This means that the kernel can be totally self contained now and is not
dependent on the last buildworld to update /usr/share/mk. This might
also make it easier to build 5.x kernels on 4.0 boxes etc, assuming
gensetdefs and config(8) are updated.
are two supported chips, the NetChip 1080 (only prototypes available)
and the EzLink cable. Any other cable should be supported however as they
are all very much alike (there is a difference between them wrt
performance).
It uses Netgraph.
This driver was mostly written by Doug Ambrisko and Julian Elischer and
I would like to thank Whistle for yet another contribution. And my
aplogies to them for me sitting on the driver for so long (2 months).
Also, many thanks to Reid Augustin from NetChip for providing me with a
prototype of their 1080 chip.
Be aware of the fact that this driver is very immature and has only been
tested very lightly. If someone feels like learning about Netgraph however
this is an excellent driver to start playing with.
- Break out the support for the XMAC II's PHY into an miibus driver.
- Reorganize the probe/attach stuff using newbus. Each XMAC is now
attached to the parent GEnesis controller using newbus. This is
necessary since each XMAC must also have an attached miibus, and
the miibus read/write register routines need to be able to get
at the softc struct for each XMAC, not the one for the parent
controller. This allows me to get rid of the grotty code I added
for selecting the unit numbers for the ifnet interfaces: the unit
numbers are now derived from the newbus-assigned unit numbers,
which should track with the ifnet interface numbers. I think.
At the very least, there should never be any collisions.
- Add support for the SK-9821 and SK-9822 1000baseTX adapters. Special
thanks to SysKonnect for loaning me two adapters for testing.
vintage system, well before the ppbus changes. When I called it an
"example" module, I meant as an example for the rest of the ppbus client
drivers, not that it was worthless. I'll mail my 5.8MB world.log to
anybody who doesn't believe me.
Wrongly accused by: obrien
include this in all kernels. Declare some const *intrq_present
variables that can be checked by a module prior to using *intrq
to queue data.
Make the if_tun module capable of processing atm, ip, ip6, ipx,
natm and netatalk packets when TUNSIFHEAD is ioctl()d on.
Review not required by: freebsd-hackers
- Split terminal emulation code from the main part of the driver so
that we can have alternative terminal emulator modules if we like in
the future. (We are not quite there yet, though.)
- Put sysmouse related code in a separate file, thus, simplifying the
main part of the driver.
As some files are added to the source tree, you need to run config(8)
before you compile a new kernel next time.
You shouldn't see any functional change by this commit; this is only
internal code reorganization.
NICs. (Finally!) The PCMCIA, ISA and PCI varieties are all supported,
though only the ISA and PCI ones will work on the alpha for now.
PCCARD, ISA and PCI attachments are all provided. Also provided an
ancontrol(8) utility for configuring the NIC, man pages, and updated
pccard.conf.sample. ISA cards are supported in both ISA PnP and hard-wired
mode, although you must configure the kernel explicitly to support the
hardwired mode since you have to know the I/O address and port ahead
of time.
Special thanks to Doug Ambrisko for doing the initial newbus hackery
and getting it to work in infrastructure mode.
USB-EL1202A chipset. Between this and the other two drivers, we should
have support for pretty much every USB ethernet adapter on the market.
The only other USB chip that I know of is the SMC USB97C196, and right
now I don't know of any adapters that use it (including the ones made
by SMC :/ ).
Note that the CATC chip supports a nifty feature: read and write combining.
This allows multiple ethernet packets to be transfered in a single USB
bulk in/out transaction. However I'm again having trouble with large
bulk in transfers like I did with the ADMtek chip, which leads me to
believe that our USB stack needs some work before we can really make
use of this feature. When/if things improve, I intend to revisit the
aue and cue drivers. For now, I've lost enough sanity points.
Packets are received inside USB bulk transfer callbacks, which run at
splusb() (actually splbio()). The packet input queues are meant to be
manipulated at splimp(). However the locking apparently breaks down under
certain circumstances and the input queues can get trampled.
There's a similar problem with if_ppp, which is driven by hardware/tty
interrupts from the serial driver, but which must also manipulate the
packet input queues at splimp(). The fix there is to use a netisr, and
that's the fix I used here. (I can hear you groaning back there. Hush up.)
The usb_ethersubr module maintains a single queue of its own. When a
packet is received in the USB callback routine, it's placed on this
queue with usb_ether_input(). This routine also schedules a soft net
interrupt with schednetisr(). The ISR routine then runs later, at
splnet, outside of the USB callback/interrupt context, and passes the
packet to ether_input(), hopefully in a safe manner.
The reason this is implemented as a separate module is that there are
a limited number of NETISRs that we can use, and snarfing one up for
each driver that needs it is wasteful (there will be three once I get
the CATC driver done). It also reduces code duplication to a certain
small extent. Unfortunately, it also needs to be linked in with the
usb.ko module in order for the USB ethernet drivers to share it.
Also removed some uneeded includes from if_aue.c and if_kue.c
Fix suggested by: peter
Not rejected as a hairbrained idea by: n_hibma
-U_KERNEL became negative when all all the genassym.c's were converted
to be cross-built.
Use "genassym ... > ${.TARGET}", not "genassym -o $@ ...", so that
genassym(1) doesn't need to support -o.
Removed duplicate -D_KERNEL from CFLAGS.
Removed triplicate -D_KERNEL from flags for compiling svr4_locore.s.
-U_KERNEL became negative when all all the genassym.c's were converted
to be cross-built.
Use "genassym ... > ${.TARGET}", not "genassym -o $@ ...", so that
genassym(1) doesn't need to support -o.
Removed duplicate -D_KERNEL from flags for compiling linux_locore.s.
Kawasaki LSI KL5KUSB101B chip, including the LinkSys USB10T, the
Entrega NET-USB-E45, the Peracom USB Ethernet Adapter, the 3Com
3c19250 and the ADS Technologies USB-10BT. This device is 10mbs
half-duplex only, so there's miibus or ifmedia support. This device
also requires firmware to be loaded into it, however KLSI allows
redistribution of the firmware images (I specifically asked about
this; they said it was ok).
Special thanks to Annelise Anderson for getting me in touch with
KLSI (eventually) and thanks to KLSI for providing the necessary
programming info.
Highlights:
- Add driver files to /sys/dev/usb
- update usbdevs and regenerate attendate files
- update usb_quirks.c
- Update HARDWARE.TXT and RELNOTES.TXT for i386 and alpha
- Update LINT, GENERIC and others for i386, alpha and pc98
- Add man page
- Add module
- Update sysinstall and userconfig.c
is an application space macro and the applications are supposed to be free
to use it as they please (but cannot). This is consistant with the other
BSD's who made this change quite some time ago. More commits to come.
USB ethernet chip. Adapters that use this chip include the LinkSys
USB100TX. There are a few others, but I'm not certain of their
availability in the U.S. I used an ADMtek eval board for development.
Note that while the ADMtek chip is a 100Mbps device, you can't really
get 100Mbps speeds over USB. Regardless, this driver uses miibus to
allow speed and duplex mode selection as well as autonegotiation.
Building and kldloading the driver as a module is also supported.
Note that in order to make this driver work, I had to make what some
may consider an ugly hack to sys/dev/usb/usbdi.c. The usbd_transfer()
function will use tsleep() for synchronous transfers that don't complete
right away. This is a problem since there are times when we need to
do sync transfers from an interrupt context (i.e. when reading registers
from the MAC via the control endpoint), where tsleep() us a no-no.
My hack allows the driver to have the code poll for transfer completion
subject to the xfer->timeout timeout rather that calling tsleep().
This hack is controlled by a quirk entry and is only enabled for the
ADMtek device.
Now, I'm sure there are a few of you out there ready to jump on me
and suggest some other approach that doesn't involve a busy wait. The
only solution that might work is to handle the interrupts in a kernel
thread, where you may have something resembling a process context that
makes it okay to tsleep(). This is lovely, except we don't have any
mechanism like that now, and I'm not about to implement such a thing
myself since it's beyond the scope of driver development. (Translation:
I'll be damned if I know how to do it.) If FreeBSD ever aquires such
a mechanism, I'll be glad to revisit the driver to take advantage of
it. In the meantime, I settled for what I perceived to be the solution
that involved the least amount of code changes. In general, the hit
is pretty light.
Also note that my only USB test box has a UHCI controller: I haven't
I don't have a machine with an OHCI controller available.
Highlights:
- Updated usb_quirks.* to add UQ_NO_TSLEEP quirk for ADMtek part.
- Updated usbdevs and regenerated generated files
- Updated HARDWARE.TXT and RELNOTES.TXT files
- Updated sysinstall/device.c and userconfig.c
- Updated kernel configs -- device aue0 is commented out by default
- Updated /sys/conf/files
- Added new kld module directory
sys/modules Makefile after completing a buildworld.
History:
The bulk of this code was obtained from NetBSD approximately one year
ago (I have taken care to preserve the original NetBSD copyrights and
I thank the authors for their work.) At that time, the OSF/1 code was
what was left over from their initial bootstrapping off of OSF/1 and
did not provide support for executing shared binaries.
I have independently added support for shared libraries, and support
for some of the more obscure system calls. This code has been
available for testing and comment since January of 1999 and running on
production machines here at Duke since April.
Known working applications include:
- Netscape (all versions I've tried)
- Mathematica 3.0.2
- Splus 3.4
- ArcInfo 7.1
- Matlab (version unknown)
- SimOS
- Atom instrumented binaries (built on a real OSF/1 system)
Applications which are known not to work:
- All applications linking to libmach
- Adobe Acrobat (uses libmach)
This has been tested with applications running against shared
libraries from OSF/1 (aka Tru64) 4.0D and 4.0F.
Reviewed by: marcel, obrien
BDE-lint by: obrien
Agreed in principal to by: msmith
needed for ages, but keeps getting cut/pasted into new Makefiles.
(Once apon a time it was used to activate mount arguments in
<sys/mount.h>, but that was killed with extreme prejudice long ago)
opt_global.h and opt_svr4.h, instead of from the command line. This
brings them in-line with most of the rest of the kernel.
svr4_ioctl.c has also failed to compile with debugging for a while
now; fixed by adding systm.h and socketvar.
Some svr4 source files are automatically generated from syscalls.master;
these have been committed as consequential changes, otherwise everyone
will have to "make svr4_sysent.c".
Changes:
sys/svr4/svr4.h include opt_global.h and opt_svr4.h
sys/svr4/svr4_ioctl.c include svr4.h, sys/systm.h and sys/socketvar.h
sys/svr4/svr4_ipc.c include svr4.h
sys/svr4/svr4_resource.c include svr4.h
sys/svr4/svr4_socket.c include svr4.h
sys/svr4/svr4_ttold.c include svr4.h
sys/svr4/syscalls.master include svr4.h
sys/svr4/svr4_syscallnames.c dependent on syscalls.master
sys/svr4/svr4_sysent.c dependent on syscalls.master
sys/svr4/svr4_syscall.h dependent on syscalls.master
sys/svr4/svr4_proto.h dependent on syscalls.master
sys/modules/svr4/Makefile create opt_global.h and opt_svr4.h
packet divert at kernel for IPv6/IPv4 translater daemon
This includes queue related patch submitted by jburkhol@home.com.
Submitted by: queue related patch from jburkhol@home.com
Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project
which it replaces. The new driver supports all of the chips supported
by the ones it replaces, as well as many DEC/Intel 21143 10/100 cards.
This also completes my quest to convert things to miibus and add
Alpha support.
NGM_BINARY2ASCII, which convert control messages to ASCII and back.
This allows control messages to be sent and received in ASCII form
using ngctl(8), which makes ngctl a lot more useful.
This also allows all the type-specific debugging code in libnetgraph
to go away -- instead, we just ask the node itself to do the ASCII
translation for us.
Currently, all generic control messages are supported, as well as
messages associated with the following node types: async, cisco,
ksocket, and ppp.
See /usr/share/examples/netgraph/ngctl for an example of using this.
Also give ngctl(8) the ability to print out incoming data and
control messages at any time. Eventually nghook(8) may be subsumed.
Several other misc. bug fixes.
Reviewed by: julian
socket attach code. We now have at least a chance for pccard devices
appearing in the future.
This is a snapshot of ongoing work. Proceed at your own risk.
- Convert to new bus attachment scheme. Thanks to Blaz Zupan for doing
the initial work here. One thing I changed was to have the attach
and detach routines work like the PCI drivers, which means that in
theory you should be able to load and unload the driver like the PCI
NIC drivers, however the pccard support for this hasn't settled down
yet so it doesn't quite work. Once the pccard work is done, I'll have
to revisit this.
- Add device wi0 to PCCARD. If we're lucky, people should be able to
install via their WaveLAN cards now.
- Add support for signal strength caching. The wicontrol utility has
also been updated to allow zeroing and displaying the signal strength
cache.
- Add a /sys/modules/wi directory and fix a Makefile to builf if_wi.ko.
Currently this module is only built for the i386 platform, though once
the pccard stuff is done it should be able to work on the alpha too.
(Theoretically you should be able to plug one of the WaveLAN/IEEE ISA
cards into an alpha with an ISA slot, but we'll see how that turns out.
- Update LINT to use only device wi0. There is no true ISA version of
the WaveLAN/IEEE so we'll never use an ISA attachment.
- Update files.i386 so that if_wi is dependent on card.
make development easier and push the ability of newbus to load busses
to the test.
Not added to sys/modules/Makefile because it isn't ready to break the
nightly snapshots for alpha yet :-).
NOTE: This is only for NEWCARD. The old pccard stuff will not build
as a loadable module.
code. You can now build the newcard's pcic driver as a module for all
the joy that will bring you, which currently isn't so much joy as it
is pain.
The old pccard module will never be made to work again, so I think
this is OK. Note, it still remains disabled in sys/modules/Makefile
on purpose.
Been in production for 3 years now. Gives Instant Frame relay to if_sr
and if_ar drivers, and PPPOE support soon. See:
ftp://ftp.whistle.com/pub/archie/netgraph/index.html
for on-line manual pages.
Reviewed by: Doug Rabson (dfr@freebsd.org)
Obtained from: Whistle CVS tree
In order to make this work, I created a pseudo-PHY driver to deal with
Macronix chips that use the built-in NWAY support and symbol mode port.
This is actually all of them, with the exception of the original MX98713
which presents its NWAY support via the MII serial interface.
The mxphy driver actually manipulates the controller registers directly
rather than using the miibus_readreg()/miibus_writereg() bus interface
since there are no MII registers to read. The mx driver itself pretends
that the NWAY interface is a PHY locayed at MII address 31 for the sole
purpose of allowing the mxphy_probe() routine to know when it needs to
attach to a host controller.
the AMI PCI controllers using the 8LD firmware interface (40LD firmware
will be supported as soon as I have hardware to test with).
These controllers are rebadged by Dell as the PERC, as well as by HP
and possibly other vendors.
apm_saver uses the apm_display() routine from the apm system to
"suspend" the "display" part of the machine.
This is beneficial for some laptops (or other machines with
non-traditional displays) that choke on the 'green' saver's
effect.
Another way of looking at this is that it's the same as a screen
saver that does an 'apm -d 0' to blank the display and an 'apm -d 1'
to bring it back. One probably ought to use these commands to make
sure the effect will be correct before using it unattended.
for the AN985 "Centaur" chip, which is apparently the next genetation
of the "Comet." The AN985 is also a tulip clone and is similar to the
AL981 except that it uses a 99C66 EEPROM and a serial MII interface
(instead of direct access to the PHY registers).
Also updated various documentation to mention the AN985 and created
a loadable module.
I don't think there are any cards that use this chip on the market yet:
the datasheet I got from ADMtek has boxes with big X's in them where the
diagrams should be, and the sample boards I got have chips without any
artwork on them.
2) s/MODLOAD/KMODLOAD/ to be consistent with the rest of the variables
(KMOD, KMODOWN, KMODGRP, etc) and definition of MODLOAD/UNLOAD in the
Makefile of the ATAPI module
3) textual fixups
the Davicom DM9100 and DM9102 chipsets, including the Jaton Corporation
XPressNet. Datasheet is available from www.davicom8.com.
The DM910x chips are still more tulip clones. The API is reproduced
pretty faithfully, unfortunately the performance is pretty bad. The
transmitter seems to have a lot of problems DMAing multi-fragment
packets. The only way to make it work reliably is to coalesce transmitted
packets into a single contiguous buffer. The Linux driver (written by
Davicom) actually does something similar to this. I can't recomment this
NIC as anything more than a "connectivity solution."
This driver uses newbus and miibus and is supported on both i386
and alpha platforms.
this PHY and the Davicom DM9101 have exactly the same register definitions.
One of them is probably a clone of the other. I'm not sure which.
This is needed for the Davicom DM9102 10/100 PCI ethernet driver which
will be committed shortly.
SiS 900 and SiS 7016 PCI fast ethernet chipsets. Full manuals for the
SiS chips can be found at www.sis.com.tw.
This is a fairly simple chipset. The receiver uses a 128-bit multicast
hash table and single perfect entry for the station address. Transmit and
receive DMA and FIFO thresholds are easily tuneable. Documentation is
pretty decent and performance is not bad, even on my crufty 486. This
driver uses newbus and miibus and is supported on both the i386 and
alpha architectures.
due to the fact that there are non-MII cards supported by the same
driver and I don't have all of the cards available for testing. There's
also the 3c905B-COMBO which has MII, AUI and BNC media ports all in one
package. Supporting the COMBO is difficult because we have to add the
10base5 and 10base2 media types to the same ifmedia struct as the
MII-attached types, however there is no way to force the miibus and
child PHYs into existence before xl_attach() completes, so there is
no ifmedia struct available in xl_attach(). What we do inistead is
use the mediainit method as a callback: when a child PHY is attached,
it calls the miibus mediainit routine which selects a default media.
This routing also calls the NIC driver's mediainit method (if it
implements one) at which point we can safely add the other media
types.
discussed on current.
The following variables are defined (for now):
osname (defaults to "Linux")
Allow users to change the name of the OS as returned by uname(2),
specially added for all those Linux Netscape users and statistics
maniacs :-) We now have what we all wanted!
osrelease (defaults to "2.2.5")
Allow users to change the version of the OS as returned by uname(2).
Since -current supports glibc2.1 now, change the default to 2.2.5
(was 2.0.36).
oss_version (defaults to 198144 [0x030600])
This one will be used by the OSS_GETVERSION ioctl (PR 12917) which I
can commit now that we have the MIB. The default version number is the
lowest version possible with the current 'encoding'.
A note about imprisoned processes (see jail(2)):
These variables are copy-on-write (as suggested by phk). This means that
imprisoned processes will use the system wide value unless it is written/set
by the process. From that moment on, a copy local to the prison will be
used.
A note about the implementation:
I choose to add a single pointer to struct prison, because I didn't like the
idea of changing struct prison every time I come up with a new variable. As
a side effect, the extra storage is only needed when a variable is set from
within the prison. This also minimizes kernel bloat when the Linuxulator is
not used; both compiled in or as a module.
Reviewed by: bde (first version only) and phk
PCI fast ethernet controller. Currently, the only card I know that uses
this chip is the D-Link DFE-550TX. (Don't ask me where to buy these: the
only cards I have are samples sent to me by D-Link.)
This driver is the first to make use of the miibus code once I'm sure
it all works together nicely, I'll start converting the other drivers.
The Sundance chip is a clone of the 3Com 3c90x Etherlink XL design
only with its own register layout. Support is provided for ifmedia,
hardware multicast filtering, bridging and promiscuous mode.
MII-compliant PHY drivers. Many 10/100 ethernet NICs available today
either use an MII transceiver or have built-in transceivers that can
be programmed using an MII interface. It makes sense then to separate
this support out into common code instead of duplicating it in all
of the NIC drivers. The mii code also handles all of the media
detection, selection and reporting via the ifmedia interface.
This is basically the same code from NetBSD's /sys/dev/mii, except
it's been adapted to FreeBSD's bus architecture. The advantage to this
is that it automatically allows everything to be turned into a
loadable module. There are some common functions for use in drivers
once an miibus has been attached (mii_mediachg(), mii_pollstat(),
mii_tick()) as well as individual PHY drivers. There is also a
generic driver for all PHYs that aren't handled by a specific driver.
It's possible to do this because all 10/100 PHYs implement the same
general register set in addition to their vendor-specific register
sets, so for the most part you can use one driver for pretty much
any PHY. There are a couple of oddball exceptions though, hence
the need to have specific drivers.
There are two layers: the generic "miibus" layer and the PHY driver
layer. The drivers are child devices of "miibus" and the "miibus" is
a child of a given NIC driver. The "miibus" code and the PHY drivers
can actually be compiled and kldoaded as completely separate modules
or compiled together into one module. For the moment I'm using the
latter approach since the code is relatively small.
Currently there are only three PHY drivers here: the generic driver,
the built-in 3Com XL driver and the NS DP83840 driver. I'll be adding
others later as I convert various NIC drivers to use this code.
I realize that I'm cvs adding this stuff instead of importing it
onto a separate vendor branch, but in my opinion the import approach
doesn't really offer any significant advantage: I'm going to be
maintaining this stuff and writing my own PHY drivers one way or
the other.
a module. Also modified the code to work on FreeBSD/alpha and added
device vr0 to the alpha GENERIC config.
While I was in the neighborhood, I noticed that I was still using
#define NFPX 1 in all of the Makefiles that I'd copied from the fxp
module. I don't really use #define Nfoo X so it didn't matter, but
I decided to customize this correctly anyway.
ethernet controllers based on the AIC-6915 "Starfire" controller chip.
There are single port, dual port and quad port cards, plus one 100baseFX
card. All are 64-bit PCI devices, except one single port model.
The Starfire would be a very nice chip were it not for the fact that
receive buffers have to be longword aligned. This requires buffer
copying in order to achieve proper payload alignment on the alpha.
Payload alignment is enforced on both the alpha and x86 platforms.
The Starfire has several different DMA descriptor formats and transfer
mechanisms. This driver uses frame descriptors for transmission which
can address up to 14 packet fragments, and a single fragment descriptor
for receive. It also uses the producer/consumer model and completion
queues for both transmit and receive. The transmit ring has 128
descriptors and the receive ring has 256.
This driver supports both FreeBSD/i386 and FreeBSD/alpha, and uses newbus
so that it can be compiled as a loadable kernel module. Support for BPF
and hardware multicast filtering is included.
- Split syscons source code into manageable chunks and reorganize
some of complicated functions.
- Many static variables are moved to the softc structure.
- Added a new key function, PREV. When this key is pressed, the vty
immediately before the current vty will become foreground. Analogue
to PREV, which is usually assigned to the PrntScrn key.
PR: kern/10113
Submitted by: Christian Weisgerber <naddy@mips.rhein-neckar.de>
- Modified the kernel console input function sccngetc() so that it
handles function keys properly.
- Reorganized the screen update routine.
- VT switching code is reorganized. It now should be slightly more
robust than before.
- Added the DEVICE_RESUME function so that syscons no longer hooks the
APM resume event directly.
- New kernel configuration options: SC_NO_CUTPASTE, SC_NO_FONT_LOADING,
SC_NO_HISTORY and SC_NO_SYSMOUSE.
Various parts of syscons can be omitted so that the kernel size is
reduced.
SC_PIXEL_MODE
Made the VESA 800x600 mode an option, rather than a standard part of
syscons.
SC_DISABLE_DDBKEY
Disables the `debug' key combination.
SC_ALT_MOUSE_IMAGE
Inverse the character cell at the mouse cursor position in the text
console, rather than drawing an arrow on the screen.
Submitted by: Nick Hibma (n_hibma@FreeBSD.ORG)
SC_DFLT_FONT
makeoptions "SC_DFLT_FONT=_font_name_"
Include the named font as the default font of syscons. 16-line,
14-line and 8-line font data will be compiled in. This option replaces
the existing STD8X16FONT option, which loads 16-line font data only.
- The VGA driver is split into /sys/dev/fb/vga.c and /sys/isa/vga_isa.c.
- The video driver provides a set of ioctl commands to manipulate the
frame buffer.
- New kernel configuration option: VGA_WIDTH90
Enables 90 column modes: 90x25, 90x30, 90x43, 90x50, 90x60. These
modes are mot always supported by the video card.
PR: i386/7510
Submitted by: kbyanc@freedomnet.com and alexv@sui.gda.itesm.mx.
- The header file machine/console.h is reorganized; its contents is now
split into sys/fbio.h, sys/kbio.h (a new file) and sys/consio.h
(another new file). machine/console.h is still maintained for
compatibility reasons.
- Kernel console selection/installation routines are fixed and
slightly rebumped so that it should now be possible to switch between
the interanl kernel console (sc or vt) and a remote kernel console
(sio) again, as it was in 2.x, 3.0 and 3.1.
- Screen savers and splash screen decoders
Because of the header file reorganization described above, screen
savers and splash screen decoders are slightly modified. After this
update, /sys/modules/syscons/saver.h is no longer necessary and is
removed.
that doesn't have it. This is achieved by having minimal do-nothing stubs
enabled when there are no bpfilter devices configured.
Driver modules should be built with BPF enabled for maximum
convenience (but can be built without it for maximum performance).