Re: [gentoo-embedded] x86 SBC Gentoo Embedded HotTo version 0.07

[Natanael Copa <mlists@tanael.org>]

Best regards
Natanael Copa

people are talking about?
http://en.wikipedia.org/wiki/Top-posting

and then scroll to the top again
to get a clue about what

when you have to scroll to
the bottom of every posting

Is it only me who thinks
that is is pretty annoying


S. ancelot wrote:

>
> Hi,
>
> If I remember, the best thing to do is using a squashfs filesystem.
>
> Taking the filesystem completely in ram is a bad idea and unnecessary 
> (CF are lifetime warranty if you only read it !).
>
> Are you using catalyst ???
>
>
> I advice you trying GNAP in order to understand how to go on ...
>
> Best regards
> Steph
>
>
> Marcel Romijn wrote:
>
>> Hi Heath,
>>
>> I know about the limited number of write cycles on CF. Therefore I want
>> the CF only to supply the kernel and the ramdisk image. My intention is
>> to run Linux and my application completely from ramdisk.
>> I want my device to be complately silent, therefore it has a fanless
>> ME6000 board, no fans in the case and no harddisk (actually strange to
>> 'hear' a computer boot in complete silence!). The CF is on an IDE
>> converter and is recognized as /dev/hda1 (although for testing it has a
>> normal harddisk connected).
>>
>> I was able to follow your howto to the end.
>> Although I had some problems where the boot process stopped after
>> "Freeing unused kernel memory". This turned out to be a typo in
>> /etc/fstab on my side.
>>
>> Now that I have bootable configuration, I can look into what it takes to
>> have the system files in a ramdisk image and have it mounted as '/'.
>>
>> I think I could just create an initrd from the whole system and have
>> grub and the kernel extract it in memory and mount it.
>> I have not done much investigation on it, be it seems to me that the
>> /linuxrc in the initrd can be fairly simple. Actually just calling the
>> /sbin/init once the ramdisk is mountded as '/'.
>>
>> Anyone any experience with this?
>>
>> PS. Maybe we should spawn of another thread about VIA Epia boards, CF
>> and booting. I saw Pierre Cassimans is interested in this subject as
>> well.
>> This might go off topic for the Gentoo Embedded Howto.
>>
>> Marcel
>>
>> -----Original Message-----
>> From: Heath Holcomb [mailto:liquidcable@bulah.com] Sent: Sunday, 14 
>> August, 2005 0:53
>> To: gentoo-embedded@lists.gentoo.org
>> Subject: Re: [gentoo-embedded] x86 SBC Gentoo Embedded HotTo version
>> 0.07
>>
>> On Friday 12 August 2005 01:39 am, Marcel Romijn wrote:
>>  
>>
>>> Hello Heath,
>>>
>>> Nice writedown! I haven't made it to the end yet (lack of time), but
>>>   
>>
>> I'm
>>  
>>
>>> getting there...
>>>
>>> I noticed some issues along the way (not counting grub begin spelled
>>>   
>>
>> as
>>  
>>
>>> "grug" or "gurb" ;-) )
>>>
>>> In step 3 you write:
>>>
>>> <snip>
>>> # Set root password for the embedded_rootfs
>>> chromm /embedded_rootfs
>>> passwd
>>> rm /embedded_rootfs/etc/passwd-
>>> Exit
>>> </snip>
>>>
>>> I presume 'chromm' should have been 'chroot' ?
>>> If it is indeed 'chroot' then you should either do "rm /etc/passwd-"
>>> before the "exit" or the "exit" before the "rm
>>> /embedded_rootfs/etc/passwd-".
>>>   
>>
>>
>> Yes, "chromm" should be "chroot".  The order is correct, as far as I can
>> tell.
>> chroot /embedded_rootfs
>> passwd
>> rm /embedded_rootfs/etc/passwd-
>> exit
>>
>>
>>  
>>
>>> A few lines down, you write:
>>>
>>> <snip>
>>> rm -R /embedded_rootfs/var/db/pkg/ *
>>> </snip>
>>>
>>> As a reletive newbie, doing a quick copy/paste of this command late in
>>> the evening as root in '/', this wiped out all files, except the ones
>>> that were firmly locked.
>>> Fortunately, I'm going through you HowTo in VMWare, so I could restore
>>>   
>>
>> a
>>  
>>
>>> previous snapshot ;-)
>>>
>>> I presume the space before the '*' should have been omitted?
>>>
>>> <snip>
>>> rm -R /embedded_rootfs/var/db/pkg/*
>>> </snip>
>>>   
>>
>>
>> Major typo on my part.  Fixed in version 0.08.
>>
>>  
>>
>>> My aim is to create an embedded Gentoo for a Via Epia ME6000, which
>>> reads the kernel and a ramdisk image from CF and then runs completely
>>> from RAM.
>>> If I'm not mistaken, you were heading for a Via Epia as well?
>>>   
>>
>>
>> My target will be a Via based SBC.  From what I have read using a
>> ramdisk on a x86 based platform really does not buy you much.  But 
>> you sure don't
>> want to write to the CF all that often (limited write cycles, usallay 
>> 100,000 to
>>
>> 300,000).  So I plan on mounting the / partition of the CF as read only
>> and creating a separate partition that is mounted read/write and have my
>> embedded application and only my application write to that partition.
>>
>>  
>>
>>> Regards,
>>>
>>> Marcel Romijn
>>>
>>>
>>> -----Original Message-----
>>> From: Heath Holcomb [mailto:liquidcable@bulah.com]
>>> Sent: Monday, 08 August, 2005 4:17
>>> To: gentoo-embedded@lists.gentoo.org
>>> Subject: [gentoo-embedded] x86 SBC Gentoo Embedded HotTo version 0.07
>>>
>>> Version 0.07
>>> Please add, delete, modify. Thanks!
>>>
>>> Several fixes.  Root password now works.  Several work arounds are no
>>> longer
>>> need, as the embedded Gentoo team has fixed them (I'm guess because I
>>>   
>>
>> no
>>  
>>
>>> longer get those errors).  There is still one problem when "emerge -e
>>> system"
>>> for groff.  Bug 98187 (http://bugs.gentoo.org/show_bug.cgi?id=98187).
>>> Check
>>> out the bug report for the temp fix/work around (USE="-sandbox" emerge
>>> -e
>>> system).
>>>
>>> I've update my website with this version also.
>>> http://www.bulah.com/embeddedgentoo.html
>>>
>>>
>>>
>>>   
>>
>> #-----------------------------------------------------------------------
>>  
>>
>>> ---------
>>> # Embedded Gentoo How-To for x86
>>> #
>>> # A how-to guide to setup a Gentoo embedded environment, you must be
>>> root.
>>> # These commands are to be run on your development system,
>>> # any x86 Gentoo Linux computer will do.  The system should be fast,
>>> # to speed development.  The target can be any x86 based SBC.  I'm
>>> # using a Geode based SBC.  Latter I'll use a Via based SBC.
>>> #
>>> # version 0.07
>>> # 2005.8.7
>>> #
>>> # Heath Holcomb (heath at bulah.com)
>>> # Ned Ludd (original commands posted)
>>> # Lloyd Sargent (contributor)
>>> # Yuri Vasilevski (contributor)
>>> # Mike George (contributor)
>>> # Kammi Cazze (contributor)
>>> # Marius Schaefer (contributor)
>>> #
>>> # Definitions and Terms
>>> # system_rootfs = your regular rootfs, development computer
>>> # 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
>>> # http://www.gentoo.org/doc/en/handbook/index.xml
>>> # http://www.epiawiki.org
>>> # http://epia.kalf.org
>>> # Gentoo embedded mailing list (gentoo-embedded@lists.gentoo.org)
>>> #
>>> #
>>> # Overview of process (steps)
>>> # 1 - Prepare the development_rootfs from your system_rootfs
>>> # 2 - Build the development_rootfs
>>> # 3 - Build the embedded_rootfs
>>> # 4 - Build and install non-system programs to the embedded_rootfs
>>> # 5 - Build and install a kernel to the embedded_rootfs
>>> # 6 - Deploy embedded_rootfs to target
>>> #
>>>
>>>   
>>
>> #-----------------------------------------------------------------------
>>  
>>
>>> ---------
>>>
>>> #----- Step 1 - Prepare the development_rootfs from your system_rootfs
>>> -------
>>>
>>> # You must be root.
>>> su -
>>>
>>> # Create the development_rootfs.
>>> # I use i586 because 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 -xvjpf stage1-x86-uclibc-2005.0.tar.bz2 -C
>>> /opt/i586-gentoo-uclibc-linux/
>>>
>>> # Mount the proc and portage directories to your development_rootfs.
>>> # Makes your system_rootfs's proc and portage directory available from
>>> inside
>>> # of your development_rootfs (after chrooting).
>>> 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.
>>> chroot /opt/i586-gentoo-uclibc-linux /bin/bash --login
>>>
>>>
>>> #----- Step 2 - Build the development_rootfs
>>> ---------------------------------
>>>
>>> # Create new environment and load variables into memory.
>>> env-update
>>> source /etc/profile
>>>
>>> # Modify make.conf file to your liking/needs.
>>> nano -w /etc/make.conf
>>> # This is for my target, Geode x86 processor.
>>> /*
>>> USE="bitmap-fonts minimal truetype-fonts mmx"
>>> CHOST="i586-gentoo-linux-uclibc"
>>> CFLAGS="-march=i586 -Os -pipe -fomit-frame-pointer -mmmx"
>>> CXXFLAGS="${CFLAGS}"
>>> FEATURES="buildpkg"
>>>
>>> VIDEO_CARDS="chips"
>>> UCLIBC_CPU="586MMX"
>>> */
>>>
>>> # Set profile to use 2.6 kernel.
>>> # The current stage uses 2.4 by default, and for most cases you are
>>> going
>>> # to want a 2.6.x kernel.
>>> cd /etc/
>>> unlink make.profile
>>> ln -s ../usr/portage/profiles/uclibc/x86 make.profile
>>>
>>> # Start the bootstrap script.
>>> cd /usr/portage/scripts
>>> ./bootstrap.sh -p -v
>>> ./bootstrap.sh
>>>
>>> # Emerge the system ebuild for the development_rootfs.
>>> emerge -e system
>>>
>>> #----- Step 3 - Build the embedded_rootfs
>>> ------------------------------------
>>>
>>> # Create the embedded_rootfs directory.
>>> mkdir /embedded_rootfs
>>>
>>> # Emerge baselayout-lite into embedded_rootfs.
>>> # This gives your system a basic file structure.
>>> # 1.0_pre1 is the only one that is stable, right?
>>> cd /usr/portage/sys-apps/baselayout-lite/
>>> ROOT=/embedded_rootfs emerge baselayout-lite-1.0_pre1.ebuild
>>>
>>> # Workaround 1
>>> # Baselayout-lite is still beta, so a few fixes are needed.
>>> # There needs to be a directory "log" in /var.
>>> # Inittab calls for /usr/bin/tail, but it needs to /usr/bin.
>>> mkdir /embedded_rootfs/var/log
>>> nano -w /embedded_rootfs/etc/inittab
>>> /*
>>> #tty3::respawn:/usr/bin/tail -f /var/log/messages
>>> tty3::respawn:/bin/tail -f /var/log/messages
>>> */
>>>
>>> # Emerge uclibc into the embedded_rootfs.
>>> # Use the -K option because we don't get the extra files created by
>>>   
>>
>> the
>>  
>>
>>> # build/emerge process into our embedded rootfs which needs to be as
>>> # small as possible.
>>> ROOT=/embedded_rootfs emerge -K uclibc
>>>
>>> # Emerge busybox into the embedded_rootfs.
>>> # First you must emerge it into your development_rootfs.
>>> # This does not create the symlinks in our development embedded
>>>   
>>
>> rootfs.
>>  
>>
>>> emerge busybox
>>> ROOT=/embedded_rootfs emerge -K busybox
>>>
>>> # Create the symlinks for busybox in the embedded_rootfs.
>>> mkdir /embedded_rootfs/proc
>>> mount -o bind /proc/ /embedded_rootfs/proc/
>>> chroot /embedded_rootfs /bin/busybox --install -s
>>> umount /embedded_rootfs/proc
>>>
>>> # Set time zone in your embedded_rootfs.
>>> # See http://leaf.sourceforge.net/doc/guide/buci-tz.html for details.
>>> # For central standard time in the US, use "CST6CDT".
>>> nano -w /embedded_rootfs/etc/TZ
>>> /*
>>> CST6CDT
>>> */
>>>
>>> # Install a boot loader (usually grug or lilo).
>>> # Once you copy/deploy your embedded_rootfs to your target SBC you
>>>   
>>
>> will
>>  
>>
>>> # have to run grub on the command line to write to the master boot
>>> record
>>> # (MBR).
>>> # For some reason not all of /boot/grub is copied over to the
>>> # embedded_rootfs, so a extra manual copy step is needed.
>>> # The --nodeps gets rip of the run time need of ncurses.
>>> emerge --nodeps grub
>>> ROOT=/embedded_rootfs emerge -K --nodeps grub
>>> cp -R /boot/grub /embedded_rootfs/boot/
>>>
>>> # Modify your boot configure file.
>>> # The example below is for a gurb, for a boot partition on /dev/hda1
>>>   
>>
>> and
>>  
>>
>>> only
>>> # one partition on the target SBC system.
>>> nano -w /embedded_rootfs/boot/grub/grub.conf
>>> /*
>>> default 0
>>> timeout 10
>>> splashimage=(hd0,0)/boot/grub/splash.xpm.gz
>>>
>>> title=Linux 2.6.x
>>> root (hd0,0)
>>> kernel /vmlinuz-2.6.x root=/dev/hda1 vga=792
>>> */
>>>
>>> # Set root password for the embedded_rootfs
>>> chromm /embedded_rootfs
>>> passwd
>>> rm /embedded_rootfs/etc/passwd-
>>> exit
>>>
>>> # Modify fstab.
>>> # Below is mine, yours may vary.
>>> nano -w /embedded_rootfs/etc/fstab
>>> /*
>>> /dev/hda1        /        reiserfs    defaults
>>> 0 0
>>> none            /proc        proc        defaults
>>> 0 0
>>> none            /sys        sysfs        defaults
>>> 0 0
>>> none            /dev/shm    tmpfs    defaults    0 0
>>> */
>>>
>>> # Clean up the embedded_rootfs.
>>> # Don't know why these files are there in the first place, so if
>>>   
>>
>> anyone
>>  
>>
>>> # can tell me why.....
>>> rm -R /embedded_rootfs/var/db/pkg/ *
>>> rm -R /embedded_rootfs/var/lib/portage/
>>>
>>> #---- Step 4 - Build and install non-system programs to the
>>> embedded_rootfs --
>>>
>>> # Emerge other software you need for you embedded target.
>>> # This is very wildly depending on your needs.
>>> # Also your proprietary application will be done here.
>>> emerge foo*
>>> ROOT=/embedded_rootfs emerge -K foo*
>>>
>>>
>>> #---- Step 5 - Build and install a kernel to the embedded_rootfs
>>> -------------
>>>
>>> # Install a kernel into embedded_rootfs.
>>> # First we will emerge it into our development_rootfs, then configure
>>> and
>>> # build it.
>>> emerge vanilla-sources
>>> cd /usr/src/
>>> cd linux
>>> make menuconfig
>>> # Configure your kernel for your TARGET SBC here.  I HIGHLY suggest
>>>   
>>
>> you
>>  
>>
>>> # configure the kernel to compile everything into the kernel, and
>>> nothing
>>> # as a module.
>>> make
>>> ROOT=/embedded_rootfs make modules_install
>>> cp /usr/src/linux/arch/i386/boot/bzImage
>>> /embedded_rootfs/boot/vmlinuz-2.6.x
>>>
>>> # A few notes on compiling your kernel.
>>> # If deploying to Compact Flash/DiskOnChip/SD use ext2, as the
>>> journaling
>>> # filing systems "write" to much for a flash device.
>>> # If deploying to a hard drive use a journaling filing system, such as
>>> # ext3 or reiserfs.
>>>
>>>
>>> #---- Step 6 - Deploy embedded_rootfs to target
>>> ------------------------------
>>>
>>> # Prepare a Gentoo (or any Linux distro) system on the target SBC
>>>   
>>
>> using
>>  
>>
>>> a
>>> # harddrive.  This is known as the target development rootfs.
>>> # We will create a partition (/embedded_rootfs) that will server as
>>>   
>>
>> our
>>  
>>
>>> # "test" partition to deploy our embedded_rootfs that we generate on
>>>   
>>
>> our
>>  
>>
>>> # development_system.
>>> #
>>> # I use the following partitions to speed development (yours may
>>>   
>>
>> vary):
>>  
>>
>>> # /dev/hda1 - /embedded_rootfs - 1 GB
>>> # /dev/hda2 - /boot - 100 MB
>>> # /dev/hda3 - swap - (size varies, 512 MB is a good number)
>>> # /dev/hda4 - / - (what is left, at least 1.5 GB per 2005.0 install
>>> guide
>>> specs)
>>> #
>>> # Copy over your embedded_rootfs from you development system to your
>>> target
>>> # system and the directory /embedded_rootfs.  This needs to be done
>>>   
>>
>> via
>>  
>>
>>> NFS as
>>> # need to preserve the permissions.
>>> #
>>> #The following commands are done from the
>>> # target development rootfs.
>>> mount -t reiserfs /dev/hda1 /mnt/embedded_rootfs
>>> mount -t nfs\
>>> 192.168.0.10:/opt/i586-gentoo-uclibc-linux/embedded_rootfs\
>>> /mnt/nfs_embedded_rootfs
>>> cp -adpR /mnt/nfs_embedded_rootfs/* /mnt/embedded_rootfs
>>>
>>>
>>> # Modify your target system's gurb.conf (or lilo.conf) for allow you
>>>   
>>
>> to
>>  
>>
>>> boot
>>> # to the embedded_rootfs partition.
>>> #
>>> # Reboot, and if all goes well you'll be greeted with a login prompt.
>>> #
>>> # Fin.
>>>
>>>
>>>
>>> -- 
>>> heath holcomb
>>> liquidcable at bulah.com
>>> www.bulah.com
>>> -- 
>>> gentoo-embedded@gentoo.org mailing list
>>>   
>>
>>
>>  
>>

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