tl;dr - I brought up Wheezy with an i486 kernel using under 200MB of storage. Then I summarized verbosely using markdown and URLs.
# Install of emdebian grip (wheezy) August 2012 Here is an installation report written more as a story as an attempt to include the context and motivations as well as the technical details. While working on this task, I realized much of what is written has come from experts with great knowledge of the subject punctuated by strange but sometimes enlightening errors found by people with little knowledge of the subject. In each case the context and motivation was so well understood by the authors that it wasn't even written down. # Motivation ## Origins A few years back I set up a computer dedicated to a single task, placed it in a safe place connected to some additional analog electronic devices. Of course, doing this in the early 21st century, it all had to be Internet connected. To help keep it safe, I installed Debian on it, to follow the benefits of security updates. But it also got the benefits of more general updates to keep up with progress in the world: I had installed Debian's Sarge version - and over the years upgraded to Debian's newer stable versions (Etch, Lenny and finally Squeeze). It became reachable via IPv6 as well as IPv4 and kept chugging away at its few tasks. It was a happy little computer. ## Natural Disaster [June 2012 North American derecho](http://en.wikipedia.org/wiki/June_2012_North_American_derecho) The effects of combining wind, trees and power lines meant that the main power to this happy little computer became quite disturbed. Several cycles of power on / power off / power on / power off were observed over just a few minutes, possibly accompanied by unobserved voltage spikes. (The lightning accompanying the wind was well observed.) Then the power was off for several days. When the lights came on, the happy little computer did not boot. Even the power supply for the analog electronic devices no longer supplied power. ## Post mortem The happy little computer was no longer happy. The motherboard BIOS would run, but not find a hard drive. The hard drive was no longer working, and would not come up even when attached to a newer, non-traumatized computer. But what's more - even known good hard disks were not found by the unhappy little computers BIOS. Time to put the old hard disk, the motherboard and its power supply into the appropraite recycling dumpster. ## More crufty old hardware It's now August 11, 2012. I was remarking that failure of an old IDE hard drive was really no surprise, and I really think I've got good backup copies of the important stuff. While that vintage technology did the job just fine, I was worried that any technology refresh would bring us into a new motherboard with SATA interfaces, and a new SATA hard drive, and associated power supply with SATA power pins.... "I've got some extra solid-state disk chips from retired thin client computers that you could use...", said a compassionate, helpful colleague. These turned out to be 40 pin PATA Disk on Module devices with a whopping 256MB capacity. I also got two with only 32MB. Thanks! SimpleTech 256MB IDE Flash Drive Disk On Module DOM [like](http://www.ebay.com/itm/SimpleTech-128MB-IDE-Flash-Drive-Disk-On-Module-DOM-060130-FL1-003-94000-01201-0-/140742916320?pt=US_USB_Flash_Drives&hash=item20c4ee78e0) [PQI DiskOnModule DOM 32mb Flash Memory p/n FD032-019PR](http://www.5rltd.com/productcart/pc/viewPrd.asp?idproduct=790&idcategory=73) This will let me use some other cast-away pre-SATA motherboard to rebuild the system. (Yes, I know very well that even in these trying times we can afford to buy new stuff. But that's beside the point. The old system was built of dumpster-grade parts - so should the new system to replace it. Using other people's trash is a design goal.) ## A new (old) computer I found a motherboard: a mini-ITX VIA EPIA system. Nice, small. No gigabit ethernet. No SATA. 256M RAM. Perfect. It does have a parallel port. (Try that trick with a new Atom-based board...) So off I went to install Debian. I was able to netboot the beta version of the debian-installer for Wheezy. (Easy for me, but I do not recommend that Beginners try this if they wish to retain their Beginner status. I happen to already have a pre-existing up to date Debian system providing DHCP and tftp for my home network, and I've netbooted plenty of things before.) I turns out that 256 MB of disk space is not enough to install Debian Wheezy. So I put aside the flash disk-on-module device and went ahead and installed Debian Wheezy on a 12 GB laptop hard disk. The sensible thing to do, of course, is just run standard Debian on the available laptop hard disk, and move on to replace the failed computer. Instead of doing the sensible thing - I figured it was time to use the Embedded version of Debian. # Emdebian "Why use Emdebian rather than Debian? The most obvious reason is installation sizes." -- [Embedded Debian](http://www.emdebian.org/) "What's Emdebian Grip all about? Simply a smaller Debian. Smaller packages, smaller downloads, smaller sets of packages, smaller installation sizes and smaller update sizes; yet always and completely binary compatible with Debian. Every backtrace from an Emdebian Grip device will match the backtrace on a Debian machine of the same architecture, package version etc. Packages can be mixed trivially (with some allowances for strict dependencies like -dbg packages). The name is a derivative of Squeeze - to make Debian smaller, we take a hold of it; Grip it." -- [[Neil Williams, 15 November 2010](http://www.linux.codehelp.co.uk/serendipity/index.php?/archives/217-Documenting-Emdebian-intro.html) It would be cool if I cound make a replacement computer system that used disk on chip. The old system produced hard drive noise for years on end. Quieter is better. Low power is better, since then the power supply, too, can be fanless. Maybe use [one of these](http://www.mini-box.com/DC-DC). Starting with the laptop disk install is good. The Wheezy base system installs and runs fine on i486 level of CPU and only 256 MB of RAM. And it gave me a stepping stone for installing Emdebian on the 256 MB module. While Debian as a whole is remarkably well documented, the Emdebian specific methods and tools are minimally documented. Most current embdebian use is in the realm of small, battery powered ARM CPU computers, and yet I find myself using 10 year old computer parts. But there are good things on the web sites, wiki pages, blogs and mailing lists that are worth amplifying by quoting them here. ## Web page wisdom [Flavors of Emdebian](http://www.emdebian.org/emdebian/flavours.html) - Grip, Baked and Crush flavors. I am interested in [Grip](http://www.emdebian.org/grip/). [Multistrap](http://www.emdebian.org/multistrap/index.html) [grip-wheezy.conf](http://www.emdebian.org/multistrap/examples/grip-wheezy.conf) [EmdebianIntegration](http://wiki.debian.org/EmdebianIntegration) - the work in progress to improve automation and maintainability so that what began as Emdebian in the form of a project separate from Debian becomes merely another feature included in Debian. [Emdebian 2.0](]http://www.emdebian.org/release/squeeze.html) - the squeeze release. ## Mailing list wisdom "Successful debootstrap of armel with emdebian!" "Just a quick note to let you know that I've just finished setting up a debootstrapped armel using almost solely the emdebian repositories. Great work, guys!!" -- [Bill Gatliff et al, mailing list thread 09 Jan 2009](https://lists.debian.org/debian-embedded/2009/01/msg00013.html) "Crush? There are no packages for Crush outside ARM for Lenny. (not armel or armhf). There is no method of adding packages to Crush - none at all. Until we have MultiArch in Debian and cross-building can be migrated to MultiArch, there have been and will be no updates for Crush." "The apt-grip manpage is slightly out of date because the bit about adding packages to Grip directly is currently postponed." "Once the EmdebianIntegration is complete, there will be a mechanism. Right now, sid-grip is a best-effort and is still playing catch up with a completely rewritten set of tools and wheezy-grip is not being updated until sid-grip is in a better state. These things take time." "Recommendation is to use Squeeze from www.emdebian.org/grip and complement that with the output of apt-grip to create your own local repository." -- [Neil Williams, 30 Dec 2011](https://lists.debian.org/debian-embedded/2011/12/msg00004.html) ## Blog wisdom mkdir /media/grip/ mount /dev/sdc1 /media/grip/ sudo debootstrap lenny /media/grip/ http://www.emdebian.org/grip/ cd /media/grip/ mount -o bind /dev/ dev/ mount -o bind /proc proc/ chroot . /bin/bash aptitude update aptitude install linux-image-2.6.28-1-686 initramfs-tools aptitude install what-you-want aptitude install grub grub-install /dev/sdc update-grub exit umount dev/ umount proc/ cd ../ umount grip/ "Now you have a bootable EmDebian Grip install" -- [Giovanni Toraldo, 20 March 2010](http://gionn.net/howto-install-emdebian-grip-deboostrap) The [Codehelp blog](http://www.linux.codehelp.co.uk/serendipity/). # My approach First spend some time playing around with chroot installs of several versions of Emdebian, then wrap up by forging ahead with a wheezy based grip install. ## Cargo Culting Now I have used the debootstrap tool before, and understand the workings of chroot and the bind mounts used by Giovanni Toraldo. Alas Debian's Lenny version is old, and recently security updates for it have stopped. So I proceeded to give that method a try using the current stable and supported Debian version squeeze. I also saw things not work, and failed just like others before me. The *debootstrap* method has bugs, and more recently people have been having much better luck and put more effort into developing the *multistrap* method. The term "Cargo Cult" came up in discussion, and I entertained the thought that next time someone asks what my religious affiliation is I just might answer "Cargo Cult". I have certainly just been doing some [Cargo Cult Programming](http://en.wikipedia.org/wiki/Cargo_cult_programming). However, I am not on a remote Pacific island. I have lots of Internet resources and now have software running where I can try things out and see what happens using experimental methods. (Even back when I was on a remote Pacific island I was able to obtain documentation and do some low-level programming to get my computers working better.) ## Wheezy install Despite the advice of the knowledgeable developers of emdebian found on the web pages and mailing list posts I was not content to install the known-good stable software. I wanted to poke at things as they exist *today*, see what breaks, and offer some current work-arounds that might just get folded into the next release. I figured I'd go with the multistrap install method rather than try pre-seeding the Debian Installer since it seemed that multistrap would end up with a smaller installation size. Time to do some [Yak Shaving](http://theagileadvisors.com/the-agile-team/so-there-i-am-shaving-a-yak/). # Install notes It seemed like a good idea to fetch the emdebian archive keyring. aptitude install emdebian-archive-keyring multistrap emdebian-grip Partition and mount embedded storage device. Mine showed up as /dev/sda yours might very likely be different. fdisk /dev/sda mkfs.ext4 /dev/sda1 mkdir /media/grip/ mount /dev/sda1 /media/grip/ (If you don't run fdisk and instead just use the partitions left on the device by an embedded Windows installation you may find when you go to install grub it will fail because there is not enough room between the start of the disk and the start of the first partition for grub to store stuff.) Multistrap: get pre-built gripped binary packages. wget http://www.emdebian.org/multistrap/examples/grip-wheezy.conf multistrap -d /media/grip -f grip-wheezy.conf apt-grip: make your own gripped binary packages from standard pre-built debian binary pockages. These are packages I wanted installed, but multistrap could not find. TMPDIR=/var/tmp apt-grip --build-only -M http://ftp.us.debian.org/debian/ linux-image-3.2.0-3-486 kmod linux-base initramfs-tools klibc-utils cpio udev libkmod2 libuuid-perl libklibc libudev0 grub-common grub-pc grub-pc-bin grub2-common libdevmapper1.02.1 libfreetype6 libfuse2 gettext-base dmsetup libasprintf0c2 cp /var/lib/apt-grip/output/* /media/grip/root/ Enter chroot: cd /media/grip/ cp /etc/resolv.conf etc/ cp /etc/hostname etc/ echo /dev/sda1 / ext4 rw,relatime,user_xattr,barrier=1,data=ordered 0 0 > etc/mtab mount -o bind /dev/ dev/ mount -o bind /proc proc/ chroot . /bin/bash I'm not sure it was necessary, but I created a tentative etc/mtab in case that information was useful to initramfs-tools when installing the kernel. ## Things done in the chroot Set the root password in order to be able to log in after reboot. passwd Also add a non-root user: adduser user Install all the fresh-made embedded debs: cd /root dpkg -i *deb Get some packages: apt-get update apt-get install grub-common grub-pc grub-pc-bin grub2-common apt-get install ssh isc-dhcp-client ifupdown apt-get install what-you-want Keep an eye on remaining disk space. Actually, grub might not install the first time, you might need to fiddle with boot/grub/device.map or at least examine what's in there to better drive grub-install. Exit chroot. exit ## Back outside the chroot Edit the etc/fstab - I used blkid /dev/sda1 to some up with a UUID to use for the root partition. Edit the grip etc/network/interfaces so that eth0 comes up when booting. cat >> etc/network/interfaces auto eth0 iface eth0 inet dhcp Since I'm using the same hostname for the embedded disk as I am for the laptop disk (after all, it is the same motherboard, same ethernet MAC address) I copy the ssh host keys: cp /etc/ssh/ssh_host* etc/ssh/ssh_host* Reboot and reconfigure the BIOS to boot from the Flash disk. # Epilogue Finally, on 19 August 2012, I have an Emdebian Wheezy box that boots and runs with a 256 MB IDE flash drive. df -Th gives me something along the lines of: Filesystem Type Size Used Avail Use% Mounted on /dev/sda1 ext4 241M 199M 30M 87% / And I've already gotten updated packages from the emdebian repository. Very nice to see progress. TODO: see what filesystem tuning might help better use the flash device, along the lines of [Tips for running Linux on a flash device](http://www.cyrius.com/debian/nslu2/linux-on-flash.html) To all who made this possible - Thank you for all the great work you did! The remaining work I did went quickly and easily because you have done such a good job. -Maitland (If you've read this far... Comments? Please trim your replies.) -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/[email protected]
