I've got a zc702 board with only the 7511 chip, and had been happily running a system with HDMI (using the cf_adv7511_zc702 reference design rev 6310ae0, and kernel rev 40d8cf29d). I tried updating to the current revisions (reference design 5e8e14cfb and kernel d82229d2), and now HDMI doesn't work. I rebuilt everything - reference design bitstream, FSBL, kernel + device tree, and boot image, so I don't think I have a version mismatch problem. The bootloader and root filesystem are the same.
The system boots and I can interact with it over the serial console, but there is no HDMI output. The /dev/fb0 device exists, and `find /sys/bus/i2c` finds the relevant I2C handles:
There don't appear to be any significant warnings during boot, so I'm not really sure where to begin debugging. What logs should I be looking at, and what should I be looking for?