Loading kernel image and ramdisk through SD card

Dear All,
i am having an ARM based embedded system having SD card slot.Originally i am porting ramdisk and zimage through serial port.I want to update my application by using SDcard.Is it possible?
Sdcard is already running in that system.

And Is it possible to combine zimage and ramdisk to make a single image.
How can we do it?

Please help me insorting out this problem.

Regards,
Ravi

At minimum, you would need a bootloader that has drivers for the SD card. Does the system have some a boot ROM, or flash, that can be modified? If yes, then you might be able to cobble your own bootloader together, if you have an existing driver for the SD card on that architecture.

Sounds like a lot of work. Maybe you should look at some other product that already has such a capability. There are plenty of initrd tutorials out on the web. Google is your friend.

--- rod.