Difference between revisions of "Beagleboard:BeagleBone Debian Image Migration"
(→cape-universal) |
(Enabling the ADC) |
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See also this survey of [[BeagleBone DTBs]]. | See also this survey of [[BeagleBone DTBs]]. | ||
+ | |||
+ | ===== Enabling the ADC ===== | ||
+ | |||
+ | This requires configuring the ADC via device tree, e.g. by loading the <code>/lib/firmware/BB-ADC-00A0.dtbo</code> overlay ([https://github.com/beagleboard/bb.org-overlays/blob/master/src/arm/BB-ADC-00A0.dts source code]) using capemgr: | ||
+ | |||
+ | echo BB-ADC >/sys/devices/platform/bone_capemgr/slots |
Revision as of 02:58, 11 January 2017
Contents
Kernel
What changes were made to sysfs?
3.8 kernel sysfs entry 4.x kernel sysfs entry /sys/devices/bone_capemgr.* /sys/devices/platform/bone_capemgr /sys/devices/ocp.* /sys/devices/platform/ocp/ /sys/devices/ocp.*/helper.*/AIN* /sys/bus/iio/devices/iio:device0
Device Tree
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 bone_capemgr.enable_partno
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:
3.8 kernel
cape_disable=capemgr.disable_partno= |
4.x kernel
dtb= |
---|---|
(blank) | am335x-boneblack.dtb |
BB-BONELT-HDMI | ? |
BB-BONELT-HDMI,BB-BONELT-HDMIN | am335x-boneblack-emmc-overlay.dtb |
BB-BONE-EMMC-2G | am335x-boneblack-hdmi-overlay.dtb |
BB-BONE-EMMC-2G,BB-BONELT-HDMI | am335x-boneblack-nhdmi-overlay.dtb |
BB-BONE-EMMC-2G,BB-BONELT-HDMI,BB-BONELT-HDMIN | am335x-boneblack-overlay.dtb |
See also this survey of BeagleBone DTBs.
Enabling the ADC
This requires configuring the ADC via device tree, e.g. by loading the /lib/firmware/BB-ADC-00A0.dtbo
overlay (source code) using capemgr:
echo BB-ADC >/sys/devices/platform/bone_capemgr/slots