Difference between revisions of "Beagleboard:BeagleBone Debian Image Migration"

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m (Fix capitalization of sysfs)
(Add remark on disabling cape-universal)
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==Device Tree==
 
==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
 +
 
===== Disabling eMMC or HDMI =====
 
===== 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:
 
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:

Revision as of 19:14, 10 September 2016

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
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.