Debian: Getting Started with the i.MX6x SABRE Lite

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This is a page about the NXP based i.MX6; i.MX6x SABRE Lite.

Vendor Documentation

Basic Requirements

Bootloader: U-Boot

Das U-Boot – the Universal Boot Loader: http://www.denx.de/wiki/U-Boot
These directions going forward now assume your using the “factory” v2013.04 U-Boot. Please verify with: “version”

U-Boot > version
U-Boot 2013.04-00308-ge1290a7 (Jun 18 2013 - 13:38:20)
arm-none-linux-gnueabi-gcc (Freescale MAD -- Linaro 2011.07 -- Built at 2011/08/10 09:20) 4.6.2 20110630 (prerelease)
GNU ld (Freescale MAD -- Linaro 2011.07 -- Built at 2011/08/10 09:20) 2.21.52.20110702
U-Boot >

If your board has something different, take a look here: [i.MX6x SABRE Lite SPI Flash Recovery|linuxonarm:i.MX6x SABRE Lite SPI Flash Recovery] for software developers, the mainline U-Boot directions are now here: [i.MX6x SABRE Lite Mainline U-Boot|linuxonarm:i.MX6x SABRE Lite Mainline U-Boot]

Linux Kernel

This script will build the kernel, modules, device tree binaries and copy them to the deploy directory.
Download:

#user@localhost:~$
git clone https://github.com/RobertCNelson/armv7-multiplatform ./kernelbuildscripts
cd kernelbuildscripts/

For v5.4.x (Longterm 5.4.x):

#user@localhost:~/kernelbuildscripts$
git checkout origin/v5.4.x -b tmp

For v5.4.x-rt (Longterm 5.4.x + Real-Time Linux):

#user@localhost:~/kernelbuildscripts$
git checkout origin/v5.4.x-rt -b tmp

For v5.10.x (Longterm 5.10.x):

#user@localhost:~/kernelbuildscripts$
git checkout origin/v5.10.x -b tmp

For v5.10.x-rt (Longterm 5.10.x + Real-Time Linux):

#user@localhost:~/kernelbuildscripts$
git checkout origin/v5.10.x-rt -b tmp

For v5.15.x (Longterm 5.15.x):

#user@localhost:~/kernelbuildscripts$
git checkout origin/v5.15.x -b tmp

For v5.15.x-rt (Longterm 5.15.x + Real-Time Linux):

#user@localhost:~/kernelbuildscripts$
git checkout origin/v5.15.x-rt -b tmp

Build:

#user@localhost:~/kernelbuildscripts$
./build_kernel.sh

Root File System

Debian 11

User Password
debian temppwd
root root

Download:

#user@localhost:~$
wget -c https://rcn-ee.com/rootfs/eewiki/minfs/debian-11.3-minimal-armhf-2022-04-15.tar.xz

Verify:

#user@localhost:~$
sha256sum debian-11.3-minimal-armhf-2022-04-15.tar.xz

#sha256sum output:
575738843651de2962f251447f4742d4f33313d6f7f5edf282a401207f5e6646  debian-11.3-minimal-armhf-2022-04-15.tar.xz

Extract:

#user@localhost:~$
tar xf debian-11.3-minimal-armhf-2022-04-15.tar.xz

Setup microSD card

We need to access the External Drive to be utilized by the target device. Run lsblk to help figure out what linux device has been reserved for your External Drive.

#Example: for DISK=/dev/sdX
lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 465.8G  0 disk
├─sda1   8:1    0   512M  0 part /boot/efi
└─sda2   8:2    0 465.3G  0 part /                <- Development Machine Root Partition
sdb      8:16   1   962M  0 disk                  <- microSD/USB Storage Device
└─sdb1   8:17   1   961M  0 part                  <- microSD/USB Storage Partition

#Thus you would use:
export DISK=/dev/sdb

#Example: for DISK=/dev/mmcblkX
lsblk
NAME      MAJ:MIN   RM   SIZE RO TYPE MOUNTPOINT
sda         8:0      0 465.8G  0 disk
├─sda1      8:1      0   512M  0 part /boot/efi
└─sda2      8:2      0 465.3G  0 part /                <- Development Machine Root Partition
mmcblk0     179:0    0   962M  0 disk                  <- microSD/USB Storage Device
└─mmcblk0p1 179:1    0   961M  0 part                  <- microSD/USB Storage Partition

#Thus you would use:
export DISK=/dev/mmcblk0

Erase partition table/labels on microSD card:

sudo dd if=/dev/zero of=${DISK} bs=1M count=50

Create Partition Layout:
With util-linux v2.26, sfdisk was rewritten and is now based on libfdisk.

#Check the version of sfdisk installed on your pc is atleast 2.26.x or newer.
sudo sfdisk --version

#Example Output
sfdisk from util-linux 2.27.1

#sfdisk >= 2.26.x
sudo sfdisk ${DISK} <<-__EOF__
1M,48M,0x83,*
,,,-
__EOF__

Format Partition:
With mkfs.ext4 1.43, we need to make sure metadata_csum and 64bit ext4 features are disabled.
As the version of U-Boot needed for this target CAN NOT correctly handle reading files with these newer ext4 options.

#mkfs.ext4 -V
sudo mkfs.ext4 -V
mke2fs 1.43-WIP (15-Mar-2016)
        Using EXT2FS Library version 1.43-WIP

#mkfs.ext4 >= 1.43
for: DISK=/dev/mmcblkX
sudo mkfs.ext2 -L boot ${DISK}p1
sudo mkfs.ext4 -L rootfs -O ^metadata_csum,^64bit ${DISK}p2
 
for: DISK=/dev/sdX
sudo mkfs.ext2 -L boot ${DISK}1
sudo mkfs.ext4 -L rootfs -O ^metadata_csum,^64bit ${DISK}2

Mount Partition:
On most systems these partitions may be auto-mounted…

sudo mkdir -p /media/boot/
sudo mkdir -p /media/rootfs/
 
for: DISK=/dev/mmcblkX
sudo mount ${DISK}p1 /media/boot/
sudo mount ${DISK}p2 /media/rootfs/
 
for: DISK=/dev/sdX
sudo mount ${DISK}1 /media/boot/
sudo mount ${DISK}2 /media/rootfs/

6x_bootscript to uEnv.txt wrapper

Create wrapper script “6x_bootscript.txt” boot script: (nano 6x_bootscript.txt)

#~/6x_bootscript.txt
echo "6x_bootscript -> uEnv.txt wrapper..."
if test -n $disk; then
setenv mmcdev $disk
setenv mmcpart 1
fi
load mmc ${mmcdev}:${mmcpart} ${loadaddr} uEnv.txt
env import -t ${loadaddr} ${filesize}
run uenvcmd

Using mkimage (u-boot-tools pkg) create boot script

#user@localhost:~$
mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n "wrapper" -d ./6x_bootscript.txt ./6x_bootscript

uEnv.txt based bootscript

Create uEnv.txt boot script: (nano uEnv.txt)

#~/uEnv.txt
initrd_high=0xffffffff
fdt_high=0xffffffff
 
fdtfile=imx6q-sabrelite.dtb
 
console=ttymxc1,115200n8
optargs=console=tty0
video=
 
mmcroot=/dev/mmcblk0p2 ro
 
#This gets complex when both microSD & MMC media is present at bootup:
#microSD:
#mmcroot=/dev/mmcblk0p2 ro
#MMC:
#mmcroot=/dev/mmcblk1p2 ro
 
mmcrootfstype=ext4 rootwait fixrtc
 
loadkernel=load mmc ${mmcdev}:${mmcpart} 0x12000000 zImage
loadinitrd=load mmc ${mmcdev}:${mmcpart} 0x18080000 initrd.img; setenv initrd_size 
loadfdt=load mmc ${mmcdev}:${mmcpart} 0x18000000 /dtbs/${fdtfile}
 
#zImage/initrd.img:
#boot_fdt=run loadkernel; run loadinitrd; run loadfdt
 
#zImage:
boot_fdt=run loadkernel; run loadfdt
 
mmcargs=setenv bootargs console=${console} ${optargs} root=${mmcroot} rootfstype=${mmcrootfstype} video=${video}
 
#zImage/initrd.img:
#uenvcmd=run boot_fdt; run mmcargs; bootz 0x12000000 0x18080000:${initrd_size} 0x18000000
 
#zImage:
uenvcmd=run boot_fdt; run mmcargs; bootz 0x12000000 - 0x18000000

Copy 6x_bootscript/uEnv.txt to the boot partition:

#user@localhost:~$
sudo cp -v ./6x_bootscript /media/boot/
sudo cp -v ./uEnv.txt /media/boot/

Install Kernel and Root File System

To help new users, since the kernel version can change on a daily basis. The kernel building scripts listed on this page will now give you a hint of what kernel version was built.

-----------------------------
Script Complete
eewiki.net: [user@localhost:~$ export kernel_version=5.X.Y-Z]
-----------------------------

Copy and paste that “export kernel_version=5.X.Y-Z” exactly as shown in your own build/desktop environment and hit enter to create an environment variable to be used later.

export kernel_version=5.X.Y-Z

Copy Root File System

#Debian; Root File System: user@localhost:~$
sudo tar xfvp ./debian-*-*-armhf-*/armhf-rootfs-*.tar -C /media/rootfs/
sync

Copy Kernel Image

Kernel Image:

#user@localhost:~$
sudo cp -v ./kernelbuildscripts/deploy/${kernel_version}.zImage /media/boot/zImage

Copy Kernel Device Tree Binaries

#user@localhost:~$
sudo mkdir -p /media/boot/dtbs/
sudo tar xfvo ./kernelbuildscripts/deploy/${kernel_version}-dtbs.tar.gz -C /media/boot/dtbs/

Copy Kernel Modules

#user@localhost:~$
sudo tar xfv ./kernelbuildscripts/deploy/${kernel_version}-modules.tar.gz -C /media/rootfs/

File Systems Table (/etc/fstab)

#user@localhost:~/$
sudo sh -c "echo '/dev/mmcblk0p2  /  auto  errors=remount-ro  0  1' >> /media/rootfs/etc/fstab"
sudo sh -c "echo '/dev/mmcblk0p1  /boot/uboot  auto  defaults  0  2' >> /media/rootfs/etc/fstab"

Remove microSD/SD card

sync
sudo umount /media/boot
sudo umount /media/rootfs

SPI Flash Recovery

[i.MX6x SABRE Lite SPI Flash Recovery]

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