Re: NetBSD-5 appears to have forgotten how to execute 0.9A binaries

[David Laight <david%l8s.co.uk@localhost>]

On Mon, Sep 10, 2012 at 03:20:34PM -0700, Brian Buhrow wrote:
>       hello.  I have a server which was, up until yesterday, running
> NetBSD-4.0-stable.  After I updated it to NetBSD-5.1 with sources from July
> 18 2012, I find my binaries from NetBSD-0.9A no longer run.  The problem
> seems to be that the file loader doesn't flag them as being a.out
> executables, and the a.out emulation engine isn't turned on.  I have some
> other binaries from NetBSD-1.2, which work fine, so it's not entirely
> broken.
>       I'm not asking for this to be fixed in the main-line tree, but can
> someone give me a hint as to where the code is that decides which emulation
> engine to start in the kernel when an executable is run?  I figure I can
> probably fix it in my tree, file a bug, and if anyone else needs it, they
> can patch their tree.

ISTR the file is passed to each emulation in turn, so they contain their
own tests to accept the file. But that might be after it is detected as ELF.

Shouldn't be that hard to find the 'magic branch' instruction ...

        David

-- 
David Laight: david%l8s.co.uk@localhost