[Clfs-support] clfs-embedded-sysroot (ARM) queries

[Andrew Bradford]

On Thu, May 5, 2011 at 8:13 AM, bv <bvl at btconnect.com> wrote:
> I dabbled with porting clfs to the beagleboard (ARM-based)  a few years ago.
> I looked at development clfs and noticed   the branch called sysroot.

IMO, the sysroot book is kind of the unloved child right now.  It
hasn't had any updates to book content in almost 2 years.  Just an
FYI, there may be errors that have already been fixed in the embedded
or main books.  Both embedded and the main book are receiving much
more attention.
If you find issues (and subsequent fixes) when working with it, please
email this list or -dev.

Something you may want to look at (if you haven't yet) is the embedded
book.  It will build for BeagleBoards.  I have a BeagleBoard-xM, it
boots and works :)
Boot output of a slightly older version of embedded CLFS without
network support:
https://gist.github.com/874183

The current embedded 20110419 book boots, too.  I just don't have
output up online yet as I'm working on getting my kernel config
correct in order to support the USB Ethernet chip on the -xM.

> a) How does one port  the  newly minted system from the mother X86-based-
> machine to the target (ARM-based)  machine?

I just copy the whole ${CLFS}-final directory over to the SD card.
The first partition on the SD card is a FAT partition and holds the
MLO (first stage TI bootloader), u-boot (normal bootloader), and
kernel.  The second partition is an ext3 partition and holds the root
filesystem (in my boot output, it's technically the 3rd partition, but
its the same idea).

> b) what are the target boards for the clfs sysroot arm-based efforts?

I don't know, sorry.  The embedded book works for various armv4t and
Cortex-A8 based boards, based on conversations I've had via email and
IRC.  It really just comes down to kernel config.  Pretty much any ARM
core newer than armv4t that supports 'arm' mode should work using the
EABI (so things like Cortex-M3 won't but armv5t will).  Older cores
might work with the OABI, but haven't heard much of people trying
that.  Thumb mode is iffy in the embedded book right now.

> c) there does not seem to be a bootloader for the arm target machine, so (as
> with a) above ) how  does one boot the newely minted clfs system on the target
> machine?

Currently, I'm using the provided u-boot that came with my
BeagleBoard-xM to boot.  I'm working on modifying it so that it boots
without requiring manual intervention to use the settings I want.  I'm
not there yet.  After that (at some point), I'll be working to write
up u-boot build instructions as an example for the embedded book.  No
timeline on that yet, though.

-Andrew