[Buildroot] Genimage last partition size issue

[Gustavo Zacarias]

On 26/05/16 15:41, Thomas Petazzoni wrote:

> Well, I was thinking of really creating a 4 GB image file when you have
> a 4 GB SD card, so that the partition table is exactly in the state it
> will be on the SD card. But by using sparse files, the 4 GB image file
> isn't really taking up 4 GB on your disk, and you don't have to dd the
> entire 4 GB, since zeros can be skipped.
>
> Thomas

Yes, that would be suitable, expect for 8 GB cards where you "loose" 
space :)
The other approach which i briefly mentioned is on first boot running a 
resize script that adjusts the partition table to grow the last 
partition to fit the running block device and resizes the filesystem.
Of course it has some limitations, like ext2/3/4 filesystems (some 
others as well) and having some tools around for the trick.
Regards.