tz/linuxOS_D21X
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
1d3a392fd3
linuxOS_D21X/doc/topics/sdk/boot/uboot-load-env-variables.html

249 lines
32 KiB
HTML
Raw Normal View History

add doc v1.2.7
2025-01-23 08:35:08 +00:00
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh-cn" lang="zh-cn" data-whc_version="27.0">
<head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><meta name="viewport" content="width=device-width, initial-scale=1.0"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><meta name="description" content="如前面所述，环境变量的处理有两个阶段： 环境变量初始 环境变量读取 如下面的调用流程， env_init() 在 board_init_f() 阶段执行，但具体的加载过程 在 board_init_r() 阶段执行。 reset // arch/riscv/cpu/start.S |-&gt; save_boot_params // ..."/><meta name="DC.rights.owner" content="(C) 版权 2025"/><meta name="copyright" content="(C) 版权 2025"/><meta name="generator" content="DITA-OT"/><meta name="DC.type" content="concept"/><meta name="DC.relation" content="../../../topics/sdk/boot/uboot-stage.html"/><meta name="DC.relation" content="../../../topics/sdk/boot/uboot-post-init.html"/><meta name="DC.relation" content="../../../topics/sdk/boot/uboot-cmd-stage.html"/><meta name="DC.contributor" content="yan.wang"/><meta name="DC.contributor" content="yan.wang"/><meta name="DC.date.modified" content="2024-01-15"/><meta name="DC.format" content="HTML5"/><meta name="DC.identifier" content="concept_tyf_bm3_pzb"/><meta name="DC.language" content="zh-CN"/><title>环境变量加载</title><!-- Generated with build number 2024112209. --><meta name="wh-path2root" content="../../../"/><meta name="wh-toc-id" content="concept_tyf_bm3_pzb-d4445e2467"/><meta name="wh-source-relpath" content="topics/sdk/boot/uboot-load-env-variables.dita"/><meta name="wh-out-relpath" content="topics/sdk/boot/uboot-load-env-variables.html"/>
<link rel="stylesheet" type="text/css" href="../../../webhelp/app/commons.css?buildId=2024112209"/>
<link rel="stylesheet" type="text/css" href="../../../webhelp/app/topic.css?buildId=2024112209"/>
<script src="../../../webhelp/app/options/properties.js?buildId=20250123154945"></script>
<script src="../../../webhelp/app/localization/strings.js?buildId=2024112209"></script>
<script src="../../../webhelp/app/search/index/keywords.js?buildId=20250123154945"></script>
<script defer="defer" src="../../../webhelp/app/commons.js?buildId=2024112209"></script>
<script defer="defer" src="../../../webhelp/app/topic.js?buildId=2024112209"></script>
<link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-styles-web.css?buildId=2024112209"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/notes.css?buildId=2024112209"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-common.css?buildId=2024112209"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-images.css?buildId=2024112209"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/footnote.css?buildId=2024112209"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-web-watermark.css?buildId=2024112209"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/topic-body-list.css?buildId=2024112209"/></head>
<body id="concept_tyf_bm3_pzb" class="wh_topic_page frmBody">
<a href="#wh_topic_body" class="sr-only sr-only-focusable">
跳转到主要内容
</a>
<header class="navbar navbar-default wh_header">
<div class="container-fluid">
<div class="wh_header_flex_container navbar-nav navbar-expand-md navbar-dark">
<div class="wh_logo_and_publication_title_container">
<div class="wh_logo_and_publication_title">
<a href="http://www.artinchip.com" class=" wh_logo d-none d-sm-block "><img src="../../../company-logo-white.png" alt=" Linux SDK 使用指南 SDK 指南文件 "/></a>
<div class=" wh_publication_title "><a href="../../../index.html"><span class="booktitle"> <span class="ph mainbooktitle">Linux SDK 使用指南</span> <span class="ph booktitlealt">SDK 指南文件</span> </span></a></div>
</div>
</div>
<div class="wh_top_menu_and_indexterms_link collapse navbar-collapse" id="wh_top_menu_and_indexterms_link">
</div>
</div>
</div>
</header>
<div class=" wh_search_input navbar-form wh_topic_page_search search " role="form">
<form id="searchForm" method="get" role="search" action="../../../search.html"><div><input type="search" placeholder="搜索 " class="wh_search_textfield" id="textToSearch" name="searchQuery" aria-label="搜索查询" required="required"/><button type="submit" class="wh_search_button" aria-label="搜索"><span class="search_input_text">搜索</span></button></div></form>
</div>
<div class="container-fluid" id="wh_topic_container">
<div class="row">
<nav class="wh_tools d-print-none navbar-expand-md" aria-label="Tools">
<div data-tooltip-position="bottom" class=" wh_breadcrumb "><ol class="d-print-none"><li><span class="home"><a href="../../../index.html"><span>主页</span></a></span></li><li><div class="topicref" data-id="id"><div class="title"><a href="../../../topics/sdk/chapter-advanced-app.html">高级应用</a><div class="wh-tooltip"><p class="shortdesc">系统、存储、多媒体、接口、安全等模块的详细配置和设计说明。</p></div></div></div></li><li><div class="topicref" data-id="uBoot"><div class="title"><a href="../../../topics/sdk/boot/uboot-module.html">U-Boot</a><div class="wh-tooltip"><p class="shortdesc">启动支持的基本功能以及运行时的基本硬件环境。</p></div></div></div></li><li><div class="topicref" data-id="uBoot_0"><div class="title"><a href="../../../topics/sdk/boot/uboot-stage.html">U-Boot 阶段</a></div></div></li><li class="active"><div class="topicref" data-id="concept_tyf_bm3_pzb"><div class="title"><a href="../../../topics/sdk/boot/uboot-load-env-variables.html">环境变量加载</a></div></div></li></ol></div>
<div class="wh_right_tools">
<button class="wh_hide_highlight" aria-label="切换搜索突出显示" title="切换搜索突出显示"></button>
<button class="webhelp_expand_collapse_sections" data-next-state="collapsed" aria-label="折叠截面" title="折叠截面"></button>
<div class=" wh_navigation_links "><span id="topic_navigation_links" class="navheader">
<span class="navprev"><a class="- topic/link link" href="../../../topics/sdk/boot/uboot-post-init.html" title="后初始化" aria-label="上一主题: 后初始化" rel="prev"></a></span>
<span class="navnext"><a class="- topic/link link" href="../../../topics/sdk/boot/uboot-cmd-stage.html" title="命令行阶段" aria-label="下一主题: 命令行阶段" rel="next"></a></span> </span></div>
<div class=" wh_print_link print d-none d-md-inline-block "><button onClick="window.print()" title="打印此页" aria-label="打印此页"></button></div>
<button type="button" id="wh_toc_button" class="custom-toggler navbar-toggler collapsed wh_toggle_button navbar-light" aria-expanded="false" aria-label="Toggle publishing table of content" aria-controls="wh_publication_toc">
<span class="navbar-toggler-icon"></span>
</button>
</div>
</nav>
</div>
<div class="wh_content_area">
<div class="row">
<nav id="wh_publication_toc" class="col-lg-3 col-md-3 col-sm-12 d-md-block d-none d-print-none" aria-label="Table of Contents Container">
<div id="wh_publication_toc_content">
<div class=" wh_publication_toc " data-tooltip-position="right"><span class="expand-button-action-labels"><span id="button-expand-action" role="button" aria-label="Expand"></span><span id="button-collapse-action" role="button" aria-label="Collapse"></span><span id="button-pending-action" role="button" aria-label="Pending"></span></span><ul role="tree" aria-label="Table of Contents"><li role="treeitem"><div data-tocid="revinfo_linux-d4445e1079" class="topicref" data-id="revinfo_linux" data-state="leaf"><span role="button" class="wh-expand-btn"></span><div class="title"><a href="../../../topics/revinfo/revinfo_linux.html" id="revinfo_linux-d4445e1079-link">修订记录</a></div></div></li><li role="treeitem" aria-expanded="false"><div data-tocid="id-d4445e1096" class="topicref" data-id="id" data-state="not-ready"><span role="button" tabindex="0" aria-labelledby="button-expand-action id-d4445e1096-link" class="wh-expand-btn"></span><div class="title"><a href="../../../topics/sdk/env/sdk-compile.html" id="id-d4445e1096-link">SDK 编译</a><div class="wh-tooltip"><p class="shortdesc">介绍不同编译环境下 SDK 的详细编译流程。</p></div></div></div></li><li role="treeitem" aria-expanded="false"><div data-tocid="tocId-d4445e1240" class="topicref" data-state="not-ready"><span role="button" tabindex="0" aria-labelledby="button-expand-action tocId-d4445e1240-link" class="wh-expand-btn"></span><div class="title"><a href="../../../topics/sdk/advanced/lb_usage_commands.html" id="tocId-d4445e1240-link">使用指南</a></div></div></li><li role="treeitem" aria-expanded="false"><div data-tocid="concept_rcx_czh_pzb-d4445e1360" class="topicref" data-id="concept_rcx_czh_pzb" data-state="not-ready"><span role="button" tabindex="0" aria-labelledby="button-expand-action concept_rcx_czh_pzb-d4445e1360-link" class="wh-expand-btn"></span><div class="title"><a href="../../../topics/sdk/chapter-app.html" id="concept_rcx_czh_pzb-d4445e1360-link">应用场景</a><div class="wh-tooltip"><p class="shortdesc">描述了 SDK 在不同应用场景中的配置和使用，包括系统更新、OTA、安全方案等。</p></div></div></div></li><li role="treeitem" aria-expanded="false"><div data-tocid="id-d4445e1678" class="topicref" data-id="id" data-state="not-ready"><span role="button" tabindex="0" aria-labelledby="button-expand-action id-d4445e1678-link" class="wh-expand-btn"></span><div class="title"><a href="../../../topics/sdk/peripheral/peripheral-intro.html" id="id-d4445e1678-link">外设移植</a><div class="wh-tooltip"><p class="shortdesc"><span class="ph">触摸屏、显示器、WIFI 模块、按键</span>等外设的介绍和使用说明。</p></div></div></div></li><li role="treeitem" aria-expanded="false"><div data-tocid="id-d4445e1964" class="topicref" data-id="id" data-state="not-ready"><span role="button" tabindex="0" aria-labelledby="button-expand-action id-d4445e1964-link" class="wh-expand-btn"></span><div class="title"><a href="../../../topics/sdk/bringup/chapter-bringup.html" id="id-d4445e1964-link">BringUp</a><div class="wh-tooltip"><p class="shortdesc">在硬件上电后快速初始化系统，为操作系统的启动准备好必要的硬件环境。</p></div></div></div></li><li role="treeitem" aria-expanded="true"><div data-tocid="id-d4445e2153" class="topicref" data-id="id" data-state="expanded"><span role="button" tabindex="0" aria-labelledby="button-collapse-action id-d4445e2153-link" class="wh-expand-btn"></span><div class="title"><a href="../../../topics/sdk/chapter-advanced-app.html" id="id-d4445e2153-link">高级应用</a><div class="wh-tooltip"><p class="shortdesc">系统、存储、多媒体、接口、安全等模块的详细配置和设计说明。</p></div></div></div><ul role="group" class="navbar-nav nav-list"><li role="treeitem" aria-expanded="true"><div data-tocid="uBoot-d4445e2170" class="topicref" data-id="uBoot" data-state="expanded"><span role="button" tabindex="0" aria-labelledby="button-collapse-action uBoot-d4445e2170-link" class="wh-expand-btn"></span><div class="titl
</div>
</nav>
<div class="col-lg-9 col-md-9 col-sm-12" id="wh_topic_body">
<button id="wh_close_publication_toc_button" class="close-toc-button d-none" aria-label="Toggle publishing table of content" aria-controls="wh_publication_toc" aria-expanded="true">
<span class="close-toc-icon-container">
<span class="close-toc-icon"></span>
</span>
</button>
<div class=" wh_topic_content body "><main role="main"><article class="- topic/topic concept/concept topic concept" role="article" aria-labelledby="ariaid-title1">
<span class="edit-link" style="font-size:12px; opacity:0.6; text-align:right; vertical-align:middle"><a target="_blank" title="Edit this document" href="http://172.16.35.88/tasks/jdssno1uvvbf2mltu9kb9v3if05d5gopuakboe8hlud18rma/edit/F:/aicdita/aicdita-cn/topics/sdk/boot/uboot-load-env-variables.dita">Edit online</a></span><h1 class="- topic/title title topictitle1" id="ariaid-title1">环境变量加载</h1>
<div class="date inPage">15 Jan 2024</div><div style="color: gray;">
Read time: 2 minute(s)
</div>
<div class="- topic/body concept/conbody body conbody">
<div class="- topic/p p" data-ofbid="d148996e33__20250123155214">
<div class="- topic/div div">
<p class="- topic/p p" data-ofbid="d148996e37__20250123155214">如前面所述，环境变量的处理有两个阶段：</p>
<ol class="- topic/ol ol" id="concept_tyf_bm3_pzb__ol_vng_wbh_bzb" data-ofbid="concept_tyf_bm3_pzb__ol_vng_wbh_bzb">
<li class="- topic/li li" data-ofbid="d148996e42__20250123155214">
<p class="- topic/p p" data-ofbid="d148996e44__20250123155214">环境变量初始</p>
</li>
<li class="- topic/li li" data-ofbid="d148996e48__20250123155214">
<p class="- topic/p p" data-ofbid="d148996e50__20250123155214">环境变量读取</p>
</li>
</ol>
<div class="- topic/p p" data-ofbid="d148996e55__20250123155214">如下面的调用流程， <span class="+ topic/keyword pr-d/apiname keyword apiname">env_init()</span> 在 <span class="+ topic/keyword pr-d/apiname keyword apiname">board_init_f()</span>
阶段执行，但具体的加载过程 在 <span class="+ topic/keyword pr-d/apiname keyword apiname">board_init_r()</span>
阶段执行。<pre class="+ topic/pre pr-d/codeblock pre codeblock language-c" id="concept_tyf_bm3_pzb__codeblock_fkq_nmr_c1c" data-ofbid="concept_tyf_bm3_pzb__codeblock_fkq_nmr_c1c"><code>reset <em class="hl-comment">// arch/riscv/cpu/start.S</em>
|-&gt; save_boot_params <em class="hl-comment">// arch/riscv/mach-artinchip/lowlevel_init.S</em>
|-&gt; ...
|-&gt; board_init_f(); <em class="hl-comment">// common/board_f.c</em>
|-&gt; setup_reloc(); <em class="hl-comment">// common/board_f.c</em>
|-&gt; jump_to_copy(); <em class="hl-comment">// common/board_f.c</em>
|-&gt; relocate_code(); <em class="hl-comment">// arch/riscv/cpu/start.S</em>
|-&gt; invalidate_icache_all()
|-&gt; flush_dcache_all()
|-&gt; board_init_r();
| <em class="hl-comment">// 逐个调用 init_sequence_r 里面的函数，其中包括 initr_env</em>
|-&gt; initr_env(); <em class="hl-comment">// common/board_r.c</em>
|-&gt; should_load_env(<strong class="hl-keyword">void</strong>);<em class="hl-comment">// common/board_r.c</em>
| <em class="hl-comment">// 由于没有在 DTS 中进行配置，总是返回 1</em>
| <em class="hl-comment">// fdtdec_get_config_int(gd-&gt;fdt_blob, "load-environment", 1);</em>
|-&gt; env_relocate(); <em class="hl-comment">// env/common.c</em>
|-&gt; env_load(); <em class="hl-comment">// env/env.c</em></code></pre></div>
<p class="- topic/p p" data-ofbid="d148996e69__20250123155214">U-Boot 支持在多种存储介质中保存环境变量，并且提供了一个插拔式的机制，用于实现从 不同的存储介质中加载环境变量内容。</p>
<div class="- topic/p p" data-ofbid="d148996e72__20250123155214">在添加新的环境变量加载器时，只需要实现对应存储介质的 <span class="+ topic/keyword pr-d/apiname keyword apiname">load</span> 和 <span class="+ topic/keyword pr-d/apiname keyword apiname">save</span> 函数，
然后通过宏 <span class="+ topic/keyword pr-d/apiname keyword apiname">U_BOOT_ENV_LOCATION</span> 将对应的信息添加到
<code class="+ topic/ph pr-d/codeph ph codeph">.u_boot_list_2</code> 链接段中。 比如下面的定义，将生成
<code class="+ topic/ph pr-d/codeph ph codeph">.u_boot_list_2_env_driver_2_spinand</code>
信息。<pre class="+ topic/pre pr-d/codeblock pre codeblock language-c" id="concept_tyf_bm3_pzb__codeblock_djh_4mr_c1c" data-ofbid="concept_tyf_bm3_pzb__codeblock_djh_4mr_c1c"><code>U_BOOT_ENV_LOCATION(spinand) = {
.location = ENVL_SPINAND,
ENV_NAME(<span class="hl-string">"SPINAND"</span>)
.load = env_spinand_load,
#<strong class="hl-keyword">if</strong> defined(CMD_SAVEENV)
.save = env_save_ptr(env_spinand_save),
#endif
};</code></pre></div>
<div class="- topic/p p" data-ofbid="d148996e94__20250123155214"><span class="+ topic/keyword pr-d/apiname keyword apiname">env_driver_lookup()</span> 函数首先通过检查当前的启动设备，然后从
<code class="+ topic/ph pr-d/codeph ph codeph">.u_boot_list_2</code> 段中查找对应启动设备的 ENV
加载驱动，最后调用对应的驱动读取并导入环境变量内容。<pre class="+ topic/pre pr-d/codeblock pre codeblock language-c" id="concept_tyf_bm3_pzb__codeblock_jd5_4mr_c1c" data-ofbid="concept_tyf_bm3_pzb__codeblock_jd5_4mr_c1c"><code>env_load(); <em class="hl-comment">// env/env.c</em>
|-&gt; env_driver_lookup(ENVOP_LOAD, prio);
| |-&gt; loc = env_get_location(); <em class="hl-comment">// board/artinchip/d211/env_location.c</em>
| | |-&gt; bd = aic_get_boot_device(); <em class="hl-comment">// 获取当前的启动设备</em>
| |
| |-&gt; _env_driver_lookup(loc);
| |-&gt; drv = ll_entry_start();
| <em class="hl-comment">// 查找指定存储介质的 env 加载驱动</em>
|
|-&gt; drv-&gt;load();
<em class="hl-comment">// 此处调用个存储介质的对应函数</em>
env_ram_load(); <em class="hl-comment">// board/artinchip/d211/env_location.c</em>
env_spinand_load(); <em class="hl-comment">// env/spinand.c</em>
env_sf_load(); <em class="hl-comment">// env/sf.c</em>
env_mmc_load(); <em class="hl-comment">// env/mmc.c</em></code></pre></div>
<p class="- topic/p p" data-ofbid="d148996e104__20250123155214">具体各种存储介质中，环境变量保存的位置可参考<a xml:lang="zh-CN" lang="zh-CN" class="- topic/xref xref" href="save-env-variable-on-memory-medium.html">存储介质上的保存</a>。</p>
</div>
</div>
</div>
</article></main></div>
</div>
</div>
</div>
</div>
<footer class="navbar navbar-default wh_footer">
<div class=" footer-container mx-auto ">
<title>footer def</title>
<style><!--
.p1 {
font-family: FangZhengShuSong, Times, serif;
}
.p2 {
font-family: Arial, Helvetica, sans-serif;
}
.p3 {
font-family: "Lucida Console", "Courier New", monospace;
}
--></style>
<div class="webhelp.fragment.footer">
<p class="p1">Copyright © 2019-2024 广东匠芯创科技有限公司. All rights reserved.</p>
</div><div>
<div class="generation_time">
Update Time: 2025-01-23
</div>
</div>
</div>
</footer>
<button id="go2top" class="d-print-none" title="返回顶部">
<span class="oxy-icon oxy-icon-up"></span>
</button>
<div id="modal_img_large" class="modal">
<span class="close oxy-icon oxy-icon-remove"></span>
<div id="modal_img_container"></div>
<div id="caption"></div>
</div>
<script src="${pd}/publishing/publishing-styles-AIC-template/js/custom.js" defer="defer"></script>
</body>
</html>
Reference in New Issue Copy Permalink