Alternative EVK Hardware Configurations
Each Genio EVK provides different hardware configurations, for example,
Genio 1200 and Genio 700 EVK provide various display output interface combinations.
All Genio EVKs have optional camera daughterboards.
In most cases, these hardware configurations are mutually exclusive to each other. For example, the Ethernet port and the HDMI port on Genio 350 EVK cannot be enabled at the same time, because they occupy the same hardware pins.
As a result, we need to use different device trees to represent different hardware configurations. Instead of duplicating the device tree source files, we could use device tree overlays to modify the board device tree to provide different configurations.
The Genio boot firmwares provide several hardware configurations for you to apply. This section shows you how to apply different device tree overlays, and provides a list of pre-installed DTBO files in each boot firmware.
Apply Device Tree Overlays
The device tree overlays are binary files organized in the FIRMWARE partition as described in the
Partition Layout section. The directory structure looks like this:
FIRMWARE
└── mediatek
├── genio-1200-evk
│ ├── apusys.dtbo
│ ├── camera-ar0430-ap1302-csi0.dtbo
│ ├── display-dp.dtbo
│ ├── display-hdmi.dtbo
│ ├── ...
│ ├── genio-1200-evk.dtb
│ ├── gpu-mali.dtbo
│ └── video.dtbo
├── genio-350-evk
│ ├── ...
└── genio-700-evk
└── ...
To apply a dtbo, simply add its filename to the list_dtbo U-Boot environment variable. There are several
approaches to set a U-boot environment variable, including:
Modify the
u-boot-initial-envconfiguration file in boot firmwares and flash themmc0boot1partition.Use
setenvandsaveenvcommands in U-Boot interactive console
The following sections show the steps to do so:
Modify U-Boot Environment Variables with Flash Tool
To modify the list_dtbo variable using the genio-flash tool,
follow these steps:
Open then
u-boot-initial-envtext file in the image directory, and locate the linelist_dtbo=:dtb_path=/FIRMWARE/mediatek/genio-1200-evk/ efi_dtb_prefixes=${dtb_path} / /dtb/ /dtb/current/ check_fastboot_entry=setenv fastboot_entry 0 boot_conf=#conf-mediatek_genio-1200-evk.dtb#conf-gpu-mali.dtbo#conf-video.dtbo list_dtbo= gpu-mali.dtbo video.dtbo apusys.dtbo storage=mmc storage_dev=0 boot_scripts=fitImage
Append the dtbo file name you want to apply at the end of the line, for example,
display-hdmi.dtbolist_dtbo= gpu-mali.dtbo video.dtbo apusys.dtbo display-hdmi.dtbo
Save and close the file.
You can then simply flash the Ubuntu image and the
list_dtbovariable will be updated. If your EVK board is already flashed an Ubuntu image and you only want to modify the U-Boot environment variables, use the following command:genio-flash mmc0boot1This only modifies the boot partition that stores U-Boot environment variables.
Modify U-Boot Environment Variables with Interactive Console
Alternatively you could modify U-Boot environment through the interactive console.
During U-Boot boot process, when you see the line
Hit any key to stop autoboot, press any key in the UART console to gain access to the interactive console:Hit any key to stop autoboot: 0 =>
In the console, use the command
printenvto list existing variable values:=> printenv list_dtbo list_dtbo= gpu-mali.dtbo video.dtbo apusys.dtbo
Use the command
setenvto set variables. In the example below, we append the dtbo filedisplay-hdmi.dtboto existing values, and usesaveenvto write the result to persistent storage.=> setenv list_dtbo "gpu-mali.dtbo video.dtbo apusys.dtbo display-hdmi.dtbo" => saveenv Saving Environment to MMC... Writing to MMC(0)... OK
You can then reboot the board, or use the following command to continue the boot flow:
=> run distro_bootcmd
U-Boot Log for Device Tree Overlay
After you updated the environment variable, reboot the board.
U-Boot would apply the overlay and you should see the following U-Boot log in the UART console:
Hit any key to stop autoboot: 0
base: /FIRMWARE/mediatek/genio-1200-evk/
fdtfile: genio-1200-evk.dtb
fdtaddr: 0x44000000
Probing mmc 0:3 for device tree...
Loading dtb '/FIRMWARE/mediatek/genio-1200-evk//genio-1200-evk.dtb'
107888 bytes read in 5 ms (20.6 MiB/s)
Loading overlay '/FIRMWARE/mediatek/genio-1200-evk//gpu-mali.dtbo'
3505 bytes read in 3 ms (1.1 MiB/s)
Loading overlay '/FIRMWARE/mediatek/genio-1200-evk//video.dtbo'
9139 bytes read in 3 ms (2.9 MiB/s)
Loading overlay '/FIRMWARE/mediatek/genio-1200-evk//apusys.dtbo'
12434 bytes read in 2 ms (5.9 MiB/s)
Loading overlay '/FIRMWARE/mediatek/genio-1200-evk//display-hdmi.dtbo'
609 bytes read in 3 ms (198.2 KiB/s)
switch to partitions #0, OK
mmc0(part 0) is current device
In the example above we appended display-hdmi.dtbo and
it disables the built-in DSI panel, leaving only the HDMI porting enabled.
Please refer to the tables below for the effect of each overlay file.
List of Overlay Files for Each Genio EVK
Genio 1200 EVK Overlays
DTBO name |
Usage |
|---|---|
Camera overlays are mutually exclusive: |
|
|
Enables MIPI-CSI0 port for DTB-D1V1-D2 (RAW sensor). |
|
Enables MIPI-CSI1 port for DTB-D1V1-D2 (RAW sensor). |
|
Enables MIPI-CSI2 port for DTB-D1V1-D2 (RAW sensor). |
|
Enables MIPI-CSI0 for DTB-D1V1-D6 (YUV sensor). |
|
Enables MIPI-CSI1 for DTB-D1V1-D6 (YUV sensor). |
|
Enables MIPI-CSI2 for DTB-D1V1-D6 (YUV sensor). |
Display overlays are mutually exclusive: |
|
|
Enables DPoC(Display Port over Type-C) external display and disables all other display interfaces. |
|
Enables both DSI and eDP panels. Disables both DPoC and HDMI output. |
|
Enables DSI panel, eDP panel, and DPoC port. This is a triple display setup and the maximum resolution is reduced. |
|
Enables DSI panel, eDP panel, and HDMI port. This is a triple display setup and the maximum resolution is reduced. |
|
Enables DSI panel, DPoC port, and HDMI port. This is a triple display setup and the maximum resolution is reduced. |
|
Enables the eDP panel only. |
|
Enables the HDMI and DPoC ports only. All built-in panels are disabled. |
|
All display interfaces are disabled. |
Genio 700 EVK Overlays
DTBO name |
Usage |
|---|---|
Display overlays are mutually exclusive: |
|
|
Enables DPoC(Display Port over Type-C) external display, and disables all other display interfaces. |
|
Enables DSI panel only. |
|
Enables DSI panel and DPoC port. |
|
Enables both DSI and eDP panels. Disables both DPoC and HDMI output. |
|
Enables eDP output. This disables the default DSI panel output. |
|
Enables HDMI port and displays all other display interfaces. |
|
Disables DSI panel and enables both HDMI and DPoC output. |
Genio 510 EVK Overlays
DTBO name |
Usage |
|---|---|
Display overlays are mutually exclusive: |
|
|
Enables DPoC(Display Port over Type-C) external display, and disables all other display interfaces. |
|
Enables DSI panel only. |
|
Enables DSI panel and DPoC port. |
|
Enables both DSI and eDP panels. Disables both DPoC and HDMI output. |
|
Enables eDP output. This disables the default DSI panel output. |
|
Enables HDMI port and displays all other display interfaces. |
|
Disables DSI panel and enables both HDMI and DPoC output. |
Genio 350 EVK Overlays
DTBO name |
Usage |
|---|---|
|
Enables on-board ethernet port and disables HDMI port. The on-board switch |
Camera overlays are mutually exclusive: |
|
|
Single camera on MIPI-CSI0. |
|
Single camera on MIPI-CSI1. |
|
Dual camera on MIPI-CSI0 and MIPICSI1. |
Display overlays are mutually exclusive: |
|
|
Enables HDMI port but disables DSI panel and the Ethernet port. |
|
Enables all display interfaces. |
Source Code of Overlay Files
All Genio EVK overlay files are maintained in the kernel tree, along with the device tree file of each Genio EVK.
Please visit the kernel repository and navigate to path arch/arm64/boot/dts/mediatek:
For example,
Note
Please make sure the kernel version tag matches the actual kernel images you are currently using.