date int64 1,220B 1,719B | question_description stringlengths 28 29.9k | accepted_answer stringlengths 12 26.4k | question_title stringlengths 14 159 |
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1,636,111,100,000 |
I tried to install eCryptfs on my server to open an eCryptfs I did on my home computer.
I got these errors.
$ sudo mount -t ecryptfs /home/(place)/enc/ /home/(place)/enc/
Unable to get the version number of the kernel module. Please make
sure that you have the eCryptfs kernel module loaded, you have sysfs
mount... |
It seems that OpenVZ is the problem (again). OpenVZ uses the parent kernel and I can't do anything with that.
| Cannot mount eCryptfs |
1,636,111,100,000 |
I'm trying to customize my initrd on kernel 2.4.
At some point, inside the file linuxrc, I have the opportunity to set my root device setting the /proc/sys/kernel/real-root-dev variable
The example on docs is the one belowe:
echo 0x301 > /proc/sys/kernel/real-root-dev
where 0x301 is for /dev/hda1
What I'm looking f... |
See this file for your kernel (probably most hasn't even changed over the major kernel versions):
http://www.mjmwired.net/kernel/Documentation/devices.txt
| Initrd : Were can I found the code for real-root-dev |
1,636,111,100,000 |
I am new to linux as of yesterday. I'm using linux puppy to try to get the most out of a 10 year old, slow laptop. I installed it fine, no problems there, but as soon as I try to use my usb dongle's install CD, the problems start.
The CD included support for linux as well as windows, so I copied the linux files off th... |
You need to install kernel headers to compile a module. The kernel headers are not part of the kernel source (or at least not all of them are), they are generated when the kernel is compiled, and some of these headers depend on compilation options.
There is an unofficial kernel header package. If you prefer to do thin... | /lib/modules/2.6.37.6/build missing in linux puppy? what should I do? |
1,636,111,100,000 |
If a previous kernel (assuming it is not from the stone age) compiles successfully, does it make sense to assume that old config file if copied to the new kernel, will compile successfully too?
What things need to be taken care of?
|
Copy the old .config file and then, to know what needs to be taken care of, use make oldconfig. You will be prompted interactively for needed changes in your config file. It's almost safe to answer with the default option to every question. (Usually you don't care about new drivers, and you want to use new features wh... | Precautions to be taken while make oldconfig |
1,636,111,100,000 |
I would like to make a bootable USB/Floopy/LiveCD with linux kernel and Grub.
After booting to that USB/Floopy/LiveCD using VirtualBox or directly, it will show my own customized Grub screen and then it will execute my C or Pascal application.
I was trying to download grub but I am not sure which one I should use. Is... |
There are only two versions of grub listed there, the 1x series (most recent being 0.97) and the 2x series (most recent being 1.99). Both can be customized and used for your purpose. The 1x series has more standard compatibility with old hardware and distros, but we the 2x series is coming along nicly and many major d... | Which Grub to use for a custom portable boot image? |
1,636,111,100,000 |
Why does this work:
truncate -s 2043G foo
...while this fails:
truncate -s 2044G foo
Why 2043 gigabytes, of all values?
|
You're probably using a filesystem that has a 2TB maximum file size (for example, ext3 with a 4KB or 8KB block size). truncate won't let you specify a target file size greater than the maximum your file system supports; 2044GB is very close to 2TB. I'm not sure why it's not exactly 2048GB that causes the problem; it's... | Why does truncate fail for sizes above 2043G in ext3? |
1,636,111,100,000 |
I have a really basic doubt, which part creates all these directories, where is this configuration of creating directories stored while installing a new OS?
What is the order in which these directories are created? Are they created after /boot has been mounted by the kernel, by which part of the kernel?
|
The root filesystem is mounted first (readonly) at bootime, as your bootlog could tell you :
[kernel] [ 2.242830] VFS: Mounted root (ext4 filesystem) readonly on device 8:24.
It will then be remounted at init time :
[kernel] [ 2.266181] Run /sbin/init as init process
...
[kernel] [ 6.882156] EXT4-fs (sdb8): ... | Who actually mounts the file system and creates directories like /bin, /dev, /etc |
1,636,111,100,000 |
This question is an extension of why do we need to pass buffers to system calls in order to have information returned? Why can't system calls allocate the buffer internally? since memory allocation is one of many motivations to pass callbacks to syscalls.
I would like to to pass an allocate callback to a syscall varia... |
System calls run kernel code. The kernel doesn't trust user mode code, so if a system call takes a callback, it can't execute that callback in kernel mode. It must execute the callback in user mode.
The system call can't know for sure what the callback will do. The callback may make system calls of its own. For exampl... | Why do syscalls not accept userspace callback functions? |
1,636,111,100,000 |
I'm looking for a way to replace my keyboard kernel module to a custom one. I have a Logitech MK710 keyboard + mouse set for this purpose, with a USB receiver with those 2 interfaces. Automatically, this USB receiver is managed by default usb, usbhid or logitech-hidpp-device modules, there is some information (note: 1... |
Most likely you are being tripped up by initramfs: a copy of the original HID driver module has been stored in there when your current kernel was installed, and if you haven't regenerated initramfs when adding your module, your customized one won't be in there.
At boot time, the USB support modules are among the first... | Replace HID device driver with custom one |
1,636,111,100,000 |
I dont like the intel mei kernel modules so I made a file in /etc/modprobe.d/blacklist.conf that has the following contents:
blacklist mei
blacklist mei_mei
blacklist mei_hdcp
blacklist mei_wdt
It works for everything except mei and mei_me as shown by the output of lsmod | grep mei:
mei_me 45056 0
me... |
Use this option : Blacklist with fake install
add the following line to your /etc/modprobe.d/blacklist.conf
install mei /bin/true
Then:
sudo depmod -ae
sudo update-initramfs -u
| modprobe blacklist not working Debian 11 |
1,636,111,100,000 |
Background: I'm using QEMU to virtualize xv6-riscv on top of WSL2. I'm looking to create some sort of clean OS shutdown process reminiscent of Linux's exit command. Currently I'm using Ctrl-a x to kill qemu, but I want to be able to do this programmatically from within the OS.
I know that the Linux exit command simply... |
TL;DR
From the supervisor mode:
(*(volatile uint32 *) 0x100000) = 0x5555;
You also need to change the kernel page table to map the address 0x100000. You can see this commit for full implementation.
Long answer
Unfortunately, the documentation for QEMU RISC-V emulator is poor. So we need to dive into the code. We know... | Writing an OS shutdown process for QEMU (xv6) |
1,636,111,100,000 |
The NOTES section of $ man 5 sysctl.conf states: The description of individual parameters can be found in the kernel documentation.
But is there a way for me to find this kernel documentation offline? Is it a package that I'd need to install?
For example, I came across the kernel.panic parameter, which on my system is... |
But is there a way for me to find this kernel documentation offline? Is it a package that I'd need to install?
Yes, most distributions provide the kernel documentation for their kernel in a package. On Debian, this is linux-doc, which is a meta-package pulling in the default kernel’s documentation for whichever rele... | Where to get offline documentation/descriptions of individual sysctl kernel tunable parameters? |
1,636,111,100,000 |
We have physical Linux machine with 16 cpus
lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 16
We want to disable 14 cpus on that machine , so its actually like we have linux machine with only 2 cpu
In order to achieve this , I did ... |
This might or might not depending on the application.
If the application simply uses APIs to poll the number of available cores, it might not work because the Linux kernel might return all the cores.
However disabling CPU cores in BIOS must work - it depends on your BIOS implementation, so please consult with your mot... | rhel + how to disable CPU's on my machine |
1,636,111,100,000 |
I have onboard SATA controller, and also an additional RAID controller card:
00:17.0 SATA controller: Intel Corporation Device a282
...
04:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS-3 3108 [Invader] (rev 02)
When linux kernel boots, disks connected on the LSI raid controller are recognized/enume... |
I was looking into something similar in the past - changing the order of the disks and the network cards for a monolithic kernel.
The order how the drivers are loaded gets decided during compilation - by initcall_levels (from lower to higher, include/linux/init.h) and then by
positions in the Makefiles.
I do not think... | change order of SATA and RAID controller when booting linux kernel |
1,636,111,100,000 |
I have a bespoke monitoring application I'm deploying on a linux cluster I wish to secure.
I would like the process not to be possible to kill.
That said, senior users need root.
I read that I can use kernel threads to achieve this. I would literally rather crash the OS than keep it up without this process.
Is this po... |
If senior users do not need complete and unfettered root access you could allow them to become root just to use the needed functions via sudo (or setuid programs, service daemons, ...)
| Kill OS if process is killed |
1,636,111,100,000 |
I want to boot Arch Linux directly from UEFI.
My idea is to create a boot entry using the tool efibootmgr; I used this command:
efibootmgr --create --label "arch-test" --loader /vmlinuz-linux --unicode 'root=PARTUUID=f2083749-8bbc-570b-ab3b-e79d72fa08ac rw initrd=\initramfs-linux.img' --verbose
I followed the Arch ... |
-l | --loader NAME
Specify a loader (defaults to \\elilo.efi)
A kernel with EFI-stub is still not a loader. To boot from BIOS it has to be an EFI-application. All the boot loaders have .EFI suffix. I think it is possible to turn a kernel into such a directly bootable object, but normally it is one of... | Boot kernel from UEFI directly |
1,636,111,100,000 |
Currently I'm using Kernel version 3.10.0-1062.el7.x86_64
and I want to downgrade to 3.10.0-957.27.2.el7.x86_64 (that was not installed, it needed to support existing project)
I've tried:
yum install kernel-3.10.0-957.27.2.el7.x86_64
Failed to set locale, defaulting to C
Loaded plugins: fastestmirror
Loading mirror s... |
... want to downgrade to 3.10.0-957.27.2.el7.x86_64
kernel-3.10.0-957.27.2.el7.x86_64 was saved / is stored at CERN :
https://linuxsoft.cern.ch/cern/centos/7/updates/x86_64/Packages/kernel-3.10.0-957.27.2.el7.x86_64.rpm
Ref. https://linuxsoft.cern.ch/cern/centos/7/updates/x86_64/repoview/kernel.html ... and ref. Goo... | install centos older kernel version |
1,636,111,100,000 |
I use Mint 19.2, and I try to see CPU backtrace by the following process.
$ sudo -s
# sysctl -w kernel.sysrq=1
# echo l > /proc/sysrq-trigger
But, nothing happened. I researched more online and I tried the following input key check, and the response for the command was this.
# dmesg | grep -i sysrq
... |
The kernel will only display messages on the console and to the kernel message buffer, which is usually logged by syslog with facility 'kernel' and which can also be read by using dmesg.
The kernel has no concept of "the current terminal", so what you want is not possible.
| SysRq doesn't display any result on terminal |
1,636,111,100,000 |
lsmod -> tun 16587 0 - Live 0xbf0e1000
Openvpn error: Cannot open TUN/TAP dev /dev/net/tun no such file or directory
I tried creating a dummy directory but the error changes to Cannot open TUN/TAP dev /dev/net/tun: Is a directory.
edit:
System: ARM Linux 3.10.0
|
/dev/net/tun is character device not file nor directory. Check it with ls command:
ls -lad /dev/net/tun
It shall look like (notice first c):
crw-rw-rw- 1 root root 10, 200 Feb 10 21:38 /dev/net/tun
To fix unload tun module:
rmmod tun
remove /dev/net/tun directory if it exist (directory is marked with d instead of c... | TUN Module Loaded but OpenVPN /dev/net/tun no such file or directory |
1,636,111,100,000 |
I need to retrieved the grab state of an evdev device in a program. More specifically, I need to retrieve the state of the grab pointer in the evdev struct seen here: https://elixir.bootlin.com/linux/v4.20/source/drivers/input/evdev.c#L42 (if it is NULL or not NULL). Is this at all possible from userspace, e.g. throug... |
To determine whether a device is currently grabbed, from userspace, you can try to grab it yourself; either using the EVIOCGRAB ioctl yourself, or libevdev_grab in libevdev:
if (!ioctl(evdevfd, EVIOCGRAB, (void *) 1)) {
// We grabbed the device, no one else had it; release it
ioctl(evdevfd, EVIOCGRAB, (void *)... | Access grab state of evdev device |
1,534,554,907,000 |
I previously followed the answer in this question: Attaching USB-Serial device with custom PID to ttyUSB0 on embedded
Now, I need to revert that step so that the device id I echoed to new_id doesn't map to ttyUSB0 every time I connect it. The file, new_id, seems to have '0403 e0d0' permanently written to it now. I've ... |
I looked into this, and it does seem like remove_id was never implemented for usb-serial. Should be able to take the work in drivers/usb/core/driver.c and implement remove_id in drivers/usb/serial/bus.c.
Sorry for not having an easy answer.
| How to remove device id from manually entered usb-serial driver |
1,534,554,907,000 |
I am developing an embedded Linux device. I have successfully created an InitramFS CPIO archive that runs quickly after boot. Now, I want to change the initial kernel command line to include "quiet" parameter so I can boot even faster.
However, once the splash screen is displayed in the InitramFS, I want to remove the... |
You can't really change the kernel command-line after boot, but what you can do is reproduce the effects of setting or unsetting the quiet command-line through other means, which should accomplish what you want to achieve here.
In short, to increase verbosity once you don't want quiet anymore, you can use this command... | Linux Modify/Add Kernel Command Line from InitramFS "UserSpace" |
1,534,554,907,000 |
I'm trying to debug a prototype CPU that throws unhandled signal 11s and signal 7s in the startup process.
Here is what the kernel prints out. I have added extra print statements to the kernel to debug exactly which userspace processes are exhibiting the error.
[ 0.880000] Execing: /usr/bin/readlink
[ 0.884000] ... |
If I'm reading the kernel's source correctly, this line:
readlink[85]: unhandled signal 7 code 0x1 at 0x00000020000b8f60 in libc-2.26.so[2000049000+13e000]
Tells you what you need to know. libc is loaded at hexadecimal 0x2000049000, and is 0x13e000 bytes long. The address that the signal happened at is 0x00000020000b... | Interpreting the unhandled signal exception in Linux |
1,534,554,907,000 |
I'm trying to use a compressed squashfs ubi volume as my root file system. The idea is to have two ubi volumes. Volume one contains a read-only squashfs file system. Volume two is re-sizable and uses the remaining flash space. It contains a writable ubifs file system. These two ubi volumes are to be overlayed using ov... |
Squashfs needs a block device to run, thus you need the block emulation over UBI. First make sure it is enabled in your kernel.
You can test this by using the ubiblock command on a running system. For example, running ubiblock -c /dev/ubi0_0 will create the devnode /dev/ubiblock0_0.
Once you have the dependency, you ... | Using squashfs on top of ubi as root file system |
1,534,554,907,000 |
Whilst reading both https://lwn.net/Articles/391222/ and http://man7.org/linux/man-pages/man5/proc.5.html I have come across the terms oom_score and badness. Both numbers have the same basic meaning; the higher they are, the more likely the associated task is to be OOM-killed when the host is under memory pressure.
Wh... |
It looks like it is:
oom_score = badness * 1000 / totalpages
based on the kernel code https://github.com/torvalds/linux/blob/master/fs/proc/base.c#L549.
static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task)
{
unsigned long totalpages = to... | What is the relationship between oom_score and badness? |
1,534,554,907,000 |
I am trying to use read-only overlayfs(no workdir and upperdir) inside custom initrd.
This works fine in completely booted OS:
mkdir /tmp/ovl1 /tmp/ovl2 /tmp/merged
mount -t overlay none -o lowerdir=/tmp/ovl1:/tmp/ovl2 /tmp/merged
This also works if I use busybox sh as shell, which has built-in mount command.
Inside ... |
I was sure, that module is statically compiled in kernel, but I was wrong: CONFIG_OVERLAY_FS=m.
After adding the overlay module to initrd everything works fine.
| Can not mount overlayfs inside initrd |
1,534,554,907,000 |
I am studying Professional Linux Kernel Architecture and I am in Chapter 3 Memory Management. While I studied kernel address space itself is split into direct mapping area, vmalloc area, kmap area and fixed mapping area.
What I am wondering is just like below.
Can direct mapping area(896MB) of kernel address space ... |
Answers to questions 1 and 2: no, once paging has been enabled, the CPU instructions only use virtual addresses, which are translated to physical addresses using the MMU before reading or writing RAM. The __va and __pa macros don't access memory, they just convert addresses between the address spaces. On a 32-bit mach... | Kernel address space and Kernel page table |
1,534,554,907,000 |
I have both 3.2 and 2.6 installed on a server, but neither sudo apt-get dist-upgrade nor sudo apt-get install linux-image-3.2.0-4-amd64 can upgrade the kernel.
user@server:~$ uname -a
Linux server 2.6.32-5-xen-amd64 #1 SMP Tue May 13 18:41:58 UTC 2014 x86_64 GNU/Linux
user@server:~$ lsb_release -a
No LSB modules are ... |
My hosting provider doesn't use the normal Debian grub setup where GRUB_DEFAULT is declared in the file /etc/default/grub. For me, I had to manually edit the file /boot/grub/menu.lst and change the default directive to 0.
Make sure to ask your host if they've got an alternative setup for grub.
| Stuck on old kernel when trying to upgrade from Squeeze to Wheezy |
1,534,554,907,000 |
After a reboot or crash, the syslog does not save any messages from the previous session. What should I do to tell syslogd/klogd to append to syslog instead of overwriting every session? I feel I am missing something obvious.
Some background on my system:
Distribution: Yocto (poky) with busybox
Method of launching kl... |
It seems /var/log/ directory was redirected to /var/volatile/log/ at boot which is mounted as tempfs so the data wouldn't be saved across a reboot/crash. Commenting out the line that mounts /var/volatile/ directory as tmpfs in the /etc/fstab file seems to have worked.
| How to get syslogd/klogd to append to syslog after reboot instead of overwriting? |
1,534,554,907,000 |
I don't know how to properly debug the kernel configuration process when an option that should be on ( because it doesn't really depends on anything and it doesn't conflict with anything that I can think of ) , really can't find a way to live beyond make olddefconfig .
Among other things I'm using
CONFIG_SYS_SUPPORTS_... |
Manually changing the .config file without Kconfig is discouraged as it might lead to unexpected behavior. In your case the best solution would be to run
make menuconfig
and selecting the configuration option from the menuconfig (the parameter you are looking for should be under arch/mips).
| How to force a CONFIG_ option to stay on? |
1,534,554,907,000 |
Let's say that I have a following network topology:
Theoretical total(Tx + Rx) bandwidth for all four hosts in total is 100Mbps. Now if I execute Iperf in UDP mode in all four hosts simultaneously and force each Iperf instance to put 50Mbps(-b 50m in Iperf client) of traffic on wire, then Iperf does not put as much t... |
The kernel and the NIC communicate the same way the kernel
(specifically, a device driver, which is part of the kernel)
communicates with any other device (e.g., serial communications device
(like keyboard, mouse, or RS232), disk (or disk-like mass storage device),
display, security token, etc.) – they talk directly t... | How does Linux kernel know that collisions occurred in Ethernet collision domain? |
1,534,554,907,000 |
I am trying to install a new kernel on Ubuntu Server and I am unable to complete it due to a "gzip: stdout: no space left on device" error. The full error was produced after running sudo make modules_install install:
INSTALL /lib/firmware/cpia2/stv0672_vp4.bin
INSTALL /lib/firmware/yam/1200.bin
INSTALL /lib/firm... |
"make modules_install install" tries to build initrd image on /boot partition, which has 162 megabytes free, which is simply not enough.
If you want to compile kernel yourself on Ubuntu, you need to prepare at least 1GB free space on /boot partition.
| Unable to install new kernel in ubuntu server. "gzip: stdout: No space left on device" error even though abundant disk space |
1,534,554,907,000 |
I have the source of Linux 3.4.0 to which I added some modifications. I know that here (ftp://ftp.kernel.org/pub/linux/kernel/v3.x/) I can find all the 107 patches that need to be applied to my source to update it to the 3.4.107 version.
I read that I have to apply them one by one: first the 3.4.1, then the 3.4.2, th... |
Each patch in https://www.kernel.org/pub/linux/kernel/v3.x/ applies to the first release of the corresponding series, so you should apply https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.4.107.xz directly to your 3.4.0 source tree. Incremental patches are available, but they're stored separately, in https://www.ke... | Linux kernel patches: can I skip some? |
1,534,554,907,000 |
Q: Is it normal if a RHEL 6.5 machine kernel panics if I type the LUKS password a few times wrong?
|
Yes. The init process, which always had process ID 1, exited. UNIX operating systems panic by design when this happens, because essentally, without init, the system cannot continue to do much of anything useful. (That's not technically quite true, some things can continue, but it's not supposed to happen and it consid... | Kernel panic if LUKS password is bad x times |
1,534,554,907,000 |
I have a binary that repacks android kernel (not mkbootimg).
I'm making a script to automate the process.
I don't want any output on the screen. So I have redirected the output to a file named foo.log.
The command is - kernel_make "$zImage" "$ramdisk" "$cmdline" "$image" &> data/local/working/foo.log
My current work... |
grep is the way to go, it returns 0 if a match is found. You don't actually need to output the line, so just discard the line and use the test. In your case, it would just be
lastline=$(tail -n1 logfile)
if grep pattern <<<"$lastline" &>/dev/null; then
echo "yay, found pattern"
else
echo "darn"
fi
Observe the... | How to return 0 if a pattern is matched from a file? [duplicate] |
1,534,554,907,000 |
The very little documentation about /proc/filesystems says it is a "list of supported file systems". I see a lot of file system modules in /lib/modules/linux_ver/kernel/fs, most of which do not appear in /proc/filesystems, nevertheless mount appears to have no problem using those file system modules.
So what is the us... |
If there is an available module for the file system you want to mount but it's not yet loaded and hence isn't yet shown in /proc/filesystems, then it will be loaded on-demand which it why you don't have any problem mounting.
After having mounted such a file system, then that file system type should have appeared in /p... | What is /proc/filesystems supposed to be and why is it different from /lib/modules/linux_ver/kernel/fs? |
1,534,554,907,000 |
Based on https://www.kernel.org/ kernel 3.12 is released in 2014-04-23 and kernel 3.10 is released in 2014-04-27.
Based on release date, 3.12 is older and based on version number 3.10 is older.
Which one is newer? Which one has more features? Does 3.12 have 3.10 features?
|
You should familiarize yourself with the different branches:
Longterm There are usually several "longterm maintenance" kernel releases provided for
the purposes of backporting bugfixes for older kernel trees. Only
important bugfixes are applied to such kernels and they don't usually
see very frequent releases, especi... | Kernel 3.12 or 3.10? which one has more features, newer and better? |
1,534,554,907,000 |
I'm using buildroot to generate my images and for sure there is the option of compression with the help of different methods (LZO, LZMA, gzip, ...).
So far i found these 3 compression options in buildroot (v. 2013.11):
Kernel compression Mode (in make linux-menuconfig)
Built-in initramfs compression mode (in make lin... |
The three different options are for three different aspects of the generated Linux system, the kernel itself, the initramfs and the result file system.
Kernel compression Mode: this compresses the compiled kernel image. For example, on my Ubuntu 12.04 machine, the kernel is at /boot/vmlinuz-3.8.0-35-generic
Built-in... | I want to understand Buildroot - the 3 compression config options (kernel, initramfs & rootfs) |
1,534,554,907,000 |
I would like to install Arch Linux on my Acer TravelMate 5735Z. Sadly, it has a Intel GMA 4500 MHD graphic card. This means, I suffer from Kernel Bug [GM45] black screen at boot (0 backlight?).
When I boot from the installation CD for Arch Linux 2013.10.01, I can see the menu that lets me choose to install arch/boot t... |
You need to hit E at the GRUB menu. According to the bug report you linked to, the workaround is to add i915.invert_brightness=1 to your kernel parameters. Scroll down to the kernel line and change it to (emphasis mine):
linux /boot/x86_64/vmlinuz archisobasedir=arch archisolabel=ARCH_201310 initrd=boot/x86_64/archis... | How can I install Arch Linux on a Laptop with Intel GMA 4500 MHD? |
1,534,554,907,000 |
As seen here, compiling the Android kernel requires a prebuilt GCC toolchain (or the equivalent from the Android NDK). Cross-compilation makes sense; we are compiling code for a device with a different platform.
However, the guide to compiling the Android source does not anywhere require that one download a toolchain ... |
You need the gcc toolchain for both.
The toolchain is part of the android source tree. Before you build the entire android source, you use the "lunch" tool, which sets the environment variables such that a prebuilt toolchain can be used.
http://source.android.com/source/building-running.html#choose-a-target
The page a... | Why does building an Android kernel need a toolchain, but compiling the entire source does not? |
1,534,554,907,000 |
Recently, after performing a routine software upgrade, I notice a huge surge in the number of warnings from the kernel that goes like this:
warning kern [10839.717480] phy0 -> rt2800usb_txdone: Warning - Got TX
status for an empty queue 0, dropping warning kern [10839.895305]
phy0 -> rt2800usb_entry_txstatus_ti... |
This looks to be an active bug in the rt2800usb driver. There's an open issue in the Fedora's bugzilla database here, titled:
Bug 913631 - Slow wireless connection using rt2800usb driver (Asus USB-N13 dongle).
TX status timeout
The term TX refers to transfer (i.e. sending) and RX refers to receiver (i.e. receiving)... | What is TX status timeout and do I have to worry about it? |
1,534,554,907,000 |
I have recently compiled a minimal kernel for my Intel(R) Pentium(R) Dual CPU T3400 @ 2.16GHz, and chose CONFIG_MCORE2 (Core 2/newer Xeon) under "Processor type and features > Processor family"
I don't know if this is related, but my laptop has 2GB of RAM, and the resulting kernel, when compiled, limited my RAM to ... |
Look, your CPU family cpu family : 6, which matches the description in CONFIG_MCORE2:
Newer ones have 6 and older ones 15
That's the right config to choose.
And your memory issue, as you disabled HIGHMEM, your kernel can only use 896M memory space.
| Which "Processor family" to choose under "Processor type and features"? |
1,534,554,907,000 |
I didn't really know where to ask this question, so since Joli OS uses the linux kernel and they don't seem to have a forum here I go.
All the official information I could gather says it doesn't work on ARM devices yet. But when I went to GitHub to look at the code I saw an arm subfolder in jolicloud-robby-kernel/arch... |
Linux can run on ARM, and if all sources are available, with enough work most disro's could be ported. As far as JoliOS, everything seems to indicate ARM support is very experimental. If you are experienced, with embedded systems, then hacking a project might yield a usable system. It is not the type of project I w... | Joli OS on ARM devices |
1,534,554,907,000 |
Linux supports a set of different disk label or partition table formats. For example, Sun Disk Labels and MS-DOS partition tables are both disk labels that contain (largely) the same information (partitioning) in different formats. Please note, I'm not referring to filesystems like ext{2,3,4} but disklabels like the m... |
kpartx uses the device mapper tools to create devices over the underlying media; you should be able to implement your partition parser in userspace and create DM mappings that expose parts of the underlying system to the kernel as block devices.
That absolves you of all the complexity of in-kernel work, and should sti... | Writing Linux Kernel module for non-MSDOS disk labels/partition tables |
1,534,554,907,000 |
For dacades X windows system is either BASH, C or etc. But is there any X windows system or any wrapper which can interpret HTML, CSS, Javascript to general Windows system?
I would like to build this: http://www.google.com/tv/features.html
(everything comes from my web server, and get render as UI)
What is the best wa... |
ǝʃƃoo⅁ ɹɐǝ◖
while I'm not aware of anything that fits your description, you could have a look at the Mozilla Project's "Chromeless":
Instead building a whole new platform, we suggest that the web itself should be the platform. That a developer could design the browser using standard web technologies combined with a m... | Is there any X windows system, which is HTML, CSS, Javascript? Such as Web Browser? |
1,534,554,907,000 |
After executing...
sudo modprobe rt3572sta
I get...
Invalid module format
What does it mean? I'm trying to get Wusb600n v2 working on Lucid Lynx.
Does it mean that kernel versions aren't compatible?
|
It means that the file you are trying to load is not a valid kernel module. Either it never was, or it has been corrupted, or possibly it is for an architecture other than the one you have ( 32 vs 64 bit ).
| What does 'Invalid module format' mean? |
1,534,554,907,000 |
Is there support for Kernel versions 2.4-2.6 in RedHat Enterprise Linux versions 4 and 5?
|
Both RHEL versions 4 and 5 shipped with 2.6 series Linux kernels.
It is possible but difficult to manually compile your own 2.4 kernel for RHEL 4, but even that is problematic because of the dependencies on 2.6 features. I don't think it would be practically possible with RHEL 5.
In order to use 2.4 kernels you need t... | RedHat Enterprise Edition Kernel Support |
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I used the Reiser4 fs for some time and would love to see it get into the mainline kernel. I would think the project can still go forward even if Hans is not able to contribute these days. Is there any mention on a mailing list or elsewhere of plans to get Reiser4 into the mainline kernel?
|
The reason isn't so much technical or necessarily political, but perhaps pragmatic. Edward Shishkin says that before it goes mainline it needs vendor support
Hello Michael.
I don't see any technical obstacles for Reiser4 inclusion. There are only organisation ones: I don't think it will be accepted without support ... | Status of adding Reiser4 to the Linux kernel |
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I have heard that different distributions of Linux have the same Linux kernel up to that the Linux kernels may be in different versions. Do different distributions of Unix also share the same kernel up to different versions? What are some examples of various distributions of Unix? I've only heard of BSD.
|
Linux is, in a narrow sense, a kernel. In a more common wider sense, “Linux” means a software distribution (an operating system and some applications) containing this kernel. See Is Linux a Unix?.
At any given point in time, each Linux distribution contains different versions of each of the thousands of pieces it's ma... | Kernels of different distributions of Unix and of Linux |
1,534,554,907,000 |
I've never done a kernel patch before, and I've just recently started looking into how it's done. I notice that for a patch's filename, it tells us the kernel version (i.e dm-raid45-2.6.25-rc2_20080221.patch.bz2). So, I know that definitely for kernel 2.6.25, I'd need to apply this patch. But, I just want to make sure... |
First of all, you shouldn't need to patch your kernel just because it's not the latest. You would normally rely on your distribution maintainers to do patching. You might need to patch if you had some kind of uncommon hardware, but most of the time, you just need a different or newer kernel module that is supplied s... | kernel patches - knowing when to do them |
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I tried asking my question on TI's forum, but I am not getting much feedback, so I thought I'd try my luck here.
You can see my ongoing discussion with TI here: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1158936/am3359-caught-segv-when-distro-s-systemd-starting
We have been working with ... |
This issue was fixed on the TI Forum, here is the link for those interested.
https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1158936/am3359-caught-segv-when-distro-s-systemd-starting
In summary, the issue was that my VDD_MPU(1.1V) was driven by my PMIC and the PMIC driver was not properly ini... | AM335x - Custom Board <SEGV> when running Systemd |
1,534,554,907,000 |
Historically yarrow algorithm had a kernel process with the name of yarrow. But after replacing it with Fortuna, the kernel process disappears.
What is the name of the new kernel process of Fortuna's algorithm in the permanent kernel processes?
|
The name of the kthread is rand_harvestq and was changed in this commit in sys/dev/random/random_harvestq.c:165.
The name was prior yarrow or fortuna depending on how the kernel was compiled see line sys/dev/random/randomdev_soft.c:85
| What is the name of fortuna's kernel process in FreeBSD? |
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Virtualbox 5.1.34 (and below) crashes and prints strange error messages like segementation faults or kills the x11/wayland server.
This strange behavior occurs on ubuntu22, debian bookworm, debian sid, archlinux after upgrading the host kernel to 5.18.3.
|
After some internet recherche I found this nice discussion on the virtualbox forum. At first I thought my vm installation troubles but it happens on all guest machines.
The solution up to now is to use an older kernel (< 5.17.11) or to install the the test build:
Virtualbox (6.1.34.xx) crashes frequently on debian ... | Virtualbox < 5.1.34 crashes frequently on kernel > 5.18 |
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The latest Linux kernel now takes more than half of my /boot space. Next time I want to upgrade, how do I do that? Can I purge the current in-use kernel and then issue aptitude full-upgrade or do-release-upgrade? Seems dangerous and with possible side effects (loss of config?)
$ df -h /boot
Filesystem Size Used ... |
I managed to halve the size taken by the initrd and associated files by simply changing MODULES=most to MODULES=dep in /etc/initramfs-tools/initramfs.conf
I left the compression unchanged as it was already using lz4 which, I believe, is currently the better compression ratio.
Then run sudo update-initramfs -u -k all t... | How to upgrade with kernel taking more than half of /boot |
1,628,434,039,000 |
According to fs/proc/array.c:130, the following array defines various process states:
/*
* The task state array is a strange "bitmap" of
* reasons to sleep. Thus "running" is zero, and
* you can test for combinations of others with
* simple bit tests.
*/
static const char * const task_state_array[] = {
/* st... |
The task state represented by “X” isn’t TASK_DEAD, it’s the EXIT_DEAD exit state. TASK_DEAD itself isn’t a reportable state, and while EXIT_DEAD is, it isn’t supposed to be visible in practice.
EXIT_DEAD’s role is similar to what you describe for TASK_DEAD: a task’s exit state is set to EXIT_DEAD shortly before its ta... | In what circumstances will a process be in state X (dead)? |
1,628,434,039,000 |
Consider the output of /boot/System.map-5.8.0-50-generic and /proc/kallsyms on Ubuntu 20.10 (Groovy Gorilla):
$ sudo cat /boot/System.map-5.8.0-50-generic | grep sys_call_table
ffffffff820002e0 D sys_call_table
ffffffff82001360 D ia32_sys_call_table
ffffffff82002120 D x32_sys_call_table
$ sudo cat /proc/kallsyms | gre... |
Yes, this is caused by KASLR. Note that all addresses are offset by the same amount. The kernel doesn’t know about System.map so it doesn’t update it.
I’m not aware of any way of detecting whether KASLR is enabled from userspace at runtime, short of comparing /proc/kallsyms and System.map, or possibly causing a panic ... | Why don't the addresses in `/boot/System.map-*` and `/proc/kallsyms` match? |
1,628,434,039,000 |
I'm running Linux (Debian 10) on a Chromebook (Eve) using a stock Chrome OS kernel (4.4.x) with minor modifications. Everything runs (mostly) fine except that TTY console cannot be accessed via Ctrl+Alt+Fn, which does switch framebuffers as intended (i.e. Ctrl+F1 switches to DM and Crtl+F2 switches to desktop), but th... |
After noticing that /dev/fb0 didn't exist despite having loaded fbcon and a framebuffer device module, I figured it out:
Build i915 as a loadable module instead of built-in and make sure that legacy fbdev support is enabled. (Building it as a loadable module is perhaps not necessary, I only did it to ensure I could b... | How can I enable TTY console? |
1,628,434,039,000 |
Since yesterday, I am having regular total freeze of my OS, archlinux, with no clear reason why.
The only thing I'm doing is browsing the internet with Firefox while it happens.
The audio, bluetooth are still working during these freezes, but I have no way to interact with the system...
I tried to find something helpf... |
This is probably the same issue that is discussed here and here.
A short-term solution (that works for me too) is uninstalling xf86-video-intel.
| OS freezes completely |
1,628,434,039,000 |
Is there any equivalent in Debian for hotpatching kernels, similar to kpatch in Red Hat Linux?
|
You can try KernelCare, Ksplice.
You can try this tutorial if you want to use kpatch.
I don't use Debian for some time.
See the wiki page about the kpatch feature.
| Is there a way to hotpatch a kernel in Debian |
1,628,434,039,000 |
Due to shortage of free built-in SATA 3.0 plugs (6 totally) on my motherboard (Gigabyte 970A-DS3 rev.3) I've got an Adaptec RAID 5405 (3G SAS/SATA RAID) to move all "slow" SATA 1.0/2.0 devices to be connected to this card without creating any RAID. Adaptec RAID 5405 has one SFF-8087 connector and allows to connect up ... |
There is no possible to expose disk drives directly as block devices through Adaptec RAID controller. Almost all controllers from Adaptec don't support this feature - at least 5405, 5805 and, more general, a whole 3 and 5 series, though no information about 6 series of RAID controllers. Controller's BIOS doesn't allo... | SATA disk drive behind Adaptec RAID 5405 can't be detected as block device |
1,628,434,039,000 |
A question has been bugging my mind recently.
Since virtually all proprietary modules are out of tree (and therefore not compiled against any kernel versions), I'm wondering how exactly they are compiled and loaded.
Many major organizations allow for the download of a single .tar.gz, .deb or whatever and it just wor... |
The general approach is to ship an object file containing the proprietary code, and a “shim”, provided as source code, which is rebuilt for the appropriate kernels when necessary. The interface code handles all the module interface for the kernel, including symbol imports with version strings etc.
For example, NVIDIA ... | How do proprietary modules work for majority of kernel versions? |
1,628,434,039,000 |
How can I send dmesg printout to ftrace subsystem?
I like correlate the dmesg msg with the functions call graph in ftrace.
Thanks
|
Found it:
cd /sys/kernel/debug/
echo 1 > events/printk/enable
| How can I send dmesg printout to ftrace subsystem? |
1,628,434,039,000 |
I'm learning linux kernel debugging and dmesg is the tool that output kernel debug log:
...
[ 2.988000] Trace:
[ 2.988000] [<ffffffff80942810>] __warn+0x160/0x190
[ 2.988000] [<ffffffff8111ae9c>] dwc3_probe+0xc1c/0x1e60
[ 2.988000] [<ffffffff8111ae9c>] dwc3_probe+0xc1c/0x1e60
[ 2.988000] [<ffffffff80fe... |
From this Stack Overflow answer:
[10991.880408] EIP: 0060:[<c06969d4>] EFLAGS: 00210246 CPU: 0
[10991.880411] EIP is at iret_exc+0x7d0/0xa59
That gives you the faulting instruction pointer, both directly and in symbol+offset form. The part after the slash is the size of the function.
Assuming a similar format, ffff... | How to understand Trace from dmesg? |
1,628,434,039,000 |
This page says that RANDOMIZE_BASE is for KASLR and it randomizes the physical AND virtual addresses which is obvious in 32-bit and comprehensible in 64-bit.
But what does RANDOMIZE_MEMORY do exactly? This page says:
Randomizes the base virtual address of kernel memory sections (physical memory mapping, vmalloc & vme... |
RANDOMIZE_BASE is a feature available on most architectures which randomises the virtual and physical base address of the kernel.
RANDOMIZE_MEMORY is an x86-64-specific feature which additionally randomises the offsets of page_offset_base, vmalloc_base, vmemmap_base, i.e. the locations of the physical mapping in kerne... | Difference between CONFIG_RANDOMIZE_BASE and CONFIG_RANDOMIZE_MEMORY in Linux kernel config |
1,628,434,039,000 |
I'm encountering these errors when trying to compile a new kernel under Gentoo...
scripts/kconfig/conf --syncconfig Kconfig
DESCEND objtool
CC kernel/bounds.s
CC arch/x86/kernel/asm-offsets.s
GEN scripts/gdb/linux/constants.py
CALL scripts/checksyscalls.sh
CC [M] arch/x86/kvm/../../../v... |
According to bug 671650, elfutils-0.175 has problems with alignments.
Switching into linker ld.gold unveiled massive ammount of warnings about section alignments.
Try reverting to elfutils-0.173:
# emerge dev-libs/elfutils-0.173
And then rebuild your kernel.
sys-kernel/gentoo-sources-4.19.3 on my system builds and loa... | objdump : file format not recognized |
1,628,434,039,000 |
when doing
echo 1 > /sys/bus/pci/slots/[slot number]/power
will kernel change the value in some(or particular) register of PCIe configuration space of this device?
In my understanding, when a system ( PC ) power-on, the power already provide to PCIe devices, but kernel can still control some slot to be ON and OFF ( ... |
Here is my tracing ( let me know if I am wrong )
power_write_file()
https://elixir.bootlin.com/linux/v4.10/source/drivers/pci/hotplug/pci_hotplug_core.c#L95
slot->ops->disable_slot(slot);
ops->disable_slot = disable_slot;
https://elixir.bootlin.com/linux/v4.10/source/drivers/pci/hotplug/pciehp_core.c#L107
static int... | echo 1 > /sys/bus/pci/slots/[slot number]/power is changing value of PCIe configuration space register? |
1,628,434,039,000 |
I tried to install Fedora-Workstation-Live 28 from USB, at the start of the Installation as I choose [Start Fedora-Workstation-Live 28] I get the following error. Any solution?
[1.81660] ---[end Kernel] panic - not syncing: VFS: unable to mount root fs on unknown-block(0,0).
(Sys: Lenovo z51 70 - OS: Linux, Ubun... |
Solved. obviously the problem was from the USB so i tried to format the USB again with this command:
sudo dd if=/dev/zero of=/dev/sdb
then burning the .iso file on it. now it shows the installing page with no problem.
| Kernel panic while installing Fedora 28 |
1,628,434,039,000 |
I'm trying to capture what looks like a kernel error/stack trace when I run the command sudo zpool import. There error starts with:
[104.877657] BUG: unable to handle kernel paging request at 00000000ffff4167
...
I've tried simply redirecting stderr to a file with sudo zpool import &> err_file but that doesn't seem ... |
The error message isn't being written to the console by the zpool command. The kernel is writing the message. It's most likely being written to the console via syslog/rsyslog.
You might be able to find the error message by running dmesg which will print the kernel messages. dmesg > err_file
| Capturing kernel error/stack trace after running a command in bash |
1,628,434,039,000 |
I am continuously facing problems one after another, first I had this problem on Ubuntu I didn't got solution so I installed fedora and deleted Ubuntu. Now on booting I get this. After startup it shows error that:
BOOT_IMAGE=/boot/bmlinuz-4.14.13-300.fc27.x86_64 crashed,
in its description it shows that this is hardw... |
In your error message, that is a known ACPI firmware bug, that generates the error _SB.PCxxx and it affects several operating systems besides Linux. It affects FreeBSD and OpenBSD too, for instance.
Upgrade to the latest BIOS for your model from the Lenovo official site.
| ACPI exception: could not find/resolve named package element: AMD 3(dspkginit-381) |
1,628,434,039,000 |
THE SCENARIO
I'm writing a demo module to be inserted in Kernel and then write on system, for which I've already made entries in Header file and Table file.
PROCEDURE FOLLOWED SO FAR
I compiled the kernel using
/linux-4.12.9$ sudo make -j4
In which I got some warnings and NO ERROR. Unable to grab those warnings anyw... |
The issue was with supported libraries and packages I was using.
To compile the latest kernel at this time of writing, you must have these 4 Packages / Libraries installed:
libssl-dev
libncurses5-dev
qt4-default
qt4-dev-tools
Although I'm bit skeptical about qt4's dev-tools and default, since I've downloaded togethe... | aes-x86_64.ko No such file or directory for Module Installation failure after 4.12.9 Kernel compilation |
1,628,434,039,000 |
Supposedly I have a file that's distributed among different sectors. As an example, assuming both physical and logical sectors are 512B. A user process issues a request for the kernel to read the file. Let's say this file uses 3 distributed sectors on the hard drive.
1) Does the hard drive read all of the sectors at ... |
It depends. Modern kernels of Unix-like operating systems tend to have pretty complex code to make I/O faster. The best known feature is caching: if a sector has been read in the past, there may still be a copy in memory, in which case no request is sent to the hard drive at all. Other typical acceleration features in... | How does the kernel sends I/O requests to a hard drive? |
1,628,434,039,000 |
I am running Debian on QNAP ts-119P+. It is running well, but I am experiencing
something a little bit annoying. When I use lsblk, there is obviously sda, but also flash memory chips (mtdblockX), that contain firmware and I will never need to access them in the system. Is there some way to hide them? I tried to hide t... |
You can hide certain devices from being listed by lsblk with its -e (or --exclude) option as lsblk -e <major number>.
| Linux disable/hide mtdblock devices from lsblk |
1,628,434,039,000 |
I am learning operating systems. I have a doubt. For example if scheduling policy for some set of process(set 1) is SCHED_RR and scheduling policy for some other set of processes(set 2) is SCHED_FIFO .
Now when kernel has to pick some process from these 2 sets, which scheduling policy does Linux uses?
Is it possib... |
man sched
Conceptually, the scheduler maintains a list of runnable threads
for each possible sched_priority value. In order to determine
which thread runs next, the scheduler looks for the nonempty list
with the highest static priority and selects the thread at the
head of this list.
A thread'... | what is Linux global scheduling policy? |
1,628,434,039,000 |
I'm using a VPS from a VPS provider that run a 2.6 kernel, RHEL with OpenVZ virtualization system. I want to use ipset utility to manage ip sets on my iptables firewall.
This is the error I'm getting when creating an ipset:
mindaugas@517713:~$ sudo ipset create cf_ipv4 hash:net
ipset v6.20.1: Cannot open session to k... |
So, you're not really using a RHEL kernel (and the fact you used apt-get makes me wonder if it is RHEL at all), but an OpenVZ container. OpenVZ containers rely on features provided by the hosting system's kernel, which in this case doesn't support ipsets. There's nothing you can install in the container that will ma... | RHEL: can't use ipset utility with error: cannot open session to kernel |
1,628,434,039,000 |
I'm reading Robert Love's Linux Kernel Development in order to learn more about, well, Linux kernel development!
But in Chapter 2: Getting Started with the Kernel, I'm instructed to download and install the kernel. This confuses me. "Building the kernel is easy", he says. Yet the thought of installing a Linux kernel ... |
make install simply copies the kernel image to the /boot directory. make modules_install copies the modules to /lib/modules/kernel-version/. Most linux distributions these days boot using grub, so you need to run update-grub to notice the new kernel image in /boot, and add an entry to boot it to the grub configurati... | How do I run the Linux kernel? |
1,628,434,039,000 |
I am using openSUSE Tumbleweed. I've bought a new PCI-E Wireless card, that supports 5G WiFi (Intel 5100 AGN). It doesn't show up in lspci and even if I take old adapter out it still cannot see my new one. I have tried switching it off and on again in BIOS, but nothing helps. The driver must be installed according to... |
Your laptop has a BIOS whitelist and the Intel 5100 is not on it
I would recommend calling Lenovo and ordering an Intel wifi card with 5 Ghz from them that will work with the X220 as the option to update the BIOS with a version that eliminates the whitelist might render the laptop useless.
I found the maintenance manu... | Change Wireless adapter driver in Linux |
1,628,434,039,000 |
I'm doing some research that has to do with GPGPU resilience with NVIDIA graphics cards and I've been looking for a way to, as accurately as possible, simulate hardware failure. I know about cudaDeviceReset() and using intentionally failing asserts() within the kernel; correct me if I'm wrong but I don't think these a... |
You can manipulate some of the pci bus registers of the device fairly easily with setpci. Note: this is dangerous and may crash your system!
For example, find the pci bus and slot for your graphics board:
$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integ... | How to simulate GPU hardware failure? |
1,628,434,039,000 |
I am trying to understand linux syscalls mechanism. I am reading a book and it in the book it says that exit function look like that(with gdb):
mov $0x0,%ebx
mov $0x1,%eax
80 int $0x80
I understand that this is a syscall to exit, but in my Debian it looks like that:
jmp *0x8049698
push $0x8
jmp 0x80482c0
may... |
Your code's exit() call ends up getting linked to the C library (libc) function exit(), which may not actually do the int $0x80.
The call from your code's invocation of exit() function is actually compiled as call instruction into the Program Linkage Table, or PLT. The run-time dynamic linker takes care of mapping th... | Linux exit function |
1,628,434,039,000 |
Please read the full question before attempting to answer, this is a bit oddball of a situation.
I support a lot of server hardware test functionality, and essentially end up managing several internal Linux distributions, supporting various kernels (and, in a bit, CPU architectures as well). These servers are PXE/iPXE... |
Speaking about Debian-derived distributions:
They can differentiate multiple architectures within the same repository (including 32bit vs 64bit).
The kernel modules are stored in a kernel-specific tree /lib/modules/$(uname -r)/ so you could build a package that included a module for all your possible different kernel... | Managing Pre-Built Kernel Modules Across Kernel Versions |
1,628,434,039,000 |
I'm specifically asking about CONFIG_SND_MAX_CARDS in the kernel.
From the code using this config, for example in sound/usb/card.c for USB cards, soundcards are stored in plain arrays which are looped over.
Why does the kernel not use lists and have an unlimited number of soundcards?
I know unlimited is not possible ... |
In the good old times of ISA sound cards, it was not possible to create device nodes in /dev/ dynamically, so all devices had to be preallocated. This resulted in a limit of 8 sound cards, and the drivers were written with this limit in mind.
Later, when devfs and USB were introduced, this limit was removed. However, ... | Why does Linux have a maximum number of sound cards? [closed] |
1,628,434,039,000 |
I'm trying to use my new Wacom (CTL-490DW-S (Intuos DRAW)) drawing tablet with Linux Mint.
I have an PC with a clean install (due to me messing up so many times already!) of Linux Mint:
Linux Mint 17.3
Cinnamon 2.8.6 32-bit
Kernel 3.19.0-32-generic
The PC is a:
Intel Core 2 Quad Q8200 @ 2.33GHz x4
3.8GiB Memory
11... |
I was in the same boat. Was able to get the tablet recognized on Arch linux by installing linux-headers, and input-wacom-dkms from AUR which did the patching of the kernel. I'm not sure if it will work on Debian-based distros (Ubuntu/Mint) but there's a python script for input-wacom-dkms here. From what I've read the... | Linux Kernel - Wacom Tablet (CTL-490DW-S) - Lockout |
1,628,434,039,000 |
I am writing a stackable file system which requires some database file. I am thinking of taking it as mount time argument and then reading it's content into private field of superblock of mounted FS. Precisely I intend to do this:
mount -t wrapfs -o pattdb=database.db /some/mounted/point /mount/point
Here I'm having ... |
Mount time argument with -o option is received in raw_data field of wrapper file system's mount function.
struct dentry *wrapfs_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *raw_data)
This function is defined in main.c and for the case above, raw_data points to string patt... | passing file in mount options |
1,445,774,632,000 |
I have an iMac mid 2011 running OSX and I am trying to install Arch Linux following this guide. I successfully set up a dual boot last year following a similar procedure but now I can't even start since I get a kernel panic while booting from the live usb installation of archiso: right before the login prompt. I'm 100... |
I installed the linux-lts package as suggested by @mikeserv from chroot and I set it as the default boot option from the grub configuration.
This way I could boot nicely into linux 3.14 and complete the installation process. The vanilla linux kernel is installed alongside with the LTS version so using the "advanced op... | How to debug a kernel panic on boot with archiso? |
1,445,774,632,000 |
Is the whole kernel always loaded to RAM whatever the size of the RAM? In other words, can the Linux kernel be affected by paging (some part of kernel reside in virtual memory)?
|
No, (at least not that I am aware of any feature allowing for the kernel to load in swap) it makes use of the paging system (or swap) for LKM's and running processes.
The linux kernel is loaded into system memory. Depending on the size of the kernel (which would grow exponentially when used without loadable kernel mod... | Is the Linux kernel affected by paging? |
1,445,774,632,000 |
I am trying to compile a linux-sunxi kernel for my Banana pi.
Using this link: http://sunxi.org/Linux_Kernel#Compilation
Unfortunately I am getting the following message at the bottom when I am trying to compile the uImage and modules. (Step: make -j4 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- uImage modules)
Build... |
I ran into the same problem! After googling around for a good while, it finally turned out (in my case) that the kernel build toolchain is very picky about some env options, as pointed out here.
Here, in my ~/.bashrc I had export GREP_OPTIONS='--color=always' and that seems to be causing problem with the module script... | Compiling kernel but doesn't build kernel modules |
1,445,774,632,000 |
I am not asking how to shut down. I am asking how to cut of the power.
What is the function in Linux kernel code do the action of cutting of the power? And please explain the code.
|
The actual kernel code depends on the arch of your system. For x86 systems, they are located in arch/x86/kernel/reboot.c
Halt will stop the machine, and leave it in power-on state. So it just stops the kernel, but usually does not power it off.
static void native_machine_halt(void)
{
/* Stop other cpus and apics */
... | Which function in Linux kernel do the powering off action? |
1,445,774,632,000 |
I am writing a BASH script that automatically configures, builds and installs the most recent kernel image. The generated kernel should include the grsecurity patchset. It would use the previous configuration from /proc/config.gz, which I created manually when compiling the first custom kernel on the machine.
Is it sa... |
If you can't afford failure, test.
Even if you can afford failure, testing is good. If at all possible, run the build in a dedicated test environment. In many cases a virtual guest makes for an adequate test system. When you cab reboot into your updated kernel and any subsequent tests complete successfully too, only... | Automatized kernel upgrade |
1,445,774,632,000 |
Debian/Ubuntu: How to compile a Linux kernel on one machine and use on other machines (same architecture)?
I know how to do it on the same machine. But to use a compiled kernel other machines, is tricky for me.
For example,
I have done make
But how about sudo make modules_install install ?
This will install things to ... |
Since they're Debian machines, use make deb-pkg (instead of make, make install, etc.), which is part of the upstream kernel sources. That will generate a few Debian packages; you can scp those around and install with dpkg -i.
| Debian/Ubuntu:How to compile a Linux kernel on one machine and use on other machines (same architecture) |
1,445,774,632,000 |
I'm trying to debug the kernel. But I couldn't trigger kgdb with echo g > /proc/sysrq-trigger, it just prints help message.
I have enabled kernel debugging, kgdb over serial, frame pointer etc.
CONFIG_DEBUG_KERNEL=y
CONFIG_FRAME_POINTER=y
CONFIG_HAVE_ARCH_KGDB=y
CONFIG_KGDB=y
CONFIG_KGDB_SERIAL_CONSOLE=y
What could... |
Looks like setting kgdboc parameters in boot options worked, not sure why.
(I'm using libvirtd)
| sysrq-trigger doesn't accept parameter 'g' |
1,445,774,632,000 |
My external USB 3 hard drive is behaving very strangely:
If I plug it into a USB 2 port, it works fine
If I plug it into a USB 3 port, it doesn't work at all. It's not even mentioned in /var/log/messages.
If I plug a USB 2 device (memory stick) into the same USB 3 port, it works fine.
I think the USB 3 drive is ment... |
So after a lot of toying with this, it started to work, though for the life of me I can't figure out why. Here's a list of things I tried:
Didn't work
Rebooting
Unplugging and plugging it back in while the laptop is running
Booting up with it plugged in
Plugging it in post-boot up
Recompiling my kernel with the sam... | USB3 Hard Drive Not Recognised by Linux |
1,445,774,632,000 |
A "Linux debian 3.2.0-0.bpo.3-amd64 #1 SMP Thu Aug 23 07:41:30 UTC 2012 x86_64 GNU/Linux" system has at least 5 SCSI hosts:
root@debian:~# ls /sys/class/scsi_host
host0 host1 host2 host3 host4
root@debian:~# cat /sys/class/scsi_host/host0/proc_name
mpt2sas
root@debian:~# cat /sys/class/scsi_host/host1/proc_name... |
Since the large array is on a controller of a separate type (make and model, or rather: chipset), and nothing on it is needed for the system boot process, you can work around this by forcing a delayed controller initialization. The easiest way to do that is to simply blacklist the kernel module that does the kernel in... | How to skip/exclude one SCSI bus from scanning during boot? |
1,445,774,632,000 |
Is there a way to change the format of timestamp in kernel logs?
It was something like 2012-08-27T8:54:35.939421+03:00 now, I also checked sysctl -a | grep log, nothing found really.
|
No, see the kernel code in kernel/printk.c, it's hardcoded as:
sprintf(tbuf, "[%5lu.%06lu] ", (unsigned long) t, nanosec_rem / 1000)
All you can do is enable/disable that timestamp. You can have whatever reads /proc/kmsg (syslog, klog...) add the timestamp itself.
| Configure timestamp format of kernel log? |
1,445,774,632,000 |
I'm building the kernel (3.5) from /media/src_prog/linux-3.5/ to /media/sda5_k/. I've gone through the following steps:
make O=/media/sda5_k/ menuconfig
make -j2 O=/media/sda5_k/
make O=/media/sda5_k/ modules_install
And when it comes to make O=/media/sda5_k/ install all I get is:
[root@localhost linux-3.5]# make O=/... |
I haven't checked whether this still applies to 3.5, but I think the kernel makefiles only support Lilo, not Grub. Once you've manually copied the bzImage file, and the initrd or initramfs if you're using one, you need to inform Grub of the new kernel. With simple setups, it's just a matter of running update-grub. Sin... | stuck at "make install" |
1,445,774,632,000 |
Reference - http://www.linode.com/wiki/index.php/PV-GRUB#Building_Your_Own_Kernel
In order to work with Xen, a number of options that must be selected:
CONFIG_PARAVIRT_GUEST=y
CONFIG_XEN=y
CONFIG_PARAVIRT=y
CONFIG_PARAVIRT_CLOCK=y
CONFIG_XEN_BLKDEV_FRONTEND=y
CONFIG_XEN_NETDEV_FRONTEND=y
CONFIG_HVC_XEN=y
CONFIG_XEN_... |
The options in all caps are what gets written into the configuration file for the kernel you will be building (which make menuconfig generates).
There are two ways to edit it:
Open the file and change/add the entries
Browse to the relevant Xen options through the GUI, and guess their names from the all caps name. Yo... | Learning how to build my own linux kernel |
1,445,774,632,000 |
I am running Debian 6, and decided to install 2.6.38 kernel from Unstable. I also installed the headers so that I can later on :
sudo apt-get install --target-release=unstable linux-image-2.6.38-2-686-bigmem linux-headers-2.6.38-2-686-bigmem
I then re-installed virtualbox-ose-dkms to that the VirtualBox drivers for 2... |
autoconf.h moved from include/linux to include/generated in Linux 2.6.33. Authors of third-party modules must adapt their code; this has already been done upstream for VirtualBox. In the meantime, you can either patch the module source or create a symbolic link as a workaround.
As for the NMI-related errors, the NMI w... | I am failing to build VirtualBox driver for Linux 2.6.38 |
1,445,774,632,000 |
This is from here.
Extract the patch
tar -xvzf /usr/src/web100-2.5.22-200810130047.tar.gz
bzip2 web100/ web100-2.6.27-2.5.22-200810130047.patch
Test the patch
bzip2 -dc /usr/src/linux/web100/ web100-2.6.27-2.5.22-200810130047.patch.bz2 | patch -p1 --dry-run
I looked at the .patch, the diff output of many files and ... |
It's unneeded. Those instructions could be abbreviated to:
tar -xvzf /usr/src/web100-2.5.22-200810130047.tar.gz
patch -p1 --dry-run < web100/ web100-2.6.27-2.5.22-200810130047.patch
| Why is bzip2 needed in the kernel patch instructions? |
1,445,774,632,000 |
After an update/ upgrade on Debian 12 (weekly update), there is NO WiFi, files are not opening, unable to shutdown or sleep, and freezes when using sudo. The bug is fixed with a new release of kernel. But, I am NOT able to install the new kernel.
I downloaded the new kernel file to a flash drive using another laptop
... |
I got the trick from @Jaromanda X and details from u/Hendersen43 and
u/Only_Space7088 at:
https://www.reddit.com/r/debian/comments/18i60wx/networkmanager_service_freezes_the_whole_pc_after/
I am giving details to help newbees...:
I solved it by:
(1) Interrupting booting process, and changing the kernel back to the pre... | After an update (a kernel bug it seems) Debian 12 hangs when hitting sudo: Unable to install the new kernel with bug fixed |
1,445,774,632,000 |
XEN has support for ARM and it is also possible to run it on a cpu without VHE (virtual hardware extension) cap that was introduced with ARMV8.1-A extension. As I understand linux kernel of a guest vm communicates with xen hypervisor over HVC calls. HVC call is a hardware feature, as I think only available in VHE enab... |
Xen on Arm normally uses the virtualization extensions which have been present on high-end ARMv7 chips since around 2010, and are a non-optional part of ARMv8. Arm virtualization adds an extra privilege level, the hypervisor, which has its own memory virtualization. The relationship between system and hypervisor is ve... | How does XEN work without VHE on ARM? |
1,445,774,632,000 |
So I've compiled my kernel and initrd. How can I then create an image and install grub to actually load this image from a disk? My goal isn't to create a livecd out of it that is bootable from USB, as there are plenty of articles on that. My goal is to create an image (I know dd if=/dev/zero of=linux.img ... is what I... |
512 bytes is far too little for GRUB: on a classic BIOS-booting MBR-partitioned disk, GRUB also places parts of itself in the normally-unused blocks #1..#2047, as modern OSs place the start of the first partition exactly 1 MiB from the beginning of the disk, at block #2048. Typically it might use about 100 of those bl... | Create custom bootable linux image; not a livecd |
1,445,774,632,000 |
I am currently working on an embedded board with a WM8776 which uses the MCASP1 of the AM335x. This works as expected and has expected behaviour.
What I now want to do is make a driver which can switch frequencies. I have two clocks which go in into the MCASP via a clock mux via a GPIO. If this GPIO is high I have an ... |
Ok two things: between the application playing back a stream of PCM samples and the kernel side of ALSA, there's the userland alsalib with its optional internal resampling. If the application did not disable that but requested a device as is, the kernel had no way of knowing what the original sapling rate was. It's si... | Change clock bitrate (ALSA, PCM) at runtime AM335x |
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