Specifications

CONFIG_BLK_DEV_RAM_SIZE parameter so that it contains a number equal or larger than
your ramdisk (in kB). (In the 2.4 kernel series, you'll find this setting under the "Block
devices" menu choice while, in the 2.6 series, it will be under "Device drivers" -> "Block
devices".)
14.3.19. Combining a Kernel and a Ramdisk into a
Multi-File Image
Question:
I used to build a zImage.initrd file which combined the Linux kernel with a ramdisk image. Can
I do something similar with U-Boot?
Answer:
Yes, you can create "Multi-File Images" which contain several images, typically an OS (Linux) kernel
image and one or more data images like RAMDisks. This construct is useful for instance when you
want to boot over the network using BOOTP etc., where the boot server provides just a single image
file, but you want to get for instance an OS kernel and a RAMDisk image.
The typical way to build such an image is:
bash$ mkimage -A ppc -O Linux -T multi -C gzip \
-n 'Linux Multiboot-Image' -e 0 -a 0 \
-d vmlinux.gz:ramdisk_image.gz pMulti
See also the usage message you get when you call "mkimage" without arguments.
14.3.20. Adding Files to Ramdisk is Non Persistent
Quetsion:
I want to add some files to my ramdisk, but every time I reboot I lose all my changes. What can I do?
Answer:
To add your files or modifications permanently, you have to rebuild the ramdisk image. You may
check out the sources of our SELF package (Simple Embedded Linux Framework) to see how this can
be done, see for example ftp://ftp.denx.de/pub/LinuxPPC/usr/src/SELF/ or check out the sources for
ELDK (module eldk_build from our CVS server, see http://www.denx.de/re/linux.html.
See also section 14.4.1. How to Add Files to a SELF Ramdisk for another way to change the ramdisk
image.
For further hints about the creation and use of initial ramdisk images see also the file
Documentation/initrd.txt in your Linux kernel source directory.
14.3.21. Kernel Configuration for PCMCIA
Question:
Which kernel configuration options are relevant to support PCMCIA cards under Linux?
Answer:
14.3.21. Kernel Configuration for PCMCIA 183