Device Tree Overlay

max.ralf.ross · December 16, 2013, 1:53pm

Dear all,

May I ask for your advice regarding a device tree overlay problem occuring at boot time (Ubuntu on BBB). My MAX-GPIO-set-00A0.dtbo file works just nice when I use it manually by typing the command

echo MAX-GPIO-set > slots

(in /sys/devices/bone_capemgr.*). I conclude from this that the dtbo file itself is correct.

Now, when I modify uEnv.txt to load the dtbo file at boot:

optargs=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN capemgr.enable_partno=BB-UART5,MAX-GPIO-set

the MAX-GPIO-set file is not applied (however, the BB_UART5 file is applied correctly). dmesg | grep “MAX” gives the following output:

[ 0.000000] Kernel command line: console=ttyO0,115200n8 capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN capemgr.enable_partno=BB-UART5,MAX-GPIO-set root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait fixrtc ip=
[ 1.958351] bone-capemgr bone_capemgr.8: enabled_partno part_number ‘MAX-GPIO-set’, version ‘N/A’, prio ‘0’
[ 1.983096] bone-capemgr bone_capemgr.8: slot #8: ‘Override Board Name,00A0,Override Manuf,MAX-GPIO-set’
[ 2.052857] bone-capemgr bone_capemgr.8: loader: before slot-8 MAX-GPIO-set:00A0 (prio 0)
[ 2.061427] bone-capemgr bone_capemgr.8: loader: check slot-8 MAX-GPIO-set:00A0 (prio 0)
[ 2.107066] bone-capemgr bone_capemgr.8: loader: after slot-8 MAX-GPIO-set:00A0 (prio 0)
[ 2.175944] bone-capemgr bone_capemgr.8: slot #8: Requesting part number/version based 'MAX-GPIO-set-00A0.dtbo
[ 2.197751] bone-capemgr bone_capemgr.8: slot #8: Requesting firmware ‘MAX-GPIO-set-00A0.dtbo’ for board-name ‘Override Board Name’, version ‘00A0’
[ 3.396200] bone-capemgr bone_capemgr.8: failed to load firmware ‘MAX-GPIO-set-00A0.dtbo’
[ 3.404896] bone-capemgr bone_capemgr.8: loader: failed to load slot-8 MAX-GPIO-set:00A0 (prio 0)

Any ideas would be highly appreciated. Thanks in advance!

Max

jkridner · December 16, 2013, 3:10pm

Dear all,

May I ask for your advice regarding a device tree overlay problem occuring
at boot time (Ubuntu on BBB). My MAX-GPIO-set-00A0.dtbo file works just nice
when I use it manually by typing the command

echo MAX-GPIO-set > slots

(in /sys/devices/bone_capemgr.*). I conclude from this that the dtbo file
itself is correct.

Now, when I modify uEnv.txt to load the dtbo file at boot:

optargs=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN
capemgr.enable_partno=BB-UART5,MAX-GPIO-set

the MAX-GPIO-set file is not applied (however, the BB_UART5 file is applied
correctly). dmesg | grep "MAX" gives the following output:

[ 0.000000] Kernel command line: console=ttyO0,115200n8
capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN
capemgr.enable_partno=BB-UART5,MAX-GPIO-set root=/dev/mmcblk0p2 ro
rootfstype=ext4 rootwait fixrtc ip=
[ 1.958351] bone-capemgr bone_capemgr.8: enabled_partno part_number
'MAX-GPIO-set', version 'N/A', prio '0'
[ 1.983096] bone-capemgr bone_capemgr.8: slot #8: 'Override Board
Name,00A0,Override Manuf,MAX-GPIO-set'
[ 2.052857] bone-capemgr bone_capemgr.8: loader: before slot-8
MAX-GPIO-set:00A0 (prio 0)
[ 2.061427] bone-capemgr bone_capemgr.8: loader: check slot-8
MAX-GPIO-set:00A0 (prio 0)
[ 2.107066] bone-capemgr bone_capemgr.8: loader: after slot-8
MAX-GPIO-set:00A0 (prio 0)
[ 2.175944] bone-capemgr bone_capemgr.8: slot #8: Requesting part
number/version based 'MAX-GPIO-set-00A0.dtbo
[ 2.197751] bone-capemgr bone_capemgr.8: slot #8: Requesting firmware
'MAX-GPIO-set-00A0.dtbo' for board-name 'Override Board Name', version
'00A0'
[ 3.396200] bone-capemgr bone_capemgr.8: failed to load firmware
'MAX-GPIO-set-00A0.dtbo'
[ 3.404896] bone-capemgr bone_capemgr.8: loader: failed to load slot-8
MAX-GPIO-set:00A0 (prio 0)

Any ideas would be highly appreciated. Thanks in advance!

I've recently run into the same issue for the BEAGLEBOY .dts:

github.com

bear24rw/gamingcape/blob/master/software/BEAGLEBOY-00A0.dts

/*
 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
/dts-v1/;
/plugin/;

/ {
	compatible = "ti,beaglebone", "ti,beaglebone-black";

	/* identification */
	part-number = "BEAGLEBOY";
	version = "00A0";

	/* state the resources this cape uses */
	exclusive-use =
		/* the pin header uses */

This file has been truncated. show original

The load triggering code is at:

github.com

beagleboard/linux/blob/3.8/drivers/misc/cape/beaglebone/capemgr.c

/*
 * TI Beaglebone cape controller
 *
 * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
 * Copyright (C) 2012 Texas Instruments Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

This file has been truncated. show original

There is a call to request_firmware() at:

github.com

beagleboard/linux/blob/3.8/drivers/misc/cape/beaglebone/capemgr.c#L1370


      
          			slot->dtbo, slot->board_name, slot->version);
          
          	err = request_firmware(&slot->fw, slot->dtbo, dev);
          	if (err != 0) {
          		dev_err(dev, "failed to load firmware '%s'\n", slot->dtbo);
          		mutex_unlock(&info->capemap_mutex);
          		goto err_fail_no_fw;
          	}
          
          	dev_info(dev, "slot #%d: dtbo '%s' loaded; converting to live tree\n",
          			slot->slotno, slot->dtbo);
          
          	mutex_unlock(&info->capemap_mutex);
          
          	of_fdt_unflatten_tree((void *)slot->fw->data, &slot->overlay);
          	if (slot->overlay == NULL) {
          		dev_err(dev, "slot #%d: Failed to unflatten\n",
          				slot->slotno);
          		err = -EINVAL;
          		goto err_fail;
          	}

This seems to be a generic internal kernel interface:

github.com

beagleboard/linux/blob/0250b2002e6eb3a2f7a4eef526dd107bfda3f590/Documentation/firmware_class/README


 request_firmware() hotplug interface:
 ------------------------------------
	Copyright (C) 2003 Manuel Estrada Sainz

 Why:
 ---

 Today, the most extended way to use firmware in the Linux kernel is linking
 it statically in a header file. Which has political and technical issues:

  1) Some firmware is not legal to redistribute.
  2) The firmware occupies memory permanently, even though it often is just
     used once.
  3) Some people, like the Debian crowd, don't consider some firmware free
     enough and remove entire drivers (e.g.: keyspan).

 High level behavior (mixed):
 ============================

This file has been truncated. show original

It is going to take me more than a few seconds to figure out how the
devicetree overlay mechanism is providing a firmware-loading driver. I
expect there to be something accepting the fw_entry info in the DT
overlay code, but I'm not seeing it in:

Any experts want to send me in the right direction or do I need to
break out the debug tools?

Thorsten_von_Eicken1 · December 17, 2013, 7:12am

Same problem here with the UART driver. I’m having difficulties with the new enable_partno the cape manager fails to load my dtbo even through the “echo slots” works just fine. I have:
$ cat /boot/uboot/uEnv.txt
optargs=fixrtc capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN capemgr.enable_partno=BB-UART4-RTS
uenvcmd=i2c mw 0x24 1 0x3e
loadfdt=load mmc ${bootpart} ${fdtaddr} ${bootdir}/dtbs/${fdtfile}

and at boot time the cape manager says:

dmesg | grep capemgr

[ 0.000000] Kernel command line: console=ttyO0,115200n8 fixrtc capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN capemgr.enable_partno=BB-UART4-RTS root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait
[ 1.343502] bone-capemgr bone_capemgr.9: Baseboard: ‘A335BNLT,0A5C,3513BBBK3163’
[ 1.351312] bone-capemgr bone_capemgr.9: compatible-baseboard=ti,beaglebone-black
[ 1.359241] bone-capemgr bone_capemgr.9: Skipping disabled cape with part# BB-BONELT-HDMI
[ 1.367894] bone-capemgr bone_capemgr.9: Skipping disabled cape with part# BB-BONELT-HDMIN
[ 1.406433] bone-capemgr bone_capemgr.9: slot #0: No cape found
[ 1.443539] bone-capemgr bone_capemgr.9: slot #1: No cape found
[ 1.480647] bone-capemgr bone_capemgr.9: slot #2: No cape found
[ 1.517756] bone-capemgr bone_capemgr.9: slot #3: No cape found
[ 1.524025] bone-capemgr bone_capemgr.9: slot #4: specific override
[ 1.530635] bone-capemgr bone_capemgr.9: bone: Using override eeprom data at slot 4
[ 1.538680] bone-capemgr bone_capemgr.9: slot #4: ‘Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G’
[ 1.548837] bone-capemgr bone_capemgr.9: slot #5: specific override
[ 1.555443] bone-capemgr bone_capemgr.9: bone: Using override eeprom data at slot 5
[ 1.563486] bone-capemgr bone_capemgr.9: slot #5: ‘Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI’
[ 1.573537] bone-capemgr bone_capemgr.9: slot #6: specific override
[ 1.580143] bone-capemgr bone_capemgr.9: bone: Using override eeprom data at slot 6
[ 1.588187] bone-capemgr bone_capemgr.9: slot #6: ‘Bone-Black-HDMIN,00A0,Texas Instrument,BB-BONELT-HDMIN’
[ 1.598439] bone-capemgr bone_capemgr.9: enabled_partno part_number ‘BB-UART4-RTS’, version ‘N/A’, prio ‘0’
[ 1.608666] bone-capemgr bone_capemgr.9: slot #7: generic override
[ 1.615165] bone-capemgr bone_capemgr.9: bone: Using override eeprom data at slot 7
[ 1.623207] bone-capemgr bone_capemgr.9: slot #7: ‘Override Board Name,00A0,Override Manuf,BB-UART4-RTS’
[ 1.633413] bone-capemgr bone_capemgr.9: Skipping loading of disabled cape with part# BB-BONELT-HDMI
[ 1.643011] bone-capemgr bone_capemgr.9: Skipping loading of disabled cape with part# BB-BONELT-HDMIN
[ 1.652965] bone-capemgr bone_capemgr.9: loader: before slot-4 BB-BONE-EMMC-2G:00A0 (prio 1)
[ 1.661849] bone-capemgr bone_capemgr.9: loader: check slot-4 BB-BONE-EMMC-2G:00A0 (prio 1)
[ 1.670659] bone-capemgr bone_capemgr.9: initialized OK.
[ 1.676269] bone-capemgr bone_capemgr.9: loader: before slot-7 BB-UART4-RTS:00A0 (prio 0)
[ 1.684855] bone-capemgr bone_capemgr.9: loader: check slot-7 BB-UART4-RTS:00A0 (prio 0)
[ 1.707112] bone-capemgr bone_capemgr.9: loader: check slot-4 BB-BONE-EMMC-2G:00A0 (prio 1)
[ 1.722288] bone-capemgr bone_capemgr.9: loader: after slot-7 BB-UART4-RTS:00A0 (prio 0)
[ 1.736908] bone-capemgr bone_capemgr.9: slot #7: Requesting part number/version based 'BB-UART4-RTS-00A0.dtbo
[ 1.767844] bone-capemgr bone_capemgr.9: slot #7: Requesting firmware ‘BB-UART4-RTS-00A0.dtbo’ for board-name ‘Override Board Name’, version ‘00A0’
[ 62.000364] bone-capemgr bone_capemgr.9: failed to load firmware ‘BB-UART4-RTS-00A0.dtbo’
[ 62.008988] bone-capemgr bone_capemgr.9: loader: failed to load slot-7 BB-UART4-RTS:00A0 (prio 0)
[ 62.018399] bone-capemgr bone_capemgr.9: loader: check slot-4 BB-BONE-EMMC-2G:00A0 (prio 1)
[ 62.027331] bone-capemgr bone_capemgr.9: loader: after slot-4 BB-BONE-EMMC-2G:00A0 (prio 1)
[ 62.036148] bone-capemgr bone_capemgr.9: slot #4: Requesting firmware ‘cape-bone-2g-emmc1.dtbo’ for board-name ‘Bone-LT-eMMC-2G’, version ‘00A0’
[ 62.049743] bone-capemgr bone_capemgr.9: slot #4: dtbo ‘cape-bone-2g-emmc1.dtbo’ loaded; converting to live tree
[ 62.060764] bone-capemgr bone_capemgr.9: slot #4: #2 overlays
[ 62.143004] bone-capemgr bone_capemgr.9: slot #4: Applied #2 overlays.
[ 62.149936] bone-capemgr bone_capemgr.9: loader: done slot-4 BB-BONE-EMMC-2G:00A0 (prio 1)

If I then manually load the overlay it works fine:

echo BB-UART4-RTS >/sys/devices/bone_capemgr.9/slots

dmesg | tail

[ 264.848073] bone-capemgr bone_capemgr.9: part_number ‘BB-UART4-RTS’, version ‘N/A’
[ 264.848260] bone-capemgr bone_capemgr.9: slot #8: generic override
[ 264.848310] bone-capemgr bone_capemgr.9: bone: Using override eeprom data at slot 8
[ 264.848360] bone-capemgr bone_capemgr.9: slot #8: ‘Override Board Name,00A0,Override Manuf,BB-UART4-RTS’
[ 264.848632] bone-capemgr bone_capemgr.9: slot #8: Requesting part number/version based 'BB-UART4-RTS-00A0.dtbo
[ 264.848684] bone-capemgr bone_capemgr.9: slot #8: Requesting firmware ‘BB-UART4-RTS-00A0.dtbo’ for board-name ‘Override Board Name’, version ‘00A0’
[ 264.859878] bone-capemgr bone_capemgr.9: slot #8: dtbo ‘BB-UART4-RTS-00A0.dtbo’ loaded; converting to live tree
[ 264.860523] bone-capemgr bone_capemgr.9: slot #8: #2 overlays
[ 264.875574] 481a8000.serial: ttyO4 at MMIO 0x481a8000 (irq = 61) is a OMAP UART4
[ 264.878196] bone-capemgr bone_capemgr.9: slot #8: Applied #2 overlays.

What am I doing wrong?