vboot_reference/make_dev_firmware: check write protection status before making changes

vboot_reference/make_dev_firmware: check write protection status before making changes

Complete the missing part of "checking (and disabling) write protection status.
This also helps to prevent erasing RW regions on system with WP enabled and
then causing boot failure.

BUG=chrome-os-partner:1276
TEST=(1) On CR-48 with WP enabled, run make_dev_firmware.sh without turning off WP.
         Result: Error message "Write protection is still enabled. Please verify
         that hardware write protection is disabled." (as expected)
     (2) Disable WP and run again.
         Result: firmware has been changed successfully.

Change-Id: Iaf2243cb2cd3c7f83ce4f36543ea3da1e3ca55a1

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=38d3ef7

[Randall Spangler, 2011-01-04 21:27:44]

http://codereview.chromium.org/5987010/diff/1/scripts/image_signing/make_dev_...
File scripts/image_signing/make_dev_firmware.sh (right):

http://codereview.chromium.org/5987010/diff/1/scripts/image_signing/make_dev_...
scripts/image_signing/make_dev_firmware.sh:68: if [ -n "$FLAGS_from" ]; then
$FLAGS_to, right?  Doesn't matter where the image comes from; what matters is
where we're writing to.

[Hung-Te, 2011-01-05 03:43:37]

http://codereview.chromium.org/5987010/diff/1/scripts/image_signing/make_dev_...
File scripts/image_signing/make_dev_firmware.sh (right):

http://codereview.chromium.org/5987010/diff/1/scripts/image_signing/make_dev_...
scripts/image_signing/make_dev_firmware.sh:68: if [ -n "$FLAGS_from" ]; then
On 2011/01/04 21:27:44, Randall Spangler wrote:
> $FLAGS_to, right?  Doesn't matter where the image comes from; what matters is
> where we're writing to.

Done. Thanks for finding this!

[Randall Spangler, 2011-01-05 23:38:14]

LGTM, thanks