How to Config Multi-Display
Contents
- 1Introductory
- 2Contents
- 3Enter U-boot interrupt mode
- 4eDP + HDMI
- 5eDP + LVDS
- 6LVDS + HDMI
- 7eDP + DP
- 8LVDS + DP
- 9HDMI + DP
- 10Default Support Display
- 11Using envtools in Debian/Android
- 12Configurate Multi-Display of differnt resolutions in Duplicate mode
Introductory
RSB-4710 surport 4 display ports : eDP、LVDS（mipi to LVDS）、HDMI、DP （DP to HDMI）. Only two ports work at the same time .
You can config Multi-Display to eDP + HDMI 、eDP + LVDS、LVDS + HDMI 、eDP + DP、LVDS + DP、HDMI + DP.
NOTE：
Android distinguish the primary and the extend screen.
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Enter U-boot interrupt mode
Connect device to debug port, and open debug console. See more : --> .
Press "ctrl + c" key before power up the device, until get the following information on debug console :
Hit any key to stop autoboot: 0
=> <INTERRUPT>
=>
Then you can input the following cammand to config Multi-Display.
eDP + HDMI
setenv prmry_screen edp-1920x1080
setenv extend_screen hdmi-default
saveenv
reset
or
setenv prmry_screen hdmi-default
setenv extend_screen edp-1920x1080
saveenv
reset
eDP + LVDS
setenv prmry_screen edp-1920x1080
setenv extend_screen lvds-g070vw01
saveenv
reset
or
setenv prmry_screen lvds-g070vw01
setenv extend_screen edp-1920x1080
saveenv
reset
LVDS + HDMI
setenv prmry_screen hdmi-default
setenv extend_screen lvds-g070vw01
saveenv
reset
or
setenv prmry_screen lvds-g070vw01
setenv extend_screen hdmi-default
saveenv
reset
eDP + DP
setenv prmry_screen edp-1920x1080
setenv extend_screen dp-default
saveenv
reset
or
setenv prmry_screen dp-default
setenv extend_screen edp-1920x1080
saveenv
reset
LVDS + DP
setenv prmry_screen dp-default
setenv extend_screen lvds-g070vw01
saveenv
reset
or
setenv prmry_screen lvds-g070vw01
setenv extend_screen dp-default
saveenv
reset
HDMI + DP
setenv prmry_screen hdmi-default
setenv extend_screen dp-default
saveenv
reset
or
setenv prmry_screen dp-fefault
setenv extend_screen hdmi-default
saveenv
reset
Default Support Display
| Port | RSB4710 |
|---|---|
| edp | edp-1920x1080 edp-1366x768 |
| lvds | lvds-g070vw01 lvds-g150xgel05 lvds-g215hvn01 |
| hdmi | hdmi-default |
| dp | dp-default |
NOTE :
- The name of the panel must begin with "edp-"、"lvds-" 、"hdmi-" or “dp-”.
And it can be found in "kernel/include/dt-bindings/display/screen-timing/{LCDNAME}.dtsi" like :
lvds_g070vw01: lvds-g070vw01
- If there is no configuration, you will get default setting :
hdmi-default and dp-default as default setting.
- Check your configuration in Terminal or debug console.
cat /proc/cmdline
... prmry_screen=hdmi-default extend_screen=dp-default
| LVDS Name | Resolution |
|---|---|
| lvds-g070vw01 | 800x480 |
| lvds-g150xgel05 | 1024x768 |
| lvds-g215hvn01 | 1920x1080 |
Using envtools in Debian/Android
Using envtools to setup envs in Debian/Android OS is very similar in uboot.
Take “eDP+HDMI”for example :
| In uboot | In Debian/Android |
|---|---|
| setenv prmry_screen hdmi-default | fw_setenv prmry_screen hdmi-default |
| setenv extend_screen edp-1920x1080 | fw_setenv extend_screen edp-1920x1080 |
| saveenv | |
| reset | reboot |
Note :
The tool "fw_setenv" will save envs automatically in Debian/Android OS, so it isn't necessary to saveen manually.
Check current setting：
root@linaro-alip:# cat /proc/cmdline storagemedia=emmc androidboot.storagemedia=emmc androidboot.mode=normal androidboot.verifiedbootstate=orange androidboot.slot_suffix= androidboot.serialno=a2fc4116ad6b2c4f rw rootwait earlycon=uart8250,mmio32,0xff180000 swiotlb=1 console=ttyS0,115200 root=PARTUUID=614e0000-0000 rootfstype=ext4 coherent_pool=1m quiet board_info=9 prmry_screen=hdmi-default extend_screen=lvds-g070vw01 root@linaro-alip:#
Configurate Multi-Display of differnt resolutions in Duplicate mode
If Multi-Display has differnt resolution in duplicate mode, you can see all view on the screen of big resolution and the view in the top left corner on the screen of small resolution.
If you want to the same view on the two screens. Using xrandr to configurate Multi-Display of differnt resolutions in Duplicate mode in Debian OS.
Take “LVDS (1024x768) + HDMI (1920x1080)”for example:
xrandr --output HDMI-1 --scale-from 1024x768
or
xrandr --output LVDS-1 --scale-from 1920x1080