arch/arm/boot/compressed/head.s ----->调用arch/arm/boot/compressed/misc.c的decompress_kernel()
函数解压内核----->arch/arm/kernel/head.S---->arch/arm/kernel/head-common.S初始化 ---->init/main.c的asmlinkage void __init start_kernel(void)
注意在arch/arm/kernel/smp.c文件中有一个启动多核处理器的函数 void __init smp_prepare_boot_cpu(void)，被init/main.c的asmlinkage void __init start_kernel(void)调用
