U-Boot, v4.4.x/v4.9.x/v4.14.x: and v4.15.x+ support

[RobertCNelson]

So recently beagleboard.org dumped the idea of using Kernel Overlays and have replaced it with U-Boot Overlays. (just too many bugs to deal with)

Things to watch out for:

U-Boot signals to the Kernel that it has control thru "/proc/cmdline"

So if, "bone_capemgr.uboot_capemgr_enabled=1" is set in /proc/cmdline do not utilize slots file:

So if that signal thru /proc/cmdline, some important things for v4.4.x/v4.9.x/v4.14.x

v4.4.x/v4.9.x/v4.14.x:

If slots exists (/sys/devices/platform/bone_capemgr/slots), adding or removing overlays when U-Boot set things up will cause a kernel lockup...

If slots file is missing (it was removed to fix accidental hits ^ and is removed by bone_capemgr.uboot_capemgr_enabled=1 ) the /sys/devices/platform/bone_capemgr/ directory will still exist

v4.15.x:

In v4.15.x+ the /sys/devices/platform/bone_capemgr/ is no more.. (U-Boot Overlays only option)

Assumptions with U-Boot Overlays:

ADC = always enabled
cape-universal enabled by default: thus every IO available (thru config-pin).

bone_capemgr directory removed

available gpio's enabled can be search via:

"/sys/devices/platform/ocp/ocp:P*_*_pinmux"

BeagleBoard supports:

"gpio gpio_pu gpio_pd" options for "/sys/devices/platform/ocp/ocp:P*_*_pinmux/state"

PocketBeagle supports

"gpio gpio_pu gpio_pd gpio_input" options for "/sys/devices/platform/ocp/ocp:P*_*_pinmux/state"

P9_19:P9_20: now carved out, and no longer 100% tied to the cape-eeprom, it's only needed in u-boot, thus can be used as can/gpio/etc in kernel land.

PS: i'm working on integrating this into our "node-red" deb package. ;)

Regards,

[fivdi]

@RobertCNelson thanks for all the tips, they'll come in very useful. BeagleBone-IO only uses slots in one place now, to enable ADC if it isn't already enabled. If it's always enabled then that last usage of slots can be removed. If disable_uboot_overlay_adc=1 is in uEnv.txt it was explicitly disabled so that will be ok too.

PS: i'm working on integrating this into our "node-red" deb package. ;)

That's great news 😄 Will you also be integrating Johnny-Five? BeagleBone-IO is a plugin for Johnny-Five and is infinitely more useful with Johnny-Five. I'll have to admit that I'm not very familiar with node-red or the node-red deb package. Is BeagleBone-IO being added to the node-red deb package to increase the functionality of node-red? Or is BeagleBone-IO being added to the node-red deb package so that it can be installed and used independently of node-red?

[RobertCNelson]

@fivdi correct, it's already linked it up in buster as of today, as part of the node-red package. (With Johnny-Five)

https://github.com/rcn-ee/repos/blob/master/debian-10-bb-node-red-installer/version.sh#L22-L26

https://prnt.sc/hyqj7o

While it is part of the node-red package, it's in it's own directory, so i'm going to seperate our current node-red into 3 packages, beaglebone-io, johnny-five, and node-red (node-red/node-red-contrib-gpio)

debian@beaglebone:/usr/local/lib/node_modules$ ls -lha
total 0
drwxr-sr-x 1 root   staff   210 Jan 10 21:39 .
drwxrwsr-x 1 root   staff    60 Jan  7 16:45 ..
drwxr-sr-x 1 root   staff  1.8K Dec  4 20:19 async
drwxr-sr-x 1 debian debian  162 Jan 10 21:32 beaglebone-io
drwxr-sr-x 1 debian debian  230 Jan 10 02:32 bonescript
drwxr-sr-x 1 debian debian  118 Jan 10 20:53 johnny-five
drwxr-sr-x 1 debian debian  344 Jan 10 20:02 node-red
drwxr-sr-x 1 debian debian  208 Jan 10 20:54 node-red-contrib-gpio
drwxr-sr-x 1 debian debian  150 Jan 10 20:03 node-red-node-mongodb
drwxr-sr-x 1 root   staff   226 Dec  4 20:21 sensortag
drwxr-sr-x 1 debian debian  118 Jan 10 02:35 winston

and then i'm planning to backport that to stretch. (our current node-red uses octalbonescript which is now eol)

Regards,

[fivdi]

Nice, very nice indeed 😄

[fivdi]

PR #49 removes all usage of the slots file from BeagleBone-IO.

[fivdi]

@RobertCNelson

BeagleBone-IO has been updated and no longer uses slots or /sys/devices/platform/bone_capemgr/.

This means that it should function correctly on v4.4.x/v4.9.x/v4.14.x/v4.15.x. However, I'll have to admit that I only tested on v4.4 and v4.14.

BeagleBone-IO doesn't require root privileges on v4.14.x.

P9_19:P9_20 are used by BeagleBone-IO for I2C. This has always been the case although is sounds like this may not have been a good practice.

Two follow up issues based on the information you provided above have been created, #59 and #60.

Please feel free to create issues similar to this issue in the future, it would be very helpful.

I'll leave this issue open for the moment and close it after [email protected] has been published on npm.

[RobertCNelson]

@fivdi awesome!

ps, i snuck the git version in on Saturday night before the weekly build (Sunday morning), so this week's build has up to git:

8d4e9f4

https://rcn-ee.net/rootfs/bb.org/testing/2018-01-21/

After the two pull requests this morning, i triggered another build, i'll have updated *.deb packages in about another 1/2 hour. So Stretch & Buster are looking great! ;)

Regards,

[fivdi]

@RobertCNelson [email protected] has been published on npm.

After the two pull requests this morning, i triggered another build, i'll have updated *.deb packages in about another 1/2 hour.

This means that [email protected] was available in the deb package before it was published on npm.