[OE-core] [PATCH v3 0/6] bmaptool support

[Ed Bartosh]

On Tue, May 03, 2016 at 08:22:48PM +0000, Christopher Larson wrote:
> On Mon, May 2, 2016 at 12:22 PM, Ed Bartosh <ed.bartosh at linux.intel.com>
> wrote:
> 
> > Hi,
> >
> > This patchset adds ability to use bmaptool to flash images faster than
> > using traditional methods. It contains bmap-tools recipe and generation
> > of .bmap files for the images generated by bitbake and wic.
> >
> > Bmaptool is a generic tool for creating the block map (bmap) for a file
> > and and copying files using the block map. The idea is that large file
> > containing unused blocks, like raw system image files, can be copied or
> > flashed a lot faster with bmaptool than with traditional tools like
> > "dd" or "cp".
> >
> > Here is an example of flashing image using dd and bmaptool showing
> > around 25% performance gain in flashing time:
> >
> > > ls -slh
> >  19M -rw-r--r-- 1 ed ed  26M Apr 26 11:36
> > core-image-minimal-qemux86-64-20160426083554.rootfs.ext4
> > 4.0K -rw-r--r-- 1 ed ed 2.7K Apr 26 11:36
> > core-image-minimal-qemux86-64-20160426083554.rootfs.ext4.bmap
> >
> > > time dd if=core-image-minimal-qemux86-64-20160426083554.rootfs.ext4
> > of=/dev/sdb
> > 52302+0 records in
> > 52302+0 records out
> > 26778624 bytes (27 MB) copied, 2.51183 s, 10.7 MB/s
> >
> > real    0m2.515s
> > user    0m0.014s
> > sys     0m0.329s
> >
> > > time bmaptool copy
> > core-image-minimal-qemux86-64-20160426083554.rootfs.ext4 /dev/sdb
> > bmaptool: info: discovered bmap file
> > 'core-image-minimal-qemux86-64-20160426083554.rootfs.ext4.bmap'
> > bmaptool: info: block map format version 2.0
> > bmaptool: info: 6538 blocks of size 4096 (25.5 MiB), mapped 4799 blocks
> > (18.7 MiB or 73.4%)
> > bmaptool: info: copying image
> > 'core-image-minimal-qemux86-64-20160426083554.rootfs.ext4' to block device
> > '/dev/sdb' using bmap file
> > 'core-image-minimal-qemux86-64-20160426083554.rootfs.ext4.bmap'
> > bmaptool: info: 100% copied
> > bmaptool: info: synchronizing '/dev/sdb'
> > bmaptool: info: copying time: 1.8s, copying speed 10.3 MiB/sec
> >
> > real    0m1.909s
> > user    0m0.226s
> > sys     0m0.052s
> >
> > The test was repeated 5 times with the same image and the same usb stick
> > device.
> >
> > Changes in v2: Combined Alexander's and my bmap-tools recipes.
> >                Got rid of generating standalone script as it breaks build
> > of bmap-tools-native.
> >
> > Changes in v3: Returned back generation of standalone bmaptool script
> >                Implemented --bmap option for wic
> >                Added test case to test bmap generation by wic --bmap
> 
> 
> I just wanted to say, this + the sparseness series is just awesome. Such a
> timesaver in my test cycle, particularly on my old macbook which has a usb
> 2.0 sd card reader :)

Thank you! I also think bmaptool is awesome utility. It can save lots of
flushing time especially for the 'very sparse' images.

I had this work in my TODO for quite long time. Now, thanks to Alexander who did
almost all hard work, it's eventually coming to oe/yocto.

--
Regards,
Ed