make_dev_ssd: fix --remove_rootfs_verification

make_dev_ssd: fix --remove_rootfs_verification

The remove_rootfs_verification was corrupted by several issues:
1. enable_rw_mount (ext2 RO bit hack) should be performed on every rootfs
   and only after we successfully resigned the kernel.
2. for latest images, we must first resign again before changing
   boot parameter, otherwise verification would fail.
Both fixed and verified.

BUG=chromium-os:8629
TEST=(1)built a ToT image, install by USB boot, then
        ./make_dev_ssd --remove_rootfs_verification; then reboot.
        rootdev shows /dev/sda3 and is writable.
     (2)install by factory setup and then wipe so that root = sda5
        ./make_dev_ssd --remove_rootfs_verification; then reboot.
        rootdev shows /dev/sda5 and is writable.

Change-Id: I27d92964f3fbe160a207069a39516a879de64245

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=b5c991b

[Hung-Te, 2010-11-05 07:47:18]

gaurav: please review if the key resigning and boot param changing part
wad: please review the change of location for enable_rw_mount

[gauravsh, 2010-11-05 20:20:01]

lgtm for the signing and boot param change part

http://codereview.chromium.org/4525002/diff/4001/5001
File scripts/image_signing/make_dev_ssd.sh (right):

http://codereview.chromium.org/4525002/diff/4001/5001#newcode70
scripts/image_signing/make_dev_ssd.sh:70: echo "$*" | grep -q 'root=/dev/dm-0'
is looking for dm_verity a more robust test for this?

[Hung-Te, 2010-11-06 07:40:55]

http://codereview.chromium.org/4525002/diff/4001/5001
File scripts/image_signing/make_dev_ssd.sh (right):

http://codereview.chromium.org/4525002/diff/4001/5001#newcode70
scripts/image_signing/make_dev_ssd.sh:70: echo "$*" | grep -q 'root=/dev/dm-0'
Images built with --noenable_rootfs_verification will have dm_verity* and only
change root=/dev/dm-0 to /dev/sd%P%d. So I think this is the most stable way
currently.

[Will Drewry, 2010-11-08 03:00:45]

LGTM


Thanks!!

[Will Drewry, 2010-11-08 03:00:53]

LGTM


Thanks!!