build_image: improvements to right size for dynamic partitions

If partition_reserved_size is 0 or undefined, and
use_dynamic_partition_size is true, we should approach no space
and no free inodes automatically.

Estimate the space and number of inodes required, then do a first
pass build to see how much space actually used, and use those values
to refine the estimate.

Depends on tune2fs to report the characteristics of the filesystem,
so only support for ext filesystems.  In the future if there has to
be a more generic ability, either a tool per a filesystem has to be
found, or we will need root capabilities to mount the filesystem to
acquire the characteristics live from the host system.

Test: manual + python -m unittest test_build_image
Bug: 111302946
Change-Id: I933a388be43516b6de7b5007b296765bd5556fde
3 files changed
tree: febd9e2c38ea942f72fe289ccc027cf30c56853f
  1. common/
  2. core/
  3. packaging/
  4. target/
  5. tests/
  6. tools/
  7. .gitignore
  8. Android.mk
  9. buildspec.mk.default
  10. Changes.md
  11. CleanSpec.mk
  12. envsetup.sh
  13. help.sh
  14. navbar.md
  15. OWNERS
  16. README.md
  17. tapasHelp.sh
  18. Usage.txt
README.md

Android Make Build System

This is the Makefile-based portion of the Android Build System.

For documentation on how to run a build, see Usage.txt

For a list of behavioral changes useful for Android.mk writers see Changes.md

For an outdated reference on Android.mk files, see build-system.html. Our Android.mk files look similar, but are entirely different from the Android.mk files used by the NDK build system. When searching for documentation elsewhere, ensure that it is for the platform build system -- most are not.

This Makefile-based system is in the process of being replaced with Soong, a new build system written in Go. During the transition, all of these makefiles are read by Kati, and generate a ninja file instead of being executed directly. That's combined with a ninja file read by Soong so that the build graph of the two systems can be combined and run as one.