mkimage工具是u-boot用来制作镜像文件的工具，其源代码在u-boot源码的tools目录下：mkimage.c。我们使用bootm命令加载的内核和根文件系统，都要用这个工具加上个头。
语法格式：mkimage [参数]
常用参数：
| -A | CPU 架构，可选的值有： "alpha","arm","x86","ia64","m6k8","microblaze","mips","mips64","nios","nios2","ppc","s390","sh","sparc","sparc64", "blackfin","avr32" |
| -O | 操作系统。可选的值有： "4_4bsd","artos","esix","freebsd","irix","linux","lynxos","ncr","netbsd","openbsd","psos","qnx","rtems","sco","sloaris", "u-boot",vxworks" |
| -T | 镜像类型。可选的值有： "filesystem","firmware","firmware","kernel","multi","ramdisk","script","standalone","flat_dt" |
| -C | 镜像压缩类型。可选的值有： "none","bzip2","gzip" none为没有压缩 |
参考实例
为内核加上u-boot引导所需要的文件头：
[root@ledlinux ~]# mkimage -n 'linux-2.6.14' -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008000 -d zImage zImage.img
指定CPU架构和操作系统：
[root@ledlinux ~]# mkimage -A arm -O linux -a 0x20008000 -e 0x20008000 -d linux.bin.gz uImage
指定压缩格式：
[root@ledlinux ~]# mkimage -A arm -O linux -C bzip2 -a 0x20008000 -e 0x20008000 -d linux.bin.gz uImage
