[yocto] Yocto 1.5: busybox instead of tinylogin, need some help

[Hans Beckérus]

Hello. I am currently working on moving from Yocto 1.4 to 1.5 and
instantly stumbled into a few minor problems (this being one of them).
In 1.5 tinylogin is replaced by busybox. What we had before in our
distro conf (it require poky.conf) was:

# Use tmpdevfs and the busybox runtime services
VIRTUAL-RUNTIME_dev_manager = ""
VIRTUAL-RUNTIME_login_manager = "tinylogin"
#VIRTUAL-RUNTIME_init_manager = ""
VIRTUAL-RUNTIME_keymaps = ""

Obviously this does no longer work. Is it as easy as simply commenting
out VIRTUAL-RUNTIME_login_manager and leave it at the default from
packagegroup-core-boot?
Will our old init-manager also be compatible? I believe we used
tiny-init before?
Another thing, since this will require a new set of busybox options to
be enabled, and we need to modify it slightly, is there some concept
similar to configuration fragments also available for busybox? Was
thinking about how clumsy it is right now since our .bbappend for
busybox basically copied the config from the poky base meta. Using
configuration fragments would make it easier for us to migrate in the
future.

Thanks.
Hans