前言

前面尝试着编译了u-boot，kernel,并添加了rootfs，这次来生成img镜像

复制生成文件

mkdir ~/Qubot-M2H-BSP/output
cd ~/Qubot-M2H-BSP/u-boot/u-boot-sunxi-with-spl.bin ~/Qubot-M2H-BSP/output
cd ~/Qubot-M2H-BSP/kernel/arch/arm64/boot/Image ~/Qubot-M2H-BSP/output
cd ~/Qubot-M2H-BSP/kernel/arch/arm64/boot/dts/allwinner/sun50i-h618-bananapi-m2h.dtb ~/Qubot-M2H-BSP/output
cd ~/Qubot-M2H-BSP/rootfs/rootfs.tar.gz ~/Qubot-M2H-BSP/output

生成一个2G的img文件

cd output
sudo dd if=/dev/zero of=./sdcard.img bs=1M count=2048

复制生成文件

sudo fdisk sdcard.img

Welcome to fdisk (util-linux 2.37.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x67a959c0.

Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-4194303, default 2048): 40960
Last sector, +/-sectors or +/-size{K,M,G,T,P} (40960-4194303, default 4194303): 303104

Created a new partition 1 of type 'Linux' and of size 128 MiB.

Command (m for help): n
Partition type
   p   primary (1 primary, 0 extended, 3 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (2-4, default 2):
First sector (2048-4194303, default 2048): 303106
Last sector, +/-sectors or +/-size{K,M,G,T,P} (303106-4194303, default 4194303): 4194303

Created a new partition 2 of type 'Linux' and of size 1.9 GiB.

Command (m for help): w
The partition table has been altered.
Syncing disks.

关联 IMG 文件到 LOOP

sudo losetup -f ./sdcard.img 

查看关联到了哪里

sudo losetup -l

可以看到是/dev/loop18

写入 UBOOT 到 IMG 文件中偏移 8KB 的位置

sudo dd if=./u-boot-sunxi-with-spl.bin of=/dev/loop18 bs=8K seek=1

查看分区信息

sudo fdisk -l

将这两个分区映射为 loop 设备

sudo losetup -f -o 20971520 --sizelimit 134217728 sdcard.img 
sudo losetup -f -o 155238272 --sizelimit 1994740736 sdcard.img 

对于上面的代码，-o接起始偏移量 = 起始扇区 * 扇区大小，–sizelimit接分区大小 = 分区扇区数 * 扇区大小

sudo losetup -l

可以看到，一个19，一个20

格式化分区并挂载

sudo mkfs.fat /dev/loop19
sudo mkfs.ext4 /dev/loop20
sudo mount /dev/loop19 /mnt/boot
sudo mount /dev/loop20 /mnt/rootfs

创建引导脚本

nano boot.cmd

将一下命令复制到boot.cmd文件

setenv bootcmd 'fatload mmc 0:1 0x40200000 Image;fatload mmc 0:1 0x4fa00000 sun50i-h618-bananapi-m2h.dtb;booti 0x40200000 - 0x4fa00000'
setenv bootargs 'console=ttyS0,115200 root=/dev/mmcblk1p2 rootfstype=ext4 rootwait rw'

生成boot.scr文件

mkimage -C none -A arm64 -T script -d boot.cmd boot.scr

复制boot分区

sudo cp ./Image /mnt/boot/
sudo cp sun50i-h618-bananapi-m2h.dtb /mnt/boot
sudo cp boot.scr /mnt/boot

解压rootfs到rootfs分区

sudo tar -xzvf ./rootfs.tar.gz -C /mnt/rootfs/

安装内核模块到 rootfs 分区

cd ../kernel/
sudo make INSTALL_MOD_PATH=/mnt/rootfs/ modules_install

取消挂载文件

sync
sudo umount /mnt/rootfs
sudo umount /mnt/boot

取消关联

sudo losetup -d /dev/loop18
sudo losetup -d /dev/loop19
sudo losetup -d /dev/loop20

写入到 TF 卡进行测试

sudo dd if=./sdcard.img of=/dev/sdx