using genext2fs to make ramdisk.gz (2011-07-25 23:26)
Tools:http://genext2fs.sourceforge.net/
genext2fs -d root -b 16384 -i 1024 -r 0 -D device.txt -q ramdisk
gzip -f -9 ramdisk
内核参数：
RedBoot> fis load ramdisk.gz -b 0x800000
RedBoot> fis load zImage -b 0x80000
RedBoot> exec -r 0x800000 -s 0x300000 -c "root=/dev/ram console=ttyAM0,57600"
$ ./genext2fs -h
Usage: ./genext2fs [options] image
Create an ext2 filesystem image from directories/files
-x, --starting-image <image>
-d, --root <directory>
-D, --devtable <file>
-b, --size-in-blocks <blocks>
-i, --bytes-per-inode <bytes per inode>
-I, --number-of-inodes <number of inodes>
-r, --reserved-blocks <number of reserved blocks>
-g, --block-map <path> Generate a block map file for this path.
-e, --fill-value <value> Fill unallocated blocks with value.
-z, --allow-holes Allow files with holes.
-f, --faketime Set filesystem timestamps to 0 (for testing).
-q, --squash Same as "-U -P".
-U, --squash-uids Squash owners making all files be owned by root.
-P, --squash-perms Squash permissions on all files.
-h, --help
-v, --verbose
#******************************************************************************
#
# device.txt - Configuration file for genext2fs.
#
# Copyright (c) 2004 Cirrus Logic, Inc.
#
#******************************************************************************
#
# <name> <t> <mode> <u> <g> <Mj> <mn> <s> <i> <c>
# where <name> is the file name, <t> can be one of:
# f A regular file
# d Directory
# c Character special device file
# b Block special device file
# p Fifo (named pipe)
# <u> is the user id for the target file, <g> is the group id for the
# target file. The rest of the entries (<Mj>, <mn>, <s>, <i>, and <c>) apply
# only to device special files.
#
#
# Create some directories.
#
# <name> <t> <mode> <u> <g> <Mj> <mn> <s> <i> <c>
/mnt d 755 0 0 - - - - -
/proc d 555 0 0 - - - - -
/tmp d 1777 0 0 - - - - -
/var d 755 0 0 - - - - -
/var/log d 755 0 0 - - - - -
/var/run d 755 0 0 - - - - -
/var/run d 755 0 0 - - - - -
/var/run/wpa_supplicant d 755 0 0 - - - - -
/var/spool d 755 0 0 - - - - -
/var/spool/cron d 755 0 0 - - - - -
/var/spool/cron/crontabs d 755 0 0 - - - - -
/dev d 755 0 0 - - - - -
/dev/input d 755 0 0 - - - - -
/dev/misc d 755 0 0 - - - - -
/dev/pts d 755 0 0 - - - - -
/dev/snd d 755 0 0 - - - - -
#
# Adjust the permissions on some normal files.
#
# <name> <t> <mode> <u> <g> <Mj> <mn> <s> <i> <c>
/etc/rc.sysinit f 755 0 0 - - - - -
/etc/shadow f 600 0 0 - - - - -
/sbin/hotplug f 755 0 0 - - - - -
/usr/share/udhcpc/default.script f 755 0 0 - - - - -
#
# Create the necessary character device nodes.
#
# <name> <t> <mode> <u> <g> <Mj> <mn> <s> <i> <c>
/dev/mem c 640 0 0 1 1 0 0 -
/dev/kmem c 640 0 0 1 2 0 0 -
/dev/null c 640 0 0 1 3 0 0 -
/dev/zero c 640 0 0 1 5 0 0 -
/dev/random c 640 0 0 1 8 0 0 -
/dev/urandom c 640 0 0 1 9 0 0 -
/dev/ptyp c 666 0 0 2 0 0 1 8
/dev/ttyp c 666 0 0 3 0 0 1 8
/dev/tty c 666 0 0 4 0 0 1 8
/dev/tty c 666 0 0 5 0 0 0 -
/dev/console c 640 0 0 5 1 0 0 -
/dev/ptmx c 666 0 0 5 2 0 0 -
/dev/vcs c 666 0 0 7 0 0 0 -
/dev/vcs c 666 0 0 7 1 1 1 8
/dev/vcsa c 666 0 0 7 128 0 0 -
/dev/vcsa c 666 0 0 7 129 1 1 8
/dev/misc/ep93xx_ts c 666 0 0 10 240 0 0 -
/dev/input/mice c 600 0 0 13 63 0 0 -
/dev/input/mouse0 c 600 0 0 13 32 0 0 -
/dev/mixer c 600 0 0 14 0 0 0 -
/dev/dsp c 600 0 0 14 3 0 0 -
/dev/audio c 600 0 0 14 4 0 0 -
/dev/dsp1 c 600 0 0 14 19 0 0 -
/dev/audio1 c 600 0 0 14 20 0 0 -
/dev/dsp2 c 600 0 0 14 35 0 0 -
/dev/audio2 c 600 0 0 14 36 0 0 -
/dev/fb c 600 0 0 29 0 0 0 -
/dev/fb0 c 600 0 0 29 0 0 0 -
/dev/lirc c 600 0 0 61 0 0 0 -
/dev/lircd p 600 0 0 - - - - -
/dev/lircm p 600 0 0 - - - - -
/dev/mtd c 644 0 0 90 0 0 2 8
/dev/rtc c 644 0 0 10 135 0 2 -
/dev/mtdr c 644 0 0 90 1 0 2 8
/dev/rawctl c 660 0 0 162 0 0 0 -
/dev/ttyAM c 640 0 0 204 16 0 1 2
/dev/cuam c 640 0 0 205 16 0 1 2
/dev/snd/controlC0 c 640 0 0 116 0 0 0 -
/dev/snd/pcmC0D0c c 640 0 0 116 24 0 0 -
/dev/snd/pcmC0D0p c 640 0 0 116 16 0 0 -
/dev/snd/pcmC0D1c c 640 0 0 116 25 0 0 -
/dev/snd/pcmC0D2c c 640 0 0 116 26 0 0 -
/dev/snd/pcmC0D3c c 640 0 0 116 27 0 0 -
/dev/snd/pcmC0D4p c 640 0 0 116 20 0 0 -
/dev/snd/timer c 640 0 0 116 33 0 0 -
/dev/ttyUSB c 666 0 0 188 0 0 1 40
#
# Create the necessary block device nodes.
#
# <name> <t> <mode> <u> <g> <Mj> <mn> <s> <i> <c>
/dev/ram b 640 0 0 1 0 0 0 -
/dev/ram b 640 0 0 1 0 0 1 4
/dev/hda b 640 0 0 3 0 0 0 -
/dev/hda b 640 0 0 3 1 1 1 8
/dev/hdb b 640 0 0 3 64 0 0 -
/dev/hdb b 640 0 0 3 65 1 1 8
/dev/loop b 640 0 0 7 0 0 1 8
/dev/sda b 660 0 0 8 0 0 0 -
/dev/sda b 660 0 0 8 1 1 1 4
/dev/sdb b 660 0 0 8 16 0 0 -
/dev/sdb b 660 0 0 8 17 1 1 4
/dev/mtdblock b 640 0 0 31 0 0 1 8