Test big.LITTLE on Android

Linaro is taking the lead to bring big.LITTLE to Linux. From http://www.arm.com/products/processors/technologies/bigLITTLEprocessing.php, "big.LITTLE processing addresses one of today’s industry challenges: how to create a System on Chip (SoC) that provides both high performance as well as extreme power efficiency to extend battery life. "

The TSC card is here:

https://linaro.papyrs.com/KWG2012-big-LITTLE-Task-Migration

<email address hidden> is doing the initial implementation.
<email address hidden> is bringing up the A15 model in the LAVA lab.
<email address hidden> and <email address hidden> (tixy) may be able to help us get a simulator up and running locally and work to get Android running on it.

I imagine that we'll want to get Android running on the A15 with the big.LITTLE work from Grant running. Then runs some tests from Grant to validate that its working. We can use TINY_ANDROID to do the work.

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Step 1:

Write a small C program, callable from the command line that takes the following arguments

--cpu - optional to specify which CPU
--state - big, little
--frequency - a number in Hz to switch between big and little

Step 2:

Write and submit to AOSP an Android HAL that can control big little switching. Write a test that can test the HAL.

Step 3:

Write a userspace Android program allows a user to switch between big and little and specify a rate of switching. Should also provide a view into powersavings, perhaps using the same mechanism as powertutor.

From Mounir the PM:

Hangouts:
https://plus.google.com/hangouts/extras/linaro.org/118212388148355955219-7618679083?authuser=0&hl=en&eid=#

Current test Plan
https://docs.google.com/a/linaro.org/document/d/14Kta4wQ0QdKlO_iQ41EolkLm-pxw_Ggh_OW-ca6BEvM/edit

Platforms bringup - asac changes to the plan
http://pad.linaro.org/5T9dICYtbK

Blueprint
https://blueprints.launchpad.net/linux-linaro/+spec/linaro-kernel-q112-big-little-switcher

Timeline (proposed)
https://wiki.linaro.org/Internal/People/MounirBsaibes/Big.LittleWeeklyReportTemplate

__Major Milestones__

Milestones:
ARM reference Switcher 3/15/2012
Validation Ready 3/29/2012
Validate Reference Switcher 4/5/2012
Linux Integrated Switcher 4/5/2012
Validate Integrated Switcher 4/26/2012
Release Candidate 1 (RC1) 5/10/2012
General Availability (GA) 5/31/2012

__Execution Matrix__

https://docs.google.com/a/linaro.org/spreadsheet/ccc?key=0AroPySpr4FnEdGttYkhCUGVzZ2JOS0tGaU1QUm9wOHc#gid=0