version dependency system. This isn't quite finished, but it is at a
useful stage to do a functional checkpoint.
Highlights:
- version and dependency metadata is gathered via linker sets, so things
are handled the same for static kernels and code built to live in a kld.
- The dependencies are at module level (versus at file level).
- Dependencies determine kld symbol search order - this means that you
cannot link against symbols in another file unless you depend on it. This
is so that you cannot accidently unload the target out from underneath
the ones referencing it.
- It is flexible enough that we can put tags in #include files and macros
so that we can get decent hooks for enforcing recompiles on incompatable
ABI changes. eg: if we change struct proc, we could force a recompile
for all kld's that reference the proc struct.
- Tangled dependency references at boot time are sorted. Files are
relocated once all their dependencies are already relocated.
Caveats:
- Loader support is incomplete, but has been worked on seperately.
- Actual enforcement of the version number tags is not active yet - just
the module dependencies are live. The actual structure of versioning
hasn't been agreed on yet. (eg: major.minor, or whatever)
- There is some backwards compatability for old modules without metadata
but I'm not sure how good it is.
This is based on work originally done by Boris Popov (bp@freebsd.org),
but I'm not sure he'd recognize much of it now. Don't blame him. :-)
Also, ideas have been borrowed from Mike Smith.
devsw_module_handler() indirectly and not use the chain arguments. To
eliminate this indirection via that function (which does nothing now)
without duplicating a modevent handler into all the routines that don't
presently have one, supply a NOP (do nothing, return OK) routine which
is functionally equivalent to what's there now. This is a hack and is
still wrong, because there doesn't appear to be anything to reclaim
resources on an unload of a module with one of these in it. I'm not
sure whether to make the NOP handler refuse a MOD_UNLOAD event or what.
events, in order to pave the way for removing a number of the ad-hoc
implementations currently in use.
Retire the at_shutdown family of functions and replace them with
new event handler lists.
Rework kern_shutdown.c to take greater advantage of the use of event
handlers.
Reviewed by: green
particularly annoying hack, namely having the linker bash the moduledata
to set the container pointer, preventing it being const. In the process,
a stack of warnings were fixed and will probably allow a revisit of the
const C_SYSINIT() changes. This explicitly registers modules in files or
preload areas with the module system first, and let them initialize via
SYSINIT/DECLARE_MODULE later in their SI_ORDER_xxx order. The kludge of
finding the containing file is no longer needed since the registration
of modules onto the modules list is done in the context of initializing
the linker file.
This is the bulk of the support for doing kld modules. Two linker_sets
were replaced by SYSINIT()'s. VFS's and exec handlers are self registered.
kld is now a superset of lkm. I have converted most of them, they will
follow as a seperate commit as samples.
This all still works as a static a.out kernel using LKM's.
but I can't think of another (relatively) easy way of getting the info
since the boot-time initialization is not done immediately after "loading".
XXX module_register() gained an extra arg. This might break the alpha
compile, if so, just add a zero to get the old behavior.
suitable for holding object pointers (ptrint_t -> uintptr_t).
Added corresponding signed type (intptr_t). Changed/added
corresponding non-C9x types for function pointers to match. Don't
use nonstandard types to implement these types, and don't comment
on them in <machine/types.h>.
it in struct proc instead.
This fixes a boatload of compiler warning, and removes a lot of cruft
from the sources.
I have not removed the /*ARGSUSED*/, they will require some looking at.
libkvm, ps and other userland struct proc frobbing programs will need
recompiled.
the patches in freefall:/home/dfr/ld.diffs to your ld sources and set
BINFORMAT to aoutkld when linking the kernel.
Library changes and userland utilities will appear in a later commit.
