How to Add User Files to Buildroot Image on OK3562 with Linux 5.10.198
1. Introduction
This article provides a method to include files, programs, applications, libraries, etc. required by user products into the source code and then compile them into the image. This can avoid the operation of separately copying programs to the development board after flashing the image.
2. Modification Methods
2.1 Method 1: Directly Put into Source Code for Compilation
Placement Path Explanation:
User programs can be copied to the directory
/OK3562linuxsource/buildroot/board/forlinx/ok3562/fsoverlay/usr/bin.
Configuration files can be copied to the directory
/OK3562linuxsource/buildroot/board/forlinx/ok3562/fsoverlay/etc.
Library files can be copied to the directory
/OK3562linuxsource/buildroot/board/forlinx/ok3562/fsoverlay/lib.
Users can also create their own folders in the
/OK3562linuxsource/buildroot/board/forlinx/ok3562/fsoverlay/ directory to store their files.
Take the example of copying the compressed package
aarch64buildrootlinuxgnu_sdkbuildroot.tar.gz:
(1) Copy the file to the specified path
Create a directory named test under the path
/OK3562linuxsource/buildroot/board/forlinx/ok3562/fsoverlay/, and put the compressed package aarch64buildrootlinuxgnu_sdkbuildroot.tar.gz into this directory.
(2) Compile the source code
Execute the fullcompilation command ./build.sh all. After compilation, you can see that the test directory is generated in OK3562linuxfs/rootfs, which contains the compressed package.
(3) Verification on the development board
After booting the development board with the compiled update.img, it is found that the test directory exists in the file system.
In conclusion, the test is successful.
This method is permanently effective. You only need to perform the operation once. Later, when you modify the device tree or driver configuration in the source code and recompile the image, the added files will still be included.
(4) Deleting the added files
When deleting, note that in addition to deleting the files added in /OK3562linuxsource/buildroot/board/forlinx/ok3562/fsoverlay/, you also need to check if there are any remaining files in /OK3562linuxsource/buildroot/output. For example, during the compilation of the abovementioned compressed package,
test/aarch64buildrootlinuxgnu_sdkbuildroot.tar.gz is also created in /OK3562linuxsource/buildroot/output/OK3562_Linux/target/, and these files also need to be deleted manually.
Recompilation is required after deletion.
2.2 Method 2: Mount rootfs.ext2
If the source code has been compiled, or you only want to temporarily add files to a single image, you can use the method of mounting rootfs.ext2.
Path of rootfs.ext2: OK3562linuxsource/buildroot/output/OK3562_Linux/images
(1) Mount rootfs.ext2 and transfer files into it
forlinx@ubuntu:~/work/OK3562-linux-source$ cd buildroot/output/OK3562_Linux/images forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ ls rootfs.cpio rootfs.cpio.gz rootfs.ext2 rootfs.ext4 rootfs.squashfs rootfs.tar forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ mkdir rootfs forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ sudo mount rootfs.ext2 rootfs [sudo] forlinx password： forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ cd rootfs/ forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images/rootfs$ ls bin busybox.fragment dev etc home info lib lib64 linuxrc lost+found media mnt oem opt proc root run sbin sys test tmp userdata usr var forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images/rootfs$ sudo cp /mnt/hgfs/share/aarch64-buildroot-linux-gnu_sdk-buildroot.tar.gz ./ forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images/rootfs$ cd .. forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ sudo umount rootfs
In conclusion, files can be directly added to the compiled image.
Note: The default size of rootfs.ext2 is 1.7G. If you use this method to add files that are too large, you will get an error: cp: Error writing './aarch64-buildroot-linux-gnu_sdk-buildroot.tar.gz' : No space on device. You can expand rootfs.ext2 using the following commands before adding files. Note that you need to unmount rootfs.ext2 before executing these commands:
forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ dd if=/dev/zero bs=1M count=0 seek=2000 of=rootfs.ext2 // The command does not write any data to rootfs.ext2, but simply extends the size of the file to 2G. 0+0 records in 0+0 records out 0 bytes copied, 0.000348683 s, 0.0 kB/s forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ e2fsck -f rootfs.ext2 e2fsck 1.46.5 (30-Dec-2021) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory structure Pass 4: Checking reference counts Pass 5: Checking group summary information rootfs: 9137/70128 files (0.1% non-contiguous), 249143/280320 blocks forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ resize2fs rootfs.ext2 resize2fs 1.46.5 (30-Dec-2021) Resize the file system on rootfs.ext2 to 512,000 blocks (4k per block). The file system on rootfs.ext2 is now 512,000 blocks (4k per block).
forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ ls -lh Total 3.5G drwxrwxr-x 2 forlinx forlinx 4.0K 1月 7 09:30 rootfs -rw-r--r-- 1 forlinx forlinx 906M 1月 7 11:13 rootfs.cpio -rw-r--r-- 1 forlinx forlinx 385M 1月 7 11:15 rootfs.cpio.gz -rw-r--r-- 1 forlinx forlinx 2.0G 1月 7 11:21 rootfs.ext2 lrwxrwxrwx 1 forlinx forlinx 11 1月 7 11:15 rootfs.ext4 -> rootfs.ext2 drwxrwxr-x 2 forlinx forlinx 4.0K 1月 7 10:02 rootfs_old -rw-r--r-- 1 forlinx forlinx 383M 1月 7 11:15 rootfs.squashfs -rw-r--r-- 1 forlinx forlinx 920M 1月 7 11:16 rootfs.tar forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ sudo mount rootfs.ext2 rootfs forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ cd rootfs/ forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images/rootfs$ sudo cp /mnt/hgfs/share/aarch64-buildroot-linux-gnu_sdk-buildroot.tar.gz ./ forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images/rootfs$ cd .. forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ sudo umount rootfs
(2) Update the image
forlinx@ubuntu:~/work/OK3562-linux-source/buildroot/output/OK3562_Linux/images$ cd ../../../../ forlinx@ubuntu:~/work/OK3562-linux-source$ ./build.sh updateimg
(3) Verification on the development board
Development board verification
In conclusion, the test is successful.
This method is only valid once. If the source code is recompiled later, the modification fails and needs to be operated again.
