Hi,
My BBB stack has a 4.3" LCD cape – powerup diagnostics (dmesg) indicated the cape was found OK & brightness worked Ok. I was unable to view (startup) text on the display. (Ver 4.4.1-bone11). After a few days of debug, I found that the MuxPins were not properly updated and were still accessing HDMI (not modified as expected). I added an ‘echo’ into /uEnv.txt & discovered that the ‘overlay file’ was not right - it was the default chosen at power-up.
/boot/uEnv.txt has the lines (amongst others)
dtb=am335x-boneblack-overlay.dtb
Disable: HDMI
/uEnv.txt was modified - fdtfile was replaced by dtb
#loadxfdt=load mmc 0:1 ${fdtaddr} /boot/dtbs/${uname_r}/${fdtfile}
loadxfdt=load mmc 0:1 ${fdtaddr} /boot/dtbs/${uname_r}/${dtb}
Possibly modifying fdtfile is the appropriate method – Is there a better solution?
thx