https://source.android.com/source/build-numbers.html
https://developers.google.com/android/images
https://developers.google.com/android/nexus/blobs-preview
Android Study:
https://docs.google.com/document/d/1RAQLeZYSJWuYWt3cOBP7AoDTv3AJToISXBZSeJZTSkE/edit#
Lava Training:
https://docs.google.com/document/d/1nyPbITVxpw3igfrb_MXeJ2qPpUiSfXAzPIEBxhsptRc/edit
Android Kernel:
https://source.android.com/source/building-kernels.html
Getting Started:
http://developer.android.com/intl/zh-cn/training/index.html

Memory related tools and links:
http://developer.android.com/intl/zh-cn/tools/performance/comparison.html
http://tools.android.com/tips/lint
android-developers.blogspot.com/2009/02/track-memory-allocations.html
https://source.android.com/devices/tech/debug/index.html "Debugging Native Android Platform Code"
https://source.android.com/devices/tech/debug/procstats.html
https://source.android.com/devices/tech/debug/native-memory.html
https://source.android.com/devices/tech/config/kernel.html
https://source.android.com/devices/tech/config/low-ram.html

# for app developers
https://developer.android.com/training/index.html
# for platform developers
https://android.googlesource.com/

google android links:
https://issuetracker.google.com/issues?q=logcat%20surfaceflinger&p=1