $MNT
PL=`fdisk -lu $SDIMAGE | grep "${SDIMAGE}2" | awk '{print $2}'`
sudo mount -o ro,offset=$((PL*512)) $SDIMAGE $MNT
sudo tar zcvf $BACKUPDIR/lib_modules.tgz -C $MNT lib/modules
sudo tar zcvf $BACKUPDIR/lib_firmware.tgz -C $MNT lib/firmware
sudo umount $MNT

Building Procedures

create one working image

DEBIMAGE=`sed "s/AIM20//; s/LIV/DIV/" <<< ${SDIMAGE%%_*}`_Debian10_base.img
cp $SDIMAGE $DEBIMAGE
PSECS=`fdisk -lu $SDIMAGE | grep "${SDIMAGE}2" | awk '{print $4}'`
mkfs.ext4 -F -E offset=$((PL*512)) $DEBIMAGE $((PSECS/2))K

restore rootfs

sudo mount -o offset=$((PL*512)) $DEBIMAGE $MNT
sudo tar zxvf $ROOTFS.tgz -C $MNT/

set hostname

HOST=RSB-3430 # for RSB-3430
HOST=ROM-5720 # for ROM-5720
sudo su -c "echo $HOST > $MNT/etc/hostname"
sudo su -c "echo -e \"127.0.0.1\tlocalhost\n127.0.1.1\t$HOST\n\" > $MNT/etc/hosts"

restore modules & firmware

sudo tar zxvf $BACKUPDIR/lib_modules.tgz -C $MNT
sudo tar zxvf $BACKUPDIR/lib_firmware.tgz -C $MNT
sudo umount $MNT

SDcard image is ready

write to SD card

The environment variable ,SD_DEVICE, must be set properly.

sudo dd if=$DEBIMAGE of=${SD_DEVICE} bs=1M conv=fsync status=progress