[poky] Check build machine available space against IMAGE_ROOTFS_SIZE poky/meta/classes/image.bbclass

[Romain Bazile]

Hello,

Following a stupid mistake in a custom image recipe (where I set the 
IMAGE_ROOTFS_SIZE at 500GB instead of the intended 500MB), I was 
thinking that maybe it would be good to have some kind of warning if the 
ROOTFS requested size is very large, or at least larger than the build 
machine disk or available space on it.


I saw in the poky/meta/classes/image.bbclass file, line 544 ( 
https://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/meta/classes/image.bbclass#n544 
) that there is a check against a variable called IMAGE_ROOTFS_MAXSIZE. 
I couldn't find any reference anywhere in the documentation to this 
variable. I'm guessing it should be set in the image recipe. However 
this seems like a specific feature to make sure the rootfs is not bigger 
than what would be available on the target machine.


I thus have two questions:

- Is this variable deprecated? If so, if would be good to remove it from 
this file, no? If not, maybe we could add it to the documentation? I'm 
happy to do it.

- Can we, around this place in image.bbclass , add a check against 
either the size of the build machine disk, or the available space on it, 
and throw an error in case the requested rootfs size is bigger than either?

I'm not sure the change should be done in poky or in openembedded-core 
though, since this file is present in both places. Feel free to send me 
the other way if that is the case!

Cheers,
-- 
Romain Bazile
/Hardware R&D Engineer/
www.ubiant.com