now, but it's possible for ndis_reset_nic() to sleep (sometimes the
MiniportReset() method returns NDIS_STATUS_PENDING and we have
to wait for completion). To get around this, execute the ndis_reset_nic()
routine in the NDIS_TASKQUEUE thread.
- In subr_ndis.c:ndis_allocate_sharemem(), create the busdma tags
used for shared memory allocations with a lowaddr of 0x3E7FFFFF.
This forces the buffers to be mapped to physical/bus addresses within
the first 1GB of physical memory. It seems that at least one card
(Linksys Instant Wireless PCI V2.7) depends on this behavior. I
don't know if this is a hardware restriction, or if the NDIS
driver for this card is truncating the addresses itself, but using
physical/bus addresses beyong the 1GB limit causes initialization
failures.
- Create am NDIS_INITIALIZED() macro in if_ndisvar.h and use it in
if_ndis.c to test whether the device has been initialized rather
than checking for the presence of the IFF_UP flag in if_flags.
While debugging the previous problem, I noticed that bringing
up the device would always produce failures from ndis_setmulti().
It turns out that the following steps now occur during device
initialization:
- IFF_UP flag is set in if_flags
- ifp->if_ioctl() called with SIOCSIFADDR (which we don't handle)
- ifp->if_ioctl() called with SIOCADDMULTI
- ifp->if_ioctl() called with SIOCADDMULTI (again)
- ifp->if_ioctl() called with SIOCADDMULTI (yet again)
- ifp->if_ioctl() called with SIOCSIFFLAGS
Setting the receive filter and multicast filters can only be done
when the underlying NDIS driver has been initialized, which is done
by ifp->if_init(). However, we don't call ifp->if_init() until
ifp->if_ioctl() is called with SIOCSIFFLAGS and IFF_UP has been
set. It appears that now, the network stack tries to add multicast
addresses to interface's filter before those steps occur. Normally,
ndis_setmulti() would trap this condition by checking for the IFF_UP
flag, but the network code has in fact set this flag already, so
ndis_setmulti() is fooled into thinking the interface has been
initialized when it really hasn't.
It turns out this is usually harmless because the ifp->if_init()
routine (in this case ndis_init()) will set up the multicast
filter when it initializes the hardware anyway, and the underlying
routines (ndis_get_info()/ndis_set_info()) know that the driver/NIC
haven't been initialized yet, but you end up spurious error messages
on the console all the time.
Something tells me this new behavior isn't really correct. I think
the intention was to fix it so that ifp->if_init() is only called
once when we ifconfig an interface up, but the end result seems a
little bogus: the change of the IFF_UP flag should be propagated
down to the driver before calling any other ioctl() that might actually
require the hardware to be up and running.
- In subr_ndis.c, my_strcasecmp() actually behaved like my_strncasecmp():
we really need it to behave like the former, not the latter. (It was
falsely matching "RadioEnable", which defaults to 1 with "RadioEnableHW"
which the driver creates itself and to 0, because we were using
strlen("RadioEnable") as the length to test. This caused the radio to
always be turned off. :( )
- In if_ndis.c, only set IEEE80211_CHAN_A for channels if we actually
set any IEEE80211_MODE_11A rates. (ieee80211_attach() will "helpfully"
add IEEE80211_MODE_11A to ic_modecaps for you if you initialize any
802.11a channels. This caused "ndis0: 11a rates:" to erroneously be
displayed during driver load.)
- Also in if_ndis.c, when using TESTSETRATE() to add in any missing 802.11b
rates, remember to OR the rates with IEEE80211_RATE_BASIC, otherwise
comparing against existing basic rates won't match. (1, 2, 5.5 and
11Mbps are basic rates, according to the 802.11b spec.) This erroneously
cause 11Mbps to be added to the 11b rate list twice.
make the key name matching case-insensitive. There are some drivers
and .inf files that have mismatched cases, e.g. the driver will look
for "AdhocBand" whereas the .inf file specifies a registry key to be
created called "AdHocBand." The mismatch is probably a typo that went
undetected (so much for QA), but since Windows seems to be case-insensitive,
we should be too.
In if_ndis.c, initialize rates and channels correctly so that specify
frequences correctly when trying to set channels in the 5Ghz band, and
so that 802.11b rates show up for some a/b/g cards (which otherwise
appear to have no 802.11b modes).
Also, when setting OID_802_11_CONFIGURATION in ndis_80211_setstate(),
provide default values for the beacon interval, ATIM window and dwelltime.
The Atheros "Aries" driver will crash if you try to select ad-hoc mode
and leave the beacon interval set to 0: it blindly uses this value and
does a division by 0 in the interrupt handler, causing an integer
divide trap.
- Use the dh_inserted member of the dispatch header in the Windows
timer structure to indicate that the timer has been "inserted into
the timer queue" (i.e. armed via timeout()). Use this as the value
to return to the caller in KeCancelTimer(). Previously, I was using
callout_pending(), but you can't use that with timeout()/untimeout()
without creating a potential race condition.
- Make ntoskrnl_init_timer() just a wrapper around ntoskrnl_init_timer_ex()
(reduces some code duplication).
- Drop Giant when entering if_ndis.c:ndis_tick() and
subr_ntorkrnl.c:ntoskrnl_timercall(). At the moment, I'm forced to
use system callwheel via timeout()/untimeout() to handle timers rather
than the callout API (struct callout is too big to fit inside the
Windows struct KTIMER, so I'm kind of hosed). Unfortunately, all
the callouts in the callwhere are not marked as MPSAFE, so when
one of them fires, it implicitly acquires Giant before invoking the
callback routine (and releases it when it returns). I don't need to
hold Giant, but there's no way to stop the callout code from acquiring
it as long as I'm using timeout()/untimeout(), so for now we cheat
by just dropping Giant right away (and re-acquiring it right before
the routine returns so keep the callout code happy). At some point,
I will need to solve this better, but for now this should be a suitable
workaround.
(I hope.)
My original instinct to make ndis_return_packet() asynchronous was correct.
Making ndis_rxeof() submit packets to the stack asynchronously fixes
one recursive spinlock acquisition, but it's also possible for it to
happen via the ndis_txeof() path too. So:
- In if_ndis.c, revert ndis_rxeof() to its old behavior (and don't bother
putting ndis_rxeof_serial() back since we don't need it anymore).
- In kern_ndis.c, make ndis_return_packet() submit the call to the
MiniportReturnPacket() function to the "ndis swi" thread so that
it always happens in another context no matter who calls it.
wireless ever since I added the new spinlock code. Previously, I added
a special ndis_rxeof_serial() function to insure that when we receive
a packet, we never end up calling the MiniportReturnPacket() routine
until after the receive handler has finished. I set things up so that
ndis_rxeof_serial() would only be used for serialized miniports since
they depend on this property. Well, it turns out deserialized miniports
depend on a similar property: you can't let MiniportReturnPacket() be
called from the same context as the receive handler at all. The 2100B
driver happens to use a single spinlock for all of its synchronization,
and it tries to acquire it both while in MiniportHandleInterrupt() and
in MiniportReturnPacket(), so if we call MiniportReturnPacket() from
the MiniportHandleInterrupt() context, we will end up trying to acquire
the spinlock recursively, which you can't do.
To fix this, I made the ndis_rxeof_serial() handler the default. An
alternate solution would be to make ndis_return_packet() submit
the call to MiniportReturnPacket() to the NDIS task queue thread.
I may do that in the future, after I've tested things a bit more.
attempting to duplicate Windows spinlocks. Windows spinlocks differ
from FreeBSD spinlocks in the way they block preemption. FreeBSD
spinlocks use critical_enter(), which masks off _all_ interrupts.
This prevents any other threads from being scheduled, but it also
prevents ISRs from running. In Windows, preemption is achieved by
raising the processor IRQL to DISPATCH_LEVEL, which prevents other
threads from preempting you, but does _not_ prevent device ISRs
from running. (This is essentially what Solaris calls dispatcher
locks.) The Windows spinlock itself (kspin_lock) is just an integer
value which is atomically set when you acquire the lock and atomically
cleared when you release it.
FreeBSD doesn't have IRQ levels, so we have to cheat a little by
using thread priorities: normal thread priority is PASSIVE_LEVEL,
lowest interrupt thread priority is DISPATCH_LEVEL, highest thread
priority is DEVICE_LEVEL (PI_REALTIME) and critical_enter() is
HIGH_LEVEL. In practice, only PASSIVE_LEVEL and DISPATCH_LEVEL
matter to us. The immediate benefit of all this is that I no
longer have to rely on a mutex pool.
Now, I'm sure many people will be seized by the urge to criticize
me for doing an end run around our own spinlock implementation, but
it makes more sense to do it this way. Well, it does to me anyway.
Overview of the changes:
- Properly implement hal_lock(), hal_unlock(), hal_irql(),
hal_raise_irql() and hal_lower_irql() so that they more closely
resemble their Windows counterparts. The IRQL is determined by
thread priority.
- Make ntoskrnl_lock_dpc() and ntoskrnl_unlock_dpc() do what they do
in Windows, which is to atomically set/clear the lock value. These
routines are designed to be called from DISPATCH_LEVEL, and are
actually half of the work involved in acquiring/releasing spinlocks.
- Add FASTCALL1(), FASTCALL2() and FASTCALL3() macros/wrappers
that allow us to call a _fastcall function in spite of the fact
that our version of gcc doesn't support __attribute__((__fastcall__))
yet. The macros take 1, 2 or 3 arguments, respectively. We need
to call hal_lock(), hal_unlock() etc... ourselves, but can't really
invoke the function directly. I could have just made the underlying
functions native routines and put _fastcall wrappers around them for
the benefit of Windows binaries, but that would create needless bloat.
- Remove ndis_mtxpool and all references to it. We don't need it
anymore.
- Re-implement the NdisSpinLock routines so that they use hal_lock()
and friends like they do in Windows.
- Use the new spinlock methods for handling lookaside lists and
linked list updates in place of the mutex locks that were there
before.
- Remove mutex locking from ndis_isr() and ndis_intrhand() since they're
already called with ndis_intrmtx held in if_ndis.c.
- Put ndis_destroy_lock() code under explicit #ifdef notdef/#endif.
It turns out there are some drivers which stupidly free the memory
in which their spinlocks reside before calling ndis_destroy_lock()
on them (touch-after-free bug). The ADMtek wireless driver
is guilty of this faux pas. (Why this doesn't clobber Windows I
have no idea.)
- Make NdisDprAcquireSpinLock() and NdisDprReleaseSpinLock() into
real functions instead of aliasing them to NdisAcaquireSpinLock()
and NdisReleaseSpinLock(). The Dpr routines use
KeAcquireSpinLockAtDpcLevel() level and KeReleaseSpinLockFromDpcLevel(),
which acquires the lock without twiddling the IRQL.
- In ndis_linksts_done(), do _not_ call ndis_80211_getstate(). Some
drivers may call the status/status done callbacks as the result of
setting an OID: ndis_80211_getstate() gets OIDs, which means we
might cause the driver to recursively access some of its internal
structures unexpectedly. The ndis_ticktask() routine will call
ndis_80211_getstate() for us eventually anyway.
- Fix the channel setting code a little in ndis_80211_setstate(),
and initialize the channel to IEEE80211_CHAN_ANYC. (The Microsoft
spec says you're not supposed to twiddle the channel in BSS mode;
I may need to enforce this later.) This fixes the problems I was
having with the ADMtek adm8211 driver: we were setting the channel
to a non-standard default, which would cause it to fail to associate
in BSS mode.
- Use hal_raise_irql() to raise our IRQL to DISPATCH_LEVEL when
calling certain miniport routines, per the Microsoft documentation.
I think that's everything. Hopefully, other than fixing the ADMtek
driver, there should be no apparent change in behavior.
case we should wait for the resetdone handler to be called before
returning.
- When providing resources via ndis_query_resources(), uses the
computed rsclen when using bcopy() to copy out the resource data
rather than the caller-supplied buffer length.
- Avoid using ndis_reset_nic() in if_ndis.c unless we really need
to reset the NIC because of a problem.
- Allow interrupts to be fielded during ndis_attach(), at least
as far as allowing ndis_isr() and ndis_intrhand() to run.
- Use ndis_80211_rates_ex when probing for supported rates. Technically,
this isn't supposed to work since, although Microsoft added the extended
rate structure with the NDIS 5.1 update, the spec still says that
the OID_802_11_SUPPORTED_RATES OID uses ndis_80211_rates. In spite of
this, it appears some drivers use it anyway.
- When adding in our guessed rates, check to see if they already exist
so that we avoid any duplicates.
- Add a printf() to ndis_open_file() that alerts the user when a
driver attempts to open a file under /compat/ndis.
With these changes, I can get the driver for the SMC 2802W 54g PCI
card to load and run. This board uses a Prism54G chip. Note that in
order for this driver to work, you must place the supplied smc2802w.arm
firmware image under /compat/ndis. (The firmware is not resident on
the device.)
Note that this should also allow the 3Com 3CRWE154G72 card to work
as well; as far as I can tell, these cards also use a Prism54G chip.
resource_var.h.
In kern_ndis.c:ndis_convert_res(), fill in the cprd_flags and
cprd_sharedisp fields as best we can.
In if_ndis.c:ndis_setmulti(), don't bother updating the multicast
filter if our multicast address list is empty.
Add some missing updates to ndis_var.h and ntoskrnl_var.h that I
forgot to check in when I added the KeDpc stuff.
variable length, so we should not be trying to copy it into a fixed
length buffer, especially one on the stack. malloc() a buffer of the
right size and return a pointer to that instead.
Fixes a crash I discovered when testing whe a Cisco AP in infrastructure
mode, which returns several information elements that make the
ndis_wlan_bssid_ex structure larger than expected.
(NIC would claim to establish a link with an ad-hoc net but it couldn't
send/receive packets). It turns out that every time the checkforhang
handler was called by ndis_ticktask(), the driver would generate a new
media connect event. The NDIS spec says the checkforhang handler is
called "approximately every 2 seconds" but using exactly 2 seconds seems
too fast. Using 3 seconds makes it happy again, so we'll go with that
for now.
are actually layered on top of the KeTimer API in subr_ntoskrnl.c, just
as it is in Windows. This reduces code duplication and more closely
imitates the way things are done in Windows.
- Modify ndis_encode_parm() to deal with the case where we have
a registry key expressed as a hex value ("0x1") which is being
read via NdisReadConfiguration() as an int. Previously, we tried
to decode things like "0x1" with strtol() using a base of 10, which
would always yield 0. This is what was causing problems with the
Intel 2200BG Centrino 802.11g driver: the .inf file that comes
with it has a key called RadioEnable with a value of 0x1. We
incorrectly decoded this value to '0' when it was queried, hence
the driver thought we wanted the radio turned off.
- In if_ndis.c, most drivers don't accept NDIS_80211_AUTHMODE_AUTO,
but NDIS_80211_AUTHMODE_SHARED may not be right in some cases,
so for now always use NDIS_80211_AUTHMODE_OPEN.
NOTE: There is still one problem with the Intel 2200BG driver: it
happens that the kernel stack in Windows is larger than the kernel
stack in FreeBSD. The 2200BG driver sometimes eats up more than 2
pages of stack space, which can lead to a double fault panic.
For the moment, I got things to work by adding the following to
my kernel config file:
options KSTACK_PAGES=8
I'm pretty sure 8 is too big; I just picked this value out of a hat
as a test, and it happened to work, so I left it. 4 pages might be
enough. Unfortunately, I don't think you can dynamically give a
thread a larger stack, so I'm not sure how to handle this short of
putting a note in the man page about it and dealing with the flood
of mail from people who never read man pages.
for Windows are deserialized miniports. Such drivers maintain their own
queues and do their own locking. This particular driver is not deserialized
though, and we need special support to handle it correctly.
Typically, in the ndis_rxeof() handler, we pass all incoming packets
directly to (*ifp->if_input)(). This in turn may cause another thread
to run and preempt us, and the packet may actually be processed and
then released before we even exit the ndis_rxeof() routine. The
problem with this is that releasing a packet calls the ndis_return_packet()
function, which hands the packet and its buffers back to the driver.
Calling ndis_return_packet() before ndis_rxeof() returns will screw
up the driver's internal queues since, not being deserialized,
it does no locking.
To avoid this problem, if we detect a serialized driver (by checking
the attribute flags passed to NdisSetAttributesEx(), we use an alternate
ndis_rxeof() handler, ndis_rxeof_serial(), which puts the call to
(*ifp->if_input)() on the NDIS SWI work queue. This guarantees the
packet won't be processed until after ndis_rxeof_serial() returns.
Note that another approach is to always copy the packet data into
another mbuf and just let the driver retain ownership of the ndis_packet
structure (ndis_return_packet() never needs to be called in this
case). I'm not sure which method is faster.
if_ndis.c has been split into if_ndis_pci.c and if_ndis_pccard.c.
The ndiscvt(8) utility should be able to parse device info for PCMCIA
devices now. The ndis_alloc_amem() has moved from kern_ndis.c to
if_ndis_pccard.c so that kern_ndis.c no longer depends on pccard.
NOTE: this stuff is not guaranteed to work 100% correctly yet. So
far I have been able to load/init my PCMCIA Cisco Aironet 340 card,
but it crashes in the interrupt handler. The existing support for
PCI/cardbus devices should still work as before.
that Asus provides on its CDs has both a MiniportSend() routine
and a MiniportSendPackets() function. The Microsoft NDIS docs say
that if a driver has both, only the MiniportSendPackets() routine
will be used. Although I think I implemented the support correctly,
calling the MiniportSend() routine seems to result in no packets going
out on the air, even though no error status is returned. The
MiniportSendPackets() function does work though, so at least in
this case it doesn't matter.
In if_ndis.c:ndis_getstate_80211(), if ndis_get_assoc() returns
an error, don't bother trying to obtain any other state since the
calls may fail, or worse cause the underlying driver to crash.
(The above two changes make the Asus-supplied Centrino work.)
Also, when calling the OID_802_11_CONFIGURATION OID, remember
to initialize the structure lengths correctly.
In subr_ndis.c:ndis_open_file(), set the current working directory
to rootvnode if we're in a thread that doesn't have a current
working directory set.
is for an 802.11 device or not. At least one driver I have does not
support the OID_802_11_NETWORK_TYPES_SUPPORTED OID.
Also, for now, don't do anything special in the ndis_suspend() method.
I originally wanted to shut down the NIC but leave the IFF_UP flag alone
since technically the interface is meant to remain up, but an interrupt
may be delivered to the ISR on suspend, and if this happens while the
NIC is halted, we will crash, since none of the miniport driver methods
will function.
This needs to be dealt with properly later, but for now this prevents
a panic, and the resume method properly re-inits the NIC.
won't associate in BSS mode if you use AUTHMODE_SHARED. I probably don't
understand enough to know when SHARED should be used vs. OPEN or WPA.
For now, go back to what works.
on an SIOCSIFADDR (by way of brain damage in net80211).
Also, avoid trying to set NDIS_80211_AUTHMODE_AUTO since the Microsoft
documentation I have recommends not using it, and the Centrino driver
seems to dislike being told to use it.
problem with using taskqueue_swi is that some of the things we defer
into threads might block for up to several seconds. This is an unfriendly
thing to do to taskqueue_swi, since it is assumed the taskqueue threads
will execute fairly quickly once a task is submitted. Reorganized the
locking in if_ndis.c in the process.
Cleaned up ndis_write_cfg() and ndis_decode_parm() a little.
the definitions for NDIS_BUS_SPACE_IO and NDIS_BUS_SPACE_MEM logically
belong in hal_var.h. At least, that's my story, and I'm sticking to it.
Also, remove definition of __stdcall from if_ndis.c now that it's pulled
in from pe_var.h.
these add support for listing BSSIDs via wicontrol -l. I added code
to call OID_802_11_BSSID_LIST_SCAN to allow scanning for any nearby
wirelsss nets.
Convert from using individual mutexes to a mutex pool, created in
subr_ndis.c. This deals with the problem of drivers creating locks
in their DriverEntry() routines which might get trashed later.
Put some messages under IFF_DEBUG.
which has two important flags in it: the 'allocated by NDIS' flag
and the 'media specific info present' flag. There are two Windows macros
for getting/setting media specific info fields within the ndis_packet
structure which can behave improperly if these flags are not initialized
correctly when a packet is allocated. It seems the correct thing
to do is always set the NDIS_PACKET_ALLOCATED_BY_NDIS flag on
all newly allocated packets.
This fixes the crashes with the Intel Centrino wireless driver.
My sample card now seems to work correctly.
Also, fix a potential LOR involving ndis_txeof() in if_ndis.c.
the ni_dpccountlock member is an ndis_kspin_lock, not an
ndis_spin_lock (the latter is too big).
Run if_ndis.c:ndis_tick() via taskqueue_schedule(). Also run
ndis_start() via taskqueue in certain circumstances.
Using these tweaks, I can now get the Broadcom BCM5701 NDIS
driver to load and run. Unfortunately, the version I have seems
to suffer from the same bug as the SMC 83820 driver, which is
that it creates a spinlock during its DriverEntry() routine.
I'm still debating the right way to deal with this.
the RT_MESSAGETABLE resources that some driver binaries have.
This allows us to print error messages in ndis_syslog().
- Correct the implementation of InterlockedIncrement() and
InterlockedDecrement() -- they return uint32_t, not void.
- Correct the declarations of the 64-bit arithmetic shift
routines in subr_ntoskrnl.c (_allshr, allshl, etc...). These
do not follow the _stdcall convention: instead, they appear
to be __attribute__((regparm(3)).
- Change the implementation of KeInitializeSpinLock(). There is
no complementary KeFreeSpinLock() function, so creating a new
mutex on each call to KeInitializeSpinLock() leaks resources
when a driver is unloaded. For now, KeInitializeSpinLock()
returns a handle to the ntoskrnl interlock mutex.
- Use a driver's MiniportDisableInterrupt() and MiniportEnableInterrupt()
routines if they exist. I'm not sure if I'm doing this right
yet, but at the very least this shouldn't break any currently
working drivers, and it makes the Intel PRO/1000 driver work.
- In ndis_register_intr(), save some state that might be needed
later, and save a pointer to the driver's interrupt structure
in the ndis_miniport_block.
- Save a pointer to the driver image for use by ndis_syslog()
when it calls pe_get_message().
and MiniportHandleInterrupt() is fired off later via a task queue in
ndis_intrtask(). This more accurately follows the NDIS interrupt handling
model, where the ISR does a minimal amount of work in interrupt context
and the handler is defered and run at a lower priority.
Create a separate ndis_intrmtx mutex just for the guarding the ISR.
Modify NdisSynchronizeWithInterrupt() to aquire the ndis_intrmtx
mutex before invoking the synchronized procedure. (The purpose of
this function is to provide mutual exclusion for code that shares
variables with the ISR.)
Modify NdisMRegisterInterrupt() to save a pointer to the miniport
block in the ndis_miniport_interrupt structure so that
NdisSynchronizeWithInterrupt() can grab it later and derive
ndis_intrmtx from it.
driver was compiled with.
Remove debug printf from ndis_assicn_pcirsc(). It doesn't serve
much purpose.
Implement NdisMIndicateStatus() and NdisMIndicateStatusComplete()
as functions in subr_ndis.c. In NDIS 4.0, they were functions. In
NDIS 5.0 and later, they're just macros.
Allocate a few extra packets/buffers beyond what the driver asks
for since sometimes it seems they can lie about how many they really
need, and some extra stupid ones don't check to see if NdisAllocatePacket()
and/or NdisAllocateBuffer() actually succeed.
calling the haltfunc. If an interrupt is triggered by the init
or halt func, the IFF_UP flag must be set in order for us to be able
to service it.
In kern_ndis.c: implement a handler for NdisMSendResourcesAvailable()
(currently does nothing since we don't really need it).
In subr_ndis.c:
- Correct ndis_init_string() and ndis_unicode_to_ansi(),
which were both horribly broken.
- Implement NdisImmediateReadPciSlotInformation() and
NdisImmediateWritePciSlotInformation().
- Implement NdisBufferLength().
- Work around my first confirmed NDIS driver bug.
The SMC 9462 gigE driver (natsemi 83820-based copper)
incorrectly creates a spinlock in its DriverEntry()
routine and then destroys it in its MiniportHalt()
handler. This is wrong: spinlocks should be created
in MiniportInit(). In a Windows environment, this is
often not a problem because DriverEntry()/MiniportInit()
are called once when the system boots and MiniportHalt()
or the shutdown handler is called when the system halts.
With this stuff in place, this driver now seems to work:
ndis0: <SMC EZ Card 1000> port 0xe000-0xe0ff mem 0xda000000-0xda000fff irq 10 at device 9.0 on pci0
ndis0: assign PCI resources...
ndis_open_file("FLASH9.hex", 18446744073709551615)
ndis0: Ethernet address: 00:04:e2:0e:d3:f0
copyrights to the inf parser files.
Add a -n flag to ndiscvt to allow the user to override the default
device name of NDIS devices. Instead of "ndis0, ndis1, etc..."
you can have "foo0, foo1, etc..." This allows you to have more than
one kind of NDIS device in the kernel at the same time.
Convert from printf() to device_printf() in if_ndis.c, kern_ndis.c
and subr_ndis.c.
Create UMA zones for ndis_packet and ndis_buffer structs allocated
on transmit. The zones are created and destroyed in the modevent
handler in kern_ndis.c.
printf() and UMA changes submitted by green@freebsd.org
