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diff --git a/poky/documentation/sdk-manual/sdk-intro.xml b/poky/documentation/sdk-manual/sdk-intro.xml new file mode 100644 index 000000000..8642be61a --- /dev/null +++ b/poky/documentation/sdk-manual/sdk-intro.xml @@ -0,0 +1,417 @@ +<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" +"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" +[<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > + +<chapter id='sdk-intro'> +<title>Introduction</title> + +<section id='sdk-manual-intro'> + <title>Introduction</title> + + <para> + Welcome to the Yocto Project Application Development and the + Extensible Software Development Kit (eSDK) manual. + This manual provides information that explains how to use both the + Yocto Project extensible and standard SDKs to develop + applications and images. + Additionally, the manual also provides information on how to use + the popular <trademark class='trade'>Eclipse</trademark> IDE as part + of your application development workflow within the SDK environment. + <note> + Prior to the 2.0 Release of the Yocto Project, application + development was primarily accomplished through the use of the + Application Development Toolkit (ADT) and the availability + of stand-alone cross-development toolchains and other tools. + With the 2.1 Release of the Yocto Project, application development + has transitioned to within a tool-rich extensible SDK and the more + traditional standard SDK. + </note> + </para> + + <para> + All SDKs consist of the following: + <itemizedlist> + <listitem><para> + <emphasis>Cross-Development Toolchain</emphasis>: + This toolchain contains a compiler, debugger, and various + miscellaneous tools. + </para></listitem> + <listitem><para> + <emphasis>Libraries, Headers, and Symbols</emphasis>: + The libraries, headers, and symbols are specific to the image + (i.e. they match the image). + </para></listitem> + <listitem><para> + <emphasis>Environment Setup Script</emphasis>: + This <filename>*.sh</filename> file, once run, sets up the + cross-development environment by defining variables and + preparing for SDK use. + </para></listitem> + </itemizedlist> + </para> + + <para> + Additionally, an extensible SDK has tools that allow you to easily add + new applications and libraries to an image, modify the source of an + existing component, test changes on the target hardware, and easily + integrate an application into the + <ulink url='&YOCTO_DOCS_REF_URL;#build-system-term'>OpenEmbedded build system</ulink>. + </para> + + <para> + You can use an SDK to independently develop and test code + that is destined to run on some target machine. + SDKs are completely self-contained. + The binaries are linked against their own copy of + <filename>libc</filename>, which results in no dependencies + on the target system. + To achieve this, the pointer to the dynamic loader is + configured at install time since that path cannot be dynamically + altered. + This is the reason for a wrapper around the + <filename>populate_sdk</filename> and + <filename>populate_sdk_ext</filename> archives. + </para> + + <para> + Another feature for the SDKs is that only one set of cross-compiler + toolchain binaries are produced for any given architecture. + This feature takes advantage of the fact that the target hardware can + be passed to <filename>gcc</filename> as a set of compiler options. + Those options are set up by the environment script and contained in + variables such as + <ulink url='&YOCTO_DOCS_REF_URL;#var-CC'><filename>CC</filename></ulink> + and + <ulink url='&YOCTO_DOCS_REF_URL;#var-LD'><filename>LD</filename></ulink>. + This reduces the space needed for the tools. + Understand, however, that every target still needs a sysroot because + those binaries are target-specific. + </para> + + <para> + The SDK development environment consists of the following: + <itemizedlist> + <listitem><para> + The self-contained SDK, which is an + architecture-specific cross-toolchain and + matching sysroots (target and native) all built by the + OpenEmbedded build system (e.g. the SDK). + The toolchain and sysroots are based on a + <ulink url='&YOCTO_DOCS_REF_URL;#metadata'>Metadata</ulink> + configuration and extensions, + which allows you to cross-develop on the host machine for the + target hardware. + Additionally, the extensible SDK contains the + <filename>devtool</filename> functionality. + </para></listitem> + <listitem><para> + The Quick EMUlator (QEMU), which lets you simulate + target hardware. + QEMU is not literally part of the SDK. + You must build and include this emulator separately. + However, QEMU plays an important role in the development + process that revolves around use of the SDK. + </para></listitem> + <listitem><para> + The Eclipse IDE Yocto Plug-in. + This plug-in is available for you if you are an Eclipse + user. + In the same manner as QEMU, the plug-in is not literally part + of the SDK but is rather available for use as part of the + development process. + </para></listitem> + <listitem><para> + Various performance-related + <ulink url='http://www.eclipse.org/linuxtools/index.php'>tools</ulink> + that can enhance your development experience. + These tools are also separate from the actual SDK but can be + independently obtained and used in the development process. + </para></listitem> + </itemizedlist> + </para> + + <para> + In summary, the extensible and standard SDK share many features. + However, the extensible SDK has powerful development tools to help you + more quickly develop applications. + Following is a table that summarizes the primary differences between + the standard and extensible SDK types when considering which to + build: + <informaltable frame='none'> + <tgroup cols='3' align='left' colsep='1' rowsep='1'> + <colspec colname='c1' colwidth='1*'/> + <colspec colname='c2' colwidth='1*'/> + <colspec colname='c3' colwidth='1*'/> + <thead> + <row> + <entry align="left"><emphasis>Feature</emphasis></entry> + <entry align="left"><emphasis>Standard SDK</emphasis></entry> + <entry align="left"><emphasis>Extensible SDK</emphasis></entry> + </row> + </thead> + <tbody> + <row> + <entry align="left">Toolchain</entry> + <entry align="left">Yes</entry> + <entry align="left">Yes*</entry> + </row> + <row> + <entry align="left">Debugger</entry> + <entry align="left">Yes</entry> + <entry align="left">Yes*</entry> + </row> + <row> + <entry align="left">Size</entry> + <entry align="left">100+ MBytes</entry> + <entry align="left">1+ GBytes (or 300+ MBytes for minimal w/toolchain)</entry> + </row> + <row> + <entry align="left"><filename>devtool</filename></entry> + <entry align="left">No</entry> + <entry align="left">Yes</entry> + </row> + <row> + <entry align="left">Build Images</entry> + <entry align="left">No</entry> + <entry align="left">Yes</entry> + </row> + <row> + <entry align="left">Updateable</entry> + <entry align="left">No</entry> + <entry align="left">Yes</entry> + </row> + <row> + <entry align="left">Managed Sysroot**</entry> + <entry align="left">No</entry> + <entry align="left">Yes</entry> + </row> + <row> + <entry align="left">Installed Packages</entry> + <entry align="left">No***</entry> + <entry align="left">Yes****</entry> + </row> + <row> + <entry align="left">Construction</entry> + <entry align="left">Packages</entry> + <entry align="left">Shared State</entry> + </row> + </tbody> + </tgroup> + </informaltable> + <literallayout class='monospaced'> + * Extensible SDK contains the toolchain and debugger if <ulink url='&YOCTO_DOCS_REF_URL;#var-SDK_EXT_TYPE'><filename>SDK_EXT_TYPE</filename></ulink> is "full" or <ulink url='&YOCTO_DOCS_REF_URL;#var-SDK_INCLUDE_TOOLCHAIN'><filename>SDK_INCLUDE_TOOLCHAIN</filename></ulink> is "1", which is the default. + + ** Sysroot is managed through the use of <filename>devtool</filename>. Thus, it is less likely that you will corrupt your SDK sysroot when you try to add additional libraries. + + *** You can add runtime package management to the standard SDK but it is not supported by default. + + **** You must build and make the shared state available to extensible SDK users for "packages" you want to enable users to install. + </literallayout> + </para> + + <section id='the-cross-development-toolchain'> + <title>The Cross-Development Toolchain</title> + + <para> + The + <ulink url='&YOCTO_DOCS_REF_URL;#cross-development-toolchain'>Cross-Development Toolchain</ulink> + consists of a cross-compiler, cross-linker, and cross-debugger + that are used to develop user-space applications for targeted + hardware. + Additionally, for an extensible SDK, the toolchain also has + built-in <filename>devtool</filename> functionality. + This toolchain is created by running a SDK installer script + or through a + <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink> + that is based on your metadata configuration or extension for + your targeted device. + The cross-toolchain works with a matching target sysroot. + </para> + </section> + + <section id='sysroot'> + <title>Sysroots</title> + + <para> + The native and target sysroots contain needed headers and libraries + for generating binaries that run on the target architecture. + The target sysroot is based on the target root filesystem image + that is built by the OpenEmbedded build system and uses the same + metadata configuration used to build the cross-toolchain. + </para> + </section> + + <section id='the-qemu-emulator'> + <title>The QEMU Emulator</title> + + <para> + The QEMU emulator allows you to simulate your hardware while + running your application or image. + QEMU is not part of the SDK but is made available a number of + different ways: + <itemizedlist> + <listitem><para> + If you have cloned the <filename>poky</filename> Git + repository to create a + <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink> + and you have sourced the environment setup script, QEMU is + installed and automatically available. + </para></listitem> + <listitem><para> + If you have downloaded a Yocto Project release and unpacked + it to create a Source Directory and you have sourced the + environment setup script, QEMU is installed and + automatically available. + </para></listitem> + <listitem><para> + If you have installed the cross-toolchain tarball and you + have sourced the toolchain's setup environment script, QEMU + is also installed and automatically available. + </para></listitem> + </itemizedlist> + </para> + </section> + + <section id='eclipse-overview'> + <title><trademark class='trade'>Eclipse</trademark> Yocto Plug-in</title> + + <para> + The Eclipse IDE is a popular development environment and it fully + supports development using the Yocto Project. + When you install and configure the Eclipse Yocto Project Plug-in + into the Eclipse IDE, you maximize your Yocto Project experience. + Installing and configuring the Plug-in results in an environment + that has extensions specifically designed to let you more easily + develop software. + These extensions allow for cross-compilation, deployment, and + execution of your output into a QEMU emulation session. + You can also perform cross-debugging and profiling. + The environment also supports many performance-related + <ulink url='http://www.eclipse.org/linuxtools/index.php'>tools</ulink> + that enhance your development experience. + <note> + Previous releases of the Eclipse Yocto Plug-in supported + "user-space tools" (i.e. LatencyTOP, PowerTOP, Perf, SystemTap, + and Lttng-ust) that also added to the development experience. + These tools have been deprecated with the release of the + Eclipse Yocto Plug-in. + </note> + </para> + + <para> + For information about the application development workflow that + uses the Eclipse IDE and for a detailed example of how to install + and configure the Eclipse Yocto Project Plug-in, see the + "<link linkend='sdk-eclipse-project'>Developing Applications Using <trademark class='trade'>Eclipse</trademark></link>" + Chapter. + </para> + </section> + + <section id='performance-enhancing-tools'> + <title>Performance Enhancing Tools</title> + + <para> + Supported performance enhancing tools are available that let you + profile, debug, and perform tracing on your projects developed + using Eclipse. + For information on these tools see + <ulink url='http://www.eclipse.org/linuxtools/'>http://www.eclipse.org/linuxtools/</ulink>. + </para> + </section> +</section> + +<section id='sdk-development-model'> + <title>SDK Development Model</title> + + <para> + Fundamentally, the SDK fits into the development process as follows: + <imagedata fileref="figures/sdk-environment.png" align="center" width="6in" depth="5in" scalefit="100" /> + The SDK is installed on any machine and can be used to develop + applications, images, and kernels. + An SDK can even be used by a QA Engineer or Release Engineer. + The fundamental concept is that the machine that has the SDK installed + does not have to be associated with the machine that has the + Yocto Project installed. + A developer can independently compile and test an object on their + machine and then, when the object is ready for integration into an + image, they can simply make it available to the machine that has the + Yocto Project. + Once the object is available, the image can be rebuilt using the + Yocto Project to produce the modified image. + </para> + + <para> + You just need to follow these general steps: + <orderedlist> + <listitem><para> + <emphasis>Install the SDK for your target hardware:</emphasis> + For information on how to install the SDK, see the + "<link linkend='sdk-installing-the-sdk'>Installing the SDK</link>" + section. + </para></listitem> + <listitem><para> + <emphasis>Download or Build the Target Image:</emphasis> + The Yocto Project supports several target architectures + and has many pre-built kernel images and root filesystem + images.</para> + + <para>If you are going to develop your application on + hardware, go to the + <ulink url='&YOCTO_MACHINES_DL_URL;'><filename>machines</filename></ulink> + download area and choose a target machine area + from which to download the kernel image and root filesystem. + This download area could have several files in it that + support development using actual hardware. + For example, the area might contain + <filename>.hddimg</filename> files that combine the + kernel image with the filesystem, boot loaders, and + so forth. + Be sure to get the files you need for your particular + development process.</para> + + <para>If you are going to develop your application and + then run and test it using the QEMU emulator, go to the + <ulink url='&YOCTO_QEMU_DL_URL;'><filename>machines/qemu</filename></ulink> + download area. + From this area, go down into the directory for your + target architecture (e.g. <filename>qemux86_64</filename> + for an <trademark class='registered'>Intel</trademark>-based + 64-bit architecture). + Download the kernel, root filesystem, and any other files you + need for your process. + <note> + To use the root filesystem in QEMU, you need to extract it. + See the + "<link linkend='sdk-extracting-the-root-filesystem'>Extracting the Root Filesystem</link>" + section for information on how to extract the root + filesystem. + </note> + </para></listitem> + <listitem><para> + <emphasis>Develop and Test your Application:</emphasis> + At this point, you have the tools to develop your application. + If you need to separately install and use the QEMU emulator, + you can go to + <ulink url='http://wiki.qemu.org/Main_Page'>QEMU Home Page</ulink> + to download and learn about the emulator. + See the + "<ulink url='&YOCTO_DOCS_DEV_URL;#dev-manual-qemu'>Using the Quick EMUlator (QEMU)</ulink>" + chapter in the Yocto Project Development Tasks Manual + for information on using QEMU within the Yocto + Project. + </para></listitem> + </orderedlist> + </para> + + <para> + The remainder of this manual describes how to use the extensible + and standard SDKs. + Information also exists in appendix form that describes how you can + build, install, and modify an SDK. + </para> +</section> + +</chapter> +<!-- +vim: expandtab tw=80 ts=4 +--> |