Make SAFT use layout retrieved from the BIOS image.

Make SAFT use layout retrieved from the BIOS image.

This CL modifies x86-generic/fashrom_util.py to use the 
mosys tool to retrieve the flashrom memory map from the
BIOS image and use it unless explicitly overridden by the
caller.

flashrom_handler.py is being modified not to pass layout
on most flash read/write operations. Only in case the whole
flash write is requested - a custom map is used.

A cllass (LayoutScraper) is introduced in flashrom_util.py
to retrieve the text map from the image (using mosys) and 
convert it into a layout dictionary. Default maps, ec 
support and layout compiler are being deleted from this 
file, as it is not used by any other package, and SAFT does
not require these features. The upcoming CL will move
 flashrom_util.py into saft subdirectory.

Change-Id: Ifcdc59e4c2567b2d815de9f64fb41c30f0f83c97

BUG=chrome-os-partner:920
TEST=manual. Ran SAFT on a target, it still fails complaining
about wrong BINF values when both firmware images are
corrupted. Once this issue is fixed by the vendor full log
will be posted here.

[Hung-Te, 2010-09-06 14:13:28]

LGTM except some comment / coding style minor suggestions.

P.S: one more thing - since some function prototypes are changed, it maybe a
little confusing to have two flashrom_util.py in source tree with very similar
class names and function names... I'm wondering if it will be better to have
different module name here, for example saft_flashrom_util.py

http://codereview.chromium.org/3328008/diff/8001/9004
File x86-generic/flashrom_util.py (right):

http://codereview.chromium.org/3328008/diff/8001/9004#newcode62
x86-generic/flashrom_util.py:62: mosys_cmd += ' -p AGZ'
Is it really OK to add such platform name here?

If this is for developer testing on host, I'd suggest to add special platform
names when building mosys binary on your host environment, eg z600/amd64.

http://codereview.chromium.org/3328008/diff/8001/9004#newcode96
x86-generic/flashrom_util.py:96: if 'area_name' in d and d[
will it be better if we reformat this line as 
if 'area_name in d and \
  d['area_name'] in ....

http://codereview.chromium.org/3328008/diff/8001/9004#newcode234
x86-generic/flashrom_util.py:234: def get_bios_layout(self, size=None):
You don't need the size anymore, right?

http://codereview.chromium.org/3328008/diff/8001/9004#newcode265
x86-generic/flashrom_util.py:265: Returns True on success, otherwise False.
The new code does not return things anymore. Do you prefer to update the comment
or change the code?

[vb, 2010-09-06 19:35:03]

On 2010/09/06 14:13:28, Hung-Te wrote:
> LGTM except some comment / coding style minor suggestions.
> 

I addressed your comments, will retest with the firmware which does not cause
the test to fail and add the test results to the description.

> P.S: one more thing - since some function prototypes are changed, it maybe a
> little confusing to have two flashrom_util.py in source tree with very similar
> class names and function names... I'm wondering if it will be better to have
> different module name here, for example saft_flashrom_util.py
> 

sure thing, once this is in, I'll prepare another cl moving the changed file
into ./saft renaming it along the way.

http://codereview.chromium.org/3328008/diff/8001/9004
File x86-generic/flashrom_util.py (right):

http://codereview.chromium.org/3328008/diff/8001/9004#newcode62
x86-generic/flashrom_util.py:62: mosys_cmd += ' -p AGZ'
On 2010/09/06 14:13:28, Hung-Te wrote:
> Is it really OK to add such platform name here?
> 
> If this is for developer testing on host, I'd suggest to add special platform
> names when building mosys binary on your host environment, eg z600/amd64.

Good point. I just removed this code, because running on the
host does not work anyways for many other reasons.

http://codereview.chromium.org/3328008/diff/8001/9004#newcode96
x86-generic/flashrom_util.py:96: if 'area_name' in d and d[
On 2010/09/06 14:13:28, Hung-Te wrote:
> will it be better if we reformat this line as 
> if 'area_name in d and \
>   d['area_name'] in ....

IIRC using \ is discouraged in the coding style document. 
I changed it hopefully making it more readable.

http://codereview.chromium.org/3328008/diff/8001/9004#newcode234
x86-generic/flashrom_util.py:234: def get_bios_layout(self, size=None):
On 2010/09/06 14:13:28, Hung-Te wrote:
> You don't need the size anymore, right?

If fact the entire method is not used anymore.

http://codereview.chromium.org/3328008/diff/8001/9004#newcode265
x86-generic/flashrom_util.py:265: Returns True on success, otherwise False.
On 2010/09/06 14:13:28, Hung-Te wrote:
> The new code does not return things anymore. Do you prefer to update the
comment
> or change the code?

Updated the comment.

[Hung-Te, 2010-09-07 01:29:44]

LGTM