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

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(Add remark on disabling cape-universal)
(cape-universal)
Line 18: Line 18:
 
''Help! My overlay won't load! There's just this weird cape in slot 4.''
 
''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:
+
You've met [https://github.com/cdsteinkuehler/beaglebone-universal-io 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
 
   cmdline=coherent_pool=1M quiet cape_universal=enable
 
to
 
to
 
   cmdline=coherent_pool=1M quiet
 
   cmdline=coherent_pool=1M quiet
 +
 +
cape-universal is also automatically disabled if <code>bone_capemgr.enable_partno</code> 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 =====
 
===== Disabling eMMC or HDMI =====

Revision as of 06:43, 18 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

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.