<ol style="list-style-type: lower-alpha;"><li><p>a. Initialize the compilation environment of Ubuntu PC and install the software packages required for the compilation process</p></li><li><p>b. Download the source code of u-boot and Linux kernel (if cached, only update the code)</p></li><li><p>c. Compile u-boot source code and generate u-boot deb package</p></li><li><p>d. Compile the Linux source code and generate Linux-related deb packages</p></li><li><p>e. Make the deb package of Linux firmware</p></li><li><p>f. Make the deb package of the orangepi-config tool</p></li><li><p>g. Create a deb package supported by the board</p></li><li><p>h. If you are compiling the desktop image, you will also create desktop-related deb packages</p></li><li><p>i. Check whether the rootfs has been cached, if not, recreate the rootfs, if it has been cached, directly decompress and use</p></li><li><p>j. Install the previously generated deb package into rootfs</p></li><li><p>k. Make some specific settings for different development boards and different types of images, such as pre-installing additional software packages, modifying system configuration, etc.</p></li><li><p>l. Then make an image file and format the partition, the default type is ext4</p></li><li><p>m. Then copy the configured rootfs to the mirrored partition</p></li><li><p>n. Then update initramfs</p></li><li><p>o. Finally, write the bin file of u-boot into the image through the dd command</p></li></ol></li>