Re: [gentoo-embedded] x86 SBC Gentoo Embedded HowTo

[Heath H Holcomb]

I have always planned on using Compact Flash as my storage medium.  You don't 
have to us any compression if your compact flash size is large enough.  You 
just have to partition, mount / read only, no swap, and write you embedded 
application to only mount and write to the compact flash when data is really 
needed (you can use a separate partition from /).  

Flash devices have a write limit usually between 100,000 to 300,000 times, 
while hard drive writes are measured in millions or billions.  The higher end 
compact flash have something that is called ware leveling, which "moves" the 
memory cells around in the compact flash so writes are distributed through 
out the entire size of the compact flash instead of the exact same location 
every time.  This was what made DiskOnChip the preferred choice a few years 
ago when they had it and compact flash did not.  But most non-cheap compact 
flash's has were leveling today.

-- 
Heath Holcomb
heath at bulah.com
www.bulah.com


On 05 21 2005 10:19 am, michael@×××××××××××××.com wrote:
> I agree with Kammi - this is an incredibly useful howto.
>
> I'm also getting ready to install gentoo on my epia board, I'm using the
> ME6000. A major difference, though, is that I want to create the system
> on a Compact Flash card.
>
> I've already done bootable CF systems using a mix of all sort of notes
> I've found on the web. As a result, I have a mix of things I don't
> understand and I'm sure some things I don't need. This time I'd like to
> do it from scratch so that I understand every step.
>
> In the past I've built the filesystem on my desktop, then compressed it
> using cramfs, which gets written to the CF card. I think I'll do the
> same this time, but I'd be interested to hear what you all might
> recommend.
>
> Does there exist a howto that describes this whole process? If not, would
> others find it useful?
>
> Any tips, pointers, and suggestions welcome.
>
> Michael
>
> On Fri, 29 Apr 2005, Kammi Cazze wrote:
> > Hi,
> >
> > first of all i like your id of putting such a howto up. I hope you will
> > get much help from the devs. I think the problem is that this project is
> > in full development and ways of accompishing things here vary very
> > quickly and are always made better and easier to do.
> >
> > Here is some stuff you could put into it, because it won't change alot in
> > the feature ;)
> >
> > - You could mention something about how to set the timezone on the uclibc
> > box. There is a full expl. on this site:
> > http://leaf.sourceforge.net/doc/guide/buci-tz.html
> >
> >> ROOT=/Embedded RootFS emerge busybox uclibc
> >
> > You could also put baselayout-lite in it. I don't know what the status is
> > by now (ask iggy)!
> >
> > As on such a system devfs or udef is mostly unwanted, you will have to
> > create your /dev nodes manualy, because baselayout-lite only makes the
> > most neaded once, like /dev/hd* and /dev/sd*
> >
> >
> > Pierre Cassimans
> >
> >> From: Heath H Holcomb <heath@×××××.com>
> >> Reply-To: gentoo-embedded@l.g.o
> >> To: gentoo-embedded@l.g.o
> >> Subject: [gentoo-embedded] x86 SBC Gentoo Embedded HowTo version 0.03
> >> (unfinished)
> >> Date: Fri, 29 Apr 2005 08:49:21 -0500
> >>
> >> Version 0.03
> >> Please add, delete, modify. Thanks!
> >>
> >>> -----------------------------------------------------------------------
> >>>---------------- Embedded Gentoo How-To for x86
> >>>
> >>> Commands to setup a Gentoo embedded environment, you must be root.
> >>> These commands are to be run on your developement system,
> >>> any x86 Gentoo Linux computer will do.  The system should be fast,
> >>> to speed developement.  The target can be any x86 based SBC.  I'm
> >>> using a Geode based SBC.  Latter I'll use a Via based SBC.
> >>>
> >>> version 0.03
> >>> 2005.29.04
> >>>
> >>> Heath Holcomb (heath at bulah.com)
> >>> Ned Ludd (original commands posted)
> >>> Yuri Vasilevshi (contributor)
> >>> Mike George (contributor)
> >>>
> >>> Development RootFS = what you use to build the Embedded RootFS
> >>> Embedded RootFS = rootfs you deploy to the target system
> >>> SBC = single board computer (here it's an x86 based)
> >>>
> >>> References
> >>>
> >>>> //www.gentoo.org/doc/en/handbook/index.xml
> >>>> //www.epiawiki.org
> >>>> //epia.kalf.org
> >>>
> >>> Gentoo embedded mailing list (gentoo-embedded@l.g.o)
> >>>
> >>>
> >>> -----------------------------------------------------------------------
> >>>----------------
> >>>
> >>> create the Development RootFS
> >>> I use i586 becasue of target is a Geode processor
> >>
> >> mkdir -p /opt/i586-gentoo-uclibc-linux/usr/portage
> >>
> >> # download the latest stage 1 tarball
> >> wget \
> >> http://gentoo.osuosl.org/experimental/x86/embedded/stages/stage1-x86-ucl
> >>ibc-2005.0.tar.bz2
> >>
> >> # untar the stage to the Development RootFS
> >> tar -xvjf stage1-x86-uclibc-2005.0.tar.bz2 -C
> >> /opt/i586-gentoo-uclibc-linux/
> >>
> >>> mount the Development RootFS proc and portage directories
> >>> don't understand this someone please add comments
> >>
> >> mount --bind /proc /opt/i586-gentoo-uclibc-linux/proc/
> >> mount --bind /usr/portage /opt/i586-gentoo-uclibc-linux/usr/portage
> >>
> >> # copy over DNS information to the Development RootFS
> >> cp /etc/resolv.conf /opt/i586-gentoo-uclibc-linux/etc/resolv.conf
> >>
> >> # chroot into the Development RootFS, create new environment, load
> >> variables
> >> into memory
> >> chroot /opt/i586-gentoo-uclibc-linux /bin/bash --login
> >> env-update
> >> source /etc/profile
> >>
> >> # modify make.conf file to your liking
> >> nano -w /etc/make.conf
> >> # this is for my target, Geode x86 processor
> >> CHOST="i586-gentoo-linux-uclibc"
> >> CFLAGS="-march=i586 -Os -pipe -fomit-frame-pointer -mmmx"
> >> CXXFLAGS="${CFLAGS}"
> >> FEATURES="buildpkg"
> >>
> >> # work around for bug 90306
> >> mknod -m 0444 /dev/random c 1 8
> >> mknod -m 0444 /dev/urandom c 1 9
> >>
> >> # start the bootstrip script
> >> cd /usr/portage/scripts
> >> ./bootstrap.sh -p -v
> >> ./bootstrap.sh
> >>
> >> # emerge system
> >> emerge -e system
> >> # fixes a emerge ebuild bug, this should go away soon
> >> emerge python
> >> # continue with the rest of the emerge system
> >> emerge -e system
> >>
> >>> modify make.conf and set you USE flags for the target embedded build
> >>> these use flags build a smaller system with no documentation, man or
> >>> info
> >>
> >> pages installed
> >> # the make-symlinks option of for busybox to automatically create the
> >> symlinks
> >> to it
> >> nano -w /etc/make.conf
> >> USE="make-symlinks nodoc noinfo noman"
> >>
> >>> build busybox and uclibc, put into the Embedded RootFS (/Embedded
> >>> RootFS)
> >>> don't understand exactally how this works, someone please add comments
> >>
> >> mkdir /Embedded RootFS
> >> ROOT=/Embedded RootFS emerge busybox uclibc
> >>
> >> # emerge other software you need for you embedded target
> >> ROOT=/Embedded RootFS emerge xxxxxxxxx
> >>
> >> # install a kernel into Embedded RootFS
> >> ROOT=/Embedded RootFS emerge vanilla-sources
> >> cd /Embedded RootFS/usr/src
> >> ln -s linux-
> >>
> >> ......... more stuff here ...........
> >> ......... install xorg-x11, less than 10MB hopefully
> >> ......... install light window manager (blackbox, windowmaker, ???)
> >> ......... install very light X11 toolkit (?????)
> >> ......... purge to the Embedded RootFS of unwanted files and libaries
> >> ......... edit all config files
> >> ......... set up the test harddrive on the target SBC
> >> ......... install grub or lilo on the test harddrive on the target SBC
> >> ......... transfer Embedded RootFS to the test harddrive on the target
> >> SBC ......... debug system, and rebuild
> >> ......... deploy Embedded RootFS from the test harddrive to flash
> >> ......... (DiskOnChip, Compact Flash)
> >> ......... tweak, rebuild, redeploy
> >>
> >> --
> >> Heath Holcomb
> >> heath@×××××.com
> >> www.bulah.com
> >> --
> >> gentoo-embedded@g.o mailing list
> >
> > _________________________________________________________________
> >
> >
> > --
> > gentoo-embedded@g.o mailing list

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