2 This FAQ answers a few questions about the RAM disks used in the
3 SnapGear/uClinux distribution. Specifically, how to increase
4 the size of /var/tmp, /etc/config or /tmp. How to build images
5 and change the settings as well as some gotchas.
7 Firstly, if you look in the /etc/rc file on the target
8 you may see the following:
10 /bin/expand /etc/ramfs.img /dev/ram1
11 mount -t proc proc /proc
12 mount -t ext2 /dev/ram1 /var
18 The file ramfs.img is an ext2 file system image that has been compressed.
19 The expand utility will unpack this into /dev/ram1.
20 This can then be mounted as an ext2 file system.
22 This is controlled by the user options specified by the "make menuconfig"
23 tool, follow this path:
27 Target Platform Selection --->
29 [*] Customize Vendor/User Settings (NEW)
31 Miscellaneous Configuration --->
32 (128K) RAMFS Image <--- ( change the option here )
38 And you should have a larger image. You can easily use images up to
39 4MiB, and once you go beyond that you need to increase the RAMdisk
40 maximum size in the kernel config.
42 If you do not want all the RAM for the image allocated until you have
43 filled it with files, then you need to enable the
45 "expand should not write zeroes"
47 option using the same mechanism above.
49 If you want to look deeper then the
53 directory contains more information including a mkrd script that shows
54 you how to make one of the images.
57 Phil Wilshire <philwil@earthlink.net>
58 David McCullough <davidm@snapgear.com>