编译Android 6.0的BeagleBone Black SD卡启动后无显示求助

Since you’ve already confirmed Android is running and connected an FTDI cable to the BBB’s serial port, let’s leverage that setup and work through targeted steps to debug your non-functional Cape:

1. Capture & Analyze Serial Boot Logs #

First, pull the full boot log via your FTDI connection—this will reveal critical kernel and Android initialization details hidden from the display. Use a terminal tool like screen or minicom to connect:

screen /dev/ttyUSB0 115200  # Adjust /dev/ttyUSB0 to match your system's FTDI device

Focus on these key sections in the log:

• Kernel Hardware Detection: Look for lines mentioning your Cape’s model, I2C/SPI bus activity, or driver probe failures. If the kernel doesn’t recognize the Cape’s hardware, it won’t pass control to Android’s display stack.
• Device Tree Overlays: BBB Capes rely on device tree overlays to enable hardware. Check if the correct overlay for your Cape is being loaded during boot—missing overlays are a common culprit here.
• Android HAL Initialization: Watch for errors related to the display or peripheral hardware abstraction layer (HAL). If the HAL can’t bind to the Cape’s driver, the display won’t activate.

2. Verify Cape Compatibility with Your Android Build #

The beagleboneblack_sd-eng target may not include out-of-the-box support for your specific Cape. Dig into the AOSP source you compiled:

• Check the device tree files (under device/ti/beagleboneblack/ or kernel/arch/arm/boot/dts/) to see if your Cape’s overlay is included or referenced.
• Look for driver modules for your Cape’s display controller—if they’re missing, you’ll need to add them to the build configuration (e.g., updating BoardConfig.mk or device.mk).

3. Rule Out Hardware Issues #

Before diving deeper into software, confirm your Cape works outside of Android:

• Flash a standard BBB Debian image and test the Cape. If it fails here, you’re likely dealing with a loose connection, faulty Cape, or power supply issue (some Capes require extra power beyond what the BBB provides).
• Double-check the Cape’s pin alignment—misaligned pins can prevent hardware detection even if the BBB boots successfully.

4. Inspect Android System Logs #

Once Android is fully booted, use the serial connection (or adb if you can get a USB connection working) to pull system logs:

adb logcat  # If adb is available
# Or via serial:
logcat -d > android_system_log.txt

Search the logs for keywords like display, cape, driver, or your Cape’s specific model to pinpoint initialization failures or runtime errors.

内容的提问来源于stack exchange，提问作者user7345878