unexpected udev events when booting am335x

Hi Denis,

Denis Kholodkov said:

have custom board with am335x. It is almost the same as beagle-bone

Is your board based on BeagleBone or BeagleBoneBlack?

Denis Kholodkov said:

I decided to build kernel 4.8 from official git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git repository.

If BeagleBoneBlack, I would suggest you to use the linux kernel 4.4.19 available from the official TI SDK ti-processor-sdk-linux-am335x-evm-03.01.00.06

Regards,
Pavel

Hi, Pavel.
My board is "spin-off" of old beagle-bone. Deep creative refactoring of... Really nothing more but mcu-ddr-pmic bundle.
I really don't like ti-SDK-linux... My opinion it is strong brake on system evolution. I have some years bad experience of patching ti-evm-sdk to new needed features.
Nevertheless I misunderstand... Is all Sitara features develops on SDK and later migrate to official kernel, or may be SDK is deadlock branch, wich starts on some kernel grade every time when previous too old? And all troubles warnings and so will never be solved on official repository?
Now I see, that official origin brings me all I need. It looks like everything fine, but some log-messages cause doubt.

Denis,

TI has made investments to ensure that its software SDKs are compatible with not only standard TI hardware, but also open-source tools such as BeagleBone. See the below pdf files for more info:

www.ti.com/.../spry204.pdf
www.ti.com/.../spry259.pdf
www.ti.com/.../spry245.pdf
www.ti.com/.../spry230.pdf

Can you also provide the full console log (from u-boot up to udev issue)? It seems to me that this issue is more related to the filesystem than the linux kernel. What filesystem you are using here?

Regards,
Pavel

Hi, Pavel.
This is full log:
Starting kernel ...

[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 4.8.0-11417-g24532f7-dirty (master@mint-dev) (gcc version 4.7.3 20130328 (prerelease) (crosstool-NG linaro-1.13.1-4.7-2013.04-20130415 - Linaro GCC 2013.04) ) #29 Tue Nov 1 13:18:24 MSK 2016
[ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c5387d
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] OF: fdt:Machine model: SIT sm160.02
[ 0.000000] cma: Reserved 16 MiB at 0x8d800000
[ 0.000000] Memory policy: Data cache writeback
[ 0.000000] CPU: All CPU(s) started in SVC mode.
[ 0.000000] AM335X ES2.1 (neon )
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 64704
[ 0.000000] Kernel command line: console=ttyO0,115200n8 root=/dev/nfs nfsroot=169.254.254.254:/exports/rootfs,nolock rw ip=dhcp
[ 0.000000] PID hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
[ 0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
[ 0.000000] Memory: 224204K/261120K available (6144K kernel code, 341K rwdata, 1320K rodata, 1024K init, 8026K bss, 20532K reserved, 16384K cma-reserved, 0K highmem)
[ 0.000000] Virtual kernel memory layout:
[ 0.000000] vector : 0xffff0000 - 0xffff1000 ( 4 kB)
[ 0.000000] fixmap : 0xffc00000 - 0xfff00000 (3072 kB)
[ 0.000000] vmalloc : 0xd0800000 - 0xff800000 ( 752 MB)
[ 0.000000] lowmem : 0xc0000000 - 0xd0000000 ( 256 MB)
[ 0.000000] pkmap : 0xbfe00000 - 0xc0000000 ( 2 MB)
[ 0.000000] .text : 0xc0008000 - 0xc0700000 (7136 kB)
[ 0.000000] .init : 0xc0900000 - 0xc0a00000 (1024 kB)
[ 0.000000] .data : 0xc0a00000 - 0xc0a55640 ( 342 kB)
[ 0.000000] .bss : 0xc0a57000 - 0xc122d8a0 (8027 kB)
[ 0.000000] Running RCU self tests
[ 0.000000] NR_IRQS:16 nr_irqs:16 16
[ 0.000000] IRQ: Found an INTC at 0xfa200000 (revision 5.0) with 128 interrupts
[ 0.000000] OMAP clockevent source: timer2 at 24000000 Hz
[ 0.000021] sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 89478484971ns
[ 0.000054] clocksource: timer1: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 79635851949 ns
[ 0.000114] OMAP clocksource: timer1 at 24000000 Hz
[ 0.000717] clocksource_probe: no matching clocksources found
[ 0.001513] Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar
[ 0.001534] ... MAX_LOCKDEP_SUBCLASSES: 8
[ 0.001546] ... MAX_LOCK_DEPTH: 48
[ 0.001557] ... MAX_LOCKDEP_KEYS: 8191
[ 0.001568] ... CLASSHASH_SIZE: 4096
[ 0.001578] ... MAX_LOCKDEP_ENTRIES: 32768
[ 0.001589] ... MAX_LOCKDEP_CHAINS: 65536
[ 0.001599] ... CHAINHASH_SIZE: 32768
[ 0.001610] memory used by lock dependency info: 5167 kB
[ 0.001622] per task-struct memory footprint: 1536 bytes
[ 0.001660] Calibrating delay loop... 545.99 BogoMIPS (lpj=2729984)
[ 0.107941] pid_max: default: 32768 minimum: 301
[ 0.108446] Security Framework initialized
[ 0.108604] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.108624] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)
[ 0.113758] CPU: Testing write buffer coherency: ok
[ 0.115777] Setting up static identity map for 0x80100000 - 0x80100070
[ 0.124322] devtmpfs: initialized
[ 0.174625] VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 3
[ 0.175589] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[ 0.177732] pinctrl core: initialized pinctrl subsystem
[ 0.184589] NET: Registered protocol family 16
[ 0.192825] DMA: preallocated 256 KiB pool for atomic coherent allocations
[ 0.258017] omap_hwmod: debugss: _wait_target_disable failed
[ 0.341859] OMAP GPIO hardware version 0.1
[ 0.395459] omap-gpmc 50000000.gpmc: could not find pctldev for node /ocp/l4_wkup@44c00000/scm@210000/pinmux@800/nandflash_pins_s0, deferring probe
[ 0.398403] No ATAGs?
[ 0.398431] hw-breakpoint: debug architecture 0x4 unsupported.
[ 0.451596] edma 49000000.edma: TI EDMA DMA engine driver
[ 0.455589] SCSI subsystem initialized
[ 0.456474] usbcore: registered new interface driver usbfs
[ 0.456655] usbcore: registered new interface driver hub
[ 0.456883] usbcore: registered new device driver usb
[ 0.458037] omap_i2c 44e0b000.i2c: could not find pctldev for node /ocp/l4_wkup@44c00000/scm@210000/pinmux@800/pinmux_i2c0_pins, deferring probe
[ 0.458179] omap_i2c 4802a000.i2c: could not find pctldev for node /ocp/l4_wkup@44c00000/scm@210000/pinmux@800/pinmux_i2c1_pins, deferring probe
[ 0.458505] pps_core: LinuxPPS API ver. 1 registered
[ 0.458522] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[ 0.458592] PTP clock support registered
[ 0.460538] omap-mailbox 480c8000.mailbox: omap mailbox rev 0x400
[ 0.465530] clocksource: Switched to clocksource timer1
[ 0.467159] VFS: Disk quotas dquot_6.6.0
[ 0.467763] VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[ 0.475108] NET: Registered protocol family 2
[ 0.477569] TCP established hash table entries: 2048 (order: 1, 8192 bytes)
[ 0.477658] TCP bind hash table entries: 2048 (order: 4, 73728 bytes)
[ 0.478886] TCP: Hash tables configured (established 2048 bind 2048)
[ 0.479142] UDP hash table entries: 256 (order: 2, 20480 bytes)
[ 0.479480] UDP-Lite hash table entries: 256 (order: 2, 20480 bytes)
[ 0.480774] NET: Registered protocol family 1
[ 0.483246] RPC: Registered named UNIX socket transport module.
[ 0.483275] RPC: Registered udp transport module.
[ 0.483290] RPC: Registered tcp transport module.
[ 0.483304] RPC: Registered tcp NFSv4.1 backchannel transport module.
[ 0.485877] hw perfevents: enabled with armv7_cortex_a8 PMU driver, 5 counters available
[ 0.491809] futex hash table entries: 256 (order: 1, 11264 bytes)
[ 0.492055] audit: initializing netlink subsys (disabled)
[ 0.492357] audit: type=2000 audit(0.480:1): initialized
[ 0.495128] workingset: timestamp_bits=14 max_order=16 bucket_order=2
[ 0.497598] NFS: Registering the id_resolver key type
[ 0.498068] Key type id_resolver registered
[ 0.498088] Key type id_legacy registered
[ 0.509277] io scheduler noop registered
[ 0.509310] io scheduler deadline registered
[ 0.509430] io scheduler cfq registered (default)
[ 0.512094] pinctrl-single 44e10800.pinmux: 142 pins at pa f9e10800 size 568
[ 0.516226] omap_uart 44e09000.serial: no wakeirq for uart0
[ 0.516900] 44e09000.serial: ttyO0 at MMIO 0x44e09000 (irq = 158, base_baud = 3000000) is a OMAP UART0
[ 1.155306] console [ttyO0] enabled
[ 1.161575] omap_uart 48022000.serial: no wakeirq for uart1
[ 1.167727] 48022000.serial: ttyO1 at MMIO 0x48022000 (irq = 159, base_baud = 3000000) is a OMAP UART1
[ 1.179138] omap_uart 48024000.serial: no wakeirq for uart2
[ 1.185163] 48024000.serial: ttyO2 at MMIO 0x48024000 (irq = 160, base_baud = 3000000) is a OMAP UART2
[ 1.196542] omap_uart 481a6000.serial: no wakeirq for uart3
[ 1.202571] 481a6000.serial: ttyO3 at MMIO 0x481a6000 (irq = 161, base_baud = 3000000) is a OMAP UART3
[ 1.213834] omap_uart 481a8000.serial: no wakeirq for uart4
[ 1.219918] 481a8000.serial: ttyO4 at MMIO 0x481a8000 (irq = 162, base_baud = 3000000) is a OMAP UART4
[ 1.231178] omap_uart 481aa000.serial: no wakeirq for uart5
[ 1.237264] 481aa000.serial: ttyO5 at MMIO 0x481aa000 (irq = 163, base_baud = 3000000) is a OMAP UART5
[ 1.250458] omap_rng 48310000.rng: OMAP Random Number Generator ver. 20
[ 1.304904] brd: module loaded
[ 1.337108] loop: module loaded
[ 1.342671] mtdoops: mtd device (mtddev=name/number) must be supplied
[ 1.352637] libphy: Fixed MDIO Bus: probed
[ 1.425668] davinci_mdio 4a101000.mdio: davinci mdio revision 1.6
[ 1.432063] davinci_mdio 4a101000.mdio: detected phy mask fffffffe
[ 1.440301] libphy: 4a101000.mdio: probed
[ 1.444515] davinci_mdio 4a101000.mdio: phy[0]: device 4a101000.mdio:00, driver SMSC LAN8710/LAN8720
[ 1.455794] cpsw 4a100000.ethernet: Detected MACID = 84:eb:18:e9:09:17
[ 1.467952] PPP generic driver version 2.4.2
[ 1.473610] PPP BSD Compression module registered
[ 1.478631] PPP Deflate Compression module registered
[ 1.483941] PPP MPPE Compression module registered
[ 1.489206] usbcore: registered new interface driver asix
[ 1.495011] usbcore: registered new interface driver ax88179_178a
[ 1.501580] usbcore: registered new interface driver cdc_ether
[ 1.507863] usbcore: registered new interface driver smsc75xx
[ 1.514026] usbcore: registered new interface driver smsc95xx
[ 1.520218] usbcore: registered new interface driver net1080
[ 1.526338] usbcore: registered new interface driver cdc_ncm
[ 1.534193] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 1.541104] ehci-omap: OMAP-EHCI Host Controller driver
[ 1.547043] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 1.553609] ohci-omap3: OHCI OMAP3 driver
[ 1.558380] usbcore: registered new interface driver usb-storage
[ 1.565040] usbcore: registered new interface driver usbserial
[ 1.571319] usbcore: registered new interface driver usbserial_generic
[ 1.578689] usbserial: USB Serial support registered for generic
[ 1.585094] usbcore: registered new interface driver cp210x
[ 1.591120] usbserial: USB Serial support registered for cp210x
[ 1.597479] usbcore: registered new interface driver ftdi_sio
[ 1.603627] usbserial: USB Serial support registered for FTDI USB Serial Device
[ 1.611425] usbcore: registered new interface driver usb_serial_simple
[ 1.618422] usbserial: USB Serial support registered for carelink
[ 1.624981] usbserial: USB Serial support registered for zio
[ 1.631080] usbserial: USB Serial support registered for funsoft
[ 1.637535] usbserial: USB Serial support registered for flashloader
[ 1.644317] usbserial: USB Serial support registered for google
[ 1.650682] usbserial: USB Serial support registered for vivopay
[ 1.657137] usbserial: USB Serial support registered for moto_modem
[ 1.663831] usbserial: USB Serial support registered for novatel_gps
[ 1.670648] usbserial: USB Serial support registered for hp4x
[ 1.676829] usbserial: USB Serial support registered for suunto
[ 1.683169] usbserial: USB Serial support registered for siemens_mpi
[ 1.692314] mousedev: PS/2 mouse device common for all mice
[ 1.703362] omap_rtc 44e3e000.rtc: rtc core: registered 44e3e000.rtc as rtc0
[ 1.711273] i2c /dev entries driver
[ 1.719326] omap_wdt: OMAP Watchdog Timer Rev 0x01: initial timeout 60 sec
[ 1.730673] omap_hsmmc 48060000.mmc: Got CD GPIO
[ 1.798118] ledtrig-cpu: registered to indicate activity on CPUs
[ 1.804985] usbcore: registered new interface driver usbhid
[ 1.810902] usbhid: USB HID core driver
[ 1.816337] oprofile: using arm/armv7
[ 1.821043] Initializing XFRM netlink socket
[ 1.827569] NET: Registered protocol family 10
[ 1.840026] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
[ 1.849276] NET: Registered protocol family 17
[ 1.854033] NET: Registered protocol family 15
[ 1.859230] Key type dns_resolver registered
[ 1.863926] omap_voltage_late_init: Voltage driver support not added
[ 1.871454] ThumbEE CPU extension supported.
[ 1.880289] omap_hsmmc 48060000.mmc: no support for card's volts
[ 1.886664] mmc0: error -22 whilst initialising SD card
[ 1.919780] omap-gpmc 50000000.gpmc: omap_device: omap_device_enable() called from invalid state 1
[ 1.929264] omap-gpmc 50000000.gpmc: use pm_runtime_put_sync_suspend() in driver?
[ 1.937167] omap-gpmc 50000000.gpmc: GPMC revision 6.0
[ 1.942819] gpmc_mem_init: disabling cs 0 mapped at 0x0-0x1000000
[ 1.954860] nand: device found, Manufacturer ID: 0x2c, Chip ID: 0x48
[ 1.961618] nand: Micron MT29F16G08ABABAWP
[ 1.965933] nand: 2048 MiB, SLC, erase size: 512 KiB, page size: 4096, OOB size: 224
[ 1.974109] using OMAP_ECC_BCH16_CODE_HW ECC scheme
[ 1.979765] 12 ofpart partitions found on MTD device 8000000.nand
[ 1.986180] Creating 12 MTD partitions on "8000000.nand":
[ 1.991836] 0x000000000000-0x000000080000 : "SPL"
[ 2.006679] 0x000000080000-0x000000100000 : "SPL.backup1"
[ 2.018358] 0x000000100000-0x000000180000 : "SPL.backup2"
[ 2.030287] 0x000000180000-0x000000200000 : "SPL.backup3"
[ 2.041656] 0x000000200000-0x000000280000 : "NAND.dt"
[ 2.052579] 0x000000280000-0x000000380000 : "u-boot"
[ 2.063485] 0x000000380000-0x000000400000 : "u-boot-env"
[ 2.074629] 0x000000400000-0x000000c00000 : "kernel"
[ 2.086562] 0x000000c00000-0x000010c00000 : "file-system"
[ 2.114602] 0x000010c00000-0x000012c00000 : "System log"
[ 2.128156] 0x000012c00000-0x000014c00000 : "P2K log"
[ 2.141386] 0x000014c00000-0x000080000000 : "Data store"
[ 2.301465] random: fast init done
[ 2.322609] tps6521x_pwrbutton tps65217-pwrbutton: No IRQ resource!
[ 2.329383] tps6521x_pwrbutton: probe of tps65217-pwrbutton failed with error -22
[ 2.338281] tps65217 0-0024: TPS65217 ID 0xe version 1.2
[ 2.344048] omap_i2c 44e0b000.i2c: bus 0 rev0.11 at 400 kHz
[ 2.377512] rtc-isl12022 1-006f: rtc core: registered rtc-isl12022 as rtc1
[ 2.387525] at24 1-0057: 128 byte 24c01 EEPROM, writable, 1 bytes/write
[ 2.396097] at24 1-0050: 8192 byte 24c64 EEPROM, writable, 1 bytes/write
[ 2.403198] omap_i2c 4802a000.i2c: bus 1 rev0.11 at 400 kHz
[ 2.417371] vdd_mpu: ramp_delay not set
[ 2.421669] cpufreq: cpufreq_online: CPU0: Running at unlisted freq: 550000 KHz
[ 2.429808] cpufreq: cpufreq_online: CPU0: Unlisted initial frequency changed to: 600000 KHz
[ 2.442359] vdd_mpu: ramp_delay not set
[ 2.448250] omap_rtc 44e3e000.rtc: setting system clock to 2000-01-01 00:00:00 UTC (946684800)
[ 2.474584] net eth0: initializing cpsw version 1.12 (0)
[ 2.576356] SMSC LAN8710/LAN8720 4a101000.mdio:00: attached PHY driver [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=4a101000.mdio:00, irq=-1)
[ 2.598229] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 5.686359] cpsw 4a100000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
[ 5.695291] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 5.715600] Sending DHCP requests ., OK
[ 5.776059] IP-Config: Got DHCP answer from 169.254.254.254, my address is 169.254.161.147
[ 5.784718] IP-Config: Complete:
[ 5.788128] device=eth0, hwaddr=84:eb:18:e9:09:17, ipaddr=169.254.161.147, mask=255.255.0.0, gw=255.255.255.255
[ 5.799182] host=169.254.161.147, domain=, nis-domain=(none)
[ 5.805596] bootserver=169.254.254.254, rootserver=169.254.254.254, rootpath= nameserver0=169.254.254.254
[ 5.817358] vmmcsd_fixed: disabling
[ 5.863454] VFS: Mounted root (nfs filesystem) on device 0:13.
[ 5.873819] devtmpfs: mounted
[ 5.879100] Freeing unused kernel memory: 1024K (c0900000 - c0a00000)
INIT: version 2.88 booting
[info] Using makefile-style concurrent boot in runlevel S.
[warn] Files under mount point '/run' will be hidden. ... (warning).
[....] Starting the hotplug events dispatcher: udevd[ 9.894957] udevd[215]: starting version 175
. ok
[....] Synthesizing the initial hotplug events...udevd[250]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b platform:Fixed MDIO bus': No such file or directory

udevd[252]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:NocpT<NULL>Csimple-bus': No such file or directory

udevd[253]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:NusbT<NULL>Cti,am33xx-usb': No such file or directory

udevd[303]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b platform:tps65217-charger': No such file or directory
udevd[304]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:Ntps65217-pwrbuttonT<NULL>Cti,tps65217-pwrbutton': No such file or directory

udevd[302]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b platform:tps65217-bl': No such file or directory


udevd[245]: error changing net interface name eth0 to eth88: Device or resource busy

udevd[323]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:Nl4_wkupT<NULL>Cti,am3-l4-wkupCsimple-bus': No such file or directory

done.
udevd[324]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:NsocT<NULL>Cti,omap-infra': No such file or directory

udevd[326]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:Nwkup_m3T<NULL>Cti,am3352-wkup-m3': No such file or directory
udevd[327]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:NprcmT<NULL>Cti,am3-prcm': No such file or directory


udevd[328]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:NscmT<NULL>Cti,am3-scmCsimple-bus': No such file or directory
udevd[329]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:NmpuT<NULL>Cti,omap3-mpu': No such file or directory


udevd[331]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:Nscm_confT<NULL>Csyscon': No such file or directory

udevd[332]: failed to execute '/sbin/modprobe' '/sbin/modprobe -b of:Nwkup_m3_ipcT<NULL>Cti,am3352-wkup-m3-ipc': No such file or directory

[ ok ] Waiting for /dev to be fully populated...done.
[ ok ] Setting hostname to 'nfs-deploy-armhf'...done.
[ ok ] Will now mount local filesystems:.
[warn] Not activating swap as requested via bootoption noswap. ... (warning).
[ ok ] Checking minimum space in /tmp...done.
[ ok ] Cleaning up temporary files...[....] Cleaning /tmp...done.
[ ok .
[ 21.080245] random: crng init done
[warn] Filesystem type 'devpts' is not supported. Skipping mount. ... (warning).
[warn] Filesystem type 'devpts' is not supported. Skipping mount. ... (warning).
[warn] Filesystem type 'devpts' is not supported. Skipping mount. ... (warning).
[ ok ] Setting kernel variables ... /etc/sysctl.conf...done.
[ ok ] Initializing random number generator...done.
[ ok ] Configuring network interfaces...done.
[ ok ] Cleaning up temporary files....
INIT: Entering runlevel: 2
[info] Using makefile-style concurrent boot in runlevel 2.
[ ok ] Starting enhanced syslogd: rsyslogd.
[ ok ] Starting internet superserver: inetd.
[ ok ] Running local boot scripts (/etc/rc.local).
tftp: error received from server <File not found>
tftp: aborting

Debian GNU/Linux 7 nfs-deploy-armhf ttyO0

I use "debian wheezy" rootfs build by multistrup with little device-specific modification. Log above is boot from NFS rootfs, wich is used for system deployment while device fabrication.

Denis,

So you are using non-TI kernel with non-TI FS on your BeagleBone based board. I would suggest you to check this issue with the BeagleBone community at http://beagleboard.org

Regards,
Pavel

You're right, Pavel.
And We must add "with no beagle-bone board"
At first post I wrote "almost the same", and later clarified where... "mcu+ram+pmic", nothing else.
My question was not about beagle bone, but about best practise to avoid udev events on unnecessary hardware. And if SoC subsystems like PRCM and so really need driver support, or may be this nodes supressed by synthetic dummy code which is not populated on oficial linux kernel?