[FE training-materials-updates] slides/buildroot: move the section about patches, and improve it
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Fri May 22 13:47:59 CEST 2015
Repository : git://git.free-electrons.com/training-materials.git
On branch : master
Link : http://git.free-electrons.com/training-materials/commit/?id=5b9aa92931518416440c1e4f5f18c75b96d39ebc
>---------------------------------------------------------------
commit 5b9aa92931518416440c1e4f5f18c75b96d39ebc
Author: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Date: Fri May 22 13:47:25 2015 +0200
slides/buildroot: move the section about patches, and improve it
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
>---------------------------------------------------------------
5b9aa92931518416440c1e4f5f18c75b96d39ebc
.../buildroot-advanced-packages.tex | 204 +++++++++++++++++++++
slides/buildroot-advanced/buildroot-advanced.tex | 65 -------
2 files changed, 204 insertions(+), 65 deletions(-)
diff --git a/slides/buildroot-advanced-packages/buildroot-advanced-packages.tex b/slides/buildroot-advanced-packages/buildroot-advanced-packages.tex
index 5063077..d08577c 100644
--- a/slides/buildroot-advanced-packages/buildroot-advanced-packages.tex
+++ b/slides/buildroot-advanced-packages/buildroot-advanced-packages.tex
@@ -100,6 +100,210 @@ OWL_LINUX_REDISTRIBUTE = NO
\end{frame}
+\subsection{Patching packages}
+
+\begin{frame}{Patching packages: why?}
+ \begin{itemize}
+ \item In some situations, it might be needed to patch the source
+ code of certain packages built by Buildroot.
+ \item Useful to:
+ \begin{itemize}
+ \item Fix cross-compilation issues
+ \item Backport bug or security fixes from upstream
+ \item Integrate new features or fixes not available upstream, or
+ that are too specific to the product being made
+ \end{itemize}
+ \item Patches are automatically applied by Buildroot, during the
+ {\em patch} step, i.e after extracting the package, but before
+ configuring it.
+ \item Buildroot already comes with a number of patches for various
+ packages, but you may need to add more for your own packages, or
+ to existing packages.
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Patch application ordering}
+ \begin{itemize}
+ \item Overall the patches are applied in this order:
+ \begin{enumerate}
+ \item Patches mentionned in the \code{<pkg>_PATCH} variable of the
+ package \code{.mk} file. They are automatically downloaded
+ before being applied.
+ \item Patches present in the package directory
+ \code{package/<pkg>/*.patch}
+ \item Patches present in the {\em global patch directories}
+ \end{enumerate}
+ \item In each case, they are applied:
+ \begin{itemize}
+ \item In the order specified in a \code{series} file, if available
+ \item Otherwise, in alphabetic ordering
+ \end{itemize}
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{Patch conventions}
+ \begin{itemize}
+ \item There are a few conventions and best practices that the
+ Buildroot project encourages to use when managing patches
+ \item Their name should start with a sequence number that
+ indicates the ordering in which they should be applied.
+ \begin{block}{ls package/nginx/*.patch}
+ {\scriptsize
+\begin{verbatim}
+0001-auto-type-sizeof-rework-autotest-to-be-cross-compila.patch
+0002-auto-feature-add-mechanism-allowing-to-force-feature.patch
+0003-auto-set-ngx_feature_run_force_result-for-each-featu.patch
+0004-auto-lib-libxslt-conf-allow-to-override-ngx_feature_.patch
+0005-auto-unix-make-sys_nerr-guessing-cross-friendly.patch
+\end{verbatim}}
+ \end{block}
+ \item Each patch should contain a description of what the patch
+ does, and if possible its upstream status.
+ \item Each patch should contain a \code{Signed-off-by} that
+ identifies the author of the patch.
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{Patch example}
+
+\begin{block}{}
+{\tiny
+\begin{verbatim}
+From 81289d1d1adaf5a767a4b4d1309c286468cfd37f Mon Sep 17 00:00:00 2001
+From: Samuel Martin <s.martin49 at gmail.com>
+Date: Thu, 24 Apr 2014 23:27:32 +0200
+Subject: [PATCH 1/5] auto/type/sizeof: rework autotest to be cross-compilation
+ friendly
+
+Rework the sizeof test to do the checks at compile time instead of at
+runtime. This way, it does not break when cross-compiling for a
+different CPU architecture.
+
+Signed-off-by: Samuel Martin <s.martin49 at gmail.com>
+---
+ auto/types/sizeof | 42 ++++++++++++++++++++++++++++--------------
+ 1 file changed, 28 insertions(+), 14 deletions(-)
+
+diff --git a/auto/types/sizeof b/auto/types/sizeof
+index 9215a54..c2c3ede 100644
+--- a/auto/types/sizeof
++++ b/auto/types/sizeof
+@@ -14,7 +14,7 @@ END
+
+ ngx_size=
+
+-cat << END > $NGX_AUTOTEST.c
++cat << _EOF > $NGX_AUTOTEST.c
+[...]
+\end{verbatim}}
+\end{block}
+
+\end{frame}
+
+\begin{frame}{Global patch directories}
+ \begin{itemize}
+ \item You can include patches for the different packages in their
+ package directory, \code{package/<pkg>/}.
+ \item However, doing this involves changing the Buildroot sources
+ themselves, which may not be appropriate for some highly specific
+ patches.
+ \item The {\em global patch directories} mechanism allows to specify
+ additional locations where Buildroot will look for patches to
+ apply on packages.
+ \item \code{BR2_GLOBAL_PATCH_DIR} specifies a space-separated list
+ of directories containing patches.
+ \item These directories must contain sub-directories named after the
+ packages, themselves containing the patches to be applied.
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{Global patch directory example}
+
+\begin{block}{Patching {\em strace}}
+{\tiny
+\begin{verbatim}
+$ ls package/strace/*.patch
+0001-linux-aarch64-add-missing-header.patch
+
+$ find ~/patches/
+~/patches/
+~/patches/strace/
+~/patches/strace/0001-Demo-strace-change.patch
+
+$ grep ^BR2_GLOBAL_PATCH_DIR .config
+BR2_GLOBAL_PATCH_DIR="$(HOME)/patches"
+
+$ make strace
+[...]
+>>> strace 4.10 Patching
+
+Applying 0001-linux-aarch64-add-missing-header.patch using patch:
+patching file linux/aarch64/arch_regs.h
+
+Applying 0001-Demo-strace-change.patch using patch:
+patching file README
+[...]
+\end{verbatim}}
+\end{block}
+
+\end{frame}
+
+\begin{frame}{Generating patches}
+ \begin{itemize}
+ \item To generate the patches against a given package source code,
+ there are typically two possibilities.
+ \item Use the upstream version control system, often {\em Git}
+ \item Use a tool called \code{quilt}
+ \begin{itemize}
+ \item Useful when there is no version control system provided by
+ the upstream project
+ \item \url{http://savannah.nongnu.org/projects/quilt}
+ \end{itemize}
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Generating patches: with Git}
+
+ Needs to be done outside of Buildroot: you cannot use the Buildroot
+ package build directory.
+
+ \begin{enumerate}
+ \item Clone the upstream Git repository\\
+ \code{git clone git://...}
+ \item Create a branch starting on the tag marking the stable
+ release of the software as packaged in Buildroot\\
+ \code{git checkout -b buildroot-changes v3.2}
+ \item Import existing Buildroot patches (if any)\\
+ \code{git am /path/to/buildroot/package/<foo>/*.patch}
+ \item Make your changes and commit them\\
+ \code{git commit -s -m ``this is a change''}
+ \item Generate the patches\\
+ \code{git format-patch v3.2}
+ \end{enumerate}
+
+\end{frame}
+
+\begin{frame}{Generating patches: with Quilt}
+
+ \begin{enumerate}
+ \item Extract the package source code:
+ \code{tar xf /path/to/dl/<foo>-<version>.tar.gz>}
+ \item Inside the package source code, reate a directory for patches\\
+ \code{mkdir patches}
+ \item Import existing Buildroot patches\\
+ \code{quilt import /path/to/buildroot/package/<foo>/*.patch}
+ \item Apply existing Buildroot patches\\
+ \code{quilt push -a}
+ \item Create a new patch\\
+ \code{quilt new 0001-fix-header-inclusion.patch}
+ \item Edit a file\\
+ \code{quilt edit main.c}
+ \item Refresh the patch\\
+ \code{quilt refresh}
+ \end{enumerate}
+
+\end{frame}
+
\subsection{User, permission and device tables}
\begin{frame}[fragile]{Package-specific users}
diff --git a/slides/buildroot-advanced/buildroot-advanced.tex b/slides/buildroot-advanced/buildroot-advanced.tex
index 7162846..88a6ad4 100644
--- a/slides/buildroot-advanced/buildroot-advanced.tex
+++ b/slides/buildroot-advanced/buildroot-advanced.tex
@@ -1,70 +1,5 @@
\section{Advanced topics}
-\begin{frame}{Global patch directories}
- \begin{itemize}
- \item You can include patches for the different packages in their
- package directory, \code{package/<pkg>/}.
- \item However, doing this involves changing the Buildroot sources
- themselves, which may not be appropriate for some highly specific
- patches.
- \item The {\em global patch directories} mechanism allows to specify
- additional locations where Buildroot will look for patches to
- apply on packages.
- \item \code{BR2_GLOBAL_PATCH_DIR} specifies a space-separated list
- of directories containing patches.
- \item These directories must contain sub-directories named after the
- packages, themselves containing the patches to be applied.
- \end{itemize}
-\end{frame}
-
-\begin{frame}{Patch application ordering}
- \begin{itemize}
- \item Overall the patches are applied in this order:
- \begin{enumerate}
- \item Patches mentionned in the package \code{<pkg>_PATCH} variable
- \item Patches present in the package directory
- \code{package/<pkg>/*.patch}
- \item Patches present in the global patch directories
- \end{enumerate}
- \item In each case, they are applied:
- \begin{itemize}
- \item In the order specified in a \code{series} file, if available
- \item Otherwise, in alphabetic ordering
- \end{itemize}
- \end{itemize}
-\end{frame}
-
-\begin{frame}[fragile]{Global patch directory example}
-
-\begin{block}{Patching {\em strace}}
-{\tiny
-\begin{verbatim}
-$ ls package/strace/*.patch
-0001-linux-aarch64-add-missing-header.patch
-
-$ find ~/patches/
-~/patches/
-~/patches/strace/
-~/patches/strace/0001-Demo-strace-change.patch
-
-$ grep ^BR2_GLOBAL_PATCH_DIR .config
-BR2_GLOBAL_PATCH_DIR="$(HOME)/patches"
-
-$ make strace
-[...]
->>> strace 4.10 Patching
-
-Applying 0001-linux-aarch64-add-missing-header.patch using patch:
-patching file linux/aarch64/arch_regs.h
-
-Applying 0001-Demo-strace-change.patch using patch:
-patching file README
-[...]
-\end{verbatim}}
-\end{block}
-
-\end{frame}
-
\begin{frame}{{\tt BR2\_EXTERNAL}}
\begin{itemize}
\item Storing your custom packages, custom configuration files and
More information about the training-materials-updates
mailing list