新手指南：如何编译自己的固件

本指南的目标是指导你通过简单的几个步骤，编译出自己的，可以用于烧写的固件. 适用于windows用户和Debian/Ubuntu用户. 需要使用一个64位版本的windows，以及至少8GB的剩余磁盘空间. 在Mac上也类似 (可以使用Virtualbox), 但是我没有，所以没测试过.

自己编译固件的好处是减少空间占用，路由器的flash通常小于16MB. 再有，就是有一些选项只能在编译时改变，比如BusyBox中包含的一些feature. 再比如SquashFS的block size，block size较大时，压缩效果更好，但是加载文件的时间会变长.

其它指导固件编译的文档: Beginners guide to building your own firmware, Using the Image Builder.

如果你已经有了Debian/Ubuntu server，可以跳至下一步part 2.

除了在windows上安装虚拟机外，windows 10 用户可以在Microsoft Store安装Ubuntu并跳至第二步. 安装后，运行以下命令:

sudo apt-get update
sudo apt-get upgrade

这个软件让你可以在windows上运行一个Linux虚拟机. 从virtualbox.org下载最新版本并使用默认设置安装.

Download the newest VirtualBox (VDI) 64bit Debian image (currently 9.3) from osboxes.org and unpack it using 7zip. 7zip can be downloaded from 7-zip.org.

1. Start Oracle VM Virtualbox
2. Click New
3. Name: OpenWrt
4. Type: Linux
5. Version: Debian (64-bit). See here if 64-bit is not available.
6. Hard Disk: Select “Use an existing virtual hard disk file” and choose the Debian .vdi file you just unpacked.
7. Click Create
8. Right click on the OpenWrt image and click Settings
9. Select General, Advanced, Shared Clipboard: Bidirectional
10. Select Shared Folders
11. Right click Machine Folders and select Add Shared Folder
12. Folder path: Click the down arrow, select Other and then the folder you want to share with the virtual Debian server (for transferring the firmware).
13. Folder Name: Shared
14. Select Auto-mount

1. Select the OpenWrt image and click Start
2. Wait for it to finish booting and click osboxes.org
3. Password: osboxes.org
4. Click Activities, type term in the search field and click terminal

The interface for changing the keyboard is a bit weird, but you can find the correct place like this:

1. Click Activites, type reg, click Region & Language
2. Click + under Input Sources and then the vertical dots
3. Click Other, select the language and click Add. You can now delete English.

From now on, whenever you should be in the terminal to type a command the syntax will look like this:

ls -l

meaning you should type ls -l and press enter (try it). Follow up questions with obvious answers like typing the passsword (osboxes.org) og confirming with y will not be included specifically in this guide. Cut and paste will unfortunately not work at this moment.

su -
nano /etc/apt/sources.list

You are now editing the list of servers to get updates from.

• Delete the lines containing “deb cdrom”. Lines can be deleted with ctrl-k.
• From the last two lines, remove the leading # and space, and the -updates after stretch. They should now look like this:

deb http://deb.debian.org/debian/ stretch main contrib
deb-src http://deb.debian.org/debian/ stretch main contrib

• Type ctrl-x and then y and then enter to save and exit.

apt update
apt dist-upgrade
reboot

Log in and open the terminal again when it has rebooted.

su -
apt install linux-headers-amd64 make sudo

Click Devices (top line), select the last option (Install Guest Additions). The automatic install does not seem to work, so it doesn't matter if you select cancel or run.

sh /media/cdrom/VBoxLinuxAdditions.run
poweroff

After this you will need to start the server again. Now you can change to a higher resolution so you get a larger window if you like:

1. Click Activities, type disp in the search field.
2. Click Displays, VBX
3. Select a different resolution

And lastly (hopefully you can cut and paste now). Note that cut and paste only works for text without any kind of formatting. You may need to copy the text to notepad and then copy it from there to clean it up.

su -
adduser osboxes sudo
echo ' osboxes ALL=(ALL)   ALL' >> /etc/sudoers
exit

Your virtual Debian server should now be set up correctly for following the rest of the guide. Congratulations. As a bonus, you now have a fully functional Linux computer that you can use for anything, and with the added safety of running it as a virtual machine. If you let the resolution match your monitor and select View/Full-screen mode there is almost no difference from a standalone Linux computer.

参考 Beginners guide to building your own firmware , “cd openwrt”然后运行以下命令以获得最新稳定版本:

git tag
git branch

能看到tag名，发布版本和开发分支的列表. Check out你想要的那个：

git checkout <tag or branch name>

Then continue following the Beginners guide to building your own firmware

You select a package using space one or more times. When you select something, always make sure it has a * and not an M in the selected field. * means it will be included in the image, while M means that it will only create a package for it, which kind of defeats the point of following this guide.

Except for choosing the target I suggest that you don't mess with the options above Base system. Also, in general, don't uncheck anything that is selected by default unless you really know what you're doing. If something is selected with “-*-” (so you can't uncheck it) it is because something else depends on it.

Instructions on how to include config files in the image (for instance from the backup you can download from the router): Custom files

1. Do a web search for <your router model> wikidevi. For instance, if you have an Asus RT-N56U then search for RT-N56U wikidevi. This would give https://wikidevi.com/wiki/ASUS_RT-N56U as the first response on most search engines. Find CPU on the page. In the case of RT-N56U it says Ralink RT3662F. If you type / in the builder you can search for RT-N56U. This will give a bunch of hits, which among other things says Symbol: TARGET_DEVICE_PACKAGES_ramips_rt3883_DEVICE_rt-n56u. Notice the ramips part. Now select Target System. In the list you will find “Mediatek Ralink ARM” and “Mediatek Ralink MIPS”. Given the information we have you can probably guess that the correct choice is “Mediatek Ralink MIPS”.
2. Select Subtarget. From the wikidevi page you know that it is a Ralink RT3662F, and the best fit in the list is “RT3662/RT3883 based boards”.
3. Select Target Profile. Asus RT-N56U is now listed here, so you know you chose the correct target and subtarget.

• Don't remove any of the default packages unless you know what you are doing. Some of them are crucial. See Saving firmware space
• You'll probably want the LuCi web admin interface, so choose LuCi/Collections/luci. If LuCI is not available then you have not successfully checked out the feeds, or they have been removed. This can also happen if you for instance run make clean.
• The selectable software is in the submenues from “Base system” and downwards. Start by going to LuCI / Applications, as this section lists the LuCI packages for the most commonly used software. Selecting them will also include the required dependencies.
• When you build your own firmware you can't use the downloadable kernel packages (packages named kmod-<something>), so try to make sure you select everything you need. If you need more kernel modules later you will have to build a new firmware. It is also possible to select all the kernel modules using m and copy them to the router later if needed. Packages are placed in bin/targets/*/*/packages/.

Run

make

when you have selected what you want. This will take a very long the first time. Don't use the -j option mention in the Quick image building guide, it is asking for trouble.

If it completes without errors you should now have images. If not then try running

make -j1 V=s

to get more details about the error. A common mistake is to include packages that are mutually exclusive. After a successful build you can list the generated files using this command:

ls -l bin/targets/*/*/

Copy the image files to your shared Windows path:

sudo cp bin/targets/*/*/* /media/sf_Shared

Important: Make sure the image is at least about 500 KB less than the total amount of flash ROM, as some space is needed for configuration and other data. The absolute limit will vary depending on router model and how much configuration data you want to store. You can get an indication by being on the safe side the first time, and then check how much free space there is when you have installed it.

To erase just the config:

rm ~/openwrt/.config

To check out a different version:

rm -rf ~/openwrt/

the follow part 2 of the guide from the start, except you can skip the sudo apt-get commands.

For users:

• Using the Image Builder

Mostly for developers:

• Build system – Usage
• Using Build Environments
• The build system – About
• Using the SDK

Don't hesitate to ask in this forum thread if anything in this guide is unclear.