There are many customers who have a lot of trouble with debugging the screen, and often have various problems when debugging the screen on their own. In order to help everyone debug the screen better and faster, Feiling R & D engineers have added a new function in the uboot stage of i.MX6X to make screen logo adaptation more convenient and faster. Let ’s take a look at this new Function.
This function is currently adapted to the i.MX6X platform with Linux3.0.35. The operation is very simple. We only need to set the resolution and refresh rate of the screen. , Convenient and worry-free.
Let's take a look at how to operate it!
Press the space bar on the console to enter the uboot command line within 3 seconds after the IMX6X development board is powered on. (If there is no button within 3 seconds, enter the startup process)
After entering the command line, according to the prompt menu on the screen, select '0' to enter the uboot shell setting state.
LCD screen setting examples:
Suppose we want to set the screen resolution of the IMX6X development board to 640x480 and the refresh rate of 60Hz; then we can set it according to the following command
setenv mxcfb0 video=mxcfb0:dev=lcd,640x480M@60,if=RGB24,bpp=32
saveenv
After the setting is completed, restart, uboot will display the logo picture on the LCD interface according to the resolution of 640x480.
Examples of LVDS screen settings:
We want to set the LVDS screen resolution of the IMX6X development board to 1280x800, the command is as follows:
setenvmxcfb0 video=mxcfb0:dev=ldb,1280x800M@60,if=RGB24,bpp=32
saveenv
After the setting is completed, reboot, uboot will display the logo picture on the lvds interface according to the resolution of 1280x800.
Examples of HDMI screen settings:
We want to set the HDMI screen resolution of the IMX6X development board to 1920x1080, the command is as follows:
setenv mxcfb0 video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32
saveenv
After the setting is completed, restart, uboot will display the logo image on the HDMI interface according to the resolution of 1920x1080.
The above is an example of setting three different screens on the IMX6X development board. Next, we will briefly explain the parameters mentioned above:
1. "dev = lcd" The options that dev can configure include ldb, hdmi, and lcd, respectively corresponding to the lvds interface, hdmi interface, and lcd interface;
2. If it is an LVDS interface, the set ldb mode environment variable also plays a role in uboot in the IMX6X development board. If you set ldb to sin0, the logo is displayed on the lvds0 interface, sin1 displays the logo on the lvds1 interface, and spl0 uses the spl mode Lvds screen can display logo on uboot
3. This method is not applicable to the mipi interface. Since most of the mipi interface screens need to initialize the screen, this method is not suitable for the mipi interface screens. The mipi interface screens need to be debugged according to the screen manufacturer's manual.
4. The uboot shell interface of the IMX6X development board, where 640x480M @ 60 is the resolution and refresh rate of the matching display, 640 is the width, 480 is the height, and 60 is the refresh frequency.
5. If you are interested, you can enter the printenv command to view some parameter settings in the relevant uboot.
The above is the whole process of operation, is it very simple, most common resolutions can be displayed normally by this method. If the matching display effect is not good, please add accurate display parameters in uboot or kernel according to the data sheet of the display.
Original link: https://www.forlinx.com/article_view_376.html