作者：付漢杰，hankf@xilinx.com，文章轉載自：賽靈思中文社區論壇

01 介紹

Xilinx VCU TRD 集成了圖像和視頻編解碼功能，生成的根文件系統比較大，2020.1的rootfs.cpio.gz大約有114MB。工程師可以根據自己需要裁剪，減少根文件系統大小。

在Ubuntu下，解壓rootfs.cpio.gz，得到rootfs.cpio，再解壓，得到就是文件了。

02 檢查目錄大小

使用du命令，可以檢查各個文件夾的大小。

rootfs@rootfs$ du --max-depth=1 -h 4.0K./run 8.5M./lib 20K./home 4.0K./boot 4.0K./tmp 4.0K./sys 2.9M./bin 4.0K./mnt 312M./usr 112K./var 2.8M./opt 2.0M./etc 8.0K./media 4.0K./dev 4.0K./proc 2.0M./sbin 330M

也可以看更深的目錄，排除占用空間小的目錄。

rootfs@rootfs$ du --max-depth=2 -h | grep [0-9]M 3.1M./lib/modules 8.5M./lib 2.9M./bin 206M./usr/lib 22M./usr/bin 1.3M./usr/libexec 80M./usr/share 3.8M./usr/sbin 312M./usr 2.8M./opt/vcu_qt 2.8M./opt 2.0M./etc 2.0M./sbin 330M.

rootfs$ du --max-depth=2 -h | grep [0-9]M 5.9M./lib 2.9M./bin 18M./usr/lib 5.1M./usr/bin 6.2M./usr/share 3.3M./usr/sbin 33M./usr 2.0M./sbin 45M.

03 檢查文件大小

目錄大小有助于粗略的分析根文件系統大小。要找到真正的原因，并找到減小根文件系統大小，需要分析文件大小。

使用find命令，找到文件，再使用ls命令，查看文件大小；最后使用grep命令過濾出大文件。

rootfs$ find | xargs -n 1 ls -l -h | grep [0-9]M total 4.3M -rwxr-xr-x 1 hankf hankf 1.4M May 27 13:58 libc-2.30.so -rwxr-xr-x 1 hankf hankf 1.4M May 27 13:58 ./lib/libc-2.30.so total 2.9M -rwxr-xr-x 1 hankf hankf 1.2M May 27 14:07 bash.bash -rwsr-xr-x 1 hankf hankf 1.6M May 27 14:09 busybox -rwsr-xr-x 1 hankf hankf 1.6M May 27 14:09 ./bin/busybox -rwxr-xr-x 1 hankf hankf 1.2M May 27 14:07 ./bin/bash.bash total 105M -rwxr-xr-x 1 hankf hankf 1.1M May 27 14:07 libasound.so.2.0.0 -rwxr-xr-x 1 hankf hankf 1.2M May 27 05:01 libcairo.so.2.11600.0 -rwxr-xr-x 1 hankf hankf 2.5M May 27 14:04 libcrypto.so.1.1 -rwxr-xr-x 1 hankf hankf 1.3M May 27 05:00 libepoxy.so.0.0.0 -rwxr-xr-x 1 hankf hankf 1.9M May 27 14:11 libgio-2.0.so.0.6000.7 -rwxr-xr-x 1 hankf hankf 1.2M May 27 14:11 libglib-2.0.so.0.6000.7 -rwxr-xr-x 1 hankf hankf 1.8M May 27 14:13 libgnutls.so.30.24.0 -rwxr-xr-x 1 hankf hankf 1.3M May 27 14:20 libgstreamer-1.0.so.0.1601.0 -rwxr-xr-x 1 hankf hankf 7.2M May 27 05:06 libgtk-3.so.0.2404.4 -r-xr-xr-x 1 hankf hankf 3.0M May 27 14:11 libpython3.7m.so.1.0 -rwxr-xr-x 1 hankf hankf 1.9M May 27 05:27 libQt5Charts.so.5.13.2 -rwxr-xr-x 1 hankf hankf 6.3M May 27 05:18 libQt5Core.so.5.13.2 -rwxr-xr-x 1 hankf hankf 5.8M May 27 05:18 libQt5Gui.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.9M May 27 05:18 libQt5Network.so.5.13.2 -rwxr-xr-x 1 hankf hankf 4.9M May 27 05:23 libQt5Qml.so.5.13.2 -rwxr-xr-x 1 hankf hankf 4.9M May 27 05:23 libQt5Quick.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.1M May 27 05:26 libQt5WaylandClient.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.6M May 27 05:26 libQt5WaylandCompositor.so.5.13.2 -rwxr-xr-x 1 hankf hankf 6.8M May 27 05:18 libQt5Widgets.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.3M May 27 05:18 libQt5XcbQpa.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.5M May 27 14:10 libsamplerate.so.0.1.8 -rwxr-xr-x 1 hankf hankf 1.1M May 27 14:05 libsqlite3.so.0.8.6 -rwxr-xr-x 1 hankf hankf 1.8M May 27 14:02 libstdc++.so.6.0.27 -rwxr-xr-x 1 hankf hankf 1.5M May 27 14:08 libunistring.so.2.1.0 -rwxr-xr-x 1 hankf hankf 1.5M May 27 14:03 libvpx.so.6.1.0 -rwxr-xr-x 1 hankf hankf 1.3M May 27 14:07 libX11.so.6.3.0 -rwxr-xr-x 1 hankf hankf 1.4M May 27 14:14 libxml2.so.2.9.9 -r-xr-xr-x 1 hankf hankf 3.0M May 27 14:11 ./usr/lib/libpython3.7m.so.1.0 -rwxr-xr-x 1 hankf hankf 1.9M May 27 05:18 ./usr/lib/libQt5Network.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.5M May 27 14:10 ./usr/lib/libsamplerate.so.0.1.8 -rwxr-xr-x 1 hankf hankf 6.3M May 27 05:18 ./usr/lib/libQt5Core.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.5M May 27 14:08 ./usr/lib/libunistring.so.2.1.0 -rwxr-xr-x 1 hankf hankf 4.9M May 27 05:23 ./usr/lib/libQt5Quick.so.5.13.2 total 1.7M -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 libMali.so.9.0 -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 ./usr/lib/x11/libMali.so.9.0 -rwxr-xr-x 1 hankf hankf 1.1M May 27 05:26 ./usr/lib/libQt5WaylandClient.so.5.13.2 -rwxr-xr-x 1 hankf hankf 6.8M May 27 05:18 ./usr/lib/libQt5Widgets.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.2M May 27 05:01 ./usr/lib/libcairo.so.2.11600.0 total 1.7M -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 libMali.so.9.0 -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 ./usr/lib/headless/libMali.so.9.0 -rwxr-xr-x 1 hankf hankf 1.8M May 27 14:13 ./usr/lib/libgnutls.so.30.24.0 -rwxr-xr-x 1 hankf hankf 1.9M May 27 05:27 ./usr/lib/libQt5Charts.so.5.13.2 total 4.7M total 4.6M -rwxr-xr-x 1 hankf hankf 1.1M May 27 14:11 unicodedata.cpython-37m-aarch64-linux-gnu.so -rwxr-xr-x 1 hankf hankf 1.1M May 27 14:11 ./usr/lib/python3.7/lib-dynload/unicodedata.cpython-37m-aarch64-linux-gnu.so total 1.2M total 2.0M total 2.0M -rw-r--r-- 1 hankf hankf 1.4M May 27 14:11 pip-19.2.3-py2.py3-none-any.whl -rw-r--r-- 1 hankf hankf 1.4M May 27 14:11 ./usr/lib/python3.7/ensurepip/_bundled/pip-19.2.3-py2.py3-none-any.whl total 1.8M total 1.8M total 1.3M total 9.6M ls: cannot access './usr/lib/python3.7/site-packages/setuptools/script': No such file or directory ls: cannot access '(dev).tmpl': No such file or directory ls: cannot access './usr/lib/python3.7/site-packages/setuptools/command/launcher': No such file or directory ls: cannot access 'manifest.xml': No such file or directory total 2.3M total 1.1M total 1.1M -rwxr-xr-x 1 hankf hankf 1.3M May 27 05:18 ./usr/lib/libQt5XcbQpa.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.2M May 27 14:11 ./usr/lib/libglib-2.0.so.0.6000.7 -rwxr-xr-x 1 hankf hankf 1.9M May 27 14:11 ./usr/lib/libgio-2.0.so.0.6000.7 total 2.9M -rw-r--r-- 1 hankf hankf 2.9M Jul 15 17:38 locale-archive -rw-r--r-- 1 hankf hankf 2.9M Jul 15 17:38 ./usr/lib/locale/locale-archive -rwxr-xr-x 1 hankf hankf 4.9M May 27 05:23 ./usr/lib/libQt5Qml.so.5.13.2 total 1.4M total 1.1M -rwxr-xr-x 1 hankf hankf 1.1M May 27 14:05 ./usr/lib/libsqlite3.so.0.8.6 -rwxr-xr-x 1 hankf hankf 1.5M May 27 14:03 ./usr/lib/libvpx.so.6.1.0 -rwxr-xr-x 1 hankf hankf 1.8M May 27 14:02 ./usr/lib/libstdc++.so.6.0.27 -rwxr-xr-x 1 hankf hankf 2.5M May 27 14:04 ./usr/lib/libcrypto.so.1.1 -rwxr-xr-x 1 hankf hankf 1.6M May 27 05:26 ./usr/lib/libQt5WaylandCompositor.so.5.13.2 -rwxr-xr-x 1 hankf hankf 1.3M May 27 14:07 ./usr/lib/libX11.so.6.3.0 -rwxr-xr-x 1 hankf hankf 1.1M May 27 14:07 ./usr/lib/libasound.so.2.0.0 -rwxr-xr-x 1 hankf hankf 1.4M May 27 14:14 ./usr/lib/libxml2.so.2.9.9 -rwxr-xr-x 1 hankf hankf 1.3M May 27 05:00 ./usr/lib/libepoxy.so.0.0.0 -rwxr-xr-x 1 hankf hankf 1.3M May 27 14:20 ./usr/lib/libgstreamer-1.0.so.0.1601.0 total 1.7M -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 libMali.so.9.0 -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 ./usr/lib/fbdev/libMali.so.9.0 total 1.5M total 1.7M -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 libMali.so.9.0 -rw-r--r-- 1 hankf hankf 1.7M Jul 15 17:32 ./usr/lib/wayland/libMali.so.9.0 -rwxr-xr-x 1 hankf hankf 7.2M May 27 05:06 ./usr/lib/libgtk-3.so.0.2404.4 -rwxr-xr-x 1 hankf hankf 5.8M May 27 05:18 ./usr/lib/libQt5Gui.so.5.13.2 total 13M total 1.2M total 2.2M total 22M -rwxr-xr-x 1 hankf hankf 1.1M Jul 15 17:32 ctrlsw_encoder -rwxr-xr-x 1 hankf hankf 7.7M May 27 14:28 gdb -rwxr-xr-x 1 hankf hankf 2.2M May 27 05:03 Xorg -rwxr-xr-x 1 hankf hankf 2.2M May 27 05:03 ./usr/bin/Xorg -rwxr-xr-x 1 hankf hankf 1.1M Jul 15 17:32 ./usr/bin/ctrlsw_encoder -rwxr-xr-x 1 hankf hankf 7.7M May 27 14:28 ./usr/bin/gdb total 1.8M total 1.2M total 4.0M total 1.3M total 1.2M total 1.3M total 1.3M total 1.4M total 5.4M -rw-r--r-- 1 hankf hankf 5.4M May 27 14:08 magic.mgc -rw-r--r-- 1 hankf hankf 5.4M May 27 14:08 ./usr/share/misc/magic.mgc total 1.9M total 2.2M -rw-r--r-- 1 hankf hankf 2.2M May 27 05:17 libpnp_basictools.a -rw-r--r-- 1 hankf hankf 2.2M May 27 05:17 ./usr/share/examples/widgets/tools/plugandpaint/plugins/libpnp_basictools.a total 3.8M total 2.8M -rwxr-xr-x 1 hankf hankf 2.7M Jul 15 17:34 vcu_qt -rwxr-xr-x 1 hankf hankf 2.7M Jul 15 17:34 ./opt/vcu_qt/bin/vcu_qt total 2.0M

04 去掉不必要文件

根據上述找到的大文件，禁止不使用的軟件包，就能減小根文件系統大小。

比如，在petalinux工程中，禁止下列軟件包后，rootfs.cpio.gz從114MB，減小到16.4MB。下列內容是從

project-spec/configs/rootfs_config提取的。

# CONFIG_gdb is not set # CONFIG_gdbserver is not set # CONFIG_kernel-module-hdmi is not set # CONFIG_packagegroup-core-x11 is not set # CONFIG_packagegroup-petalinux-audio is not set # CONFIG_packagegroup-petalinux-gstreamer is not set # CONFIG_packagegroup-petalinux-matchbox is not set # CONFIG_packagegroup-petalinux-qt is not set # packagegroup-petalinux-v4lutils # CONFIG_packagegroup-petalinux-v4lutils is not set # CONFIG_packagegroup-petalinux-x11 is not set # CONFIG_trd-init is not set # CONFIG_vcu-gst-app is not set # CONFIG_custom-edid is not set # CONFIG_gst-shark is not set # CONFIG_gstreamer-vcu-examples is not set # CONFIG_vcu-qt is not set

責任編輯：xj

原文標題：【干貨分享】優化rootfs的大小

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