Beagleboard:BeagleBone Debian Image Migration

cape-universal
''Help! My overlay won't load! There's just this weird cape in slot 4.''

You've met cape-universal. It is meant to often make overlays unnecessary, but you can also just disable it by changing the following line in /boot/uEnv.txt: cmdline=coherent_pool=1M quiet cape_universal=enable to cmdline=coherent_pool=1M quiet

cape-universal is also automatically disabled if  occurs in the kernel cmdline (even if its argument is blank) or any overlay is already applied via capemgr before cape-universal can be loaded.

Disabling eMMC or HDMI
HDMI and eMMC are now part of the main dtb instead of being virtual CAPEs, which means that to disable these you change the 'dtb' variable in /boot/uEnv.txt instead of using capemgr.disable_partno:

See also this survey of BeagleBone DTBs.

Enabling the ADC
This requires configuring the ADC via device tree, e.g. by loading the  overlay (source code) using capemgr:

echo BB-ADC >/sys/devices/platform/bone_capemgr/slots

The ADC will appear as an IIO device (see )

Enabling PRUSS
Same story as the ADC except using uio_pruss_enable-00A0.dtbo:

echo uio_pruss_enable >/sys/devices/platform/bone_capemgr/slots

U-Boot Overlays
U-Boot Overlays is currently under development, while the items below may work on "last weeks" version. Please report bugs to: https://github.com/beagleboard/bb.org-overlays/issues Always double check the version you are using for comparison.

U-Boot SPL 2017.03-rc1-00003-ga09f2d69d3 (Feb 08 2017 - 16:09:51) Trying to boot from MMC2 U-Boot 2017.03-rc1-00003-ga09f2d69d3 (Feb 08 2017 - 16:09:51 -0600), Build: jenkins-github_Bootloader-Builder-518

To upgrade your version of U-Boot: debian@beaglebone:~$ cd /opt/scripts/tools/developers/ debian@beaglebone:/opt/scripts/tools/developers$ sudo ./update_bootloader.sh debian@beaglebone:/opt/scripts/tools/developers$ sudo reboot

U-Boot /boot/uEnv.txt configuration
Note, do not have a "/uEnv.txt" file, backwards compatibility for ancient U-Boot's is not currently supported, so make sure to "sudo rm /uEnv.txt"... At a minimum, "enable_uboot_overlays=1" must be in /boot/uEnv.txt for U-Boot to take over loading overlays.

/boot/uEnv.txt: enable_uboot_overlays=1

U-Boot Disable onboard devices
To Disable eMMC: disable_uboot_overlay_emmc=1

To Disable HDMI VIDEO & AUDIO: disable_uboot_overlay_video=1

To Disable HDMI AUDIO: (first added in: 2017.03-rc1-00003-gb401af09b2 Build 515) disable_uboot_overlay_audio=1

To Disable WL1835: disable_uboot_overlay_wireless=1

U-Boot Override external capes
Cape device tree overlays: https://github.com/beagleboard/bb.org-overlays/

uboot_overlay_addr0=/lib/firmware/ .dtbo uboot_overlay_addr1=/lib/firmware/ .dtbo uboot_overlay_addr2=/lib/firmware/ .dtbo uboot_overlay_addr3=/lib/firmware/ .dtbo

Plus one custom cape: dtb_overlay=/lib/firmware/ .dtbo

U-Boot Cape Universal
Utilize https://github.com/cdsteinkuehler/beaglebone-universal-io config-pin.

To enable, in /boot/uEnv.txt add: (first added in: 2017.03-rc1-00003-g15396d3873 Build 516) enable_uboot_cape_universal=1