Booting an old kernel on RPI2

[Ralf Wenk]

At Sat, 4 Mar 2017 08:57:40 -0800, bob prohaska <fbsd at www.zefox.net> wrote:
> A recent world/kernel build went badly wrong, resulting in an
> "out of memory" report on the console and no further progress.
> 
> There are two spare kernels on the system, kernel.old and kernel.spare,
> but even kernel.spare, which I know worked, still produces the same
> "out of memory" prompt on the console. 
> [...]

I am having the same problem here.
It happened during make installworld of r314701. I run make installworld
while the former kernel r313407  was still active.
Now both kernels will boot up, but produce the same "out of memory"
message while going to single- or multi-user.
So it is not even possible to get a working shell in single-user mode.
As it first happens during make installworld while still running the
"old" r313407 kernel I think the cause is not the kernel itself.

Ralf