Hi out there, due to some questions here in the past I wrote down my methode how I got along with booting a harddiskless computer. The 'initrd' (init ramdisk) is in fact a zipped file containing a bitmap of a complete filesystem, eg ext2, with all the standard paths and files. In general, you can zip '/' with all files and directories to get such a initrd. The problem is, of course, that it's much to big this way. So it's the magic to reduce it by concentrate to the really needed files, which is application specific. By the way, on the CDs of the Suse Linux Distribution are some emergency filesystems as initrd which should work as a base. I myself need the initrd to boot a small card-pc which is controlling a machine. So I format a normal ramdisk for example with mke2fs and make a standard dir tree, which I need for my application, e.g.: / /bin /sbin /usr /usr/bin /usr/sbin /dev /proc /etc /lib and so on, the files therein result from your application. At me there are in general network tools, login, shells, telnet and ftp-server and my appilication. Tricky is the choosing of the needed lib files, because some programs give misleading error messages. (for example says ping: unknown protocol icmp, when a special lib file is missing.) Hint: load not working programs to an editor an search for "lib". So you should get all needed lib file names easily. Is the contens of your filesystem fixed (it ouly needs the necessary files for running, so no kernel files, no '/boot' directory etc), zip it with gzip to a file named initrd.img.gz or so. After that you heads to your destination drive. For me it's a IDE-Flash-Disk (so there are no special drivers necessary like for DiskOnChip), but this should work for floppys also, you just don't have so much space... I made a script for that, on which I can explain the steps best: All my files are under /rdisk, what has to be taken care of in the relative pathnames. This is necessary to make lilo working on this files and not on your regular harddisk files for booting your desktop machine. Script: "mkflash": #cfdisk #make a partition an make it bootable (only for flash disks) mke2fs -m0 /dev/hda1 #make ext2 filesystem mount /dev/hda1 ./mnt #mount flash to /rdisk/mnt cp -av ./boot ./mnt #copy boot folder with files cp -av ./initrd.img.gz ./mnt #copy initrd image echo echo "lilo with ./etc/lilo.conf!" ./makelilo #install kernel+initrd umount ./mnt Well: the boot folder, needed by lilo, is written to the formatted and mounted disk. In the folder has to be the kernel for your destination system, the map file and the bootsector boot.b, which you can copy from the /boot dir from your desktop machine. It's important, that the kernel was compiled with initrd support! (make menuconfig in /usr/src/linux and then make dep clean zImage). After that also our initrd.img.gz is copied to the disk. In the end, lilo is called with a command line that is in a own script "makelilo" for historical reasons: lilo -r /rdisk -C /etc/lilo.conf The parameters are a little bit doubled, but better keep on the safe side. They tell lilo to read it's config file from /rdisk/etc/headlilo.conf where the parameters for my embedded pc are. Normally it would take /etc/lilo.conf by default, what would giva a mess. The configuration file looks like this: # LILO config file # Start LILO global Section boot=/dev/hda #boote from flashdisk map=/mnt/boot/map #here's the mapfile for the Kernel: Attention Flashdisc must still be mounted install=/mnt/boot/boot.b #here's the bootsector read-only #mount the initrd readonly vga = normal # force sane state verbose = 3 #tell what you do #prompt delay=25 #wait for some useraction # End LILO global section # # Linux bootable partition config begins append="initrd=initrd.img.gz" #tell the kernel that is has a initrd #append="initrd=initrd.img.gz init=/bin/sh" #this way a shell is started after booting, good for debugging the boot sequence image = /mnt/boot/kernel #here's the Kernel initrd= /mnt/initrd.img.gz #here's the initrd root = /dev/ram #mount the ramdisk as rootfilesystem label = Linux #that's the name of our system ramdisk= 10240 #this is the size of my unzipped ramdisk in kbytes # Linux bootable partition config ends # # Okay, this way a PC should boot a linux and work just as normal, only that the system is on a ramdisk. It's especially good for embedded systems, because after a power loss the machine is booting just normal (without checking the filesystem) and is back to work in some seconds. Please eMail me if I've forgotten something.... read you Bernd -- [EMAIL PROTECTED], http://www.basysprint.de basysPrint GmbH, Guelzer Str. 15, 19258 Boizenburg, Germany Tel.: ++49-38847-99-163, Fax:++49-38847-99-192 --- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] ---- For more information on Real-Time Linux see: http://www.rtlinux.org/~rtlinux/
