How to build only usb-storage.ko? - linux-kernel

How can I build usb-storage.ko module for a running kernel distro (ubuntu)
thanks for your response.

You need the kernel source and kernel configuration (just as for compiling the complete kernel).
To build only a single file, tell make about it:
make drivers/usb/storage/usb-storage.ko

Related

Building a Linux kernel using Travis CI

How can I build a Linux kernel in Travis CI. I have added script: make menuconfig to my Travis config and it doesn't work and says
No output has been received in the last 10 minutes
How can I fix this?
Link to GitHub repo : https://github.com/ProjectPolyester/tegra_kernel and submit fixes in PRs if possible
Travis monitors your build process and if there is no output for about 10 minutes, it assumes that your process is stuck somewhere for unknown reasons, and then kills it.
Solution in your case :
You need to provide with the actual build command.
make menuconfig
actually just allows you to configure the kernel. It doesn't really starts the kernel build process. So there is no output of this command.
Also, the kernel should already be configured or you can download the appropriate .config file if its available some where online. And then there will be no need to execute:
make menuconfig
The build command
It can be simply
make
or something like
make -j3 modules ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- LOCALVERSION=-$SOURCE_VERSION
The second one is actually to perform cross compilation.
You also need to set all the prerequisites like downloading the header file etc
You may want to take a look at this script , it crosscompiles the modules only, not the entire kernel.
If you want to use the old config for a new kernel, you can use make olddefconfig. Here is my example how to compile and boot a new kernel in travis: https://github.com/avagin/criu/blob/linux-next/scripts/travis/kexec.sh#L54
I know that this is an old thread but I was recently able to get Travis CI working on building a Linux kernel
https://github.com/GlassROM-devices/android_kernel_oneplus_msm8994/commit/6ed484812bbd4a25c3b22e730b7489eaaf668da1
GCC fix is for toolchains compiled on Debian unstable, arch, gentoo, etc. These toolchains will fail to compile on Ubuntu so you'll have to use the GCC fix for these toolchains
And you really want to upgrade GCC before you even try building a kernel. Travis CI has a very old GCC that will fail if you try to compile the kernel
In my commit I'm building it with GCC 8 linaro built by myself

how to build linux kernel in OpenWrt distribution

I make a modification in linux kernel of OpenWrt and then I compile the new (kernel) with command :
make target/linux/compile V=99
but I don't found the new image under
build_dir\linux-x86_generic\linux-3.3.8
in order to upgrade the kernel in my OpenWrt running in VM VirtuaBox
how to proceed to get the new kernel and upgrade the Openwrt ?
I am a bit puzzled by the fact you are looking at the linux-x86 folder since with openWRT you usually cross-compile everytime, or at least I've never used it for not cross compilations.
What are you compiling for ?
You should see a build/$TARGET folder with a linux-x-x directory in it where the linux kernel was compiled.

compile simple hello-world c program for mips netbsd

the last week I have been trying to set-up a compiler which can compile to netbsd with mips architecture.
I cannot find anything on the internet how to do this. All documents refer to compiling the kernel to the architecture but not programs.
How can this be so hard....
host is netbsd amd64 machine
Set the compiler appropriately. Point it at the version of gcc in your TOOLDIR. In this case, something like mips--netbsd-gcc. Definitely make sure TOOLDIR is on your path, so the driver can find the proper assembler, proper loader, and proper libraries.
Take a look at the Makefile in any of src/bin/* as an example, and read through the system mk include files referenced (in src/share/mk)
Generally speaking, the goal is to have a working cross-compiler and a filesystem root for the target, all installed on your development machine. The target root is needed since you need all sorts of libraries to build userland applications. Those libraries need to be compiled for the target, not for the host.
Assuming you build everything from source, it goes as follows:
Choose a prefix for the toolchain (say /opt/mips) and another prefix for the root filesystem of the target (say /opt/target). All of those are on your development machine, not on the target!
Configure, build and install the cross-compiler for your target. This goes into the toolchain prefix.
Configure, build and install the kernel for your target, into the target root prefix. This should install the necessary kernel development headers needed later. If you can install such headers without compiling the kernel, more power to you, of course.
Configure, build and install the C library (say glibc) for your target, into the target root.
Configure, build and install whatever other libraries your userland application needs - into the target root.
Finally, configure, build and install the userland application. Once installed into the target root, you can copy it over to the target into the same prefix (say /opt/target as suggested before).
Generally to install into a different prefix - one that overlaps stuff on your build host (like /usr) - you'd need to do some tricks to fool make install into seeing the target prefix instead of your own. A simple approach would be to have a chroot environment on your build host, where you can bind-mount the prefix (say /usr) read-only, with a writable (mount_union) overlay on top of it.
When you build stuff for the target, you need to pass proper arguments to configure, of course.

Compile C file on openwrt

I have built the openwrt firmware and installed it to a device.
Now I want to compile my source code in C in the device (I can ssh into it).
However, openwrt firmware is quite basic and does not include make.
How can I install make/ equivalent to compile my C source code inside the device running openwrt firmware?
OpenWrt is not intended to work as a build server, so you won't find compiler, linker etc. in its root file system. As you mentioned before, you've successfully compiled the firmware. That means you have cross compiler at hand, so you can cross compile your software and then copy it to your system via scp.
Another approach would be to create your own feed, add your software to this feed, so that at the end you'll get an ordinary ipkg package, that you can download and install via web interface. See OpenWrt documentation for more details.
Lots of Cross Compiler are available for host system i.e PC running any Linux OS.
Just install compiler corresponding to Architecture in which Openwrt is running,
e.g If OpenWRT running on ARM architecture,
sudo apt-get install gcc-arm-linux-gnueabi
then compile source code as:
arm-linux-gcc -o yourprogram yourprogram.c

How to extract kernel headers for compiling kernel module later

I compiled various Linux kernel from git repositories. There are times when I copied the kernel to other system and need the kernel header to compile external module.
I tried to run "make headers_install" but it only generated a include/ folder. When I tried to point external module to that folder, it complains it cannot find Makefile.
What is the proper way to package kernel-header for deployment?
Thanks.
Create kernel packages instead, that's "make deb-pkg" for dpkg based distros and "make rpm-pkg" for RPM based ones. These create multiple packages, one of those is a package usable for external modules building. That should be linux-headers-* for the Debian packages and a "devel" package for he RPM versions.
In some ways this is just an expansion of the previous answer. If you look at the file scripts/package/builddeb in the kernel sources you will find script code which selects the files needed for building external modules from a kernel build and puts them into /usr/src/linux-headers-$version. I can find that script code in my local kernel version by searching for the string "# Build kernel header package" in the builddeb file. If you want to do things by hand you could execute that script code manually.

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