I try to have separate ssp modes during connection using Bluetooth btmgmt utility. Basic idea is scan current device OUI and select ssp on/off modes. But I can't get any answer from neither btmgmt con or btmgmt info commands when I put them into .service files. My system is Arch Linux arm 32-bit and bluez stack version is 5.55-1. I tried
[Unit]
Description=check Bluetooth address
[Service]
Type=oneshot
ExecStart=/usr/bin/bash -c '/usr/bin/btmgmt info >> /usr/local/lib/mac 2>&1'
without any success: it just puts nothing in output file. Some tricks like add
User=root
Group=root
or substitute ExecStart with
ExecStart=/bin/bash -c 'echo -e "$(btmgmt con)" >> /usr/local/lib/mac 2>&1
did nothing. I tried changed thing by putting btmgmt stuff in different bash script instead of start them right from service file, i.e.
ExecStart=/usr/local/lib/test1
to no avail. I'm confused completely, because of:
It doesn't seem to be general btmgmt thing problem, because I can set ssp mode from service files
in very simple manner, just using
ExecStart=btmgmt off
or
ExecStart=btmgmt off
even without full path.
It doesn't seem to be redirecting command error as well, because if I add
ExecStartPre=/usr/bin/bash -c '/usr/bin/fdisk -l > /usr/local/lib/mac 2>&1'
it does work without any problem and I see fdisk info in file (I use fdisk because it requires elevated rights same as btmgmt one).
Moreover, btmgmt info works in the same way, i.e. shows nothing in out file. It makes me think something is wrong in output of btmgmt. I talk about output because input parameters work fine in btmgmt ssp on/of commands and journalctl and systemct don't show any errors in btmgmt con/info cases, so it seems to like output generating successfully but then sending somewhere to outer space, but I'm not sure completely.
Thanks for any help in advance
Well, I make a statement: btmgmt is quite intended to be used for output at any manner, but they tried make a zillion variants of output which directed to exact result it should be: bug is buried somewhere deep inside of bt_shell_printf and struct data. I'm not ready run through all that disgusting documented code (I mean total absence of comments or more-or-less satisfactory mans), so I ended up with a liitte bit hacked version of utility downgraded to simple fprintf in output, leaving only commands I need: con, ssp, power and simplified until only current setting printing info. Everything works fine, and I can use that kind of btmgmt not with systemd only, but even with udev rules (indirectly, of course)
I know this is an old question, but I had the same problem, and managed to fix it after hours and hours of trying.
I don't know why in the world this happens to be so hard with btmgmt but here's the fix:
[Unit]
After=bluetooth.service
Description=Bluetooth service
[Service]
ExecStart=<your-process>
Group=root
StandardInput=tty
TTYPath=/dev/tty2
TTYReset=yes
TTYVHangup=yes
Type=simple
User=root
Basically, by occupying a TTY, btmgmt will think it's running in an interactive terminal, and will output as usual.
Hope this saves anyone the hell I've been through!
Related
I am trying to run an application which uses pagemap in gem5 FS mode.
But I am not able to use pagemap in gem5. It throws below error -
"assert(pagemap>=0) failed"
The line of code is:
int pagemap = open("/proc/self/pagemap", O_RDONLY);
assert(pagemap >= 0);
Also, If I try to run my application on gem5 terminal with sudo ,it throws error-
sudo command not found
How can I use sudo in gem5 ??
These problems are not gem5 specific, but rather image / Linux specific, and would likely happen on any simulator or real hardware. So I recommend that you remove gem5 from the equation completely, and ask a Linux or image specific question next time, saying exactly what image your are using, kernel configs, and provide a minimal C example that reproduces the problem: this will greatly improve the probability that you will get help.
I have just done open("/proc/self/pagemap", O_RDONLY) successfully with: this program and on this fs.py setup on aarch64, see also these comments.
If /proc/<pid>/pagemap is not present for any file, do the following:
ensure that procfs is mounted on /proc. This is normally done with an fstab entry of type:
proc /proc proc defaults 0 0
but your init script needs to use fstab as well.
Alternatively, you can mount proc manually with:
mount -t proc proc proc/
you will likely want to ensure that /sys and /dev are mounted as well.
grep the kernel to see if there is some config controlling the file creation.
These kinds of things are often easy to find without knowing anything about the kernel.
If I do:
git grep '"pagemap'
to find the pagemap string, which is likely the creation point, on v4.18 this leads me to fs/proc/base.c, which contains:
#ifdef CONFIG_PROC_PAGE_MONITOR
REG("pagemap", S_IRUSR, proc_pagemap_operations),
#endif
so make sure CONFIG_PROC_PAGE_MONITOR is set.
sudo: most embedded / simulator images don't have it, you just login as root directly and can do anything by default without it. This can be seen by the conventional # in the prompt instead of $.
I'm building a Yocto-based distribution with systemd and journald in its core.
And unfortunately I cannot get Yocto to store all logs in /var/log -> /data/log. I need journald logs as well as some other logs that are written there after multi-user.target to be persistent. /data is the persistent partition.
I have a very similar problem to this but unfortunately I couldn't modify it to work properly in my setup.
From my understanding there's two things I need to modify:
volatiles file in base-files which I hope is a config file for systemd-tmpfiles. It should tell it to create at runtime everything that journald needs. Here I modified one line:
L+ root root 0755 /var/log /data/log
fs-perms.txt
${localstatedir}/log link /data/log
I also tried to pull it off with VOLATILE_LOG_DIR set "no" (fs-perms-persistent-log.txtmodified but to no avail. And also adding some kind ofvar.confto/etc/tmpfiles.d` with a config similar to the one above. It also hasn't worked.
I launch a watch ls -l on the resulting rootfs/var and see that var/log is getting symlinked to `/data/log for a short while but later it's overridden somewhere to point to volatile/log once again.
I would greatly appreciate any advice because it seems like I'm overcomplicating this thing. It should be very easy. After all it's just making Yocto to make a symlink. But I guess this is a rather important directory to let me ln -sf /data/log /var/log.
I would also like to hear out implications of this approach.
Other than wearing out my eMMC. We can live with that because the log activity is very low compared to some other actions performed on the device. I'm mostly interested about mount order and stuff. If I remember correctly, journald will use a memory buffer until it has /var/log/journal created for it so I should be fine. But what should I do to ensure everything's in place before the logs are flushed? Do I need to modify systemd services to include RequireMountsFor or After=?
I want to be as defensive as possible so I'm looking forward to what you guys have to say on the topic.
EDIT:
Maybe I can just add a bind mount from /var/log to /data/log? If that is actually the solution I'd also like to know if there's no hidden hindrances down the road?
you can mount your persistent partition via tweaking the base-files recipe (base-files_%.bbappend)
do_install_append () {
cat >> ${D}${sysconfdir}/fstab <<EOF
# Data partition
/dev/mmcblk0p4 /data auto defaults,sync,noauto 0 2
EOF
}
dirs755 += "/data"
then you can tweak volatile-binds (volatile-binds.bbappend)
VOLATILE_BINDS = "\
/data/var/lib /var/lib\n\
/data/var/log /var/log\n\
/data/var/spool /var/spool\n\
/data/var/srv /srv\n\
"
This should hopefully help, I have not tested it fully here, but I hope this might provide you some starting point.
A persistent log data option has made it in Yocto 2.4: https://bugzilla.yoctoproject.org/show_bug.cgi?id=6132
Log data can be made persistent by defining the following in your distro config:
VOLATILE_LOG_DIR = "no"
I've posted this issue on the google groups area for mapnik already, so I'm just going to c/p from there:
I've been troubleshooting this issue for a couple days, now. Bear with me for context:
Starting from a freshly-untarred source of mapnik 2.2.0 on RHEL 6.5:
First off, running "./configure" (which just calls scons/scons.py) works great. Finishes correctly, then I run make + make install and I get exactly what I want built and installed.
My goal has been to create a mapnik 2.2.0 RPM for internal use. Please do not suggest using an "official" mapnik RPM instead (or any other already-built mapnik RPM), as my entire purpose here is to build mapnik from source and create my own RPM.
That being said, when my RPM gets to its %build phase and runs ./configure, it freezes while scons checks for freetype-config. I've let it sit for hours, and nothing happens.
After I looked at the generated config.log file, it would appear that configure is failing on an "awk" command that goes something like this:
awk '{print $\(NF-1\)}'
The command is performed on the string that results from the command:
/usr/bin/freetype-config --libs --cflags
I'm wondering, first of all, how to fix this, but second of all why this would work manually, but fail when the rpmbuild process gets to the ./configure command. I've made sure that the same user (myself) is running both ./configure commands on the exact same files.
My third question would be: why does the configure step freeze on this issue, instead of throwing some sort of error and stopping?
Note that the problem with the "awk" command is the backslashes--the error is:
awk: {print $\(NF-1\)}
^ backslash not last character on line
When I remove the backslashes, the command succeeds. Whether or not removing the backslashes is the correct thing to do in the long run, I do not know.
It would seem this is some sort of python string-parsing / encoding issue, but I'm unsure. What really confuses me is why this works manually and fails when the rpmbuild tries to do it.
My only thought is that there's some difference between the rpmbuild environment and my shell that I configured on. What it is, I do not know.
Thank you for any assistance you can provide. If I can provide any more context, please let me know.
UPDATE: an svn command runs after the awk failure, but is missing whatever number gets passed after the -r option. I'm wondering if this could be causing the hang...thoughts?
I'm writing app like System Activity in Mac. I used modified darwin.h and darwin.c from this topic.
But it seems that it shows correct info only for certain fields (and some time ago it showed all correct info but only for current process - this app), for everything else it shows correct only pid, process name, group/owner. Everything else like cpu/mem/disk usage is nulled. I think it may be something with sandbox or security. Tried to move application to /Applications and setting root/wheel 755 but it's not work, still zeroed values.
Here's my output : click
Code changed in darwin.c : click, written after a lot of commented printf lines
Also there is a free apps approved in AppStore like SystemInfo (com.lymbilesoft.systeminfoliteforiphone) that shows detailed info about disk and processes, so how do it work? Tried nm-ing it's binary but did not find something useful.
Can someone please help me with it?
I'm not sure if this is the only problem, but it certainly is possible that your app needs to run as root for this to work correctly.
However, simply installing the app in /Applications, doing chown root.wheel, and chmod 755 will not cause it to run as root. It will still run as user mobile.
In order to get the app to run as root, see this answer
I've used this technique successfully, and if you have a jailbroken phone, you can navigate to /Applications/Cydia.app and see that this launch script is how Cydia does this, too.
I use ps aux from the Terminal/Command Line. That gives me all the stuff I need, regarding your concerns.
I am trying to run a GNU make file with multiple jobs.
When I try executing ' make.exe -r -j3', the receive the following to errors:
make.exe: Do not specify -j or --jobs if sh.exe is not available.
make.exe: Resetting make for single job mode.
Do I have to add ' $(SH) -c' somewhere in the makefile? If so, where?
The error message suggests that make cannot find sh.exe. The file names indicate you are probably on CygWin. I would investigate setting the PATH to include the location of sh.exe, or defining the value of SHELL to the name (or, even, full path) of your shell.
Are you running this on Windows (more specifically, in the "windows" shell?). If you are, you might want to read this:
http://www.gnu.org/software/make/manual/make.html#Parallel
more specifically:
On MS-DOS, the ‘-j’ option has no effect, since that system doesn't support multi-processing.
Once again, assuming you're running on windows, you should get MinGW or CygWin