0、说明

mkimage工具最常用在

• 打包linux内核，增加头部信息，制作uImage
• 基于its创建itb启动文件（即FIT image）

dumpimage用在

• 解析itb，抽取内部文件

1、mkimage制作uImage

2、mkimage制作itb文件

在使用petalinux制作ZYNQ嵌入式系统时，最终产生了如下文件

yangf@ubuntu:~/src/xilinx/zcu104/xilinx-zcu104-2021.1/images/linux$ ls
bl31.bin  config     pxelinux.cfg            ramdisk.tar.gz         rootfs.ext4      system.bit      u-boot-dtb.elf   zynqmp-qemu-arm.dtb
bl31.elf  Image      ramdisk.cpio.gz         rootfs.cpio            rootfs.jffs2     system.dtb      u-boot.elf       zynqmp-qemu-multiarch-arm.dtb
BOOT.BIN  image.ub   ramdisk.cpio.gz.u-boot  rootfs.cpio.gz         rootfs.manifest  u-boot.bin      vmlinux          zynqmp-qemu-multiarch-pmu.dtb
boot.scr  pmufw.elf  ramdisk.manifest        rootfs.cpio.gz.u-boot  rootfs.tar.gz    u-boot-dtb.bin  zynqmp_fsbl.elf
yangf@ubuntu:~/src/xilinx/zcu104/xilinx-zcu104-2021.1/images/linux$ 

其中image.ub是用于启动的内核，他是怎么来的呢？就是使用mkimage通过一个its配置文件制作而成，命令如下：

mkimage -f o.its image.ub

其中o.its文件，本设计的内容如下：

/dts-v1/;

/ {
        description = "U-Boot fitImage for PetaLinux yangf";
        #address-cells = <1>;

        images {
                kernel-1 {
                        description = "Linux kernel";
                        data = /incbin/("image");
                        type = "kernel";
                        arch = "arm64";
                        os = "linux";
                        compression = "none";
                        load = <0x00080000>;
                        entry = <0x00080000>;
                        hash@1 {
                                algo = "sha256";
                        };
                };
                fdt-system-top.dtb {
                        description = "Flattened Device Tree blob";
                        data = /incbin/("fdt-system-top.dtb");
                        type = "flat_dt";
                        arch = "arm64";
                        compression = "none";
                        
                        hash@1 {
                                algo = "sha256";
                        };
                };
                ramdisk-1 {
                        description = "petalinux-initramfs-image";
                        data = /incbin/("petalinux-initramfs-image");
                        type = "ramdisk";
                        arch = "arm64";
                        os = "linux";
                        compression = "none";
                        
                        
                        hash@1 {
                                algo = "sha256";
                        };
                };
	};

        configurations {
                default = "conf-system-top.dtb";
                conf-system-top.dtb {
			description = "1 Linux kernel, FDT blob, ramdisk";
			kernel = "kernel-1";
			fdt = "fdt-system-top.dtb";
			ramdisk = "ramdisk-1";
			
                        hash@1 {
                                algo = "sha256";
                        };
                };
	};
};

其中its文件里面描述了用于打包itb文件的信息，包括文件类型，路径，压缩方式等。

执行打包后，输出的信息如下：

yangf@ubuntu:~/src/xilinx/kernel/output$ mkimage -f o.its  image.ub
FIT description: U-Boot fitImage for PetaLinux yangf
Created:         Sun Jul 18 05:51:34 2021
 Image 0 (kernel-1)
  Description:  Linux kernel
  Created:      Sun Jul 18 05:51:34 2021
  Type:         Kernel Image
  Compression:  uncompressed
  Data Size:    19827200 Bytes = 19362.50 KiB = 18.91 MiB
  Architecture: AArch64
  OS:           Linux
  Load Address: 0x00080000
  Entry Point:  0x00080000
  Hash algo:    sha256
  Hash value:   23c8dcec9b5989bed2ccb9baa15cfb8d8eae493173e227017d962ca035bec9a4
 Image 1 (fdt-system-top.dtb)
  Description:  Flattened Device Tree blob
  Created:      Sun Jul 18 05:51:34 2021
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    30783 Bytes = 30.06 KiB = 0.03 MiB
  Architecture: AArch64
  Hash algo:    sha256
  Hash value:   4be503e20bab2f9485077eb2c2c88ac562aceb0b83adc44c14e22ee7f008a066
 Image 2 (ramdisk-1)
  Description:  petalinux-initramfs-image
  Created:      Sun Jul 18 05:51:34 2021
  Type:         RAMDisk Image
  Compression:  uncompressed
  Data Size:    5120964 Bytes = 5000.94 KiB = 4.88 MiB
  Architecture: AArch64
  OS:           Linux
  Load Address: unavailable
  Entry Point:  unavailable
  Hash algo:    sha256
  Hash value:   cc95b21f470fd79ff31a6c154bcfbab23f817bcdc6cda9633554b995d1dfde45
 Default Configuration: 'conf-system-top.dtb'
 Configuration 0 (conf-system-top.dtb)
  Description:  1 Linux kernel, FDT blob, ramdisk
  Kernel:       kernel-1
  Init Ramdisk: ramdisk-1
  FDT:          fdt-system-top.dtb
  Hash algo:    sha256
  Hash value:   unavailable
yangf@ubuntu:~/src/xilinx/kernel/output$ 

3、dumpimage使用

通过mkimage -f o.its image.ub打包了image.ub文件，同样可以将image.ub解压，抽取里面的独立文件。如抽取第2单元内容 Image 2 (ramdisk-1)

dumpimage -i ./image.ub -T flat_dt -p 2 petalinux-initramfs-image