136 lines
3.9 KiB
TeX
136 lines
3.9 KiB
TeX
|
|
\begin{frame}
|
|
\frametitle{Relocatable binaries and resources}
|
|
|
|
\begin{center}
|
|
\huge Making packages relocatable
|
|
\end{center}
|
|
\end{frame}
|
|
|
|
|
|
% --------------------------------------------------------------------
|
|
|
|
\begin{frame}[containsverbatim]
|
|
\frametitle{rpath}
|
|
|
|
Runtime search path - embedded in the binaries
|
|
|
|
\vspace{1em}
|
|
|
|
\includegraphics[width=.95\textwidth,keepaspectratio]{images/so_rpath.png}
|
|
|
|
\vspace{1em}
|
|
|
|
\includegraphics[width=.95\textwidth,keepaspectratio]{images/dylib_rpath.png}
|
|
\end{frame}
|
|
|
|
% --------------------------------------------------------------------
|
|
|
|
\begin{frame}[containsverbatim]
|
|
\frametitle{rpath}
|
|
|
|
Used by the Dynamic Linker (DL) on UNIX systems
|
|
|
|
\begin{itemize}
|
|
\item rpath - almost the first place to look for the libraries,
|
|
\newline nowadays {\code{DT\_RUNPATH}} is more common than
|
|
{\code{DT\_RPATH}} as a tag
|
|
\item Search path sequence for DL -
|
|
{\code{RPATH, LD\_LIBRARY\_PATH, RUNPATH, /etc/ld.so.conf, /lib/,
|
|
/usr/lib}, …}
|
|
\end{itemize}
|
|
\end{frame}
|
|
|
|
% --------------------------------------------------------------------
|
|
|
|
\begin{frame}[containsverbatim]
|
|
\frametitle{rpath}
|
|
|
|
\begin{itemize}
|
|
\item Can be overwritten - {\code {chrpath, patchelf}}
|
|
\item Can be extracted - {\code {objdump, readelf, otool, etc.}}
|
|
\end{itemize}
|
|
|
|
\begin{codebox}{Shell}{}
|
|
$ objdump -x <path-to-library> | grep RPATH
|
|
$ readelf -d <path-to-library> | grep RPATH
|
|
$ otool -L <path-to-library>
|
|
\end{codebox}
|
|
|
|
\end{frame}
|
|
|
|
% --------------------------------------------------------------------
|
|
|
|
\begin{frame}
|
|
\frametitle{rpath}
|
|
|
|
\begin{tabular}{ | p{5cm} | p{5cm} |}
|
|
\hline
|
|
{\textbf {In Build Tree}} & {\textbf {In Install Tree}} \\
|
|
\hline
|
|
{Points to directories in the build folder
|
|
{\begin{itemize}
|
|
\item Usually full paths
|
|
\item Updated while installing
|
|
\end{itemize}}} &
|
|
{Points to directories specified during build for installation
|
|
{\begin{itemize}
|
|
\item Can be full path
|
|
\item Can be relative path
|
|
\item Can be empty
|
|
\end{itemize}}} \\
|
|
\hline
|
|
\end{tabular}
|
|
|
|
\end{frame}
|
|
|
|
% --------------------------------------------------------------------
|
|
|
|
\begin{frame}
|
|
\frametitle {Relocatable packages}
|
|
Relative or empty rpaths when installed
|
|
\begin{itemize}
|
|
\item {\code \$ORIGIN} - *nix OSs
|
|
\item {\code @rpath} (+ {\code @loader\_path}, {\code @executable\_path}) - Mac OSX \& IOS
|
|
\item Always Empty - Android\\
|
|
{\info {Usually libraries are packed with {\code APK} and loaded using {\code
|
|
dlopen} interface\\}}
|
|
\item Always Empty - for Windows\\
|
|
{\info {Only user account and system env paths are
|
|
searched for libraries, plus the current folder\\}}
|
|
\end{itemize}
|
|
|
|
\end{frame}
|
|
|
|
% --------------------------------------------------------------------
|
|
|
|
\begin{frame}
|
|
\frametitle{Making loading resources relocatable}
|
|
|
|
Resources used by package should be easily locatable\\
|
|
|
|
\textbf{Bad:} when resource paths are hardcoded in the source code\\
|
|
|
|
\textbf{Good:} when resource paths are dynamically determined at runtime\\
|
|
|
|
\end{frame}
|
|
|
|
\begin{frame}
|
|
\frametitle{Making loading resources relocatable}
|
|
|
|
You need to write a function able to determine the relative path from its
|
|
containing binary to the installation root at runtime.\\
|
|
|
|
\begin{itemize}
|
|
\item No need to hardcode resouce location in the sources
|
|
\item Path to resources should be located based on their types, such as:\\
|
|
{\code LIBRARY}, {\code BINARY}, {\code DATA}, {\code CONFIG},
|
|
etc.
|
|
\item Aware of the install tree directory structure
|
|
\item Just make sure that install tree structure is not violated
|
|
\end{itemize}
|
|
|
|
\end{frame}
|
|
|
|
% --------------------------------------------------------------------
|