如何构建 LTTng 并将其部署到嵌入式 Linux 系统？

Question

http://lttng.org/download 上可用的源 tarball 中的 README 文件似乎假设构建在同一个 Linux 系统上，该系统将成为跟踪的目标。我找到了其他资源来解释如何做到这一点（LTTng Project YouTube channel 有非常好的截屏视频），但我找不到任何关于如何交叉编译 LTTng 的说明（具体来说，我猜是 liburcu、LTTng-UST、 LTTng-tools 和 LTTng-modules），并将其全部安装在嵌入式 Linux 系统上（我可以在其中构建或重建内核，使用设备树 blob 和 - 目前 - 基于 ramdisk 的文件系统）。

我在哪里可以找到有关如何执行此操作的详细信息？

更新：正如Marko 在下面的第一条评论中指出的那样，LTTng 工具是使用autoconf 构建的。我从理论上理解，我可以为configure 找到一个“--host”选项，类似于this answer。也许我需要一个像“ARCH=arm”这样的参数到make，就像我在构建内核时使用的那样。但是，在将要使用它们的同一台机器上构建 LTTng 组件时使用的 make install 的交叉编译等效项是什么？

Answer 1

LTTng 2.x 不再需要修补内核。您需要加载内核模块 (lttng-modules) 才能进行内核跟踪。支持的最低 Linux 内核版本是 2.6.38。 您可以低至 2.6.32，但您需要根据 LTTng 2.1 release note 和 lttng-modules README 为您的内核应用 3 个补丁。

为了回答您的交叉编译问题，这是我用来交叉编译 LTTng 工具链（用于用户空间跟踪）的常用过程：

export HOST=<your host triplet (e.g. arm-linux-gnueabi)>

# Make sure your cross-compiler can be found in your $PATH
export SYSROOT=<path to the target sysroot>

export CFLAGS="--sysroot=$SYSROOT"
export CPPFLAGS="-I$SYSROOT/include"
export CXXFLAGS=$CFLAGS
export LDFLAGS="--sysroot=$SYSROOT -L$SYSROOT/usr/lib -L$SYSROOT/lib"

# Fix RPL_MALLOC issue. See [Autoconf and RPL_MALLOC][3] for more details.
export ac_cv_func_malloc_0_nonnull=yes

# Cross compile userspace-rcu. You can also use a source tarball.
git clone git://git.lttng.org/userspace-rcu.git
cd userspace-rcu
./bootstrap
./configure --prefix=$SYSROOT --host=$HOST --with-sysroot=$SYSROOT
make
make install

# Cross compile lttng-ust. You can also use a source tarball.
git clone git://git.lttng.org/lttng-ust.git
cd lttng-ust
./bootstrap
./configure --prefix=$SYSROOT --host=$HOST --with-sysroot=$SYSROOT
make
make install

# Cross compile lttng-tools. You can also use a source tarball.
git clone git://git.lttng.org/lttng-tools.git
cd lttng-tools
./bootstrap
./configure --prefix=$SYSROOT --host=$HOST --with-sysroot=$SYSROOT
make
make install

您应该能够使其适应您的平台。如果要进行内核跟踪，还需要以类似的方式交叉编译 lttng-modules。

Answer 2

更新：ARM 的 LTTng 交叉编译现在更简单了。

首先，安装所需的依赖项。例如，使用 Emdebian 工具链：

xapt -a armel -m libc6-dev libpopt-dev uuid-dev liburcu-dev

然后：

export HOST=arm-linux-gnueabi
export SYSROOT=<path to the target sysroot>

git clone git://git.lttng.org/lttng-ust.git
cd lttng-ust
./bootstrap
./configure --host=$HOST --prefix=$SYSROOT/usr/local
make -j8
make install

git clone git://git.lttng.org/lttng-tools.git
cd lttng-tools
./bootstrap
./configure --host=$HOST --prefix=$SYSROOT/usr/local
make -j8
make install

备注：有时由于 'tests' 子目录二进制文件而导致失败。在这种情况下，只需从 Makefile 中删除“测试”（在执行 ./configure 之后）。

Answer 3

我只想分享我使用的构建脚本。它还编译了一些其他缺失的依赖项。高温

它编译如下：

libuuid-libxml2-popt-libiconv-zlib-userspace-rcu-lttng-ust-lttng-tools-lttng-modules

#!/bin/bash

# install this stuff before
# apt-get install  lib32z1 lib32ncurses5 lib32bz2-1.0 bison flex build-essential
# change your flags here

export PATH=/home/build/sam9/compiler/arm-2014.05/bin:$PATH
export ac_cv_func_malloc_0_nonnull=yes ac_cv_func_realloc_0_nonnull=yes
export HOST=arm-none-linux-gnueabi
export SYSROOT=/home/build/sam9/sysroot

G_CC=arm-none-linux-gnueabi-gcc 
G_PREFIX=/usr/local

G_ARCH=arm
G_CROSS_COMPILE=arm-none-linux-gnueabi-
G_KERNELDIR=/home/build/sam9/linux-3.4.106


G_CFG_FILE="$PWD/${0%\.*}.conf" # tracking download/compile steps

G_TARBALL_DIR=$PWD/tarballs
G_SOURCES_DIR=$PWD/sources
G_BUILD_DIR=$PWD/builds

# steps for tracking progress in $G_CFG_FILE
step_start=0
step_download=1
step_compile=2

echo
echo "This script will compile and install lttng and some deps"
echo "Building for HOST=$HOST"
echo
echo "Builds are located in $G_BUILD_DIR"
echo "Sources are located in $G_SOURCES_DIR"
echo "Tarballs are located in $G_TARBALL_DIR"
echo "sysroot is located at $SYSROOT"
echo "prefix is set to $G_PREFIX"
echo
echo "press Enter to continue or CRTL-C to abort"
read

[ -e "$G_CFG_FILE" ] && . "$G_CFG_FILE" &> /dev/null

function get_src_dir()
{
    local filename="$1"
    tar -tf "$G_TARBALL_DIR/$filename"| sed -e 's@/.*@@' | uniq
}

function build()
{
    local filename="$1"
    local what="$2"
    local dir_name="$3"
    local state="$4"
    local do_bootstrap=$5

    if [ $state -eq $step_download ] ; then

        if $do_bootstrap ; then
            pushd $G_SOURCES_DIR/$dir_name
            ./bootstrap
            popd
        fi

        mkdir -p "$G_BUILD_DIR/$dir_name"       
        pushd "$G_BUILD_DIR/$dir_name"      
        if [ -n "$patch" ] ; then
            pushd "$G_SOURCES_DIR/$dir_name"        
            wget $patch -O- | patch -p1
            popd
        fi
        "$G_SOURCES_DIR/$dir_name"/configure --host=$HOST --prefix=$SYSROOT/${G_PREFIX} $EXTRA_CONF
        make -j3
        make install && echo "$what=$step_compile" >> $G_CFG_FILE
        popd
    fi
    if [ $state -eq $step_compile ] ; then
        echo ">> $what is already compiled"
    fi
}

function download()
{
    local url="$1"
    local what="$2"
    local filename="$3"
    local state="$4"

    if [ $state -lt $step_download ] ; then
        wget "$url" -O "$G_TARBALL_DIR/$filename"
        echo "$what=$step_download" >> $G_CFG_FILE
        tar -C $G_SOURCES_DIR -xf "$G_TARBALL_DIR/$filename"
        . "$G_CFG_FILE" &> /dev/null
    fi
}

function download_git()
{
    local url="$1"
    local what="$2"
    local filename="$3"
    local state="$4"

    if [ $state -lt $step_download ] ; then

        pushd $G_SOURCES_DIR
        git clone $url
        popd
        echo "$what=$step_download" >> $G_CFG_FILE
        . "$G_CFG_FILE" &> /dev/null
    fi
}

function init()
{
    local what="$1"
    eval state=\$$what

    if [ ! -n "$state" ] ; then
        echo "$what=$step_start" >> $G_CFG_FILE
        . "$G_CFG_FILE" &> /dev/null
    fi

    eval state=\$$what
}

function get_em()
{
    local url="$1"
    local what="$2"
    local filename=$(basename $url) 

    init "$what"
    download "$url" "$what" $filename $state
    eval state=\$$what
    local dir_name=$(get_src_dir $filename)
    build $filename "$what" $dir_name $state false
}

function get_em_git()
{
    local url="$1"
    local what="$2"
    local do_bootstrap="$3"
    local filename=$(basename $url) 
    filename=${filename/.git}

    init "$what"
    download_git "$url" "$what" $filename $state
    eval state=\$$what

    build $filename "$what" $filename $state $do_bootstrap
}

echo "create directories"
mkdir -p "$G_TARBALL_DIR" "$G_SOURCES_DIR" "$G_BUILD_DIR" &>/dev/null


########################
# define the packages we want to compile
########################

# this are the dependencies that are missing for our sysroot
# we will compile them and install the to the $SYSROOT
#
# --- BEGIN --- dependencies
what=libuuid
url=http://downloads.sourceforge.net/project/libuuid/libuuid-1.0.3.tar.gz
get_em $url "$what"

what=libxml2
url=ftp://gd.tuwien.ac.at/pub/libxml/libxml2-sources-2.9.2.tar.gz
EXTRA_CONF=--without-python
get_em $url "$what"
unset EXTRA_CONF

what=popt
url=ftp://anduin.linuxfromscratch.org/BLFS/svn/p/popt-1.16.tar.gz
get_em $url "$what"

what=libiconv
url=http://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.14.tar.gz
patch=http://data.gpo.zugaina.org/gentoo/dev-libs/libiconv/files/libiconv-1.14-no-gets.patch
get_em $url "$what"
unset patch

what=zlib
url=http://zlib.net/zlib-1.2.8.tar.gz
init "$what"
filename=$(basename $url)   
download "$url" "$what" $filename $state
if [ $state -eq $step_compile ] ; then
    echo ">> $what is already compiled"
else
    dir_name=$(get_src_dir $filename)
    pushd $G_SOURCES_DIR/$dir_name
    CC=$G_CC \
    LDSHARED="$G_CC -shared -Wl,-soname,libz.so.1" \
    ./configure --shared --prefix=$SYSROOT/${G_PREFIX}
    make
    make install prefix=$SYSROOT/${G_PREFIX} && echo "$what=$step_compile" >> $G_CFG_FILE
    popd
fi

# --- END --- dependencies


#######################
# compile lttng related packages and install into $SYSROOT
what=userspace_rcu
url=git://git.lttng.org/userspace-rcu.git
get_em_git $url "$what" true

what=lttng_ust
url=git://git.lttng.org/lttng-ust.git
export CPPFLAGS="-I$SYSROOT/${G_PREFIX}/include"
export LDFLAGS="-L$SYSROOT/${G_PREFIX}/lib -Wl,-rpath-link=$SYSROOT/${G_PREFIX}/lib"
get_em_git $url "$what" true
unset CPPFLAGS
unset LDFLAGS

what=lttng_tools
url=git://git.lttng.org/lttng-tools.git
export CPPFLAGS="-I$SYSROOT/${G_PREFIX}/include"
export LDFLAGS="-L$SYSROOT/${G_PREFIX}/lib -Wl,-rpath-link=$SYSROOT/${G_PREFIX}/lib"
get_em_git $url "$what" true
unset CPPFLAGS
unset LDFLAGS

what=lttng_modules
url=git://git.lttng.org/lttng-modules.git
init "$what"
filename=$(basename $url)   
filename=${filename/.git}
download_git "$url" "$what" $filename $state
if [ $state -eq $step_compile ] ; then
    echo ">> $what is already compiled"
else
    #dir_name=$(get_src_dir $filename)
    pushd $G_SOURCES_DIR/$filename
    make ARCH=$G_ARCH CROSS_COMPILE=$G_CROSS_COMPILE KERNELDIR=$G_KERNELDIR -j4
    make ARCH=$G_ARCH CROSS_COMPILE=$G_CROSS_COMPILE KERNELDIR=$G_KERNELDIR INSTALL_MOD_PATH=$SYSROOT modules_install \
        && echo "$what=$step_compile" >> $G_CFG_FILE
    popd
fi

echo
echo "INFO: the build progress for all packages is tracked in $G_CFG_FILE"