Re: RFC: Braindump on Bootloaders, Image Types, and Installers

[Darren Hart <dvhart@linux.intel.com>]

On 06/06/2012 05:39 AM, Burton, Ross wrote:
> Hi,
> 
> On 5 June 2012 21:54, Darren Hart <dvhart@linux.intel.com> wrote:
>>  * Disk Image
>>    - create partitioned images (not just volume images)
>>    - intended to be written to USB sticks, MMC drives, or SATA disks
>>    - may require a script to assemble the image for specific target
>>      devices.
> 
> Can we get an option to specify the size of the target device?  I've a
> 4GB stick that I'm using with .hddimg (being the lucky owner of a box
> that actually boots them!) and it's sad to see the rootfs being only a
> little bigger than the contents when there is about 3.5G of empty disk
> space available.

I believe this is a better fit for the diskimage type with proper
partitions. I don't have data regarding performance of a loop mounted
filesystem versus a proper block device, but my gut feel is that using
block devices for large partitions will provide a better experience.

If we did want to allow for the use of the entire disk, we should find a
way to do so without bloating the image files themselves with empty
filesystem space. Does anyone know if we can use sparse files to
accomplish this with rootfs.img?

Thanks,

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel