View source for VAR-SOM-MX6 NAND Flash Burning

{{PageHeader|VAR-SOM-MX6 - NAND Flash Burning}} {{DocImage|category1=VAR-SOM-MX6|category2=Yocto}} __toc__
= Introduction =
The Variscite VAR-SOM-MX6 / VAR-SOM-SOLO SOMs use the on-SOM NAND-Flash to boot.<br>
The file system can reside either on the NAND-Flash or the eMMC.
<br>When file system resides on NAND, UBIFS file system will be used.
<br>When file system resides on eMMC, EXT3 file system will be used.
<br>Regardless if the file system is on NAND/UBIFS or eMMC/EXT3 the u-boot will always boot from NAND.
The only exception is the VAR-DART-MX6, where boot is from eMMC completely.
{{note| NOTE:<br>This WIKI is only valid for VAR-SOM-MX6, VAR-SOM-SOLO/DUAL.
For DART-MX6 please use: [[VAR-SOM-MX6 NAND Flash Burning Dart |NAND Flash Burning Dart]]|info}}

== NAND Structure ==
When system boots, kernel logs will present 4 relevant partitions defined.
<br>0x000000000000-0x000000200000 : "spl"
<br>0x000000200000-0x000000400000 : "bootloader"
<br>0x000000400000-0x000000a00000 : "kernel"
<br>0x000000a00000-0x000040000000 : "rootfs"

== Yocto Built binaries for NAND-Flash ==
The resulted images are locaated in tmp/deploy/images/var-som-mx6.<br/>Looking at tmp/deploy/images/var-som-mx6 you will find 5 required files for a complete NAND-Flash based system that are linked to the actual file:<br/>
SPL,U-Boot, zImage, <dtb file>, fsl-image-qt5-minimal-var-som-mx6.ubi <br>

{| class="wikitable"
|-
! scope="col" | Image Name<br/>
! scope="col" | How to use<br/>
|-
| fsl-image-qt5-minimal-var-som-mx6.ubi
| A complete UBIFS file-system binary. ("rootfs")
|-
| uImage
| Linux kernel image ("kernel")
|-
| SPL-nand
| The SPL is pre-u-boot SW component, required for DDR intialization ("spl")
|-
| u-boot-nand-2014.04-r0.img
| u-boot built for nand ("bootloader")
|-
! scope="col" | Device Tree Name <br>(Choose only one, according to your SOM and carrier board<br/>
! scope="col" | SOM type<br/>
! scope="col" | Carrier Board type<br/>
! scope="col" | LCD Type<br/>
! scope="col" | Evaluation Kit name<br/>
|-
| uImage-imx6q-var-som.dtb
| VAR-SOM-MX6_V2 (Quad / Dual)
| VAR-MX6CustomBoard
| Capacitive/Resistive touch
| VAR-DVK-MX6_V2-PRO<br/>VAR-STK-MX6_V2
|-
| uImage-imx6q-var-som-vsc.dtb
| VAR-SOM-MX6_V2 (Quad / Dual)
| VAR-SOLOCustomBoard
| Capacitive LVDS touch
| N/A
|-
| uImage-imx6dl-var-som.dtb
| VAR-SOM-MX6_V2 (DualLite/ Solo)
| VAR-MX6CustomBoard
| Capacitive/Resistive touch
| N/A
|-
| uImage-imx6dl-var-som-solo-vsc.dtb
| VAR-SOM-SOLO / VAR-SOM-DUAL
| VAR-SOLOCustomBoard
| Capacitive LVDS touch
| VAR-DVK-SOLO/DUAL VAR-STK-SOLO/DUAL
|-
| uImage-imx6dl-var-som-solo.dtb
| VAR-SOM-SOLO / VAR-SOM-DUAL
| VAR-MX6CustomBoard
| Capacitive/Resistive touch
| N/A
|-
| uImage-imx6q-var-dart.dtb
| VAR-SOM-SOLO / VAR-SOM-DUAL
| VAR-DT6CustomBoard
| Capacitive LVDS touch
| VAR-STK-DT6.VAR-DVK-DT6
|-
|}

== NAND Flashing scripts==
The [[VAR-SOM-MX6 NAND Flash Burning#NAND Flashing scripts 2 |NAND flashing scripts]]  are easy-to-use example scripts for burning images into NAND Flash<br>
Note: if you followed [[VAR-SOM-MX6 Yocto Fido R2#Create an extended SD-Card |Create an extended SD-Card]] the below scripts will be included in your SD-Card. 

=== NAND recovery SDCARD partition ===
Directly raw flashed onto the SCDARD are the SPL and u-boot.
The first partition is the boot partition. It contains all device trees and kernel uImage.
<br/>/media/BOT_VAR_SOM/
<br/>uImage
<br/>imx6dl-var-som.dtb
<br/>imx6dl-var-som-solo-vsc.dtb
<br/>imx6q-var-som.dtb
<br/>imx6dl-var-som-solo.dtb
<br/>imx6q-var-dart.dtb
<br/>imx6q-var-som-vsc.dtb
<br/>The second partition is called rootfs. It is a complete Linux file system.

=== NAND recovery boot logic ===
The u-boot running from SDCARD scan the hardware and set various environment variables. This will automatically identify the platform and boot correctly.
<br/>Variables:
* screen_alternate=yes - System has a capacitive display otherwise resistive display.
* var_auto_fdt_file=Y - Automatically set the environment variables. N disable it.
* fdt_file= - one of the above device tree file.
{{note| NOTE:<br>This mechanism is not available on NAND. We identify the hardware in the flashing scripts and flash the relevant device tree onto NAND.|info}}

=== NAND recovery images locations ===
We copy the image files into the NAND recovery utility. We also change the names of the products above.
The NAND recovery utlity contains Android and Yocto.
<pre>
/media/rootfs/opt/images/
├── Android
│   └── Emmc
│       ├── boot.img
│       ├── boot-imx6q-var-dart.img
│       ├── boot-som-mx6dl-c.img
│       ├── boot-som-mx6dl-r.img
│       ├── boot-som-mx6q-c.img
│       ├── boot-som-mx6q-r.img
│       ├── boot-som-mx6q-vsc.img
│       ├── boot-som-solo-c.img
│       ├── boot-som-solo-r.img
│       ├── boot-som-solo-vsc.img
│       ├── recovery.img
│       ├── recovery-imx6q-var-dart.img
│       ├── recovery-som-mx6dl-c.img
│       ├── recovery-som-mx6dl-r.img
│       ├── recovery-som-mx6q-c.img
│       ├── recovery-som-mx6q-r.img
│       ├── recovery-som-mx6q-vsc.img
│       ├── recovery-som-solo-c.img
│       ├── recovery-som-solo-r.img
│       ├── recovery-som-solo-vsc.img
│       ├── SPL
│       ├── SPL.mmc
│       ├── SPL.new
│       ├── system.img
│       ├── u-boot-var-imx6-nand.img
│       └── u-boot-var-imx6-sd.img
└── Yocto
    ├── rootfs.tar.bz2
    ├── rootfs.ubi.img
    ├── SPL
    ├── SPL.mmc
    ├── u-boot.img
    ├── u-boot.img.mmc
    ├── uImage
    ├── uImage-imx6dl-var-som.dtb
    ├── uImage-imx6dl-var-som-solo.dtb
    ├── uImage-imx6dl-var-som-solo-vsc.dtb
    ├── uImage-imx6q-var-dart.dtb
    ├── uImage-imx6q-var-som.dtb
    └── uImage-imx6q-var-som-vsc.dtb
</pre>

=== NAND Flashing scripts ===
<pre>
Script files located on /media/rootfs/sbin/
android-emmc.sh
mkmmc_yocto.sh    
yocto-dart.sh  
yocto-nand.sh
mkmmc_android.sh
nand-recovery.sh
yocto-emmc.sh
</pre>

== Copy Yocto files into SDCARD ==
Plug the NAND recovery SDCARD into your host machine.
Then your host machine should mount the rootfs partition on /media/rootfs.
<pre>
$ export YOCTO_ROOT=~/var-som-mx6-yocto-fido

Linux:
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/uImage /media/rootfs/opt/images/Yocto
U-boot:
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/SPL-nand /media/rootfs/opt/images/Yocto/SPL
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/u-boot-nand-2014.04-r0.img /media/rootfs/opt/images/Yocto/u-boot.img
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/SPL-sd /media/rootfs/opt/images/Yocto/SPL.mmc
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/u-boot-sd-2014.04-r0.img /media/rootfs/opt/images/Yocto/u-boot.img.mmc
File System:
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/fsl-image-qt5-var-som-mx6.tar.bz2 /media/rootfs/opt/images/Yocto/rootfs.tar.bz2
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/fsl-image-qt5-minimal-var-som-mx6.ubi /media/rootfs/opt/images/Yocto/rootfs.ubi.img
Device Tree:
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/uImage-imx6dl-var-som-solo.dtb /media/rootfs/opt/images/Yocto/
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/uImage-imx6dl-var-som-solo-vsc.dtb /media/rootfs/opt/images/Yocto/
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/uImage-imx6dl-var-som.dtb /media/rootfs/opt/images/Yocto/
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/uImage-imx6q-var-som.dtb /media/rootfs/opt/images/Yocto/
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/uImage-imx6q-var-som-vsc.dtb /media/rootfs/opt/images/Yocto/
$ sudo cp ${YOCTO_ROOT}/build_x11/tmp/deploy/images/var-som-mx6/uImage-imx6q-var-dart.dtb /media/rootfs/opt/images/Yocto/
</pre>

== Flashing to NAND ==
=== Flash U-BOOT ===
Flashing U-BOOT reguire to flash 2 parts: SPL and u-boot.img.
Assume you copy SPL-nand and u-boot-nand-2014.04-r0.img to the right directory as showed above. 
<pre>
$ cd /opt/images/Yocto
$ flash_erase /dev/mtd0 0 0
$ kobs-ng init -x SPL --search_exponent=1 -v
$ flash_erase /dev/mtd1  0 0
$ nandwrite -p /dev/mtd1 u-boot.img
</pre>
=== Flash Linux Kernel ===
Flashing Linux kernel reguire to flash 2 parts: uImage and device tree.
Assume you copy uImage and device tree to the right directory as showed above. 
You also need to pick and coose the right DTB file. See table above for a complete description.
<pre>
$ cd /opt/images/Yocto
$ flash_erase /dev/mtd2 0 0
$ nandwrite -p /dev/mtd2 uImage
$ nandwrite -p /dev/mtd1 -s 0x1e0000 uImage-imx6q-var-som.dtb (Example select the right one!)
</pre>
=== Flash UBIFS ===
The parameters for the UBIFS UBI_SUB_PAGE_SIZE=2048 and UBI_VID_HDR_OFFSET=2048.
<pre>
$ cd /opt/images/Yocto
$ flash_erase /dev/mtd3 0 0
$ ubiformat /dev/mtd3 -f rootfs.ubi.img -s 2048 -O 2048
</pre>

== Flash File System to eMMC ==
Flashing eMMC is a complex task. It requires several steps including partition, format and untar the file system.
We highly recommend to use our provided scripts to perform this task.
Assuming that you use our NAND recovery utility.

Make sure the eMMC is not mounted.
<pre>
$ cd /opt/images/Yocto
$ umount /dev/mmcblk1p*
$ node=/dev/mmcblk1 
</pre>

Delete all partition from the eMMC.
<pre>
$ fdisk ${node} <<EOF
d
1
d
2
d
3
d
w
EOF

$ sync 
</pre>

Delete MBR
<pre>
$ dd if=/dev/zero of=${node} bs=512 count=1000
$ sync
</pre>

Call sfdisk to create partition table
<pre>
$ node=/dev/mmcblk1
$ seprate=40
$ total_size=`sfdisk -s ${node}`
$ total_size=`expr ${total_size} / 1024`

$ sfdisk --force -uM ${node} << EOF
,${total_size},83
EOF

</pre>

Format Linux
<pre>
$ mkfs.ext4 ${node} -Lrootfs
</pre>

Flash Linux
<pre>
$ mkdir /run/media/mmcblk1p1
$ mount ${node}  /run/media/mmcblk1p1
$ tar xvpf rootfs.tar.bz2 -C /run/media/mmcblk1p1/
</pre>

in case of Yocto eMMC file system stop at u-boot and change boot arguments to :
<pre>
$ setenv bootargs console=ttymxc0,115200 video=mxcfb1:off root=/dev/mmcblk1p1 rootwait rw
$ saveenv
</pre>

= Summary =
We describe the results of Yocto build, how to copy it to SDCARD and how to flash it to NAND and eMMC.
This page is not valid for DART-MX6. Please follow the link to the relevant page.
With the NAND recovery utility we provide a set of scripts located on /sbin and listed below. It is much safer to use them instead of the manual operation.
<br/>/media/rootfs/sbin/:
<br/>android-emmc.sh mkmmc_yocto.sh yocto-dart.sh yocto-nand.sh mkmmc_android.sh nand-recovery.sh yocto-emmc.sh.
Some of the scripts are used by the others. <br/>Please use:
* android-emmc.sh to flash Android int eMMC
* yocto-dart.sh To flash Yocto into eMMC on DART-MX6
* yocto-nand.sh To flash Yocto into NAND (not relevant on DART-MX6)
* yocto-emmc.sh To flash Yocto into eMMC (not relevant on DART-MX6)