Pins and Port configuration in the Beagleboard xM

[montal...@gmail.com]

Hi everyone,

    I´m just starting a project where I´m going to do some tests with a Beagleboard xM that needs to control an external board through a UART channel, some PWM pins, and some GPIOs.

    I´ve just prepare my SD Card with the last Debian Image from this link:

https://debian.beagleboard.org/images/bbxm-debian-9.5-lxqt-xm-armhf-2018-10-07-4gb.img.xz

   Boot the system and seems everything looks good:

U-Boot SPL 2018.09-00001-ge10814359b (Sep 10 2018 - 19:52:59 -0500)

Trying to boot from MMC1

spl_load_image_fat_os: error reading image args, err - -2

U-Boot 2018.09-00001-ge10814359b (Sep 10 2018 - 19:52:59 -0500), Build: jenkins-github_Bootloader-Builder-65

OMAP3630/3730-GP ES1.2, CPU-OPP2, L3-200MHz, Max CPU Clock 1 GHz

Model: TI OMAP3 BeagleBoard

OMAP3 Beagle board + LPDDR/NAND

I2C:   ready

DRAM:  256 MiB

NAND:  0 MiB

MMC:   OMAP SD/MMC: 0

Loading Environment from NAND... *** Warning - readenv() failed, using default environment

Beagle xM Rev C

No EEPROM on expansion board

No EEPROM on expansion board

OMAP die ID: 6c0a00029ff8000001578ca01101202e

Net:   usb_ether

starting USB...

USB0:   USB EHCI 1.00

scanning bus 0 for devices... 3 USB Device(s) found

       scanning usb for storage devices... 0 Storage Device(s) found

       scanning usb for ethernet devices... 1 Ethernet Device(s) found

Hit any key to stop autoboot:  0

switch to partitions #0, OK

mmc0 is current device

Scanning mmc 0:1...

switch to partitions #0, OK

mmc0 is current device

SD/MMC found on device 0

Checking for: /uEnv.txt ...

Checking for: /boot/uEnv.txt ...

432 bytes read in 27 ms (15.6 KiB/s)

Loaded environment from /boot/uEnv.txt

Checking if uname_r is set in /boot/uEnv.txt...

Running uname_boot ...

loading /boot/vmlinuz-4.18.11-armv7-x11 ...

6550016 bytes read in 520 ms (12 MiB/s)

loading /boot/dtbs/4.18.11-armv7-x11/omap3-beagle-xm.dtb ...

94492 bytes read in 786 ms (117.2 KiB/s)

loading /boot/initrd.img-4.18.11-armv7-x11 ...

4745973 bytes read in 390 ms (11.6 MiB/s)

debug: [console=ttyO2,115200n8 root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 quiet] ...

debug: [bootz 0x82000000 0x88080000:486af5 0x88000000] ...

## Flattened Device Tree blob at 88000000

   Booting using the fdt blob at 0x88000000

   Loading Ramdisk to 89b79000, end 89fffaf5 ... OK

   Loading Device Tree to 89b5e000, end 89b7811b ... OK

Starting kernel ...

[    4.520965] Error: Driver 'tfp410' is already registered, aborting...

[    5.108215] omap2_set_init_voltage: unable to find boot up OPP for vdd_core

[    5.115936] omap2_set_init_voltage: unable to set vdd_core

[FAILED] Failed to start Load Kernel Modules.

See 'systemctl status systemd-modules-load.service' for details.

[DEPEND] Dependency failed for robotcontrol.

[  OK  ] Started Create list of required sta…vice nodes for the current kernel.

[  OK  ] Started File System Check Daemon to report status.

         Starting Create Static Device Nodes in /dev...

         Mounting Configuration File System...

         Mounting FUSE Control File System...

         Starting Apply Kernel Variables...

[  OK  ] Mounted Configuration File System.

[  OK  ] Mounted FUSE Control File System.

[  OK  ] Started File System Check on Root Device.

[  OK  ] Started Create Static Device Nodes in /dev.

[  OK  ] Started Apply Kernel Variables.

[  OK  ] Started Journal Service.

         Starting udev Kernel Device Manager...

         Starting Remount Root and Kernel File Systems...

[  OK  ] Started Remount Root and Kernel File Systems.

         Starting Load/Save Random Seed...

         Starting Flush Journal to Persistent Storage...

         Starting udev Coldplug all Devices...

[  OK  ] Started Load/Save Random Seed.

[  OK  ] Started udev Kernel Device Manager.

[  OK  ] Started Flush Journal to Persistent Storage.

[  OK  ] Started Set the console keyboard layout.

[  OK  ] Reached target Local File Systems (Pre).

[  OK  ] Reached target Local File Systems.

         Starting Create Volatile Files and Directories...

         Starting Set console font and keymap...

         Starting Raise network interfaces...

[  OK  ] Started Set console font and keymap.

[  OK  ] Started Create Volatile Files and Directories.

         Starting Network Time Synchronization...

[  OK  ] Started Entropy daemon using the HAVEGE algorithm.

         Starting Update UTMP about System Boot/Shutdown...

[  OK  ] Started Update UTMP about System Boot/Shutdown.

[  OK  ] Started Network Time Synchronization.

[  OK  ] Reached target System Time Synchronized.

[  OK  ] Started Raise network interfaces.

[  OK  ] Started udev Coldplug all Devices.

[  OK  ] Reached target System Initialization.

[  OK  ] Listening on bonescript.socket.

[  OK  ] Listening on cloud9.socket.

[  OK  ] Started Daily apt download activities.

[  OK  ] Started Daily apt upgrade and clean activities.

[  OK  ] Started Daily Cleanup of Temporary Directories.

[  OK  ] Reached target Timers.

[  OK  ] Listening on node-red.socket.

[  OK  ] Listening on Avahi mDNS/DNS-SD Stack Activation Socket.

[  OK  ] Listening on D-Bus System Message Bus Socket.

[  OK  ] Reached target Sockets.

[  OK  ] Reached target Basic System.

         Starting LSB: Load kernel modules needed to enable cpufreq scaling...

[  OK  ] Started Deferred execution scheduler.

         Starting LSB: Start busybox udhcpd at boot time...

         Starting Restore /etc/resolv.conf i…fore the ppp link was shut down...

         Starting Login Service...

         Starting Avahi mDNS/DNS-SD Stack...

[  OK  ] Started Bonescript autorun.

[  OK  ] Started Regular background program processing daemon.

         Starting rc_battery_monitor...

         Starting BB WL18xx wlan0 Service...

         Starting Generic Board Startup...

         Starting System Logging Service...

[  OK  ] Started D-Bus System Message Bus.

[  OK  ] Started Avahi mDNS/DNS-SD Stack.

         Starting Connection service...

[  OK  ] Started System Logging Service.

[  OK  ] Started Restore /etc/resolv.conf if…before the ppp link was shut down.

[  OK  ] Started rc_battery_monitor.

[  OK  ] Started BB WL18xx wlan0 Service.

[  OK  ] Started Connection service.

[  OK  ] Started LSB: Start busybox udhcpd at boot time.

[  OK  ] Started Login Service.

[  OK  ] Reached target Network.

         Starting OpenBSD Secure Shell server...

         Starting Permit User Sessions...

         Starting The Apache HTTP Server...

[  OK  ] Reached target Network is Online.

         Starting LSB: Advanced IEEE 802.11 management daemon...

[  OK  ] Started Permit User Sessions.

[  OK  ] Started LSB: Advanced IEEE 802.11 management daemon.

         Starting Light Display Manager...

[  OK  ] Started Getty on tty1.

[  OK  ] Started LSB: Load kernel modules needed to enable cpufreq scaling.

         Starting Hostname Service...

         Starting LSB: set CPUFreq kernel parameters...

         Starting WPA supplicant...

[  OK  ] Started OpenBSD Secure Shell server.

[  OK  ] Started Hostname Service.

[  OK  ] Started LSB: set CPUFreq kernel parameters.

[  OK  ] Started WPA supplicant.

[  OK  ] Started The Apache HTTP Server.

[  OK  ] Started Light Display Manager.

[   51.872741] OF: graph: no port node found in /ocp@68000000/isp@480bc000/ports

Debian GNU/Linux 9 beagleboard ttyS2

BeagleBoard.org Debian Image 2018-10-07

Support/FAQ: http://elinux.org/Beagleboard:BeagleBoneBlack_Debian

default username:password is [debian:temppwd]

beagleboard login: debian

Password:

   My question is, as I´ll try to control the PinMux to use the P9 expansion header (to be able to use the UART2), I was curious to see the functions that this image has. I found that I can execute the config-pin -i command to see that:

debian@beagleboard:~$ config-pin -i P9_24

Pin name: P9_24

Function if no cape loaded: gpio

Function if cape loaded: default gpio gpio_pu gpio_pd gpio_input uart can i2c pru_uart pruin

Function information: gpio0_15 default gpio0_15 gpio0_15 gpio0_15 gpio0_15 uart1_txd dcan1_rx i2c1_scl pru_uart pru0_in16

Kernel GPIO id: 15

PRU GPIO id: 47

debian@beagleboard:~$ config-pin -i P9_1

Pin is not modifyable: P9_01 GND

   I can see that the P9_1 says it´s GND when it´s actully 1V8 in the schematic of my Rev C2 version

   Additionally I can see that the functions match the beagle board (non xM), so it seems the system has boot as a BBB.

   So, I´m not sure if I have a wrong image or if the config-pin -i command is not actually reflecting the xM reality, or I have to so an additional configuration when booting to correclty match the xM

   Thanks for the support.

   Regards.

[Robert Nelson]

Patches welcome, config-pin currently doesn't support the original
Beagle OR Beagle-xM..

Regards,

--
Robert Nelson
https://rcn-ee.com/

[Philip Munts]

You could try my config-pin replacement written in C: http://git.munts.com/muntsos/bootkernel/initramfs/config-pin.c

Unlike the original config-pin script, my replacement derives all pin configuration information by reading files in /sys, and doesn't have any platform dependencies. I haven't used an xM in years but it seems like it ought to work.

Phil

[Pablo Montalti]

Hi Robert, Phil

    Thanks for the fast response. So some conclusions that I´m reaching are

    . Waht I need for my pogram is to code some .c files to start a communication through a UART.

    . I'll need to change a pin function to use the UART2_RX (P9_8), that according the reference manual it´s not by default the UART2_RX.

    . I believe that my options are:

       . (a) I need to edit the DTB?. Compile a DTS file where this pin is configured as I want

       . (b) Recompile the kernel with the Phil option (config-pin.c) , and I can just edit a file (in /sys)

       . (c) Is there an API function, like open(), that can let me change the pin function directly in the .c source of my program?

    Thanks a lot for the support, sorry to ask so many things.

    Regards.

    

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[Robert Nelson]

Nice, I like it! Do you mind if I fork it, and add it to the bb-cape package?

On the xM, there's no p*pinmux ocp directory, as someone, needs to generate that list.

Regards,

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[Robert Nelson]

On Sun, Mar 3, 2019 at 9:19 AM Robert Nelson <robert...@gmail.com> wrote:
>
> Nice, I like it! Do you mind if I fork it, and add it to the bb-cape package?
>
> On the xM, there's no p*pinmux ocp directory, as someone, needs to generate that list.
>
> Regards,
>
>
> On Sun, Mar 3, 2019, 3:09 AM Philip Munts <philip...@gmail.com> wrote:
>>
>> You could try my config-pin replacement written in C: http://git.munts.com/muntsos/bootkernel/initramfs/config-pin.c

Looking more at it, i still like it a lot, the only issue i see so
far, it's missing the "-f" option that MachineKit guys use:

config-pin -f <file>

For example:

https://github.com/machinekit/machinekit/blob/master/configs/ARM/BeagleBone/Xylotex/Xylotex.bbio

the "overlay xyz" is currently ignored in those *.bbio files, but they
like to batch the gpio setting on bootup by a file..

Otherwise, i'd like to swap out our shell script and replace it with
your implementation.

[Robert Nelson]

On Sun, Mar 3, 2019 at 7:46 AM Pablo Montalti <montal...@gmail.com> wrote:
>
> Hi Robert, Phil
>
> Thanks for the fast response. So some conclusions that I´m reaching are
>
> . Waht I need for my pogram is to code some .c files to start a communication through a UART.
> . I'll need to change a pin function to use the UART2_RX (P9_8), that according the reference manual it´s not by default the UART2_RX.
> . I believe that my options are:
>
> . (a) I need to edit the DTB?. Compile a DTS file where this pin is configured as I want
> . (b) Recompile the kernel with the Phil option (config-pin.c) , and I can just edit a file (in /sys)
> . (c) Is there an API function, like open(), that can let me change the pin function directly in the .c source of my program?
>
> Thanks a lot for the support, sorry to ask so many things.

For the xM "today" you need to rebuild the *.dtb, which kernel are you
currently using? (uname -r) I have a helper repo to make just
re-building the *.dtb easier so you don't need to rebuild the whole
kernel every time..

[Philip Munts]

config-pin.c isn't part of the kernel; it is just a C reimplementation of the userland config-pin script. It isn't a perfect replacement. It eliminates the platform configuration tables in the script, but it has some limitations. One that comes to mind is that config-pin -q will display "default" for a pin that has the default configuration, but doesn't tell you *what* the default configuration is...

Phil

[Philip Munts]

Sure, go ahead and use it.

Phil

[Pablo Montalti]

Robert, Phil,

    Thanks for the support. I´ll do my best to try the option for the DTB and the option of config-pin.c from Phil. Then I´ll see what´s the way to move.

    The version of my kernel is: Linux beagleboard 4.18.11-armv7-x11, if the helper repo to compile the DTB is accessible, would be great!

    Thanks again

    Regards.

El dom., 3 de mar. de 2019 a la(s) 14:57, Philip Munts (philip...@gmail.com) escribió:

Sure, go ahead and use it.

Phil

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