Yocto Platform Customization

Yocto

Documentation

• Yocto Project Core - Morty 2.2.1 (released on 02/24/2017)

Documentation is available from www.yoctoproject.org

• FSL Community BSP Release Notes 2.2 documentation

Documentation is available from http://freescale.github.io

VAR-SOM-MX6

Build Results

Device Tree Name	SOM type	Carrier Board type	LCD Type	Evaluation Kit name
uImage-imx6q-var-som-cap.dtb	VAR-SOM-MX6_V2 (Quad / Dual)	VAR-MX6CustomBoard	Capacitive touch	VAR-DVK-MX6_V2-PRO VAR-STK-MX6_V2
uImage-imx6q-var-som-res.dtb	VAR-SOM-MX6_V2 (Quad / Dual)	VAR-MX6CustomBoard	Resistive touch	VAR-DVK-MX6_V2-PRO 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-cap.dtb	VAR-SOM-MX6_V2 (DualLite/ Solo)	VAR-MX6CustomBoard	Capacitive touch	N/A
uImage-imx6dl-var-som-res.dtb	VAR-SOM-MX6_V2 (DualLite/ Solo)	VAR-MX6CustomBoard	Resistive touch	N/A
uImage-imx6dl-var-som-vsc.dtb	VAR-SOM-MX6_V2 (DualLite/ Solo)	VAR-SOLOCustomBoard	Capacitive LVDS 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-cap.dtb	VAR-SOM-SOLO / VAR-SOM-DUAL	VAR-MX6CustomBoard	Capacitive touch	N/A
uImage-imx6dl-var-som-solo-res.dtb	VAR-SOM-SOLO / VAR-SOM-DUAL	VAR-MX6CustomBoard	Resistive touch	N/A
uImage-imx6q-var-dart.dtb	VAR-SOM-SOLO / VAR-SOM-DUAL	VAR-DT6CustomBoard	Capacitive LVDS touch	VAR-DVK-DT6 VAR-STK-DT6

Device tree

Build the device tree for Dualite/Solo on VAR-MX6CustomBoard with capacitive touchscreen:
$ make -j4 imx6dl-var-som-cap.dtb

Build the device tree for Dualite/Solo on VAR-MX6CustomBoard with resistive touchscreen:
$ make -j4 imx6dl-var-som-res.dtb

Build the device tree for Dualite/Solo on VAR-SOLOCustomBoard:
$ make -j4 imx6dl-var-som-vsc.dtb

Build the device tree for Quad/Dual on VAR-MX6CustomBoard with capacitive touchscreen:
$ make -j4 imx6q-var-som-cap.dtb

Build the device tree for Quad/Dual on VAR-MX6CustomBoard with resistive touchscreen:
$ make -j4 imx6q-var-som-res.dtb

Build the device tree for Quad/Dual on VAR-SOLOCustomBoard:
$ make -j4 imx6q-var-som-vsc.dtb

Build the device tree for VAR-SOM-SOLO on VAR-MX6CustomBoard with capacitive touchscreen:
$ make -j4 imx6dl-var-som-solo-cap.dtb

Build the device tree for VAR-SOM-SOLO on VAR-MX6CustomBoard with resistive touchscreen:
$ make -j4 imx6dl-var-som-solo-res.dtb

Build the device tree for VAR-SOM-SOLO on VAR-SOLOCustomBoard:
$ make -j4 imx6dl-var-som-solo-vsc.dtb

Build the device tree for DART-MX6:
$ make -j4 imx6q-var-dart.dtb

DART-6UL

Build Results

File Name	Description
zImage-imx6ul-var-dart-emmc_wifi.dtb	Device tree blob for DART-6UL with eMMC & WI-FI enabled. (SD card & NAND disabled)
zImage-imx6ul-var-dart-nand_wifi.dtb	Device tree blob for DART-6UL with NAND flash & WI-FI enabled. (SD card & eMMC disabled)
zImage-imx6ul-var-dart-sd_emmc.dtb	Device tree blob for DART-6UL with SD card & eMMC enabled (WIFI & NAND disabled)
zImage-imx6ul-var-dart-sd_nand.dtb	Device tree blob for DART-6UL with SD card & NAND flash enabled (WIFI & eMMC disabled)
zImage-imx6ull-var-dart-emmc_wifi.dtb	Device tree blob for DART-6ULL with eMMC & WI-FI enabled. (SD card & NAND disabled)
zImage-imx6ull-var-dart-nand_wifi.dtb	Device tree blob for DART-6ULL with NAND flash & WI-FI enabled. (SD card & eMMC disabled)
zImage-imx6ull-var-dart-sd_emmc.dtb	Device tree blob for DART-6ULL with SD card & eMMC enabled (WIFI & NAND disabled)
zImage-imx6ull-var-dart-sd_nand.dtb	Device tree blob for DART-6ULL with SD card & NAND flash enabled (WIFI & eMMC disabled)

Device tree

Build only the device tree for DART-6UL with eMMC and WiFi:
$ make -j4 imx6ul-var-dart-emmc_wifi.dtb

Build only the device tree for DART-6UL with eMMC and SD card:
$ make -j4 imx6ul-var-dart-sd_emmc.dtb

Build only the device tree for DART-6UL with NAND flash and WiFi:
$ make -j4 imx6ul-var-dart-nand_wifi.dtb

Build only the device tree for DART-6UL with NAND flash and SD card:
$ make -j4 imx6ul-var-dart-sd_nand.dtb

Build only the device tree for DART-6ULL with eMMC and WiFi:
$ make -j4 imx6ull-var-dart-emmc_wifi.dtb

Build only the device tree for DART-6ULL with eMMC and SD card:
$ make -j4 imx6ull-var-dart-sd_emmc.dtb

Build only the device tree for DART-6ULL with NAND flash and WiFi:
$ make -j4 imx6ull-var-dart-nand_wifi.dtb

Build only the device tree for DART-6ULL with NAND flash and SD card:
$ make -j4 imx6ull-var-dart-sd_nand.dtb

SD card image file tree

/opt/images/
└── Yocto
    ├── imx6ul-var-dart-emmc_wifi.dtb
    ├── imx6ul-var-dart-nand_wifi.dtb
    ├── imx6ul-var-dart-sd_emmc.dtb
    ├── imx6ul-var-dart-sd_nand.dtb
    ├── imx6ull-var-dart-emmc_wifi.dtb
    ├── imx6ull-var-dart-nand_wifi.dtb
    ├── imx6ull-var-dart-sd_emmc.dtb
    ├── imx6ull-var-dart-sd_nand.dtb
    ├── rootfs.tar.bz2
    ├── rootfs.ubi
    ├── SPL-nand
    ├── SPL-sd
    ├── u-boot.img-nand
    ├── u-boot.img-sd
    └── zImage

Boot board with a bootable SD card

Note: Boot from SD card eliminates Wifi as the Wifi and SD card are using same SDIO interface.
A typical use-case, is to boot from SD card, flash eMMC or NAND flash, and re-boot form eMMC/NAND to have Wi-Fi operational.

Setting the Boot DIP switches

Booting your system from an SD card requires switching the Boot DIP switches. See picture below.

• "00" The current position in the picture will set the system to boot from SD card.
• "01" Moving the right switch will set the system to boot from eMMC
• "10" Moving the left switch will set the system to boot from NAND flash
• "11" is illegal.

Be aware that your system has eMMC or NAND but never both.

Automatic device Tree selection in U-Boot

Upon reset you will see the U-Boot SPL printouts. It will print also the SOM configuration:
On-SOM storage: SD only, eMMC, NAND.
WIFI if chip exits.
For example:

U-Boot SPL 2015.10-00532-g482dc88 (Jan 03 2016 - 10:05:42)
i.MX6UL SOC 
Part number: DART-6U-A01
Assembly: AS11
Date of production: 2015 Dec 31
DART-6UL configuration: eMMC WIFI
Ram size: 512
Boot Device: SD

As explained in the above Build Results table we have 4 optional configurations.
We implemented in U-Boot and automatic device tree selection, so when kernel boots, the U-Boot will load the corresponding device tree according to On-SOM configuration.

SOM Type	Boot From	SOM Internal FLASH	SOM has WIFI/BT	Device Tree selected
DART-6UL	SD	eMMC	Don't Care	imx6ul-var-dart-sd_emmc.dtb
DART-6UL	SD	NAND	Don't Care	imx6ul-var-dart-sd_nand.dtb
DART-6UL	eMMC	eMMC	Yes	imx6ul-var-dart-emmc_wifi.dtb
DART-6UL	eMMC	eMMC	NO	imx6ul-var-dart-sd_emmc.dtb
DART-6UL	NAND	NAND	YES	imx6ul-var-dart-nand_wifi.dtb
DART-6UL	NAND	NAND	NO	imx6ul-var-dart-sd_nand.dtb
DART-6ULL	SD	eMMC	Don't Care	imx6ull-var-dart-sd_emmc.dtb
DART-6ULL	SD	NAND	Don't Care	imx6ull-var-dart-sd_nand.dtb
DART-6ULL	eMMC	eMMC	Yes	imx6ull-var-dart-emmc_wifi.dtb
DART-6ULL	eMMC	eMMC	NO	imx6ull-var-dart-sd_emmc.dtb
DART-6ULL	NAND	NAND	YES	imx6ull-var-dart-nand_wifi.dtb
DART-6ULL	NAND	NAND	NO	imx6ull-var-dart-sd_nand.dtb

Note: Boot from SD card eliminates Wifi as the Wifi and SD card are using same SDIO interface.
A typical use-case, is to boot from SD card, flash eMMC or NAND flash, and re-boot form eMMC/NAND to have Wi-Fi operational.

Disable Automatic Device Tree selection

To disable the automatic device tree selection in U-Boot:

$ setenv var_auto_fdt_file=N
$ saveenv

Now you can set the device tree to meet your requirements. For example:

$ setenv fdt_file=imx6ul-var-dart-sd_emmc.dtb
$ saveenv

Will select device tree that has SD and eMMC regardless if the SOM has WIFI.

$ setenv fdt_file=imx6ul-var-dart-sd_nand.dtb
$ saveenv

Will select device tree that has SD and NAND regardless if the SOM has WIFI.

Comment:
Make sure you don't set am illegal value like "imx6ul-var-dart-sd_nand.dtb" in a SOM that has eMMC flash.