you can configure the router to boot from a cisco ios image on the flash memory card, rather than from system flash memory. the router boots the image on the flash memory card, copies the image to onboard dram, and then executes the image from dram. the router does not execute the image directly from the flash memory card.

    follow these steps to specify the image on the flash memory card as the boot image:

    step 1 enter privileged exec mode:

    router] enable

    password: password

    step 2 enter global configuration mode:

    router# configure terminal

    step 3 enter the boot system flash {slot0: | slot1:}[partition:filename] command to specify the boot image location and name. in the following example, the boot image is located on the flash memory card in the 0 slot, partition 3, and the filename is new.image:

    router(config)# no boot system

    router(config)# boot system flash slot0:3:new.image

    if you omit the partition and filename variables, you are prompted for them.

    step 4 set the configuration register to 0x2102 (the default setting), which indicates that the router should attempt to boot a cisco ios image from flash memory:

    router(config)# config-register 0x2102

    step 5 exit global configuration mode:

    router(config)# exit

    step 6 enter the copy running-config startup-config command to save the configuration changes to nvram.

    step 7 enter the reload command to reload the router. when the router reloads, it will boot the image new.image from the flash memory card in slot 0.