U-Boot boot image

Command "bootm" will boot the image. 

// entry point to handle bootm command
do_bootm() 
  // get the boot image meta data information
  // image header info are in structure image_header
  bootm_start
    // entry point address
    images.ep = image_get_ep(&images.legacy_hdr_os_copy);
    // os load address, after unzip
    images.os.load = image_get_load(os_hdr);
  // load os image
  bootm_load_os
    // un-compress image to os.load address
    gunzip
  // when booting linux, boot_fn points to do_bootm_linux, 
  // for ARM, function implemented in arch/arm/lib/boom.c
  boot_fn
    // jump to the linux kernel
    boot_jump_linux
      kernel_entry = (void (*)(int, int, uint))images->ep;
      kernel_entry(0, machid, r2);