Openwrt学习笔记（一）——系统架构

ゝ一纸荒年。 2022-07-14 13:24 945阅读 0赞

下表是OpenWrt系统架构和其他系统架构的对比（列表中有些url打不开，请自行翻/墙）：

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   <th style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); font-weight:bold; background-color:rgb(238,238,238); text-align:left"> &nbsp;</th> 
   <th colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); font-weight:bold; background-color:rgb(238,238,238); text-align:center"> Desktop Distributions</th> 
   <th colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); font-weight:bold; background-color:rgb(238,238,238); text-align:center"> OpenWrt</th> 
   <th style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); font-weight:bold; background-color:rgb(238,238,238); text-align:center"> <a href="https://en.wikipedia.org/wiki/Android%20%28operating%20system%29" title="https://en.wikipedia.org/wiki/Android (operating system)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Android</a></th> 
   <th style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); font-weight:bold; background-color:rgb(238,238,238); text-align:left"> <a href="https://en.wikipedia.org/wiki/Replicant%20%28operating%20system%29" title="https://en.wikipedia.org/wiki/Replicant (operating system)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Replicant</a></th> 
   <th style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); font-weight:bold; background-color:rgb(238,238,238); text-align:left"> <a href="https://en.wikipedia.org/wiki/Mer%20%28software%20distribution%29" title="https://en.wikipedia.org/wiki/Mer (software distribution)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">mer-based</a></th> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> Typical main memory size</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> <strong><span style="color:red">128 MiB</span></strong>&nbsp;to 16 GiB (or more)</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> <strong><span style="color:red">32 MiB</span></strong>&nbsp;to 512 MiB<sup style="font-size:0.8em; line-height:1; vertical-align:super"><a href="https://wiki.openwrt.org/doc/techref/architecture#fn__1" style="outline:none; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">1)</a></sup></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> min&nbsp;<strong><span style="color:red">92 MiB</span></strong>&nbsp;for Android 2.1&nbsp;<br> min&nbsp;<strong><span style="color:red">340 MiB</span></strong>&nbsp;for Android 4.0</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> ?</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left; background-color:rgb(238,238,238)"> Supported instruction sets</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center; background-color:rgb(238,238,238)"> almost anything</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center; background-color:rgb(238,238,238)"> almost anything</td> 
   <td colspan="3" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center; background-color:rgb(238,238,238)"> x86, 86-64, ARM, MIPS32</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> non-volatile storage space</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> 100 MiB</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> 8 MiB<sup style="font-size:0.8em; line-height:1; vertical-align:super"><a href="https://wiki.openwrt.org/doc/techref/architecture#fn__2" style="outline:none; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">2)</a></sup></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> 150MiB for Android 2.1<br> 512MiB for Android 4.0</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> ?</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <a href="https://en.wikipedia.org/wiki/Kernel%20%28computing%29" title="https://en.wikipedia.org/wiki/Kernel (computing)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">kernel</a></td> 
   <td colspan="7" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:center"> <strong><code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://en.wikipedia.org/wiki/Linux%20kernel" title="https://en.wikipedia.org/wiki/Linux kernel" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Linux kernel</a></code></strong></td> 
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   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> FOSS&nbsp;and binary drivers</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> FOSS&nbsp;drivers: e.g.&nbsp;<a href="https://en.wikipedia.org/wiki/Comparison%20of%20open-source%20wireless%20drivers" title="https://en.wikipedia.org/wiki/Comparison of open-source wireless drivers" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">802.11</a>;&nbsp;<a href="https://wiki.openwrt.org/doc/hardware/internet.access.technologies" title="doc:hardware:internet.access.technologies" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">Iaccess</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> Android binary drivers</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/C%20standard%20library" title="https://en.wikipedia.org/wiki/C standard library" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">C standard library</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/GNU%20C%20Library" title="https://en.wikipedia.org/wiki/GNU C Library" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">glibc</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/uClibc" title="https://en.wikipedia.org/wiki/uClibc" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">uClibc</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/Bionic%20%28software%29" title="https://en.wikipedia.org/wiki/Bionic (software)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">bionic</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> glibc +&nbsp;<a href="https://en.wikipedia.org/wiki/Hybris%20%28software%29" title="https://en.wikipedia.org/wiki/Hybris (software)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">libhybris</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> eglibc 2.15</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/init" title="https://en.wikipedia.org/wiki/init" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">init</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/init" title="https://en.wikipedia.org/wiki/init" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">init</a><br> <a href="https://en.wikipedia.org/wiki/Upstart" title="https://en.wikipedia.org/wiki/Upstart" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Upstart</a><br> <a href="https://en.wikipedia.org/wiki/Initng" title="https://en.wikipedia.org/wiki/Initng" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Initng</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <strong><code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://en.wikipedia.org/wiki/systemd" title="https://en.wikipedia.org/wiki/systemd" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">systemd</a></code></strong></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> busybox-initd</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <strong><code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://wiki.openwrt.org/doc/techref/procd" title="doc:techref:procd" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">procd</a></code></strong></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> Android init-fork</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre">systemd</code></td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <a href="https://en.wikipedia.org/wiki/rsyslog" title="https://en.wikipedia.org/wiki/rsyslog" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">rsyslog</a>&nbsp;/&nbsp;<a href="https://en.wikipedia.org/wiki/syslog-ng" title="https://en.wikipedia.org/wiki/syslog-ng" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">syslog-ng</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> busybox-klogd, busybox-syslogd</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/watchdog" title="https://en.wikipedia.org/wiki/watchdog" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">watchdog</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> busybox-watchdog</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/udev" title="https://en.wikipedia.org/wiki/udev" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">udev</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://wiki.openwrt.org/doc/techref/hotplug" title="doc:techref:hotplug" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">hotplug2</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ubox?</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/cron" title="https://en.wikipedia.org/wiki/cron" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">cron</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://wiki.openwrt.org/doc/howto/ntp.client" title="doc:howto:ntp.client" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">busybox-crond</a></code></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/at%20%28Unix%29" title="https://en.wikipedia.org/wiki/at (Unix)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">atd</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <em>na</em></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/D-Bus" title="https://en.wikipedia.org/wiki/D-Bus" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">D-Bus</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://wiki.openwrt.org/doc/techref/ubus" title="doc:techref:ubus" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">ubus</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> Binder</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> ?</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> D-Bus</td> 
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   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> network configuration</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/NetworkManager" title="https://en.wikipedia.org/wiki/NetworkManager" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">NetworkManager</a>&nbsp;+&nbsp;GUI</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://wiki.openwrt.org/doc/techref/netifd" title="doc:techref:netifd" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">netifd</a></code></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ConnectivityManager<br> (not&nbsp;<a href="https://connman.net/" title="https://connman.net/" style="outline:none; text-decoration:none; color:rgb(0,0,136); padding:0px 0px 0px 18px" rel="nofollow">ConnMan = ConnectionManager</a>!)</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ?</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ConnMan</td> 
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  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/GLib" title="https://en.wikipedia.org/wiki/GLib" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">GLib</a>&nbsp;<br> (GObject, Glib, GModule, GThread, GIO)</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://wiki.openwrt.org/doc/techref/libubox" title="doc:techref:libubox" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">libubox</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ?</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ?</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> Qt-based?</td> 
  </tr> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> &nbsp;</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/PulseAudio" title="https://en.wikipedia.org/wiki/PulseAudio" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">PulseAudio</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <a href="https://wiki.openwrt.org/doc/howto/pulseaudio" title="doc:howto:pulseaudio" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">PulseAudio</a>&nbsp;(optional)</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> PulseAudio</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> PulseAudio</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> PulseAudio</td> 
  </tr> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <a href="https://en.wikipedia.org/wiki/Package%20management%20system" title="https://en.wikipedia.org/wiki/Package management system" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Package management system</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/dpkg" title="https://en.wikipedia.org/wiki/dpkg" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">dpkg</a>/<a href="https://en.wikipedia.org/wiki/Advanced%20Packaging%20Tool" title="https://en.wikipedia.org/wiki/Advanced Packaging Tool" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">APT</a><br> <a href="https://en.wikipedia.org/wiki/RPM%20Package%20Manager" title="https://en.wikipedia.org/wiki/RPM Package Manager" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">RPM</a>/<a href="https://en.wikipedia.org/wiki/Yellowdog%20Updater,%20Modified" title="https://en.wikipedia.org/wiki/Yellowdog Updater, Modified" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">yum</a><br> <a href="https://en.wikipedia.org/wiki/Portage%20%28software%29" title="https://en.wikipedia.org/wiki/Portage (software)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">portage</a><br> <a href="https://en.wikipedia.org/wiki/pacman%20%28package%20manager%29" title="https://en.wikipedia.org/wiki/pacman (package manager)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">pacman</a><br> …</td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://wiki.openwrt.org/doc/techref/opkg" title="doc:techref:opkg" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">opkg</a></code></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <a href="https://en.wikipedia.org/wiki/APK%20%28file%20format%29" title="https://en.wikipedia.org/wiki/APK (file format)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">apk</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ?</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <a href="https://en.wikipedia.org/wiki/RPM%20Package%20Manager" title="https://en.wikipedia.org/wiki/RPM Package Manager" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">RPM</a></td> 
  </tr> 
 </tbody> 
</table>

### 1. 从上表我们可以看到，openwrt主要的优势体现在小，它运行的内存最小只要32M，存放FW的最小size只要8M，同时能够满足大多数汇编指令集的需求，所以从硬件成本来说，openwrt操作系统可以适应于内存和flash更小的产品上，对于功能相对单一的智能产品，openwrt有它独特的优势。 ###

### 2. 不仅如此，openwrt支持使用和其他操作系统(Desktop Distributions/android)一样的linux内核，包括对802.11的支持，这也使它在无线开发方面有更多的空间。 ###

### 3. openwrt使用的C库是uClibc，并不是使用glibc，它是一个面向嵌入式Linux系统的小型的C标准库，uClibc比一般用于Linux发行版的C库GNU C Library (glibc)要小得多，glibc目标是要支持最大范围的硬件和内核平台的所有C标准，而uClibc专注于嵌入式Linux.很多功能可以根据空间需求进行取舍。 ###

### 4. 在openwrt中，文件系统的启动以及管理和其他几个系统有些不一样，而且在最新的版本中更是使用了集合度比较高的daemon进程进行控制。一般文件系统的启动都是从init进程开始的，从下表中我们可以看到，不同的操作系统，启动的进程不一样，即使是同一种“操作系统”，在新旧版本间的启动方式也不一样，比如openwrt中，将旧版本的bosybox里面的一些功能整合在了procd里面，hotplug2对热插拔事件的监听也又ubox来替代，crond仍然用busybox里面的，ubus是dbus的简化版，简洁的API接口更适用于嵌入式平台。 ###

<table> 
 <tbody> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/init" title="https://en.wikipedia.org/wiki/init" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">init</a><br> <a href="https://en.wikipedia.org/wiki/Upstart" title="https://en.wikipedia.org/wiki/Upstart" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Upstart</a><br> <a href="https://en.wikipedia.org/wiki/Initng" title="https://en.wikipedia.org/wiki/Initng" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">Initng</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <strong><code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://en.wikipedia.org/wiki/systemd" title="https://en.wikipedia.org/wiki/systemd" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">systemd</a></code></strong></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> busybox-initd</td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <strong><code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://wiki.openwrt.org/doc/techref/procd" title="doc:techref:procd" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">procd</a></code></strong></td> 
  </tr> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> <a href="https://en.wikipedia.org/wiki/rsyslog" title="https://en.wikipedia.org/wiki/rsyslog" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">rsyslog</a>&nbsp;/&nbsp;<a href="https://en.wikipedia.org/wiki/syslog-ng" title="https://en.wikipedia.org/wiki/syslog-ng" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">syslog-ng</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> busybox-klogd, busybox-syslogd</td> 
  </tr> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/watchdog" title="https://en.wikipedia.org/wiki/watchdog" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">watchdog</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> busybox-watchdog</td> 
  </tr> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/udev" title="https://en.wikipedia.org/wiki/udev" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">udev</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://wiki.openwrt.org/doc/techref/hotplug" title="doc:techref:hotplug" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">hotplug2</a></td> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204)"> ubox?</td> 
  </tr> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/cron" title="https://en.wikipedia.org/wiki/cron" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">cron</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <code style="font-family:Consolas,&quot;Andale Mono WT&quot;,&quot;Andale Mono&quot;,&quot;Bitstream Vera Sans Mono&quot;,&quot;Nimbus Mono L&quot;,Monaco,&quot;Courier New&quot;,monospace; font-size:1em; direction:ltr; text-align:left; color:rgb(51,51,51); white-space:pre"><a href="https://wiki.openwrt.org/doc/howto/ntp.client" title="doc:howto:ntp.client" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">busybox-crond</a></code></td> 
  </tr> 
  <tr> 
   <td style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/at%20%28Unix%29" title="https://en.wikipedia.org/wiki/at (Unix)" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">atd</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <em>na</em></td> 
  </tr> 
  <tr> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://en.wikipedia.org/wiki/D-Bus" title="https://en.wikipedia.org/wiki/D-Bus" style="outline:none; padding:0px 0px 0px 18px; text-decoration:none; color:rgb(0,0,136)" rel="nofollow">D-Bus</a></td> 
   <td colspan="2" style="padding:0.3em 0.5em; margin:0px; vertical-align:top; border:1px solid rgb(204,204,204); text-align:left"> <a href="https://wiki.openwrt.org/doc/techref/ubus" title="doc:techref:ubus" style="outline:none; text-decoration:none; color:rgb(0,0,136); background-color:inherit" rel="nofollow">ubus</a></td> 
  </tr> 
 </tbody> 
</table>

###     ###

### 5. netifd是用来监控和配置网络信息 ###

### 6. libubox是一些管理工具 ###

### 7. opkg是openwrt里面安装一些应用程序的工具，就像ubuntu里面的apt-get, 安卓里面的apk ###

### 总的来说，运行一个openwrt系统至少需要一个32M内存+8M flash, 它支持linux内核，新版本文件系统的主要管理工具包括procd,ubox,ubus,netifd和opkg.    ###