[buildroot]hciconfig can't open HCI socket error - bluetooth

I am using buildroot-2014.05 git.It has been cross-compiled to below toolchains.
"ELF 32-bit LSB shared object, MIPS, MIPS32 rel2 version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.16, not stripped
"
I am getting below error message.
# hciconfig
Can't open HCI socket.: Address family not supported by protocol

Sounds like your kernel is not configured correctly. In your kernel config make sure CONFIG_BT and the appropriate configs beneath that are enabled.

Ensure the corresponding kernel modules are loaded. You should have at least bluetooth, btusb when running the following:
lsmod | grep bluetooth
If the kernel modules did not show up, try adding them:
modprobe -vvv bluetooth
modprobe -vvv btusb
If modprobe failed, check the files in /etc/modprobe.d in cases they are
black-listed there.

Related

No such file or directory when run executable file on Embedded Linux

I'm working with a Target board which use micro controller MCIMX6DP6AVT8AA - i.MX 6 series 32-bit MPU, Dual ARM Cortex-A9 core, 850MHz, FCBGA 624
(refer http://www.nxp.com/webapp/search.partparamdetail.framework?PART_NUMBER=MCIMX6DP6AVT8AA). My board run Linux kernel 3.1.1
I use cross-compile toolchain arm-poky-linux-gnueabi, run on host Ubuntu14.04 to build a Application for Target board. After built successful, i checked the output file as below
~$ file MyApp
MyApp: ELF 32-bit LSB executable, ARM, EABI5 version 1
(SYSV), dynamically linked (uses shared libs), for GNU/Linux 3.1.1,
BuildID[sha1]=a800b4033343517d3368a3f3ca0c87eb98f6c1ba, not stripped
But when i run it on Target board, there was error
~$ ./MyApp
-sh: ./MyApp: No such file or directory
I don't know what i did wrong ?
The message is very likely coming from the dynamic linker. Look at the output of:
ldd MyApp
It will tell you all the library dependencies and where they are found on the system. Install those which hadn't been found.

Invalid module format with matching vermagic value

I have a problem with one of my kernel modules for Linux 4 tegra on the Jetson tk1. I'm trying to integrate a Camera driver into the kernel
I'm trying to insert a module into the kernel and I've compiled everything on the target machine. Here's the modinfo of the kernel module.
filename: /home/ubuntu/mymodule.ko
license: GPL v2
author: John Doe
description: SoC Camera driver
alias: of:N*T*Cnvidia,mymodule*
alias: i2c:mymodule
depends:
vermagic: 3.10.40-svn469 SMP preempt mod_unload ARMv7 p2v8
parm: test_pattern:int
The uname -r command outputs this :
3.10.40-svn469
I still get this output when I am running sudo insmod mymodule.ko
insmod: ERROR: could not insert module mymodule.ko: Invalid module format
I've tried looking into the dmesg/syslog/kern log files but there's no information about why my module insertion is failing. I also looked around on other threads and it usually says to verify that the module was compiled using the correct headers. From my understanding, is the "vermagic" and the "uname -r" are similar I'm assuming that the versions are correct (I might be very wrong about that).
I'm running out of ideas and I'd like to know if I missed something.
Cheers.

Compile Kernel module on Chromebook

I am running an ARMv7 Chromebook with crouton. I would like to get CIFS shares mounted, but it appears that CIFS is not in the kernel. So I downloaded the same kernel version source as I am on, compiled the cifs.ko module, and attempted to load it. But I received this error:
# insmod cifs.ko
insmod: ERROR: could not insert module cifs.ko: Operation not permitted
The module is compiled as an ARM module, I checked with file:
# file cifs.kocifs.ko: ELF 32-bit LSB relocatable, ARM, version 1, BuildID[sha1]=e14d1772583fae478e2b113b57ce81c214e511af, not stripped
What gives?
Chromium OS does not allow adding kernel modules by default. Use this script to disable module locking. https://github.com/divx118/crouton-packages/blob/master/README.md
More information on modifying the Chromium OS kernel can be found here:
https://github.com/dnschneid/crouton/wiki/Build-kernel-headers-and-install-Virtualbox-(x86) Generally the entire crouton repository / wiki is a lot of help.

Failed to execute /init

I am trying to build a basic root filesystem using Buildroot, for an embedded system (the Banana PI D1).
I am using a kernel from an SDK supplied by the SoC vendor. From this repo I am using only the kernel, found in src/kernel.
There's nothing remarkable about the Buildroot configuration. It builds with no errors and the resulting root filesystem looks like it contains everything I would expect.
I have configured it to build the filesystem as an initramfs embedded within the zImage.
The kernel appears to start up correctly, but cannot load init and then panics:
Booting Linux on physical CPU 0
Linux version 3.4.35 (harmic#penski.harmic.moo.org) (gcc version 4.8.4 (Buildroot 2015.02) ) #7 Sat Mar 21 22:59:18 AEDT 2015
CPU: ARM926EJ-S [41069265] revision 5 (ARMv5TEJ), cr=00053177
...
Kernel command line: root=/dev/mtdblock1 ro init=/sbin/init mem=64M console=ttySAK0,115200
...
Freeing init memory: 4632K
Failed to execute /init
Failed to execute /sbin/init. Attempting defaults...
mmc0: host does not support reading read-only switch. assuming write-enable.
mmc0: new SDHC card at address 0007
mmcblk0: mmc0:0007 SD08G 7.42 GiB
mmcblk0: p1
Kernel panic - not syncing: No init found. Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.
I have tried a number of troubleshooting steps:
I've built a root filesystem using this miniroot project (took some doing, as it is quite out of date). It booted OK, using the same kernel as I am trying to use with the buildroot root fs.
I've tried using both uClibc and eglibc
I've tried using Buildroot's own cross-tools as well as the cross tools supplied by the SoC vendor
I've confirmed that the built rootfs does include an /init (it does!)
There is a gist here containing the buildroot configuration, a copy of the kernel boot log, and a listing of the contents of the generated filesystem.
What steps can I take to troubleshoot this further?
Update:
The generated rootfs.cpio.gz weighs in at 2139200 bytes. I have read that there is a maximum size of initramfs you can use, but I have not been able to find where the hard limit is documented.
I have attached a listing of the generated root filesystem to the gist linked above.
I have unpacked the rootfs on the host and inspected it. /init contains this:
#!/bin/sh
# devtmpfs does not get automounted for initramfs
/bin/mount -t devtmpfs devtmpfs /dev
exec 0</dev/console
exec 1>/dev/console
exec 2>/dev/console
exec /sbin/init $*
/sbin/init is a symlink to /bin/busybox.
/bin/busybox is dynamically linked:
$ file busybox
busybox: setuid ELF 32-bit MSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.16, stripped
$ ../../../host/usr/bin/armeb-buildroot-linux-gnueabi-readelf -a busybox | grep "Shared library:"
0x00000001 (NEEDED) Shared library: [libc.so.6]
libc.so.6 is present in /lib. /lib32 is a symlink to /lib for good measure.
The device has 64M RAM.
Both the vendor's cross tools and the buildroot cross tools are set up for eabi
As suggested by #sawdust, the problem was that the CPU was not supposed to be run in big endian mode.
After changing the target to 'ARM (Little Endian)', cleaning and re-building, it now boots correctly.
In retrospect this should have been obvious - inspecting the vendor's kernel image:
$ file zImage
zImage: Linux kernel ARM boot executable zImage (little-endian)

How to use kgdb over ethernet (kgdboe)?

i am using ubuntu 12.04 and kernel version is 3.12.6, i want to learn how to use kgdb to debug kernel. I didn't get much info. regarding kgdboe (kgdb over ethernet). I have compiled kernel and enabled kgdb in menuconfig, i have created kernel image using make bzImage on development machine and copied same on target machine, now problem is how to connect both target and development machine. i m not getting parameter set for kgbdoe. Plz help if anybody know how to use kgdb over ethernet
Have you read this:
https://www.kernel.org/pub/linux/kernel/people/jwessel/kgdb/ch03s04.html
?
You have to run debugged kernel with special options - like for example:
kgdbwait kgdbcon kgdboe=#192.168.248.76/,#192.168.242.24/00:11:22:33:44:55
and on debugging side you run following commands:
gdb
file vmlinux
target remote udp:192.168.248.76:6443
it has worked for me.
You can get the kgdboe source from here, build it and load it into your kernel:
make -C /lib/modules/$(uname -r)/build M=$(pwd)
sudo insmod kgdboe.ko
Then type 'dmesg' to see the load log and get instructions on connecting from gdb.

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