Compiling Linux Buildroot overrides local changes - linux

I am working to enable the kexec support in my propriety Linux distribution and I would like to debug the kexec tools in user space. I am adding debug prints in the kexec.c that's located in buildroot/output/build/kexec-2.0.15/kexec/kexec.c, but if I do an incremental build with make, it doesn't look like the kexec binary has been updated. If I rebuild everything from scratch with make all, the source code kexec.c has been overridden and I don't see my changes. My guess is that every full build re-extracts the kexec package and that is why my changes are not taking affect.
How do I solve this issue?

Try to use "make kexec-rebuild".

If you only want to restart the build process of a package from its
compilation step, you can run make <package>-rebuild [...]. It will restart the compilation and installation of
the package, but not from scratch: it basically re-executes make and
make install inside the package, so it will only rebuild files that
changed.
[...]
Internally, Buildroot creates so-called stamp files to keep track of
which build steps have been completed for each package. They are
stored in the package build directory,
output/build/-/ and are named .stamp_.
The commands detailed above simply manipulate these stamp files to
force Buildroot to restart a specific set of steps of a package build
process.
(from the Buildroot manual, section Understanding how to rebuild packages -- I suggest you read the whole section)
Also, look at your build log. If you don't see a line like
>>> kexec 2.0.16 Building
then the kecxec package hasn't been (re)built.

Related

Buildroot made change on the Linux Kernel, how to avoid full rebuild?

I’m experimenting with linux-kernel/net/ipv4/igmp.c. To compile I use buildroot. When I make a change on igmp.c, is a full rebuid necessary?
The easiest way to rebuild a single package from scratch is to remove its build directory in output/build. Buildroot will then re-extract, re-configure, re-compile and re-install this package from scratch. You can ask buildroot to do this with the make -dirclean command.
https://buildroot.org/downloads/manual/manual.html#rebuild-pkg
The documentation talks only about packages, but I think it doesn’t include changes on the kernel itself? How can I avoid a full rebuild?
Probably the simplest way to force a rebuild of the Linux package (or any other package) is to remove the .stamp_built file in the output/build/linux-version directory. After that just make again and it will be rebuilt and installed.
In my case :
rm output/build/linux-v4.19.253/.stamp_built
make
Linux is treated like any other package and you can rebuild it with:
$ make linux-rebuild
This is true for all packages.
-rebuild make recipe suffix means something like:
$ make all
in the build/linux/ package directory.
So if you change a file and issue that command only that file or its dependencies is built again.
Another useful recipe suffix is -menuconfig that is also available for u-boot (-rebuild too).

Installing Node in a linux grid server

So some background, I'm installing Node on a host server, but it's a grid server not a server that's solely for my website.
The grid server doesn't have a root user/ administrative powers. So to install node I found this workaround: http://iantearle.com/blog/media-temple-grid-and-nodejs . It's a Linux Grid server, I've never used Linux so if someone could explain to me what the commands mean, especially: ./configure --prefix=~/opt/
Lastly I followed the steps but when I try to run the node command in the server it says node:command not found - which is why I'm trying to understand the steps. Thanks
To explain the process:
Configure
The configure script is responsible for getting ready to build the software on your specific system. It makes sure all of the dependencies for the rest of the build and install process are available, and finds out whatever it needs to know to use those dependencies.
Unix programs are often written in C, so we’ll usually need a C compiler to build them. In these cases the configure script will establish that your system does indeed have a C compiler, and find out what it’s called and where to find it.
Make
Once configure has done its job, we can invoke make to build the software. This runs a series of tasks defined in a Makefile to build the finished program from its source code.
The tarball you download usually doesn’t include a finished Makefile. Instead it comes with a template called Makefile.in and the configure script produces a customised Makefile specific to your system.
3.Make Install
Now that the software is built and ready to run, the files can be copied to their final destinations. The make install command will copy the built program, and its libraries and documentation, to the correct locations.
--prefix=~/opt/ -> will set the build directory to /home/yourhome/opt directory.
Now if you didnt get errors while doing those 3 steps explained above make sure you did the following:
nano ~/.bash_profile
export PATH=~/opt/bin:${PATH}
nano is a text editor and you are opening .bash_profile file with it.
you need to add export PATH=~/opt/bin:${PATH} in that file and save it using ctrl+x
Then restart your terminal.
Specified github repository for nodejs is outdated. use the following link instead.
git clone https://github.com/nodejs/node.git
P.S node:command not found usually happens when the program is not installed correctly or it's executable isnt in your terminal's PATH variable.

Workflow for compiling and installing software with Puppet

I need to manually compile and install FFMPEG as one of my dependencies using Puppet manifests. I want to do this myself to customize the configuration of FFMPEG to the needs of my project.
I'm not sure as to how to structure the entire process with classes. The logic should go something like this:
If /usr/local/bin/ffmpeg doesn't exist, compile:
Install build dependencies from apt-get.
Create a directory for the library sources /tmp/ffmpeg
Download and compile the Yasm assembler
Download.
Extract.
Configure
Make
Make Install
Download and compile x264
Clone the source.
Configure.
Make
Make Install
Download and compile fdk-aac:
...
....
I can easily branch all of these out into their own modules and declare them as dependencies of FFMPEG, that's not the problem.
My main problem is understanding how to do the whole download/extract/compile process for each module only if it's not already present on the system.
How do I structure my classes to only act if the software is not already installed?
Regardless of how you go about it, you need a way to check whether your custom installation has been installed.
Common methods include
checking a file and running a command only if it is not present: http://docs.puppetlabs.com/references/latest/type.html#exec-attribute-creates
running a command only if another command returns 0: http://docs.puppetlabs.com/references/latest/type.html#exec-attribute-onlyif (alternatively, the unless attribute)

How to to build src from a CygPort?

I have a question about the structure of the source code from a cygport package.
Here is the contents of a Cygports source file:
the actual source bundle for the project (tar.gz, tar.bz2, etc.)
the any number of *.patch files.
a .cygport file
I am trying to build gedit-3.4.2 from cygports repository.
How does the .cygport file help me run the proper options in the ./configure ?
For instance, in gedit if i don't specify --disable-spell it won't proceed due to error. How do I get the list of ./configure options that were used to build the project when the cygport was built?
Is there some way we can use the cygport executable to build the cygport and change the prefix too?
Here is the contents of gedit-3.4.2-1.cygport:
inherit python gnome2
DESCRIPTION="GNOME text editor"
PATCH_URI="3.4.2-cygwin.patch"
DEPEND="gnome-common gtk-doc
girepository(Gtk-3.0)
pkgconfig(enchant)
pkgconfig(gtksourceview-3.0)
pkgconfig(libpeas-gtk-1.0)"
PKG_NAMES="${PN} ${PN}-devel"
PKG_HINTS="setup devel"
gedit_CONTENTS="--exclude=gtk-doc --exclude=libgedit* etc/ usr/bin/ usr/lib/gedit/ ${PYTHON_SITELIB#/} usr/share/"
gedit_devel_CONTENTS="usr/include/ usr/lib/gedit/libgedit* usr/lib/pkgconfig/ usr/share/gtk-doc/"
DIFF_EXCLUDES="*.desktop.in *.schemas.in *-marshal.h"
CYGCONF_ARGS="--libexecdir=/usr/lib --enable-python"
KEEP_LA_FILES="none"
EDIT Someone from Cygwin Ports mailing list said:
"The configure options are
--libexecdir=/usr/lib --enable-python
Which is from CYGCONF_ARGS."
Here is the contents of a Cygports source file:
You'd do better to think of it as a Cygwin package source file.
cygport is simply a tool for automating the creation of Cygwin binary and source packages. It is the primary tool available, but unlike with some other packaging systems, there's really nothing forcing you to use it. It is quite possible to build a Cygwin package entirely by hand, since it is really nothing more than a tarball that Cygwin's setup.exe can blindly unpack into the Cygwin root directory (typically c:\cygwin) with the expectation that this will put the package's files in sensible locations.
Before cygport existed, people did build their own ad hoc packaging systems. Many Cygwin package maintainers still use these tools they created. (Yours truly included; two of my three packages use cygport, but the third still uses a custom build system.)
Ultimately, you want to read the cygport manual, in /usr/share/doc/cygport/manual.html.
(Yes, I know, "RTFM" answers are frowned on here. But, as one who currently maintains two cygport based packages in the official Cygwin package repository, please believe me when I tell you that the manual is still the single best resource available on this topic.)
How does the .cygport file help me run the proper options in the ./configure ?
As you found out through other resources, you'd first need to edit the CYGCONF_ARGS value in the .cygport file.
The simplest possible step after that is cygport gedit-3.4.2-1.cygport all. That attempts to rebuild all the binary packages in a single step. It also builds a new source package containing updated .cygport and patch files.
If something breaks in the all build process, it is usually faster to switch to using the sub-commands contained by all instead of completely restarting the process. The all step just runs prep, compile, install, package, and finish for you, in that order. For instance, if all fails during the compilation step, there's probably no need to repeat the prep step.
(It is exceptionally uncommon for cygport or a sane build system to wreck the build tree, forcing you to re-run prep. Far more commonly, you end up needing to re-do prep when you manually wreck the build tree while trying to get a new package to build for the first time and need to start over.)
For instance, in gedit if i don't specify --disable-spell it won't proceed due to error.
You can probably fix that by installing the libaspell-devel package from the official Cygwin package repository with setup.exe.
Personally, I wouldn't disable any feature unless it meant installing unofficial packages, such as those from the Cygwin Ports project.[*] It is nice to have Cygwin Ports repository, but because it contains so many packages, installing one can end up creating an "install the world" situation: package A depends on packages B, C and D, and C depends on E, F, G, H, and G depends on I, J, K, and... Dependency hierarchies within the Cygwin package repo tend to be flatter and narrower than those in the Cygports repo.
Is there some way we can use the cygport executable to build the cygport and change the prefix too?
You have guessed that you just add --prefix=/my/private/program/tree to CYGCONF_ARGS, I trust.
[*] If you are feeling confused about "Cygwin Ports" and cygport, the naming similarity is no coincidence. cygport is a tool created by Yaakov Selkowitz for himself when creating the Cygwin Ports package repository. Later, it became popular enough among other Cygwin package maintainers that it pushed out most of the competing build systems.

Building rpm, overriding _topdir, but getting BuildRequires deps?

I have a libfoo-devel rpm that I can create, using the trick to override _topdir. Now I want to build a package "bar" which has a BuildRequires 'libfoo-devel". I can't seem to find the Right Way to get access to the contents of libfoo-devel without having to install it on the build host. How should I be doing it?
EDIT:
My build and target distros are both SuSE.
I prefer solutions that don't require mock, since I believe SuSE does not include it in its stock repo.
Subsequent EDIT:
I believe that the answer I seek is in the build package. Perhaps it's SuSE's answer to mock? Or it's the distributed version of the oBS service?
DESCRIPTION
build is a tool to build SuSE Linux
RPMs in a safe and clean way. build
will install a minimal SuSE Linux as
build system into some directory and
will chroot to this system to compile
the package. This way you don't risk
to corrupt your working system (due to
a broken spec file for example), even
if the package does not use BuildRoot.
build searches the spec file for a
BuildRequires: line; if such a line is
found, all the specified rpms are
installed. Otherwise a selection of
default packages are used. Note that
build doesn't automatically resolve
missing dependencies, so the specified
rpms have to be sufficient for the
build.
Note that if you really don't need libfoo-devel installed to build package bar the most sensible alternative would be to remove libfoo-devel from the BuildRequires directive (and maybe put the requirement where it belongs).
However, if you cannot do that for some reason, create a "development" rpm database. Basically it involves using rpm --initdb --root /path/to/fake/root. Then populate it with all of the "target packages" of your standard distro installation.
That's a lot of rpm --install --root /path/to/fake/root --justdb package-name.rpm commands, but maybe you can figure out a way to copy over your /var/lib/rpm/* database files and use those as a starting point. Once you have the alternative rpm database, you can fake the installation of the libfoo-devel package with a --justdb option. Then you'll be home free on the actual rpm build.
If neither mock nor the openSUSE Build Service are a viable choice then you will have to buckle down and install the package, either directly or in a chroot; the package provides files that the SRPM packager has decided are required to build, and hence is in the BuildRequires tag.

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