Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

MFC r314568 (by emaste):

kern_sig.c: ANSIfy and remove archaic register keyword

Sponsored by: The FreeBSD Foundation

MFC r318389 (by emaste):

Remove register keyword from sys/ and ANSIfy prototypes

A long long time ago the register keyword told the compiler to store
the corresponding variable in a CPU register, but it is not relevant
for any compiler used in the FreeBSD world today.

ANSIfy related prototypes while here.

Reviewed by: cem, jhb
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D10193

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r315900,r315973,r315974:

r315900:
Cleanup structures related to VFP and/or mcontext_t. - in mcontext_t,
rename newer used 'union __vfp' to equaly sized 'mc_spare'.
Space allocated by 'union __vfp' is too small and cannot hold full VFP
context.
- move structures defined in fp.h to more appropriate headers. - remove
all unused VFP structures.
r315973:
Save VFP state on fork(). Update the copy of VFP state in PCB before it is
cloned for new process.
r315974:
Preserve VFP state across signal delivery.

MFC r306162:

Make it possible to safely use TPIDRURW from userspace.

On amd64, arm64 and i386, we have the possibility to switch between TLS
areas in userspace. The nice thing about this is that it makes it easier
to do light-weight threading, if we ever feel like doing that. On armv6,
let's go into the same direction by making it possible to safely use the
TPIDRURW register, which is intended for this purpose.

Clean up the ARMv6 code to remove md_tp entirely. Simply add a dedicated
field to the PCB to hold the value of TPIDRURW across context switches,
like we do for any other register. As userspace currently uses the
read-only TPIDRURO register, simply ensure that we keep both values in
sync where possible. The system calls for modifying the read-only
register will simply write the intended value into both registers, so
that it lazily ends up in the PCB during the next context switch.

Approved by: andrew
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D7951

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Update comments for the MD functions managing contexts for new
threads, to make it less confusing and using modern kernel terms.

Rename the functions to reflect current use of the functions, instead
of the historic KSE conventions:
cpu_set_fork_handler -> cpu_fork_kthread_handler (for kthreads)
cpu_set_upcall -> cpu_copy_thread (for forks)
cpu_set_upcall_kse -> cpu_set_upcall (for new threads creation)

Reviewed by: jhb (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (hrs)
Differential revision: https://reviews.freebsd.org/D6731

Include machine/acle-compat.h in cdefs.h on arm if the compiler doesn't
have ACLE support built in. The ACLE (ARM C Language Extensions) defines
a set of standardized symbols which indicate the architecture version and
features available. ACLE support is built in to modern compilers (both
clang and gcc), but absent from gcc prior to 4.4.

ARM (the company) provides the acle-compat.h header file to define the
right symbols for older versions of gcc. Basically, acle-compat.h does
for arm about the same thing cdefs.h does for freebsd: defines
standardized macros that work no matter which compiler you use. If ARM
hadn't provided this file we would have ended up with a big #ifdef __arm__
section in cdefs.h with our own compatibility shims.

Remove #include <machine/acle-compat.h> from the zillion other places (an
ever-growing list) that it appears. Since style(9) requires sys/types.h
or sys/param.h early in the include list, and both of those lead to
including cdefs.h, only a couple special cases still need to include
acle-compat.h directly.

Loves it: imp

Cleanup unnecessary semicolons from the kernel.

Found with devel/coccinelle.

Remove armeb FreeBSD 6 compat shim

r296861 addressed a build failure due to undefined SYS_freebsd6_lseek
by adding a COMPAT_FREEBSD6 conditional, but we do not support FreeBSD 6
compatibility on armeb anyway so remove it completely.

Reviewed by: andrew, bz
Differential Revision: https://reviews.freebsd.org/D5643

Only check for SYS_freebsd6_lseek if the syscall code is defined.
Whether this is the right or best solution is unclear but it fixes the
build for now.

Include sys/_task.h into uma_int.h, so that taskqueue.h isn't a
requirement for uma_int.h.

Suggested by: jhb

Fix build.

A follow-up to r288492. In fact, revert the mentioned commit for
pre-VFPv3 processors, since they do require software support code to
handle denormals. For VFPv3 and later, enable flush-to-zero if
hardware does not claim full denormals arithmetic support by VMVFR1_FZ
field in mvfr1 register.

The end result is that we do use correct fpu environment on Cortexes
with VFPv3, while ARM11 (e.g. rpi) is in non-compliant flush-to-zero
mode. At least CPUs without complete hardware implementation of
IEEE 754 do not cause unhandled floating point exception on underflow,
as it was before r288492.

Noted by: ian
Tested by: gjb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Do not set 'flush to zero' VFPSCR_FZ bit by default. The correct
implementation of IEEE 754 arithmetic depends on denormals operating
correctly. Both perl test suite and paranoia tripped over the
setting.

Reported by: Stefan Parvu <sparvu@kronometrix.org>
Discussed with: andrew
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Stop checking for ARM_TP_ADDRESS when we mean to check if building for
ARMv6 or later.

Remove trailing whitespace from sys/arm/arm

Add the kernel support for Thumb-2. It is only supported on ARMv7 as the
main ARMv6 target, the Raspberry Pi, doesn't support Thumb-2.

This as been tested with a Thumb-2 userland, however building one is
currently unsupported as there are known toolchain issues breaking some
binaries. Further work will also be needed to decide on the method of
selecting which instruction set to build for, and to benchmark both to
find how building everything as Thumb-2 will affect performance.

Relnotes: yes

Remove support for reading the syscall code in OABI. This is unneeded now
we can only build for EABI.

Do not save/restore the TLS pointer on context switch for armv6. The
pointer cannot be changed directly by userland code on armv6 (it can be on
armv4), so there's no need to save/restore.

Submitted by: Michal Meloun

Cleanup up ARM *frame structures...

- Eliminate unused irqframe
- Eliminate unused saframe
- Instead of splitting r4-sp storage between the stack and switchframe,
just put all the registers in switchframe and eliminate the un_32 struct.

Submitted by: Svatopluk Kraus <onwahe@gmail.com>,
Michal Meloun <meloun@miracle.cz>

Unify interrupts bit definition and usage. While here remove PSR_C_bit.

Submitted by: Svatopluk Kraus <onwahe at gmail.com>,
Michal Meloun <meloun at miracle.cz>
Differential Revision: https://reviews.freebsd.org/D754

Merge all MD sf_buf allocators into one MI, residing in kern/subr_sfbuf.c
The MD allocators were very common, however there were some minor
differencies. These differencies were all consolidated in the MI allocator,
under ifdefs. The defines from machine/vmparam.h turn on features required
for a particular machine. For details look in the comment in sys/sf_buf.h.

As result no MD code left in sys/*/*/vm_machdep.c. Some arches still have
machine/sf_buf.h, which is usually quite small.

Tested by: glebius (i386), tuexen (arm32), kevlo (arm32)
Reviewed by: kib
Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Initialise fpscr to a sane value when we create the pcb. This sets NaNs to
be the default NaN and for denormalised numbers to be flushed to zero.

When a thread begins life it doesn't own the VFP hardware state on any cpu.

Remove all dregs of a per-thread undefined-exception-mode stack. This is
a leftover from the days when a low-level debugger had hooks in the
undefined exception vector and needed stack space to function. These days
it effectively isn't used because we switch immediately to the svc32 mode
stack on exception entry. For that, the single undef mode stack per core
that gets set up at init time works fine.

The stack wasn't necessary but it was harmful, because the space for it
was carved out of the normal per-thread svc32 stack, in effect cutting
that 8K stack in half. If svc32 mode used more than 4k of stack space it
wandered down into the undef mode stack, and then an undef exception would
overwrite a couple words on the stack while switching to svc32 mode,
corrupting the scv32 stack. Having another stack abut the bottom of the
svc32 stack also effectively mooted the guard page below the stack.

This work is based on analysis and patches submitted by Juergen Weiss.

Remove the ARM_USE_SMALL_ALLOC option and code related to it.

This was an optimization used only by a few xscale platforms. Part of
the optimization was to create a direct map for all physical pages, and
that resulted in making multiple mappings of pages in a way that bypassed
the logic in pmap.c to handle VIVT cache aliasing. It also just generally
made the code more complex and hard to maintain for all SoCs.

Reviewed by: cognet

Fix __syscall on armeb EABI. As it returns a 64-bit value it needs to place
32-bit data in r1, not r0. 64-bit data is already packed correctly.

Remove the last dregs of trapframe_t. It turns out only arm was using
this type, so remove it to make arm code more consistant with other
platforms. Thanks to bde@ for pointing out only arm used trapframe_t.

Retire arm_remap_nocache() and the data and constants associated with it.

The only remaining user was the code that allocates bounce pages for armv4
busdma. It's not clear why bounce pages would need uncached memory, but
if that ever changes, kmem_alloc_attr() would be the way to get it.

Remove #include <machine/frame.h> from all the arm code that doesn't
really need it. That would be almost everywhere it was included. Add
it in a couple files that really do need it and were previously getting
it by accident via another header.

- Create kern.ipc.sendfile namespace, and put the new "readhead" OID
there as "kern.ipc.sendfile.readahead".
- Push all nsfbuf related tunables into MD code. Don't move them
to new namespace in favor of POLA.

Reviewed by: scottl
Approved by: re (gjb)

Replace kernel virtual address space allocation with vmem. This provides
transparent layering and better fragmentation.

- Normalize functions that allocate memory to use kmem_*
- Those that allocate address space are named kva_*
- Those that operate on maps are named kmap_*
- Implement recursive allocation handling for kmem_arena in vmem.

Reviewed by: alc
Tested by: pho
Sponsored by: EMC / Isilon Storage Division

When entering exception handlers we may not have an aligned stack. This is
because an exception may happen at any time. The stack alignment rules on
ARM EABI state the only place the stack must be 8-byte aligned is on a
function boundary.

If an exception happens while a function is setting up or tearing down it's
stack frame it may not be correctly aligned. There is also no requirement
for it to be when the function is a leaf node.

The fix is to align the stack after we have stored a backup of the old stack
pointer, but before we have stored anything in the trapframe. Along with
this we need to adjust the size of the trapframe by 4 bytes to ensure the
stack below it is also correctly aligned.

Introduce new structure sfstat for collecting sendfile's statistics
and remove corresponding fields from struct mbstat. Use PCPU counters
and SFSTAT_INC() macro for update these statistics.

Discussed with: glebius

Fix stack alignment in the kernel to be on an 8 byte boundary as required
by AAPCS.

Fix breakage introduced in r246318.

Use the STACKALIGN macro to alight the stack rather than with a magic mask.

Submitted by: Christoph Mallon <christoph.mallon gmx.de>

Align td_frame as it will be placed into the sp register which must be
8 byte aligned on ARM EABI.

Flip the semantic of M_NOWAIT to only require the allocation to not
sleep, and perform the page allocations with VM_ALLOC_SYSTEM
class. Previously, the allocation was also allowed to completely drain
the reserve of the free pages, being translated to VM_ALLOC_INTERRUPT
request class for vm_page_alloc() and similar functions.

Allow the caller of malloc* to request the 'deep drain' semantic by
providing M_USE_RESERVE flag, now translated to VM_ALLOC_INTERRUPT
class. Previously, it resulted in less aggressive VM_ALLOC_SYSTEM
allocation class.

Centralize the translation of the M_* malloc(9) flags in the single
inline function malloc2vm_flags().

Discussion started by: "Sears, Steven" <Steven.Sears@netapp.com>
Reviewed by: alc, mdf (previous version)
Tested by: pho (previous version)
MFC after: 2 weeks

Eliminate an unused malloc type.

Merging projects/armv6, part 1

Cummulative patch of changes that are not vendor-specific:
- ARMv6 and ARMv7 architecture support
- ARM SMP support
- VFP/Neon support
- ARM Generic Interrupt Controller driver
- Simplification of startup code for all platforms

Final whitespace trim.

Eliminate vestiges of page coloring.

Mark MALLOC_DEFINEs static that have no corresponding MALLOC_DECLAREs.

This means that their use is restricted to a single C file.

Make md_tp a register_t not a void *. This will keep us from
accidentally dereferencng it and might be one fewer things to change
if arm64 happens...

Submitted by: rwatson's question on irc...

For architectures not using direct map , and requiring real KVA page for
sf buf allocation, use wakeup() instead of wakeup_one() to notify sf
buffer waiters about free buffer.

sf_buf_alloc() calls msleep(PCATCH) when SFB_CATCH flag was given,
and for simultaneous wakeup and signal delivery, msleep() returns
EINTR/ERESTART despite the thread was selected for wakeup_one(). As
result, we loose a wakeup, and some other waiter will not be woken up.

Reported and tested by: az
Reviewed by: alc, jhb
MFC after: 1 week

Fix ARM cache handling yet more.

1) vm_machdep.c: remove the dangling allocations so they do not
un-necessarily turn off the cache upon consecutive access.

2) busdma_machdep.c: remove the same amount than shadow mapped.

Reported by: Maks Verver
Submitted by: Mark Tinguely
Reviewed by: Grzegorz Bernacki
MFC after: 3 days

Extract the code that records syscall results in the frame into MD
function cpu_set_syscall_retval().

Suggested by: marcel
Reviewed by: marcel, davidxu
PowerPC, ARM, ia64 changes: marcel
Sparc64 tested and reviewed by: marius, also sunv reviewed
MIPS tested by: gonzo
MFC after: 1 month

Reintroduce the r196640, after fixing the problem with my testing.

Remove the altkstacks, instead instantiate threads with kernel stack
allocated with the right size from the start. For the thread that has
kernel stack cached, verify that requested stack size is equial to the
actual, and reallocate the stack if sizes differ [1].

This fixes the bug introduced by r173361 that was committed several days
after r173004 and consisted of kthread_add(9) ignoring the non-default
kernel stack size.

Also, r173361 removed the caching of the kernel stacks for a non-first
thread in the process. Introduce separate kernel stack cache that keeps
some limited amount of preallocated kernel stacks to lower the latency
of thread allocation. Add vm_lowmem handler to prune the cache on
low memory condition. This way, system with reasonable amount of the
threads get lower latency of thread creation, while still not exhausting
significant portion of KVA for unused kstacks.

Submitted by: peter [1]
Discussed with: jhb, julian, peter
Reviewed by: jhb
Tested by: pho (and retested according to new test scenarious)
MFC after: 1 week

Reverse r196640 and r196644 for now.

Remove the altkstacks, instead instantiate threads with kernel stack
allocated with the right size from the start. For the thread that has
kernel stack cached, verify that requested stack size is equial to the
actual, and reallocate the stack if sizes differ [1].

This fixes the bug introduced by r173361 that was committed several days
after r173004 and consisted of kthread_add(9) ignoring the non-default
kernel stack size.

Also, r173361 removed the caching of the kernel stacks for a non-first
thread in the process. Introduce separate kernel stack cache that keeps
some limited amount of preallocated kernel stacks to lower the latency
of thread allocation. Add vm_lowmem handler to prune the cache on
low memory condition. This way, system with reasonable amount of the
threads get lower latency of thread creation, while still not exhausting
significant portion of KVA for unused kstacks.

Submitted by: peter [1]
Discussed with: jhb, julian, peter
Reviewed by: jhb
Tested by: pho
MFC after: 1 week

ARM pmap fixes.

a) nocache-remap problem

When a page is remapped into a non-cacheable virtual memory region there
was no associated write-back invalidate operation performed. We remove
writeback of the original buffer size from bus_dmamem_alloc() and add
appropriate L1/L2 flush operation.

b) missing write-back invalidate operation

In pmap_kremove a page is removed so we must do a write-back
invalidate operation aligned to the page virtual address.

Submitted by: Michal Hajduk
Reviewed by: Mark Tinguely, rpaulo, stas
Approved by: re (kib)
Obtained from: Semihalf

Fix typo.

Remove unused variables.

Spotted out by: Christoph Mallon <christoph d0t mallon AT gmx d0t de>

Fix ARM nocache allocator:

- let the loop iterate every page (as intended), and not some multiplies
(which led to a fake exhaustion of the ARM_NOCACHE_KVA_SIZE)

- eliminate using MIN(): it compared number of pages vs. address
(ARM_TP_ADDRESS), which was bogus

Reviewed by: cognet, imp
Obtained from: Piotr Ziecik kosmo ! semihalf dot com
MFC after: 3 days

In keeping with style(9)'s recommendations on macros, use a ';'
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.

MFC after: 1 month
Discussed with: imp, rink

o Rename cpu_thread_setup() to cpu_thread_alloc() to better
communicate that it relates to (is called by) thread_alloc()
o Add cpu_thread_free() which is called from thread_free()
to counter-act cpu_thread_alloc().

i386: Have cpu_thread_free() call cpu_thread_clean() to
preserve behaviour.
ia64: Have cpu_thread_free() call mtx_destroy() for the
mutex initialized in cpu_thread_alloc().

PR: ia64/118024

It has been observed on the mailing lists that the different categories
of pages don't sum to anywhere near the total number of pages on amd64.
This is for the most part because uma_small_alloc() pages have never been
counted as wired pages, like their kmem_malloc() brethren. They should
be. This changes fixes that.

It is no longer necessary for the page queues lock to be held to free
pages allocated by uma_small_alloc(). I removed the acquisition and
release of the page queues lock from uma_small_free() on amd64 and ia64
weeks ago. This patch updates the other architectures that have
uma_small_alloc() and uma_small_free().

Approved by: re (kensmith)

Use supersection instead of standard sections to map the whole memory
when available.

Approved by: re (blanket)

- Change comments and asserts to reflect the removal of the global
scheduler lock.

Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)

Remove duplicate includes.

Submitted by: Cyril Nguyen Huu <cyril ci0 org>

- Add bounce pages for arm, largely based on the i386 implementation.
- Add a default parent dma tag, similar to what has been done for sparc64.
- Before invalidating the dcache in POSTREAD, save the bits which are in the
same cachelines than our buffers, but not part of it, and restore them after
the invalidation.

In the ARM_USE_SMALL_ALLOC case, vm_page_t may have an address < KERNBASE,
so adjust the KASSERT to reflect this.

Ooops, dump_avail[i] can be 0 if the RAM starts at 0x00000000, so check that
dump_avail[i + 1] is == 0 as a stop condition instead.
MFC after: 3 days

Rewrite ARM_USE_SMALL_ALLOC so that instead of the current behavior, it maps
whole the physical memory, cached, using 1MB section mappings. This reduces
the address space available for user processes a bit, but given the amount of
memory a typical arm machine has, it is not (yet) a big issue.
It then provides a uma_small_alloc() that works as it does for architectures
which have a direct mapping.

Oops bring back code that shouldn't have been removed by the previous
commit.

Make sure that if uma_small_alloc() gets called recursively, we just give up
and call kmem_malloc(), to avoid a deadlock.

vm_page_alloc_contig() can sleep, so don't even think about using it
in the M_NOWAIT case.

Use 8 * sizeof(int) instead of hardcoding 32, for the unlikely case this
code ever get used on a plateform where sizeof(int) != 4.

Suggested by: jmg

Try to honor BUS_DMA_COHERENT : if the flag is set, normally allocate memory
with malloc() or contigmalloc() as usual, but try to re-map the allocated
memory into a VA outside the KVA, non-cached, thus making the calls to
bus_dmamap_sync() for these buffers useless.

Try harder not to recurse.

Try to use contigmalloc() even if M_NOWAIT has been specified.

Normalize a significant number of kernel malloc type names:

- Prefer '_' to ' ', as it results in more easily parsed results in
memory monitoring tools such as vmstat.

- Remove punctuation that is incompatible with using memory type names
as file names, such as '/' characters.

- Disambiguate some collisions by adding subsystem prefixes to some
memory types.

- Generally prefer lower case to upper case.

- If the same type is defined in multiple architecture directories,
attempt to use the same name in additional cases.

Not all instances were caught in this change, so more work is required to
finish this conversion. Similar changes are required for UMA zone names.

If a thread already tries to allocate a new memory range, wait for it
instead of trying to do the same.

Validate if the value written into {FS,GS}.base is a canonical
address, writting non-canonical address can cause kernel a panic,
by restricting base values to 0..VM_MAXUSER_ADDRESS, ensuring
only canonical values get written to the registers.

Reviewed by: peter, Josepha Koshy < joseph.koshy at gmail dot com >
Approved by: re (scottl)

Don't abuse UMA_SLAB_KMEM.

Approved by: re (blanket)

Add a new arm-specific option, ARM_USE_SMALL_ALLOC. If defined, it provides
an implementation of uma_small_alloc() which tries to preallocate memory
1MB per 1MB, and maps it into a section mapping.

Correctly setup the UND stack in cpu_set_upcall(), and the trapframe in
cpu_thread_setup(), as done in cpu_fork().

Don't forget to copy the TP when forking, or bad things will happen to the
child process if it tries to use threads.

Change cpu_set_kse_upcall to more generic style, so we can reuse it
in other codes. Add cpu_set_user_tls, use it to tweak user register
and setup user TLS. I ever wanted to merge it into cpu_set_kse_upcall,
but since cpu_set_kse_upcall is also used by M:N threads which may
not need this feature, so I wrote a separated cpu_set_user_tls.

Divorce critical sections from spinlocks. Critical sections as denoted by
critical_enter() and critical_exit() are now solely a mechanism for
deferring kernel preemptions. They no longer have any affect on
interrupts. This means that standalone critical sections are now very
cheap as they are simply unlocked integer increments and decrements for the
common case.

Spin mutexes now use a separate KPI implemented in MD code: spinlock_enter()
and spinlock_exit(). This KPI is responsible for providing whatever MD
guarantees are needed to ensure that a thread holding a spin lock won't
be preempted by any other code that will try to lock the same lock. For
now all archs continue to block interrupts in a "spinlock section" as they
did formerly in all critical sections. Note that I've also taken this
opportunity to push a few things into MD code rather than MI. For example,
critical_fork_exit() no longer exists. Instead, MD code ensures that new
threads have the correct state when they are created. Also, we no longer
try to fixup the idlethreads for APs in MI code. Instead, each arch sets
the initial curthread and adjusts the state of the idle thread it borrows
in order to perform the initial context switch.

This change is largely a big NOP, but the cleaner separation it provides
will allow for more efficient alternative locking schemes in other parts
of the kernel (bare critical sections rather than per-CPU spin mutexes
for per-CPU data for example).

Reviewed by: grehan, cognet, arch@, others
Tested on: i386, alpha, sparc64, powerpc, arm, possibly more

Start all license statements with /*-

Don't include sys/user.h merely for its side-effect of recursively
including other headers.

Get the kernel stack right now that the u-area is gone.

Remove some references to U area here while trying not to break
anything. Someone with ARM hardware could do a lot more to untangle
this code.

Reviewed by: arch@

Introduce two new options, "CPU private" and "no wait", to sf_buf_alloc().
Change the spelling of the "catch" option to be consistent with the new
options. Implement the "no wait" option. An implementation of the "CPU
private" for i386 will be committed at a later date.

Implement cpu_set_upcall and cpu_set_upcall_kse.
Calculate td_frame and td_pcb the right way in cpu_thread_setup.

On Xscale, use the minicache for the kernel stack.

Define NSFBUFS and use it.

Retire cpu_sched_exit(); it is not used any more.

Import FreeBSD/arm kernel bits.
It only supports sa1110 (on simics) right now, but xscale support should come
soon.
Some of the initial work has been provided by :
Stephane Potvin <sepotvin at videotron.ca>
Most of this comes from NetBSD.