Use initramfs on x86 but not on arm for factory install image.

Use initramfs on x86 but not on arm for factory install image.

On x86, booting factory install shim on SD card needs to have the kernel
initrmafs enabled. But on ARM, booting factory install image on network does
not needs initramfs.

TEST=build_image --factory_install
BUG=chromium-os:13211, chromium-os:14098
Change-Id: Id008a3bfaf4f17772e04f02d18844dd09b33fbe1

R=rongchang@chromium.org

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=a6af201

[rongchang, 2011-04-27 11:34:20]

LGTM. But we still need SD bootable shim on arm, right?

[Mandeep Singh Baines, 2011-04-27 15:08:55]

+cc robotboy

Why is ARM different from x86?

waihong@chromium.org (waihong@chromium.org) wrote:
> Reviewers: rongchang,
> 
> Description:
> Use initramfs on x86 but not on arm for factory install image.
> 
> On x86, booting factory install shim on SD card needs to have the kernel
> initrmafs enabled. But on ARM, booting factory install image on network does
> not needs initramfs.
> 
> TEST=build_image --factory_install
> BUG=chromium-os:13211
> 
> Change-Id: Id008a3bfaf4f17772e04f02d18844dd09b33fbe1
> 
> R=rongchang@chromium.org
> 
> 
> Please review this at http://codereview.chromium.org/6901047/
> 
> SVN Base: http://git.chromium.org/git/crosutils.git@master
> 
> Affected files:
>   M build_image
> 
> 
> Index: build_image
> diff --git a/build_image b/build_image
> index
306c753135e4ef46eef2565f79e85a3a4615e8c9..8fbc2d8043d765e695c541188b2292a3bfe3c708
> 100755
> --- a/build_image
> +++ b/build_image
> @@ -190,10 +190,16 @@
OVERLAY_CHROMEOS_DIR="${SRC_ROOT}/third_party/chromiumos-overlay/chromeos/"
>  # Configure extra USE or packages for this type of build.
>  EXTRA_PACKAGES=""
>  if [ ${FLAGS_factory_install} -eq ${FLAGS_TRUE} ] ; then
> -  # Factory install needs to have the kernel initrmafs enabled,
> -  # and the factory installer added.
> +  # Factory install needs to have the factory installer added.
>    EXTRA_PACKAGES="${EXTRA_PACKAGES} chromeos-base/chromeos-factoryinstall"
> -  export USE="${USE} fbconsole initramfs"
> +  # On x86, booting factory install shim on SD card needs to have
> the kernel
> +  # initrmafs enabled. On ARM, booting factory install image on
> network does
> +  # not needs initramfs. Force to enable fbconsole to fix a display
> driver bug.
> +  if [ ${ARCH} -eq "arm" ] ; then
> +    export USE="${USE} fbconsole"
> +  else
> +    export USE="${USE} initramfs"
> +  fi
>  fi
> 
>  emerge_to_image() {
> 
> 

[Mandeep Singh Baines, 2011-04-27 17:01:11]

Talked it over with robotboy. I understand better now why this change makes
sense.

LGTM

[jrbarnette, 2011-04-27 18:33:09]

On 2011/04/27 17:01:11, Mandeep Singh Baines wrote:
> Talked it over with robotboy. I understand better now why this change makes
> sense.
> 
For posterity, could someone write up the reason, and stick it somewhere
like the bug report?

> LGTM

[Mandeep Singh Baines, 2011-04-27 19:50:01]

jrbarnette@chromium.org (jrbarnette@chromium.org) wrote:
> On 2011/04/27 17:01:11, Mandeep Singh Baines wrote:
> >Talked it over with robotboy. I understand better now why this
> >change makes
> >sense.
> 
> For posterity, could someone write up the reason, and stick it somewhere
> like the bug report?
> 

I believe the reason we are doing this is that on ARM we can netboot
(u-boot supports it). Our x86 BIOS does not currently support netbooting.
Netbooting simplifies the factory flow dramatically so its what we want
to do whenever it is available.

I'll let folks working on this issue update the bug with the official
explanation. But totally agree. We shouldn't be making these sort of
changes as simple code reviews. There should at least be a description in
a bug report of design doc somewhere.

> >LGTM
> 
> 
> 
> http://codereview.chromium.org/6901047/

[Nick Sanders, 2011-04-27 21:23:13]

Will this break SDCard boot on ARM?

[Tom Wai-Hong Tam, 2011-04-28 03:55:42]

The SDCard boot still works but you can't pop the card out during the factory
install process. Since we disable initramfs, so the rootfs is no longer in RAM,
it needs to access the SD card rootfs.

[Tom Wai-Hong Tam, 2011-04-28 04:54:08]

I added the reason in the bug of ARM network boot.

http://code.google.com/p/chromium-os/issues/detail?id=14098#c6

[Mandeep Singh Baines, 2011-04-28 15:46:39]

waihong@chromium.org (waihong@chromium.org) wrote:
> I added the reason in the bug of ARM network boot.
> 

Thanks!

> http://code.google.com/p/chromium-os/issues/detail?id=14098#c6
> 
> http://codereview.chromium.org/6901047/