The kernel config file is KERNCONF=MPC85XX, so the usual procedure applies:
1. make buildworld TARGET_ARCH=powerpc
2. make buildkernel TARGET_ARCH=powerpc TARGET_CPUTYPE=e500 KERNCONF=MPC85XX
This default config uses kernel-level FPU emulation. For the soft-float world
approach:
1. make buildworld TARGET_ARCH=powerpc TARGET_CPUTYPE=e500
2. disable FPU_EMU option in sys/powerpc/conf/MPC85XX
3. make buildkernel TARGET_ARCH=powerpc TARGET_CPUTYPE=e500 KERNCONF=MPC85XX
Approved by: cognet (mentor)
MFp4: e500
The PQ3 is a high performance integrated communications processing system
based on the e500 core, which is an embedded RISC processor that implements
the 32-bit Book E definition of the PowerPC architecture. For details refer
to: http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPC8555E
This port was tested and successfully run on the following members of the PQ3
family: MPC8533, MPC8541, MPC8548, MPC8555.
The following major integrated peripherals are supported:
* On-chip peripherals bus
* OpenPIC interrupt controller
* UART
* Ethernet (TSEC)
* Host/PCI bridge
* QUICC engine (SCC functionality)
This commit brings the main functionality and will be followed by individual
drivers that are logically separate from this base.
Approved by: cognet (mentor)
Obtained from: Juniper, Semihalf
MFp4: e500
and assignment.
- Add a reference to a struct cpuset in each thread that is inherited from
the thread that created it.
- Release the reference when the thread is destroyed.
- Add prototypes for syscalls and macros for manipulating cpusets in
sys/cpuset.h
- Add syscalls to create, get, and set new numbered cpusets:
cpuset(), cpuset_{get,set}id()
- Add syscalls for getting and setting affinity masks for cpusets or
individual threads: cpuid_{get,set}affinity()
- Add types for the 'level' and 'which' parameters for the cpuset. This
will permit expansion of the api to cover cpu masks for other objects
identifiable with an id_t integer. For example, IRQs and Jails may be
coming soon.
- The root set 0 contains all valid cpus. All thread initially belong to
cpuset 1. This permits migrating all threads off of certain cpus to
reserve them for special applications.
Sponsored by: Nokia
Discussed with: arch, rwatson, brooks, davidxu, deischen
Reviewed by: antoine
not have VTOC information about the partitions, it will be created.
This is because the VTOC information is used for the partition type
and FreeBSD's sunlabel(8) does not create nor use VTOC information.
For this purpose, new tags have been added to support FreeBSD's
partition types.
just em, there is an igb driver (this follows behavior with our Linux drivers).
All adapters up to the 82575 are supported in em, and new client/desktop support
will continue to be in that adapter.
The igb driver is for new server NICs like the 82575 and its followons.
Advanced features for virtualization and performance will be in this driver.
Also, both drivers now have shared code that is up to the latest we have
released. Some stylistic changes as well.
Enjoy :)
sectors so the geometry of large IDE disks has to be adjusted. This
corresponds to what the OpenSolaris dad(7D) driver does except that
the latter only tweaks sectors and effectively limits the mediasize
to 128GB so the cylinders and heads fields won't ever overflow. Not
limiting the mediasize is a compromise between allowing to use Sun
disk label as far as possible and being able to use the entire disk
with another disk label.
This allows to use the full capacity of large IDE disks if they were
not labeled under (Open)Solaris (in both ways of the meaning).
MFC after: 2 weeks
This allows to fix a problem with ARM kernel.bin not having the MFS image
embedded: it is objcopied from the kernel.noheader temporary ELF file, which
was not subject to embedding the MFS image previously.
Reviewed by: imp
Approved by: cognet (mentor)
a variety of bootloaders. This sometimes means that different loader
scripts are required within one ${MACHINE_ARCH}, which makes the
current practice of using ldscript.${MACHINE_ARCH} unsuitable.
Instead, make the default the current convention and allow the ld
scripts to be overridden as necessary.
If we aren't arm, pc98 or sun4v, then enable treating warnings like
errors. That doesn't mean these platforms aren't -Werror clean, just
that we haven't enforced it before. Someone with some spare time
should investigate these three platforms to see if any can be removed.
DP83847 PHYs. The main reason for using a specific driver for these
PHYs are reset quirks similar to the nsphy(4) driven DP83840A.
PR: 112654
Obtained from: NetBSD
MFC after: 2 weeks
Thanks to: mlaier for testing w/ DP83815
overridden at compile-time using kernel options of the same names.
Rather than doing a compile-time CTASSERT of buffer sizes being
even multiples of block sizes, just adjust them at boottime, as
the failure mode is more user-friendly.
MFC after: 2 months
PR: 119993
Suggested by: Scot Hetzel <swhetzel at gmail dot com>
queues (which we call slices). The NIC will steer traffic into up to
hw.mxge.max_slices different receive rings based on a configurable
hash type (hw.mxge.rss_hash_type).
Currently the driver defaults to using a single slice, so the default
behavior is unchanged. Also, transmit from non-zero slices is
disabled currently.
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
machine-independent support for superpages. (The earlier part was
the rewrite of the physical memory allocator.) The remainder of the
code required for superpages support is machine-dependent and will
be added to the various pmap implementations at a later date.
Initially, I am only supporting one large page size per architecture.
Moreover, I am only enabling the reservation system on amd64. (In
an emergency, it can be disabled by setting VM_NRESERVLEVELS to 0
in amd64/include/vmparam.h or your kernel configuration file.)
dump using mechanically generated/extracted debugging output rather than
a simple memory dump. Current sources of debugging output are:
- DDB output capture buffer, if there is captured output to save
- Kernel message buffer
- Kernel configuration, if included in kernel
- Kernel version string
- Panic message
Textdumps are stored in swap/dump partitions as with regular dumps, but
are laid out as ustar files in order to allow multiple parts to be stored
as a stream of sequentially written blocks. Blocks are written out in
reverse order, as the size of a textdump isn't known a priori. As with
regular dumps, they will be extracted using savecore(8).
One new DDB(4) command is added, "textdump", which accepts "set",
"unset", and "status" arguments. By default, normal kernel dumps are
generated unless "textdump set" is run in order to schedule a textdump.
It can be canceled using "textdump unset" to restore generation of a
normal kernel dump.
Several sysctls exist to configure aspects of textdumps;
debug.ddb.textdump.pending can be set to check whether a textdump is
pending, or set/unset in order to control whether the next kernel dump
will be a textdump from userspace.
While textdumps don't have to be generated as a result of a DDB script
run automatically as part of a kernel panic, this is a particular useful
way to use them, as instead of generating a complete memory dump, a
simple transcript of an automated DDB session can be captured using the
DDB output capture and textdump facilities. This can be used to
generate quite brief kernel bug reports rich in debugging information
but not dependent on kernel symbol tables or precisely synchronized
source code. Most textdumps I generate are less than 100k including
the full message buffer. Using textdumps with an interactive debugging
session is also useful, with capture being enabled/disabled in order to
record some but not all of the DDB session.
MFC after: 3 months
define a set of named scripts. Each script consists of a list of DDB
commands separated by ";"s that will be executed verbatim. No higher
level language constructs, such as branching, are provided for:
scripts are executed by sequentially injecting commands into the DDB
input buffer.
Four new commands are present in DDB: "run" to run a specific script,
"script" to define or print a script, "scripts" to list currently
defined scripts, and "unscript" to delete a script, modeled on shell
alias commands. Scripts may also be manipulated using sysctls in the
debug.ddb.scripting MIB space, although users will prefer to use the
soon-to-be-added ddb(8) tool for usability reasons.
Scripts with certain names are automatically executed on various DDB
events, such as entering the debugger via a panic, a witness error,
watchdog, breakpoint, sysctl, serial break, etc, allowing customized
handling.
MFC after: 3 months
captured to a memory buffer for later inspection using sysctl(8), or in the
future, to a textdump.
A new DDB command, "capture", is added, which accepts arguments "on", "off",
"reset", and "status".
A new DDB sysctl tree, debug.ddb.capture, is added, which can be used to
resize the capture buffer and extract buffer contents.
MFC after: 3 months
a pointer to struct bus_space. The structure contains function
pointers that do the actual bus space access.
The reason for this change is that previously all bus space
accesses were little endian (i.e. had an explicit byte-swap
for multi-byte accesses), because all busses on Macs are little
endian.
The upcoming support for Book E, and in particular the E500
core, requires support for big-endian busses because all
embedded peripherals are in the native byte-order.
With this change, there's no distinction between I/O port
space and memory mapped I/O. PowerPC doesn't have I/O port
space. Busses assign tags based on the byte-order only.
For that purpose, two global structures exist (bs_be_tag and
bs_le_tag), of which the address can be taken to get a valid
tag.
Obtained from: Juniper, Semihalf
and t3_push_frames).
- Import latest changes to cxgb_main.c and cxgb_sge.c from toestack p4 branch
- make driver local copy of tcp_subr.c and tcp_usrreq.c and override tcp_usrreqs so
TOE can also functions on versions with unmodified TCP
- add cxgb back to the build
processors (it's the PowerPC Operating Environment Architecture).
AIM designates the processors made by the Apple-IBM-Motorola
alliance and those we typically support.
While here, remove the NetBSD option IPKDB. It's not an option
used by us. Also, PPC_HAVE_FPU is not used by us either. Remove
that too.
Obtained from: Juniper, Semihalf
the ABI when enabled. There is no longer an embedded lock_profile_object
in each lock. Instead a list of lock_profile_objects is kept per-thread
for each lock it may own. The cnt_hold statistic is now always 0 to
facilitate this.
- Support shared locking by tracking individual lock instances and
statistics in the per-thread per-instance lock_profile_object.
- Make the lock profiling hash table a per-cpu singly linked list with a
per-cpu static lock_prof allocator. This removes the need for an array
of spinlocks and reduces cache contention between cores.
- Use a seperate hash for spinlocks and other locks so that only a
critical_enter() is required and not a spinlock_enter() to modify the
per-cpu tables.
- Count time spent spinning in the lock statistics.
- Remove the LOCK_PROFILE_SHARED option as it is always supported now.
- Specifically drop and release the scheduler locks in both schedulers
since we track owners now.
In collaboration with: Kip Macy
Sponsored by: Nokia
cards:
o RocketRAID 172x series
o RocketRAID 174x series
o RocketRAID 2210
o RocketRAID 222x series
o RocketRAID 2240
o RocketRAID 230x series
o RocketRAID 231x series
o RocketRAID 232x series
o RocketRAID 2340
o RocketRAID 2522
Many thanks to Highpoint for their continued support of FreeBSD.
Submitted by: Highpoint
o Disklabels can have between 8 and 20 partitions (inclusive).
o No device special file is created for the raw partition.
o Switch ia64 to use this backend.
o No support for boot code yet.
INCLUDE_CONFIG_FILE. Make a user to look at what config(8) actually does,
and how can one fetch actual configuration file.
Reported by: many
Reviewed by: cognet (mentor)
Approved by: cognet (mentor)
- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
defined, or also if "options DDB" is defined to provide compatibility
with existing users of stack(9).
Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to. It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.
Update stack(9) man page.
Build tested: amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested: amd64 (rwatson), arm (cognet), i386 (rwatson)
hack means you can get the units and flags to match up more easily with
serial consoles on machines with acpi tables that cause the com ports
to be probed in the wrong order (and hence get the wrong sio unit number).
This replaces the common alternative hack of editing the code to comment
out the acpi attachment. This could go away entirely when device wiring
patches are committed.
Currently, Giant is not too much contented so that it is ok to treact it
like any other mutexes.
Please don't forget to update your own custom config kernel files.
Approved by: cognet, marcel (maintainers of arches where option is
not enabled at the moment)
bumped to 800004 to note the change though userland apps should not be
affected since they use <sys/agpio.h> rather than the headers in
sys/dev/agp.
Discussed with: anholt
Repocopy by: simon
This includes:
o mtree (for legal/intel_wpi)
o manpage for i386/amd64 archs
o module for i386/amd64 archs
o NOTES for i386/amd64 archs
Approved by: mlaier (comentor)
lock optimized for almost exclusive reader access. (see also rmlock.9)
TODO:
Convert to per cpu variables linkerset as soon as it is available.
Optimize UP (single processor) case.
in the TrustedBSD MAC Framework:
- Add mac_atalk.c and add explicit entry point mac_netatalk_aarp_send()
for AARP packet labeling, rather than using a generic link layer
entry point.
- Add mac_inet6.c and add explicit entry point mac_netinet6_nd6_send()
for ND6 packet labeling, rather than using a generic link layer entry
point.
- Add expliict entry point mac_netinet_arp_send() for ARP packet
labeling, and mac_netinet_igmp_send() for IGMP packet labeling,
rather than using a generic link layer entry point.
- Remove previous genering link layer entry point,
mac_mbuf_create_linklayer() as it is no longer used.
- Add implementations of new entry points to various policies, largely
by replicating the existing link layer entry point for them; remove
old link layer entry point implementation.
- Make MAC_IFNET_LOCK(), MAC_IFNET_UNLOCK(), and mac_ifnet_mtx global
to the MAC Framework rather than static to mac_net.c as it is now
needed outside of mac_net.c.
Obtained from: TrustedBSD Project
refactored it to be a generic device.
Instead of being part of the standard kernel, there is now a 'nvram' device
for i386/amd64. It is in DEFAULTS like io and mem, and can be turned off
with 'nodevice nvram'. This matches the previous behavior when it was
first committed.
This commit includes the following core components:
* sample configuration file for sensorsd
* rc(8) script and glue code for sensorsd(8)
* sysctl(3) doc fixes for CTL_HW tree
* sysctl(3) documentation for hardware sensors
* sysctl(8) documentation for hardware sensors
* support for the sensor structure for sysctl(8)
* rc.conf(5) documentation for starting sensorsd(8)
* sensor_attach(9) et al documentation
* /sys/kern/kern_sensors.c
o sensor_attach(9) API for drivers to register ksensors
o sensor_task_register(9) API for the update task
o sysctl(3) glue code
o hw.sensors shadow tree for sysctl(8) internal magic
* <sys/sensors.h>
* HW_SENSORS definition for <sys/sysctl.h>
* sensors display for systat(1), including documentation
* sensorsd(8) and all applicable documentation
The userland part of the framework is entirely source-code
compatible with OpenBSD 4.1, 4.2 and -current as of today.
All sensor readings can be viewed with `sysctl hw.sensors`,
monitored in semi-realtime with `systat -sensors` and also
logged with `sensorsd`.
Submitted by: Constantine A. Murenin <cnst@FreeBSD.org>
Sponsored by: Google Summer of Code 2007 (GSoC2007/cnst-sensors)
Mentored by: syrinx
Tested by: many
OKed by: kensmith
Obtained from: OpenBSD (parts)
to gem_attach() as the former access softc members not yet initialized
at that time and gem_reset() actually is enough to stop the chip. [1]
o Revise the use of gem_bitwait(); add bus_barrier() calls before calling
gem_bitwait() to ensure the respective bit has been written before we
starting polling on it and poll for the right bits to change, f.e. even
though we only reset RX we have to actually wait for both GEM_RESET_RX
and GEM_RESET_TX to clear. Add some additional gem_bitwait() calls in
places we've been missing them according to the GEM documentation.
Along with this some excessive DELAYs, which probably only were added
because of bugs in gem_bitwait() and its use in the first place, as
well as as have of an gem_bitwait() reimplementation in gem_reset_tx()
were removed.
o Add gem_reset_rxdma() and use it to deal with GEM_MAC_RX_OVERFLOW errors
more gracefully as unlike gem_init_locked() it resets the RX DMA engine
only, causing no link loss and the FIFOs not to be cleared. Also use it
deal with GEM_INTR_RX_TAG_ERR errors, with previously were unhandled.
This was based on information obtained from the Linux GEM and OpenSolaris
ERI drivers.
o Turn on workarounds for silicon bugs in the Apple GMAC variants.
This was based on information obtained from the Darwin GMAC and Linux GEM
drivers.
o Turn on "infinite" (i.e. maximum 31 * 64 bytes in length) DMA bursts.
This greatly improves especially RX performance.
o Optimize the RX path, this consists of:
- kicking the receiver as soon as we've a spare descriptor in gem_rint()
again instead of just once after all the ready ones have been handled;
- kicking the receiver the right way, i.e. as outlined in the GEM
documentation in batches of 4 and by pointing it to the descriptor
after the last valid one;
- calling gem_rint() before gem_tint() in gem_intr() as gem_tint() may
take quite a while;
- doubling the size of the RX ring to 256 descriptors.
Overall the RX performance of a GEM in a 1GHz Sun Fire V210 was improved
from ~100Mbit/s to ~850Mbit/s.
o In gem_add_rxbuf() don't assign the newly allocated mbuf to rxs_mbuf
before calling bus_dmamap_load_mbuf_sg(), if bus_dmamap_load_mbuf_sg()
fails we'll free the newly allocated mbuf, unable to recycle the
previous one but a NULL pointer dereference instead.
o In gem_init_locked() honor the return value of gem_meminit().
o Simplify gem_ringsize() and dont' return garbage in the default case.
Based on OpenBSD.
o Don't turn on MAC control, MIF and PCS interrupts unless GEM_DEBUG is
defined as we don't need/use these interrupts for operation.
o In gem_start_locked() sync the DMA maps of the descriptor rings before
every kick of the transmitter and not just once after enqueuing all
packets as the NIC might instantly start transmitting after we kicked
it the first time.
o Keep state of the link state and use it to enable or disable the MAC
in gem_mii_statchg() accordingly as well as to return early from
gem_start_locked() in case the link is down. [3]
o Initialize the maximum frame size to a sane value.
o In gem_mii_statchg() enable carrier extension if appropriate.
o Increment if_ierrors in case of an GEM_MAC_RX_OVERFLOW error and in
gem_eint(). [3]
o Handle IFF_ALLMULTI correctly; don't set it if we've turned promiscuous
group mode on and don't clear the flag if we've disabled promiscuous
group mode (these were mostly NOPs though). [2]
o Let gem_eint() also report GEM_INTR_PERR errors.
o Move setting sc_variant from gem_pci_probe() to gem_pci_attach() as
device probe methods are not supposed to touch the softc.
o Collapse sc_inited and sc_pci into bits for sc_flags.
o Add CTASSERTs ensuring that GEM_NRXDESC and GEM_NTXDESC are set to
legal values.
o Correctly set up for 802.3x flow control, though #ifdef out the code
that actually enables it as this needs more testing and mainly a proper
framework to support it.
o Correct and add some conversions from hard-coded functions names to
__func__ which were borked or forgotten in if_gem.c rev. 1.42.
o Use PCIR_BAR instead of a homegrown macro.
o Replace sc_enaddr[6] with sc_enaddr[ETHER_ADDR_LEN].
o In gem_pci_attach() in case attaching fails release the resources in
the opposite order they were allocated.
o Make gem_reset() static to if_gem.c as it's not needed outside that
module.
o Remove the GEM_GIGABIT flag and the associated code; GEM_GIGABIT was
never set and the associated code was in the wrong place.
o Remove sc_mif_config; it was only used to cache the contents of the
respective register within gem_attach().
o Remove the #ifdef'ed out NetBSD/OpenBSD code for establishing a suspend
hook as it will never be used on FreeBSD.
o Also probe Apple Intrepid 2 GMAC and Apple Shasta GMAC, add support for
Apple K2 GMAC. Based on OpenBSD.
o Add support for Sun GBE/P cards, or in other words actually add support
for cards based on GEM to gem(4). This mainly consists of adding support
for the TBI of these chips. Along with this the PHY selection code was
rewritten to hardcode the PHY number for certain configurations as for
example the PHY of the on-board ERI of Blade 1000 shows up twice causing
no link as the second incarnation is isolated.
These changes were ported from OpenBSD with some additional improvements
and modulo some bugs.
o Add code to if_gem_pci.c allowing to read the MAC-address from the VPD on
systems without Open Firmware.
This is an improved version of my variant of the respective code in
if_hme_pci.c
o Now that gem(4) is MI enable it for all archs.
Pointed out by: yongari [1]
Suggested by: rwatson [2], yongari [3]
Tested on: i386 (GEM), powerpc (GMACs by marcel and yongari),
sparc64 (ERI and GEM)
Reviewed by: yongari
Approved by: re (kensmith)
providers with limited physical storage and add physical storage as
needed.
Submitted by: Ivan Voras
Sponsored by: Google Summer of Code 2006
Approved by: re (kensmith)
commented out until I can re-test them on all our architectures. I
had re@ approval to commit this a long time ago, but that's before we
were this close to the branch.
Approved by: re@
other changes too).
(without any real order)
1. Use device_get_nameunit for mutex naming
2. Add timer for low-latency playback
3. Move most mixer controls from sysctls to mixer(8) controls.
This is a largest part of this patch.
4. Add analog/digital switch (as a temporary sysctl)
5. Get back support for low-bitrate playback (with help of (2))
6. Change locking for exclusive I/O. Writing to non-PTR register
is almost safe and does not need to be ordered with PTR operations.
7. Disable MIDI until we get it to detach properly and fix memory
managment problems.
8. Enable multichannel playback by default. It is as stable as
single-channel mode. Multichannel recording is still an
experimental feature.
9. Multichannel options can be changed by loader tunables.
10. Add a way to disable card from a loader tunable.
11. Add new PCI IDs.
12. Debugger settings are loader tunables now.
14. Remove some unused variables.
15. Mark pcm sub-devices MPSAFE.
16. Partially revert (bus_setup_intr -> snd_setup_intr) since it need
to be done independently
Submitted by: Yuriy Tsibizov (driver maintainer)
Approved by: re (bmah)
and newer CPUs (including Core 2 and Core / Core 2 based Xeons). The
driver attaches to each cpu device and creates a sysctl node in that
device's sysctl context (dev.cpu.N.temperature). When invoked, the
handler binds to the appropriate CPU to ensure a correct reading.
Submitted by: Rui Paulo <rpaulo@fnop.net>
Sponsored by: Google Summer of Code 2007
Tested by: des, marcus, Constantine A. Murenin, Ian FREISLICH
Approved by: re (kensmith)
MFC after: 3 weeks
a test that assumes that char is signed by default and causes a
warning with GCC 4.2 on PowerPC.
A patch has been sent to the maintainer that addresses this.
Approved by: re (blanket)
previously conditionally acquired Giant based on debug.mpsafenet. As that
has now been removed, they are no longer required. Removing them
significantly simplifies error-handling in the socket layer, eliminated
quite a bit of unwinding of locking in error cases.
While here clean up the now unneeded opt_net.h, which previously was used
for the NET_WITH_GIANT kernel option. Clean up some related gotos for
consistency.
Reviewed by: bz, csjp
Tested by: kris
Approved by: re (kensmith)
Also rename the related functions in a similar way.
There are no functional changes.
For a packet coming in with IPsec tunnel mode, the default is
to only call into the firewall with the "outer" IP header and
payload.
With this option turned on, in addition to the "outer" parts,
the "inner" IP header and payload are passed to the
firewall too when going through ip_input() the second time.
The option was never only related to a gif(4) tunnel within
an IPsec tunnel and thus the name was very misleading.
Discussed at: BSDCan 2007
Best new name suggested by: rwatson
Reviewed by: rwatson
Approved by: re (bmah)
a proper solution.
- Add a dummy entry point which just calls the C entry points, and try to make
sure it's the first code in the binary.
- Copy a bit more than func_end to try to copy the whole load_kernel()
function. gcc4 puts code behind the func_end symbol.
Approved by: re (blanket)
included man pages on how to use it. This code is still somewhat experimental
but has been successfully tested on a number of targets. Many thanks to
Danny for contributing this.
Approved by: re
udp6_output() from udp6_output.c to udp6_usrreq.c, matching the UDPv4
structure, and allowing us to remove udp6_output.c.
Reviewed by: bz, gnn
Approved by: re (bmah)
- Add custom .c wrappers for the firmware, rather than the standard
firmware(9) generated firmware objects to work around toolchain
problems on ia64 involving linking objects produced by
ld -b -binary into the kernel.
- Move from using Myricom's ".dat" firmware blobs to using Myricom's
zlib compressed ".h" firmware header files. This is done to
facilitate the custom wrappers, and saves a fair amount of wired
memory in the case where the firmware is built in, or preloaded.
- Fix two compile issues in mxge which only appear on non-i386/amd64.
Reviewed by: mlaier, mav (earlier version with just zlib support)
Glanced at by: sam
Approved by: re (kensmith)
NET_NEEDS_GIANT, which will shortly be removed. This is done in a
away that it may be easily reattached to the build before 7.1 if
appropriate locking is added. Specifics:
- Don't install netatm include files
- Disconnect netatm command line management tools
- Don't build libatm
- Don't include ATM parts in rescue or sysinstall
- Don't install sample configuration files and documents
- Don't build kernel support as a module or in NOTES
- Don't build netgraph wrapper nodes for netatm
This removes the last remaining consumer of NET_NEEDS_GIANT.
Reviewed by: harti
Discussed with: bz, bms
Approved by: re (kensmith)
- CMT_PF states added (w/sysctl to turn the PF version on)
- sctp_input.c had a missing incr of cookie case when the
auth was bad. This meant a free was called without an
increment to refcnt, added increment like rest of code.
- There was a case, unlikely, when the scope of the destination
changed (this is a TSNH case). In that case, it would not free
the alloc'ed asoc (in sctp_input.c).
- When listed addresses found a colliding cookie/Init, then
the collided upon tcb was not unlocked in sctp_pcb.c
- Add error checking on arguments of sctp_sendx(3) to prevent it from
referencing a NULL pointer.
- Fix an error return of sctp_sendx(3), it was returing
ENOMEM not -1.
- Get assoc id was changed to use the sanctified socket api
method for getting a assoc id (PEER_ADDR_INFO instead of
PEER_ADDR_PARAMS).
- Fix it so a peeled off socket will get a proper error return
if it trys to send to a different address then it is connected to.
- Fix so that select_a_stream can avoid an endless loop that
could hang a caller.
- time_entered (state set time) was not being set in all cases
to the time we went established.
Approved by: re(ken smith)
by removing files from src/sys/coda, and updating include paths in the
new location, kernel configuration, and Makefiles. In one case add
$FreeBSD$.
Discussed with: anderson, Jan Harkes <jaharkes@cs.cmu.edu>
Approved by: re (kensmith)
Repo-copy madness: simon
ELF files. On ia64 the ELF header contains information about
characteristics of the machine code and ld(1) needs that to
determine whether input files are compatible for linking. To
this end non-ELF files are not supported by binutils on ia64.
However, the resulting ELF file seems to be correct despite the
warnings and the non-supportedness of non-ELF files and it
appears enough to unbreak the build of firmware(9) files on ia64
by simply supressing the warning.
Ran into by: gallatin@
Approved by: re (hrs)
Looks good to me: mlaier@
- Adjust lock_profiling stubs semantic in the hard functions in order to be
more accurate and trustable
- Disable shared paths for lock_profiling. Actually, lock_profiling has a
subtle race which makes results caming from shared paths not completely
trustable. A macro stub (LOCK_PROFILING_SHARED) can be actually used for
re-enabling this paths, but is currently intended for developing use only.
- Use homogeneous names for automatic variables in hard functions regarding
lock_profiling
- Style fixes
- Add a CTASSERT for some flags building
Discussed with: kmacy, kris
Approved by: jeff (mentor)
Approved by: re
the 7.0 timeframe.
This is needed because I4B is not locked and NET_NEEDS_GIANT goes away.
The plan is to lock I4B and bring everything back for 7.1.
Approved by: re (kensmith)
This commit includes only the kernel files, the rest of the files
will follow in a second commit.
Reviewed by: bz
Approved by: re
Supported by: Secure Computing
- Remove unnecessary NULL checks after M_WAITOK allocations.
- Use VOP_ACCESS instead of hand-rolled suser_cred()
calls. [1]
- Use malloc(9) KPI to allocate memory for string. The
optimization taken from NetBSD is not valid for FreeBSD
because our malloc(9) already act that way. [2]
Requested by: rwatson [1]
Submitted by: Howard Su [2]
Approved by: re (tmpfs blanket)
both 6.x and 7.x. This is based on feedbacks on this thread
http://docs.freebsd.org/cgi/getmsg.cgi?fetch=81818+0+current/freebsd-stable
and my use it on 6.x.
MFC after: 3 days
- Update the warning about UNION filesystem. It is now actively maintained,
although there are still some issues being resolved.
Reviewed by: freebsd-stable@, kris, bmah
Approved by: re (bmah)
allowing the driver for the host-PCI-bridge to indicate that
reenumeration of the PCI busses isn't supported by returning
-1 instead of a valid PCI bus number. This is needed in order
support both Tomatillo, which don't support reenumeration and
thus are apparently intended to be used for independently
numbered PCI domains only, and Psycho bridges, whose busses
need to be reenumerated on at least some E450, without the
#ifndef currently used for sun4v in order to support multiple
independently PCI domains. The actual allocation/incrementation
of the PCI bus numbers is now done in psycho(4), though it
no longer establish a mapping between bus numbers and device
nodes like ofw_pci_alloc_busno() did as that functionality
wasn't used (but can easily brought back if really needed).
The now no longer used sys/sparc64/pci/ofw_pci.c is also
removed from sys/conf/files.sun4v as ofw_pci_alloc_busno()
wasn't used there in the first place.
- In ofw_pci_default_{adjust_busrange,intr_pending}() sanity
check that the device has a parent before passing it on.
- Make psycho_softcs static to sys/sparc64/pci/psycho.c as
it's not used outside of that module.
- In sys/sparc64/pci/ofw_pcib_subr.c remove the superfluous
inclusion of opt_global.h and correct the debug output for
adjusting the subordinate bus number.
to be compiled into every driver making use of it. Use a const instance
of struct gfb_font for this as the font isn't intended to be changed at
run-time and in order to accompany the font data with height and width
info.
This allocator uses a binary buddy system with a twist. First and
foremost, this allocator is required to support the implementation of
superpages. As a side effect, it enables a more robust implementation
of contigmalloc(9). Moreover, this reimplementation of
contigmalloc(9) eliminates the acquisition of Giant by
contigmalloc(..., M_NOWAIT, ...).
The twist is that this allocator tries to reduce the number of TLB
misses incurred by accesses through a direct map to small, UMA-managed
objects and page table pages. Roughly speaking, the physical pages
that are allocated for such purposes are clustered together in the
physical address space. The performance benefits vary. In the most
extreme case, a uniprocessor kernel running on an Opteron, I measured
an 18% reduction in system time during a buildworld.
This allocator does not implement page coloring. The reason is that
superpages have much the same effect. The contiguous physical memory
allocation necessary for a superpage is inherently colored.
Finally, the one caveat is that this allocator does not effectively
support prezeroed pages. I hope this is temporary. On i386, this is
a slight pessimization. However, on amd64, the beneficial effects of
the direct-map optimization outweigh the ill effects. I speculate
that this is true in general of machines with a direct map.
Approved by: re
Please note that, this is currently considered as an
experimental feature so there could be some rough
edges. Consult http://wiki.freebsd.org/TMPFS for
more information.
For now, connect tmpfs to build on i386 and amd64
architectures only. Please let us know if you have
success with other platforms.
This work was developed by Julio M. Merino Vidal
for NetBSD as a SoC project; Rohit Jalan ported it
from NetBSD to FreeBSD. Howard Su and Glen Leeder
are worked on it to continue this effort.
Obtained from: NetBSD via p4
Submitted by: Howard Su (with some minor changes)
Approved by: re (kensmith)
- Fix so VRF's will clean themselves up when no references are around.
- Allow sctp_ifa to be passed into inpcb_bind, addr_mgmt_ep_sa to bypass
normal validation checks.
- turn auto-asconf off for subset bound sockets
- Moves all logging to use KTR. This gets rid of most
of the logging #ifdef's with a few exceptions reducing
the number of config options for SCTP.
tunnels, and was not MPSAFE. The code can be easily restored in the
event that someone with an IPX over IP tunnel configuration can work
with me to test patches.
This removes one of five remaining consumers of NET_NEEDS_GIANT.
Approved by: re (kensmith)
- update to firmware version 4.1.0
- switch over to standard method for initializing cdevs (contributed by scottl@)
- break out timer_reclaim_task to be per-port
- move msix teardown into separate function
- fix bus_setup_intr for msi-x for the multi-port case so that msi-x resources
are not corrupted on unload
- handle 10/100/1000 base-T media and auto negotiation
- bind qset to cpu even for singleq case
- white space cleanups
- remove recursive PORT_LOCK
- move mtu setting to separate function
- stop and re-init port when changing mtu
- replace all direct references to m_data with calls to mtod
- handle attach failure better by not trying to de-initialize
taskqueues when they have not been allocated
- no longer default to jumbo frames
Sponsored by: Chelsio
MFC after: 3 days
and protocol-independent host mode multicast. The code is written to
accomodate IPv6, IGMPv3 and MLDv2 with only a little additional work.
This change only pertains to FreeBSD's use as a multicast end-station and
does not concern multicast routing; for an IGMPv3/MLDv2 router
implementation, consider the XORP project.
The work is based on Wilbert de Graaf's IGMPv3 code drop for FreeBSD 4.6,
which is available at: http://www.kloosterhof.com/wilbert/igmpv3.html
Summary
* IPv4 multicast socket processing is now moved out of ip_output.c
into a new module, in_mcast.c.
* The in_mcast.c module implements the IPv4 legacy any-source API in
terms of the protocol-independent source-specific API.
* Source filters are lazy allocated as the common case does not use them.
They are part of per inpcb state and are covered by the inpcb lock.
* struct ip_mreqn is now supported to allow applications to specify
multicast joins by interface index in the legacy IPv4 any-source API.
* In UDP, an incoming multicast datagram only requires that the source
port matches the 4-tuple if the socket was already bound by source port.
An unbound socket SHOULD be able to receive multicasts sent from an
ephemeral source port.
* The UDP socket multicast filter mode defaults to exclusive, that is,
sources present in the per-socket list will be blocked from delivery.
* The RFC 3678 userland functions have been added to libc: setsourcefilter,
getsourcefilter, setipv4sourcefilter, getipv4sourcefilter.
* Definitions for IGMPv3 are merged but not yet used.
* struct sockaddr_storage is now referenced from <netinet/in.h>. It
is therefore defined there if not already declared in the same way
as for the C99 types.
* The RFC 1724 hack (specify 0.0.0.0/8 addresses to IP_MULTICAST_IF
which are then interpreted as interface indexes) is now deprecated.
* A patch for the Rhyolite.com routed in the FreeBSD base system
is available in the -net archives. This only affects individuals
running RIPv1 or RIPv2 via point-to-point and/or unnumbered interfaces.
* Make IPv6 detach path similar to IPv4's in code flow; functionally same.
* Bump __FreeBSD_version to 700048; see UPDATING.
This work was financially supported by another FreeBSD committer.
Obtained from: p4://bms_netdev
Submitted by: Wilbert de Graaf (original work)
Reviewed by: rwatson (locking), silence from fenner,
net@ (but with encouragement)
o major overhaul of the way channels are handled: channels are now
fully enumerated and uniquely identify the operating characteristics;
these changes are visible to user applications which require changes
o make scanning support independent of the state machine to enable
background scanning and roaming
o move scanning support into loadable modules based on the operating
mode to enable different policies and reduce the memory footprint
on systems w/ constrained resources
o add background scanning in station mode (no support for adhoc/ibss
mode yet)
o significantly speedup sta mode scanning with a variety of techniques
o add roaming support when background scanning is supported; for now
we use a simple algorithm to trigger a roam: we threshold the rssi
and tx rate, if either drops too low we try to roam to a new ap
o add tx fragmentation support
o add first cut at 802.11n support: this code works with forthcoming
drivers but is incomplete; it's included now to establish a baseline
for other drivers to be developed and for user applications
o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates
prepending mbufs for traffic generated locally
o add support for Atheros protocol extensions; mainly the fast frames
encapsulation (note this can be used with any card that can tx+rx
large frames correctly)
o add sta support for ap's that beacon both WPA1+2 support
o change all data types from bsd-style to posix-style
o propagate noise floor data from drivers to net80211 and on to user apps
o correct various issues in the sta mode state machine related to handling
authentication and association failures
o enable the addition of sta mode power save support for drivers that need
net80211 support (not in this commit)
o remove old WI compatibility ioctls (wicontrol is officially dead)
o change the data structures returned for get sta info and get scan
results so future additions will not break user apps
o fixed tx rate is now maintained internally as an ieee rate and not an
index into the rate set; this needs to be extended to deal with
multi-mode operation
o add extended channel specifications to radiotap to enable 11n sniffing
Drivers:
o ath: add support for bg scanning, tx fragmentation, fast frames,
dynamic turbo (lightly tested), 11n (sniffing only and needs
new hal)
o awi: compile tested only
o ndis: lightly tested
o ipw: lightly tested
o iwi: add support for bg scanning (well tested but may have some
rough edges)
o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data
o wi: lightly tested
This work is based on contributions by Atheros, kmacy, sephe, thompsa,
mlaier, kevlo, and others. Much of the scanning work was supported by
Atheros. The 11n work was supported by Marvell.
making the relevant files standard. This avoids duplication and
makes it easier to override/disable unwanted schemes. Since ARM
doesn't have a DEFAULTS configuration file, leave the source
files for the BSD and MBR partitioning schemes in files.arm for
now.
1.50 to help out with the GCC 2 to GCC 3 transition and it became
obsolete when C flags compatible with GCC 3.x became the default.
With GCC 4 in the tree this variable (i.e. GCC3) is beyond bogus
because it causes confusion when looking for the newly introduced
WITH_GCC3 option that helps the GCC 3 -> GCC 4 bump.
- Rework the entire pcm_channel structure:
* Remove rarely used link placeholder, instead, make each pcm_channel
as head/link of each own/each other. Unlock - Lock sequence due to
sleep malloc has been reduced.
* Implement "busy" queue which will contain list of busy/active
channels. This greatly reduce locking contention for example while
servicing interrupt for hardware with many channels or when virtual
channels reach its 256 peak channels.
- So I heard you like v chan ... O RLY?
Welcome to Virtual **Record** Channels (vrec, rec vchans, vchans for
recording, Rec-Chan, you decide), the ultimate solutions for your
nagging O_RDWR full-duplex wannabe (note: flash plugins) monopolizing
single record channel causing EBUSY. Vrec works exactly like Vchans
(or, should I rename it to "Vplay" :) , except that it operates on the
opposite direction (recording). Up to 256 vrecs (like vchans) are
possible.
Notes:
* Relocate dev.pcm.%d.{vchans,vchanformat,vchanrate} to each of its
respective node/direction:
dev.pcm.%d.play.* for "play" (cdev = dsp%d.vp%d)
dev.pcm.%d.rec.* for "record" (cdev = dsp%d.vr%d)
* Don't expect that it will magically give you ability to split
"recording source" (eg: 1 channel for cdrom, 1 channel for mic,
etc). Just admit that you only have a *single* recording source /
channel. Please bug your hardware vendor instead :)
- Bump maxautovchans from 4 to 16. For a full-fledged multimedia
desktop/workstation with too many soundservers installed (esound,
artsd, jackd, pulse/polypaudio, ding-dong pling plong mudkip fuh fuh,
etc), 4 seems inadequate. There will be no memory penalty here, since
virtual channels are allocate only by demand.
- Nuke/Rework the entire statically created cdev entries. Everything is
clonable through snd own clone manager which designed to withstand many
kind of abusive devfs droids such as:
* while : ; do /bin/test -e /dev/dsp ; done
* jot 16777216 0 | while read x ; do ls /dev/dsp0.$x ; done
* hundreds (could be thousands) concurrent threads/process opening
"/dev/dsp" (previously, this might result EBUSY even with just
3 contesting threads/procs).
o Reusable clone objects (instead of creating new one like there's no
tomorrow) after certain expiration deadline. The clone allocator will
decide whether to reuse, share, or creating new clone.
o Automatic garbage collector.
- Dynamic unit magic allocator. Maximum attached soundcards can be tuned
using tunable "hw.snd.maxunit" (Default to 512). Minimum is 16, and
maximum is 2048.
- ..other fixes, mostly related to concurrency issues.
joel@ will do the manpage updates on sound(4).
Have fun.
is expanded, size of expansion was not taken int consideration.
- Fix so vtag hash is 1 bigger so that it modulo's out
correctly, avoids a panic when restart with right modulo happens.
- do not dereference stcb when control->do_not_ref_stcb is set
- Fix up packet logging to not often use a lock and also to
add to options.
- Fix some logging option duplication in the sctputil.h
- upgrade to reflect state of 1.0.0.86
- move from firmware rev 3.2 to 4.0.0
- import driver bits for offload functionality
- remove binary distribution clause from top level files as it
runs counter to the intent of purely supporting the hardware
MFC after: 3 days
compiler invocation. This is just to help get over the hump of people
tracking down bugs that may cross the GCC 4.2 upgrade.
It is envisioned that this option goes away after a suitable amount
of time.
Implement all futex atomic operations in assembler to not depend on the
fuword() that does not allow to distinguish between -1 and failure return.
Correctly return 0 from atomic operations on success.
In collaboration with: rdivacky
Tested by: Scot Hetzel <swhetzel gmail com>, Milos Vyletel <mvyletel mzm cz>
Sponsored by: Google SoC 2007
Switch ia64 kernels to -fpic. This is likely wrong, but at least gets
ia64 kernels to compile and link with GCC 4.2. The previous -mno-sdata
trick is not working anymore.
different versions of FreeBSD source tree.
Old config(8) can now be used unless you want to use INCLUDE_CONFIG_FILE
option.
Approved by: imp
Reviewed by: imp
functions from their origininal place to their own files.
TCP Reassembly from tcp_input.c -> tcp_reass.c
TCP Timewait from tcp_subr.c -> tcp_timewait.c
is caused by my latest changes to config(8). You're supposed to install new
config(8) in order to prevent yourself from seeing a warning about old
version of that tool.
You should configure the kernel with a new config(8) then.
Oked by: rwatson, cognet (mentor)
This patch does the following:
- Remove un-necessary code that is not even compiling into the driver
under TW_OSL_NON_DMA_MEM_ALLOC_PER_REQUEST defines.
- Remove bundled firmware image and associated "files" entry for tw_cl_fwimg.c
- Remove bundled firmware flashing routines. We now have tw_update userspace
FreeBSD controller flash utility.
- Fix driver crash on load due to shared interrupt.
- Fix 2 lock leaks for Giant lock.
- Fix CCB leak.
- Add support for 9650SE controllers.
Many thanks to 3Ware/AMCC for continuing to support FreeBSD.
The entire code is wrapperd in #ifdef ... #endif so it won't harm
the actual implementation, but developers are encouraged to test it.
For arm, ia64, ppc, sparc64 and sun4v some work is still
needed, thus arch maintainers are encouraged to bring their arch on par
with respect to i386 and amd64.
Approved by: re (implicit?)
shared code infrastructure that is family specific and
modular. There is also support for our latest gigabit
nic, the 82575 that is MSI/X and multiqueue capable.
The new shared code changes some interfaces to the core
code but testing at Intel has been going on for months,
it is fairly stable.
I have attempted to be careful in retaining any fixes that
CURRENT had and we did not, I apologize in advance if any
thing gets clobbered, I'm sure I'll hear about it :)
Approved by pdeuskar
calls. Add MAC Framework entry points and MAC policy entry points for
audit(), auditctl(), auditon(), setaudit(), aud setauid().
MAC Framework entry points are only added for audit system calls where
additional argument context may be useful for policy decision-making; other
audit system calls without arguments may be controlled via the priv(9)
entry points.
Update various policy modules to implement audit-related checks, and in
some cases, other missing system-related checks.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA, Inc.
The name trunk is misused as the networking term trunk means carrying multiple
VLANs over a single connection. The IEEE standard for link aggregation (802.3
section 3) does not talk about 'trunk' at all while it is used throughout IEEE
802.1Q in describing vlans.
The lagg(4) driver provides link aggregation, failover and fault tolerance.
Discussed on: current@
Linux SCSI SG passthrough device API. The intention is to allow for both
running of Linux apps that want to talk to /dev/sg* nodes, and to facilitate
porting of apps from Linux to FreeBSD. As such, both native and linuxolator
entry points and definitions are provided.
Caveats:
- This does not support the procfs and sysfs nodes that the Linux SG
driver provides. Some Linux apps may rely on these for operation,
others may only use them for informational purposes.
- More ioctls need to be implemented.
- Linux uses a naming scheme of "sg[a-z]" for devices, while FreeBSD uses a
scheme of "sg[0-9]". Devfs aliasis (symlinks) are automatically created
to link the two together. However, tools like camcontrol only see the
native names.
- Some operations were originally designed to return byte counts or other
data directly as the syscall return value. The linuxolator doesn't appear
to support this well, so this driver just punts for these cases.
Now that the driver is in place, others are welcome to add missing
functionality. Thanks to Roman Divacky for pushing this work along.
When the linux port changes were imported which split the
target command list to be separate from the initiator command
list and the handle format changed to encode a type in the handle
the implications to the function isp_handle_index (which only
the NetBSD/OpenBSD/FreeBSD ports use) were overlooked.
The fault is twofold: first, the index into the DMA maps
in isp_pci is wrong because a target command handle with
the type bit left in place caused a bad index (and panic)
into dma map. Secondly, the assumption of the array
of DMA maps in either PCS or SBUS attachment structures is
that there is a linear mapping between handle index and
DMA map index. This can no longer be true if there are
overlapping index spaces for initiator mode and target
mode commands.
These changes bandaid around the problem by forcing us
to not have simultaneous dual roles and doing the appropriate
masking to make sure things are indexed correctly. A longer
term fix is being devloped.
obtaining and releasing shared and exclusive locks. The algorithms for
manipulating the lock cookie are very similar to that rwlocks. This patch
also adds support for exclusive locks using the same algorithm as mutexes.
A new sx_init_flags() function has been added so that optional flags can be
specified to alter a given locks behavior. The flags include SX_DUPOK,
SX_NOWITNESS, SX_NOPROFILE, and SX_QUITE which are all identical in nature
to the similar flags for mutexes.
Adaptive spinning on select locks may be enabled by enabling the
ADAPTIVE_SX kernel option. Only locks initialized with the SX_ADAPTIVESPIN
flag via sx_init_flags() will adaptively spin.
The common cases for sx_slock(), sx_sunlock(), sx_xlock(), and sx_xunlock()
are now performed inline in non-debug kernels. As a result, <sys/sx.h> now
requires <sys/lock.h> to be included prior to <sys/sx.h>.
The new kernel option SX_NOINLINE can be used to disable the aforementioned
inlining in non-debug kernels.
The size of struct sx has changed, so the kernel ABI is probably greatly
disturbed.
MFC after: 1 month
Submitted by: attilio
Tested by: kris, pjd
other C files:
- Move sbcreatecontrol() and sbtoxsockbuf() to uipc_sockbuf.c. While
sbcreatecontrol() is really an mbuf allocation routine, it does its work
with awareness of the layout of socket buffer memory.
- Move pru_*() protocol switch stubs to uipc_socket.c where the non-stub
versions of several of these functions live. Likewise, move socket state
transition calls (soisconnecting(), etc) to uipc_socket.c. Moveo
sodupsockaddr() and sotoxsocket().
imitating an Ethernet device, so vlan(4) and if_bridge(4) can be
attached to it for testing and benchmarking purposes. Its source
can be an introduction to the anatomy of a network interface driver
due to its simplicity as well as to a bunch of comments in it.
