I am trying to write a basic volume application. Since I'm writing this in Ruby I don't want to extend the C library or use ffi, instead I trying to write this with ruby-dbus I got the Address Property with /org/pulse_audio/server_lookup1 but the file the address points to doesn't exist. Is Pulse Audio properly configured for dbus?
Ubuntu ships Pulse Audio without D-Bus support. To enable it put the following line at the end of file /etc/pulse/default.pa:
load-module module-dbus-protocol
Restart Pulse Audio:
pkill pulseaudio; pulseaudio
Solution found at pulseaudio-mixer-cli project which demonstrates how to use pulseaudio over D-Bus.
On my system (openSUSE 12.1), PA does point to an existing socket. This code
(gist)
#! /usr/bin/env ruby
require 'rubygems'
require 'dbus'
b = DBus.session_bus
ps = b.service 'org.PulseAudio1'
po = ps.object '/org/pulseaudio/server_lookup1'
po.introspect
pi = po['org.PulseAudio.ServerLookup1']
a = pi['Address']
path = a.split('=').last
system 'stat', path
produces
$ ruby ~/snippets/dbus-pulseaudio.rb
File: `/home/mvidner/.pulse/7c5e87305bb28b5a0661f8180000054c-runtime/dbus-socket'
Size: 0 Blocks: 0 IO Block: 4096 socket
Device: 801h/2049d Inode: 1332590 Links: 1
Access: (0777/srwxrwxrwx) Uid: (11018/ mvidner) Gid: ( 100/ users)
Access: 2012-11-19 09:07:20.566053943 +0100
Modify: 2012-11-19 09:07:20.566053943 +0100
Change: 2012-11-19 09:07:20.566053943 +0100
Birth: -
Related
I have downloaded asimbench files which provided in the gem5.org website and I have modified the config/common/FSConfig.py with following changes:
def makeArmSystem(..)
..................
self.cf0 = CowIdeDisk(driveID='master')
self.cf2 = CowIdeDisk(driveID='master')
self.cf0.childImage(mdesc.disk())
self.cf2.childImage(disk("sdcard-1g-mxplayer.img"))
#Old platforms have a built-in IDE or CF controller. Default to
#the IDE controller if both exist. New platforms expect the
#storage controller to be added from the config script.
if hasattr(self.realview, "ide"):
#self.realview.ide.disks = [self.cf0]
self.realview.ide.disks = [self.cf0, self.cf2]
elif hasattr(self.realview, "cf_ctrl"):
#self.realview.cf_ctrl.disks = [self.cf0]
self.realview.cf_ctrl.disks = [self.cf0, self.cf2]
else:
self.pci_ide = IdeController(disks=[self.cf0])
pci_devices.append(self.pci_ide
I used this command:
./build/ARM/gem5.opt configs/example/fs.py --mem-size=8192MB
--disk-image=/home/yaz/gem5/full_system_images/disks/ARMv7a-ICS-Android.SMP.Asimbench-v3.img
--kernel=/home/yaz/gem5/full_system_images/binaries/vmlinux.smp.ics.arm.asimbench.2.6.35
--os-type=android-ics --cpu-type=MinorCPU --machine-type=VExpress_GEM5 --script=/home/yaz/gem5/full_system_images/boot/adobe.rcS
warn: CheckedInt already exists in allParams. This may be caused by
the Python 2.7 compatibility layer. warn: Enum already exists in
allParams. This may be caused by the Python 2.7 compatibility layer.
warn: ScopedEnum already exists in allParams. This may be caused by
the Python 2.7 compatibility layer. gem5 Simulator System.
http://gem5.org gem5 is copyrighted software; use the --copyright
option for details. gem5 version 20.0.0.3 gem5 compiled Jul 7 2020
16:17:12 gem5 started Jul 16 2020 04:41:50 gem5 executing on
yazeed-OptiPlex-9010, pid 3367 command line: ./build/ARM/gem5.opt
configs/example/fs.py --mem-size=8192MB
--disk-image=/home/yaz/gem5/full_system_images/disks/ARMv7a-ICS-Android.SMP.Asimbench-v3.img
--kernel=/home/yaz/gem5/full_system_images/binaries/vmlinux.smp.ics.arm.asimbench.2.6.35
--os-type=android-ics --cpu-type=MinorCPU --machine-type=VExpress_GEM5 --script=/home/yaz/gem5/full_system_images/boot/adobe.rcS
Global frequency set at 1000000000000 ticks per second
warn: No dot file generated. Please install pydot to generate the dot file and pdf.
info: kernel located at: /home/yaz/gem5/full_system_images/binaries/vmlinux.smp.ics.arm.asimbench.2.6.35
system.vncserver: Listening for connections on port 5900
system.terminal: Listening for connections on port 3456
system.realview.uart1.device: Listening for connections on port 3457
system.realview.uart2.device: Listening for connections on port 3458
system.realview.uart3.device: Listening for connections on port 3459
0: system.remote_gdb: listening for remote gdb on port 7000 info:
Using bootloader at address 0x80000000
info: Using kernel entry physical address at 0x140008000 warn: DTB file specified, but no
device tree support in kernel
**** REAL SIMULATION ****
warn:Existing EnergyCtrl, but no enabled DVFSHandler found. info: Entering
event queue # 0. Starting simulation...
fatal: Unable to find destination for [0x40008000:0x40008040] on system.iobus
Memory Usage: 8786764 KBytes
Thanks for helping
I was looking into the IO path of the Linux kernel, and towards the bottom in the function scsi_dispatch_cmd(), the driver code is invoked
rtn = host->hostt->queuecommand(host, cmd);
So, for my block device like /dev/sda/, is there a way to find out which hostt or scsi_host_template it is using. I want to check which function queuecommand is pointing to..
Just as a sketch of reflection on this subject.
In my machine for USB drive I can see this:
$ ls -l /dev/sdg
brw-rw---- 1 root disk 8, 96 Apr 27 01:21 /dev/sdg
$ ll /sys/dev/block/8\:96/device/drive
lrwxrwxrwx 1 root root 0 Apr 27 01:32 /sys/dev/block/8:96/device/driver -> ../../../../../../../../../bus/scsi/drivers/sd
So normally such block devices are handled through the regular Linux scsi disk driver. Which is related with e.g. usb handling:
$ lsmod | grep sd
sd_mod 49152 13
scsi_mod 225280 5 sd_mod,usb_storage,libata,uas,sg
In this particular case we can see the relation between queuecommand and mentioned drive:
$ grep queuecommand /proc/kallsyms
ffffffffc052be60 t uas_queuecommand [uas]
ffffffffc0582ad0 t queuecommand [usb_storage]
Now, being in Linux source dir:
$ grep -rnI '\.queuecommand =' | grep usb
drivers/usb/storage/uas.c:846: .queuecommand = uas_queuecommand,
drivers/usb/storage/scsiglue.c:609: .queuecommand = queuecommand,
Hope this will help you.
$ binwalk -e linux_image.img
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 Android bootimg, kernel size: 6897653 bytes, kernel addr: 0x81C08000, ramdisk size: 5959520 bytes, ramdisk addr: 0x81C08000, product name: ""
2048 0x800 Linux kernel ARM boot executable zImage (little-endian)
18479 0x482F gzip compressed data, maximum compression, from Unix, last modified: 1970-01-01 00:00:00 (null date)
6761720 0x672CF8 device tree image (dtb)
6883304 0x6907E8 Unix path: /dev/block/platform/soc/7824900.sdhci/by-name/vendor
6899712 0x694800 gzip compressed data, maximum compression, has original file name: "rootfs.cpio", from Unix, last modified: 2019-04-06 00:42:26
9706949 0x941DC5 MySQL ISAM compressed data file Version 11
$ dd if=linux_image.img of=vmlinuz bs=1 skip=2048 count=6897653
$ file vmlinuz
vmlinuz: Linux kernel ARM boot executable zImage (little-endian)
$ dd if=vmlinuz bs=1 skip=$(LC_ALL=C grep -a -b -o $'\x1f\x8b\x08\x00\x00\x00\x00\x00' vmlinuz-3.18.66-perf | head -n 1 | cut -d ':' -f 1) | zcat | grep -a 'Linux version'
Linux version 3.18.66 (build#test) (gcc version 4.9.3 (GCC) ) #1 SMP PREEMPT Fri Apr 1 13:16:33 PDT 2018
Running 'qemu-system-arm.exe -machine vexpress-a9 -cpu cortex-a7 -smp 4 -kernel vmlinuz' blank screen
If you pull a random Arm Linux kernel (including Android) from somewhere and try to run it on anything other than the hardware that it is intended to boot on, the expected result is that it crashes very early in bootup without being able to output anything to screen or serial port, ie you get a black screen and nothing happens. The most likely situation here is that your image is fine and not corrupt, it's just not built to run on the vexpress-a9 board you're running it on.
In the unlikely event that this really is a kernel built for the vexpress-a9, the next problem you have is that you haven't passed QEMU a device tree blob via the -dtb option. Modern Linux kernels don't hardcode all the information about the boards they can run on, but instead expect the bootloader (which is QEMU in this case) to pass them a data file which provides information about where all the devices are for the board. If you don't do that, then the result is the same as above: kernel crashes very early in bootup without being able to output any information, so black screen.
I've been trying to build and boot OpenEmbedded-Core on the evaluation kit for Freescale's ARM i.MX28, using the Freescale ARM layer for OpenEmbedded-Core. Unfortunately, I can't find a basic "Getting Started" guide (though there is a Yocto getting-started guide). Unfortunately, I haven't been able to "get started", to the point of successfully booting to a basic command prompt on the board's debug serial port.
Here is what I've been able to piece together, and as far as I've managed to get so far.
Fetch sources
mkdir -p oe-core/freescale-arm
cd oe-core/freescale-arm
git clone git://git.openembedded.org/openembedded-core oe-core
git clone git://github.com/Freescale/meta-fsl-arm.git
cd oe-core
git clone git://git.openembedded.org/meta-openembedded
git clone git://git.openembedded.org/bitbake bitbake
Set up environment
. ./oe-init-build-env
That puts us in a new sub-directory build and sets certain environment variables.
Edit configuration
Edit the conf/bblayers.conf and local.conf files:
conf/bblayers.conf should have the meta-fls-arm and meta-oe layers added for BBLAYERS. E.g.:
BBLAYERS ?= " \
/home/craigm/oe-core/freescale-arm/oe-core/meta \
/home/craigm/oe-core/freescale-arm/oe-core/meta-openembedded/meta-oe \
${TOPDIR}/../../meta-fsl-arm \
"
In conf/local.conf, I set:
BB_NUMBER_THREADS = "4"
PARALLEL_MAKE = "-j 4"
MACHINE = "imx28evk"
Build
bitbake core-image-minimal
I ran this build overnight, and it has completed successfully for me. Output files were in ~/oe-core/freescale-arm/oe-core/build/tmp-eglibc/deploy/images.
There are two boot options that I'd like to try, as described below. Boot from SD card is simpler, but takes quite a long time (~30 min) to write the image to the SD card. Booting from TFTP + NFS is faster, but requires more set-up.
Boot from SD Card
Write image to SD card:
sudo dd if=tmp-eglibc/deploy/images/core-image-minimal-imx28evk.sdcard of=/dev/sdc
It took something like 30 minutes (3.5 GB file). Then I put it in the board's SD card slot 0, and powered-up. It got as far as loading the kernel, then stopped:
U-Boot 2012.04.01-00059-g4e6e824 (Aug 23 2012 - 18:08:54)
Freescale i.MX28 family at 454 MHz
BOOT: SSP SD/MMC #0, 3V3
DRAM: 128 MiB
MMC: MXS MMC: 0
*** Warning - bad CRC, using default environment
In: serial
Out: serial
Err: serial
Net: FEC0, FEC1
Hit any key to stop autoboot: 0
reading boot.scr
** Unable to read "boot.scr" from mmc 0:2 **
reading uImage
2598200 bytes read
Booting from mmc ...
## Booting kernel from Legacy Image at 42000000 ...
Image Name: Linux-2.6.35.3-11.09.01+yocto-20
Created: 2012-08-23 7:53:40 UTC
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 2598136 Bytes = 2.5 MiB
Load Address: 40008000
Entry Point: 40008000
Verifying Checksum ... OK
Loading Kernel Image ... OK
OK
Starting kernel ...
Uncompressing Linux... done, booting the kernel.
Boot from TFTP + NFS
First, I tried to write U-Boot onto an SD card:
sudo dd if=tmp-eglibc/deploy/images/u-boot-imx28evk.mxsboot-sdcard of=/dev/sdc
Then I put it in the board's SD card slot 0, and powered-up. But all I got in the debug serial port was:
0x8020a01d
So, I decided to use Freescale's distribution of U-Boot for i.MX28 (from their LTIB distribution) onto an SD card. I set suitable U-Boot parameters for NFS booting with parameters from DHCP.
setenv bootargs console=ttyAMA0,115200n8
setenv bootargs_nfs setenv bootargs ${bootargs} root=/dev/nfs ip=dhcp nfsroot=,v3,tcp fec_mac=${ethaddr}
saveenv
I connected to a DD-WRT router with the following DNSmasq settings:
dhcp-boot=,,192.168.250.106
dhcp-option=17,"192.168.250.106:/home/craigm/rootfs"
On my host PC, I set up a TFTP server to serve the uImage file from ~/oe-core/freescale-arm/oe-core/build/tmp-eglibc/deploy/images/.
I also set up a root NFS server to serve the root file system. I edited /etc/exports to serve /home/craigm/rootfs. I extracted the root file system:
bitbake meta-ide-support
rm -Rf ~/rootfs
runqemu-extract-sdk tmp-eglibc/deploy/images/core-image-minimal-imx28evk.tar.bz2 ~/rootfs
Then I put the U-Boot SD card in the board's SD card slot 0, and powered-up. It got as far as this, then stopped:
...
TCP cubic registered
NET: Registered protocol family 17
can: controller area network core (rev 20090105 abi 8)
NET: Registered protocol family 29
can: raw protocol (rev 20090105)
mxs-rtc mxs-rtc.0: setting system clock to 1970-01-01 00:03:33 UTC (213)
eth0: Freescale FEC PHY driver [Generic PHY] (mii_bus:phy_addr=0:00, irq=-1)
eth1: Freescale FEC PHY driver [Generic PHY] (mii_bus:phy_addr=0:01, irq=-1)
Sending DHCP requests .
PHY: 0:00 - Link is Up - 100/Full
., OK
IP-Config: Got DHCP answer from 192.168.250.106, my address is 192.168.250.142
IP-Config: Complete:
device=eth0, addr=192.168.250.142, mask=255.255.255.0, gw=192.168.250.1,
host=192.168.250.142, domain=, nis-domain=(none),
bootserver=192.168.250.106, rootserver=192.168.250.106, rootpath=/home/craigm/rootfs
Looking up port of RPC 100003/3 on 192.168.250.106
Looking up port of RPC 100005/3 on 192.168.250.106
VFS: Mounted root (nfs filesystem) on device 0:15.
Freeing init memory: 160K
I'm not sure if it's running without a serial console, or some other problem. I can ping it on 192.168.250.142, but I can't Telnet or SSH to it.
Questions
Is there any sort of "getting started" guide for OpenEmbedded-Core on Freescale's i.MX28?
Is the Freescale ARM layer really intended for use with OpenEmbedded-Core, Yocto, or what? I don't really understand how those projects relate.
Has anyone else had success booting a minimal image of OpenEmbedded-Core on Freescale's i.MX28? If so, how did your procedure differ from mine?
I'm not sure at this stage whether the problem is just a non-functional serial console, or some other sort of issue. It's hard to diagnose these problems that prevent even getting a basic system running. Any pointers on how to diagnose at this point?
Why would the U-Boot be broken so it can't even boot?
From the boot message it looks like U-boot is working fine. U-boot is not broken.
The following boot message
2598200 bytes read
Booting from mmc ...
## Booting kernel from Legacy Image at 42000000 ...
Image Name: Linux-2.6.35.3-11.09.01+yocto-20
Created: 2012-08-23 7:53:40 UTC
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 2598136 Bytes = 2.5 MiB
Load Address: 40008000
Entry Point: 40008000
Verifying Checksum ... OK
Loading Kernel Image ... OK
OK
Starting kernel ...
Uncompressing Linux... done, booting the kernel.
By the above log u-boot has done its job.
"Booting the kernel" is the point where bootloader given the control to the kernel.
I guess the problem might be in kernel image or in memory.
To eliminate the problem of memory, try to check the manual and try to read and write in the RAM using the board's reference manual.
From the boot log RAM looks like has no problem. It has been initialized.
DRAM: 128 MiB
Check if the following message is not causing any problem.
* Warning - bad CRC, using default environment
Check if all the devices have been initialized and nothing is skipped after the bad crc warning.
I'm trying to use a somewhat old DAQ, and had to jump through a few hoops to get an old (circa 2004) device driver for it to compile (DTI-DT340 Linux-DAQ-PCI).
I've gotten to the point where it compiles, I can load the kernel module, it finds the card, and I can create the character devices using mknod.
But I can't seem to open these devices and keep getting errno 19 (ENODEV) 'No such device' when I try to
open("/dev/dt340/0",O_RDWR);
but mknod had no complaints about making it, and it's there:
# ls -l /dev/dt340/
total 0
crw-rw-r-- 1 root staff 250, 0 2009-04-23 11:02 0
crw-rw-r-- 1 root staff 250, 1 2009-04-23 11:02 1
crw-rw-r-- 1 root staff 250, 2 2009-04-23 11:02 2
crw-rw-r-- 1 root staff 250, 3 2009-04-23 11:02 3
Is there something I'm neglecting to do? What might be a reason open fails?
Here's the script I use to load the driver and make the devices.
#!/bin/bash
module="dt340"
device="dt340"
mode="664"
# invoke modprobe with all arguments we were passed
#/sbin/modprobe -t misc -lroot -f -s $module.o $* || exit 1
insmod $module.ko
# remove stale nodes
rm -f /dev/${device}/[0-3]
major=`awk "\\$2==\"$module\" {print \\$1}" /proc/devices`
mkdir -p /dev/${device}
mknod /dev/${device}/0 c $major 0
mknod /dev/${device}/1 c $major 1
mknod /dev/${device}/2 c $major 2
mknod /dev/${device}/3 c $major 3
# give appropriate group/permissions, and change the group
# not all distributions have staff; some have "users" instead
group="staff"
grep '^staff:' /etc/group > /dev/null || group="users"
chgrp $group /dev/${device}/[0-3]
chmod $mode /dev/${device}/[0-3]
Some additional info:
#grep dt340 /proc/devices
250 dt340
# lsmod | grep dt340
dt340 21516 0
# tail /var/log/messages
Apr 23 11:59:26 ve kernel: [ 412.862139] dt340 0000:03:01.0: PCI INT A -> GSI 22 (level, low) -> IRQ 22
Apr 23 11:59:26 ve kernel: [ 412.862362] dt340: In function dt340_init_one:
Apr 23 11:59:26 ve kernel: [ 412.862363] Device DT340 Rev 0x0 detected at address 0xfebf0000
#lspci | grep 340
03:01.0 Multimedia controller: Data Translation DT340
ANSWER: A printk confirmed that the -ENODEV was thrown from inside open(). Following an oldstyle
while ((pdev = pci_find_device(PCI_VENDOR_ID_DTI, PCI_ANY_ID, pdev)))
(which is deprecated), if(!pdev) ends up true, and returns the -ENODEV.
I'm inching closer - I guess I have to work through and update the pci code to use more modern mechanisms...
If the device shows up in /proc/devices, and you're sure you've got the number right in mknod, then the driver itself is refusing the open. The driver can return any error code from open() - including "no such device", which it might if it discovered a problem initialising the hardware.
I'd guess it is a problem in the driver, check the open function.
It shows up in /proc/devices, so all the generic device stuff seems to be ok.
mknod doesn't care if there is an device corresponding to the given major/minor numbers. Are you sure insmod is installing your module? What does lsmod tell you?
I'm unfamiliar with having to add the ".ko" extension. Is that something specific to your device driver?
Check through lspci and make sure hardware is properly initialized. If your system supports hotplug, pci_find_device won't work. The problem with this is a refcnt. The best way to deal and learn is to dissect the API. BOL !!