replace genext2fs with populate-extfs.sh

* The benefits:
- Really support ext4
- Support the sparse file (we lost the sparse file in the image in the past, the sparse file became into the common file)
- Fix the error reported by fsck: (ext2/ext3)

     "Inode 1025, i_size is 16384, should be 17408."

- Have a uniform code for ext2/3/4 generation

* Impact
- Build time:
a) If we build fresh core-image-sato, there is nearly no impact.

b) If we do the image generation, which means:
$ bitbake core-image-sato
$ bitbake core-image-sato -ccleansstate
$ bitbake core-image-sato
About 40 extra seconds are needed, here is my test result:
Before the patches: 4m53s
After the patches: 5m35s
This is because the genext2fs is much faster than the populate-extfs.sh, we will replace this script by the mke2fs when it supports create the filesystem from a initial directory.

- Disk space (take core-image-sato as an example)

    a) The image file size is the same as before (519M)

    b) The disk usage is a little different: (du -sh)
              before       now 
       ext2:  356M         379M
       ext3:  372M         395M
       ext4:  372M         380M

I have done some simple runtime testing on core-image-sato based on ext2/3/4, they worked well.

* The "fsck.extX -fn <image>.extX" shows it is OK.

// Robert

The following changes since commit b2ff1add530b1fec2fb7f385227a03db47015c37:

poky.conf: Don't force the addition of extra DISTRO_FEATURES (2013-08-20 22:58:04 +0100)

are available in the git repository at:

git://git.pokylinux.org/poky-contrib robert/extX
http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=robert/extX

Robert Yang (6):
e2fsprogs: the max length of debugfs argument is too short
e2fsprogs: let debugfs do sparse copy
e2fsprogs: only update the icache for ext2_inode
e2fsprogs: properly set up extent header in do_write
e2fsprogs: add populate-extfs.sh image_types.bbclass: replace genext2fs with populate-extfs.sh

 meta/classes/image_types.bbclass                   |   46 +++---
 .../e2fsprogs-1.42.8/debugfs-extent-header.patch   |   47 +++++++
 .../e2fsprogs-1.42.8/debugfs-sparse-copy.patch     |  147 ++++++++++++++++++++
 .../e2fsprogs-1.42.8/debugfs-too-short.patch       |   41 ++++++
 .../e2fsprogs/e2fsprogs-1.42.8/fix-icache.patch    |   69 +++++++++
 .../e2fsprogs/e2fsprogs-1.42.8/populate-extfs.sh   |   96 +++++++++++++
 .../recipes-devtools/e2fsprogs/e2fsprogs_1.42.8.bb |    6 +
 7 files changed, 424 insertions(+), 28 deletions(-)
 create mode 100644 meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/debugfs-extent-header.patch
 create mode 100644 meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/debugfs-sparse-copy.patch
 create mode 100644 meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/debugfs-too-short.patch
 create mode 100644 meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/fix-icache.patch
 create mode 100644 meta/recipes-devtools/e2fsprogs/e2fsprogs-1.42.8/populate-extfs.sh

1.7.10.4