By default to boot image bzImage of a Linux kernel you need to use the bootloader. If you try to boot the image directly it will give the error:
Booting from Hard Disk... Direct booting from floppy is no longer supported. Please use a boot loader program instead. Remove disk and press any key to reboot . . .
In the older versions of Linux it was possible with:
Is it possible to boot without a bootloader in the newer versions of the kernel? If so, how?