build_image: hard-code verity_depth to 0

build_image: hard-code verity_depth to 0

Plan is to eventually deprecate depth as a configurable parameter.
depth=0 means compute the depth based on a regular trie with a
single block of hashes at the root node.

BUG=chromium-os:9752
TEST=platform_DMVerity

Change-Id: I5c5f1b1f2c2079d7e1ef6c7a55c859b463a59aee

R=wad@chromium.org,taysom@chromium.org,ups@chromium.org,gauravsh@chromium.org,jimherbert@chromium.org

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=de16252

[Will Drewry, 2011-04-07 01:22:09]

Does it make sense just to change the default to "0" and that way if we want to
profile alternate tree depths in the future we can?

[Mandeep Singh Baines, 2011-04-07 15:44:46]

wad@chromium.org (wad@chromium.org) wrote:
> Does it make sense just to change the default to "0" and that way if
> we want to
> profile alternate tree depths in the future we can?
> 

I want to remove configurable depth because it allows for
simplification of the code. I can literally remove hundreds of lines of
code by removing this functionality. All of the special-case root
hash checks can go away.

> http://codereview.chromium.org/6810006/

[Paul T, 2011-04-07 15:50:28]

LGTM

[Will Drewry, 2011-04-07 16:28:09]

On Thu, Apr 7, 2011 at 10:44 AM, Mandeep Singh Baines <msb@chromium.org> wrote:
> wad@chromium.org (wad@chromium.org) wrote:
>> Does it make sense just to change the default to "0" and that way if
>> we want to
>> profile alternate tree depths in the future we can?
>>
>
> I want to remove configurable depth because it allows for
> simplification of the code. I can literally remove hundreds of lines of
> code by removing this functionality. All of the special-case root
> hash checks can go away.

Cool - I wasn't sure if this was jut dropping the interface but
leaving the implementation :)

[Will Drewry, 2011-04-07 16:28:19]

On Thu, Apr 7, 2011 at 11:28 AM, Will Drewry <wad@chromium.org> wrote:
> On Thu, Apr 7, 2011 at 10:44 AM, Mandeep Singh Baines <msb@chromium.org>
wrote:
>> wad@chromium.org (wad@chromium.org) wrote:
>>> Does it make sense just to change the default to "0" and that way if
>>> we want to
>>> profile alternate tree depths in the future we can?
>>>
>>
>> I want to remove configurable depth because it allows for
>> simplification of the code. I can literally remove hundreds of lines of
>> code by removing this functionality. All of the special-case root
>> hash checks can go away.
>
> Cool - I wasn't sure if this was jut dropping the interface but
> leaving the implementation :)
>

LGTM

[Will Drewry, 2011-04-07 16:29:21]

On Thu, Apr 7, 2011 at 11:28 AM, Will Drewry <wad@chromium.org> wrote:
> On Thu, Apr 7, 2011 at 11:28 AM, Will Drewry <wad@chromium.org> wrote:
>> On Thu, Apr 7, 2011 at 10:44 AM, Mandeep Singh Baines <msb@chromium.org>
wrote:
>>> wad@chromium.org (wad@chromium.org) wrote:
>>>> Does it make sense just to change the default to "0" and that way if
>>>> we want to
>>>> profile alternate tree depths in the future we can?
>>>>
>>>
>>> I want to remove configurable depth because it allows for
>>> simplification of the code. I can literally remove hundreds of lines of
>>> code by removing this functionality. All of the special-case root
>>> hash checks can go away.
>>
>> Cool - I wasn't sure if this was jut dropping the interface but
>> leaving the implementation :)
>>
>
> LGTM
>

[For what it's worth, once all the scripts are updated,
chromeos-setimage will also need to be updated to not parse out the
depth, the signer tests will need to be sync, etc.]

thanks again!
will