IoTGateway/BSP/Android/Gettingstarted/How to set HDMI

HDMI Introduction
HDMI (High-Definition Multimedia Interface) is a compact audio/video interface for transmitting uncompressed digital video data and uncompressed/compressed digital audio data. HDMI connects digital audio/video sources-such as set-top boxes, Blu-ray Disc
players, personal computers (PCs), video game consoles, and AV receivers to compatible digital audio devices, computer monitors, and digital televisions.
HDMI supports, on a single cable, any TV or PC video format, including standard, enhanced, and high-definition video, up to 8 channels of digital audio, and a Consumer Electronics Control (CEC) connection. The CEC allows HDMI devices to control each
other when necessary and allows the user to operate multiple devices with one remote control handset.
Because HDMI is electrically compatible with the signals used by Digital Visual Interface (DVI), no signal conversion is necessary, nor is there a loss of video quality when a DVI-to-HDMI adapter is used.
The HDMI Transmitter (HDMI TX) consists of two parts:

• HDMI TX Controller
• HDMI TX PHY

depicts the HDMI TX integration scheme into the i.MX 6Dual/6Quad.

The default display is LVDS. If you want to change the display to HDMI

1. Enter bootloader

a. setenv

setenv bootargs console=ttymxc0,115200 init=/init video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off vmalloc=384M androidboot.console=ttymxc0 consoleblank=0 androidboot.hardware=freescale cma=384M androidboot.selinux=disabled androidboot.dm_verity=disabled

b. boot to Android

#boot

2. Check Linux device tree setting

If you want to check the HDMI device tree setting, you can check kernel_imx/arch/arm/boot/dts/imx6qdl-advantech.dtsi

Using HDMI/hdmi as keywords to search the file, you can see the device tree setting such as

&hdmi_audio {
        status = "okay";
};

&hdmi_cec {
        status = "okay";
};

&hdmi_core {
        ipu_id = <1>;
        disp_id = <1>;
        status = "okay";
};