Ganael Laplanche | 3 Aug 15:32 2015

Boot loader arguments (was: ZFS support for EFI)

Hi Eric,

I am replying to this -quite old now- post :

> More importantly, the EFI loader doesn't seem to make use of its
> command-line arguments at all.  But a ZFS-enabled loader would really
> need the ability to take arguments from boot1 (or grub, or whatever
> else).

where you were suggesting it would be interesting for the EFI loader to make 
use of its arguments, which is still not the case.

We've faced a similar problem here, where we needed the EFI loader be able to 
locally override the root-path offered through BOOTP. A quick fix would have 
been to hardcode the root-path but instead we chose to pass it through an 
argument to the loader (which then sets a new environment variable : 

Find attached the two -simple- patches that allow such an operation. I don't 
know if they can be interesting for you or for upstream inclusion (though they 
are probably *not* ready for direct inclusion yet).

Best regards,


Ganaël LAPLANCHE <ganael.laplanche <at>>
freebsd-hackers <at> mailing list
(Continue reading)

Patrick Mooney | 31 Jul 20:20 2015

Interpretation of POSIX.1-2008 for recvmsg

I have been researching differences in recvmsg() behavior across platforms
(namely Illumos and Linux) with respect to MSG_PEEK and 0-length buffers.
Certain Linux software I am attempting to run under Illumos makes a recvmsg()
call with a 0-length iovec and flags set to MSG_PEEK in order to interrogate
the size of a queued dgram.  On native Linux, recvmsg() returns the size of the
queued dgram (with the MSG_TRUNC flag set).  On both Illumos and FreeBSD, a
size of 0 is returned (with MSG_TRUNC set as well).  In reading the POSIX spec
(, it is
not clear that returning 0 in this case is correct behavior.

Here is a small test program I wrote up to display the differences in behavior:

The output on Linux:
peek len: 20 errno: 0 flags: 20
recv len: 20 errno: 0 flags: 0
... versus BSD and Illumos:
peek len: 0 errno: 2 flags: 12
recv len: 20 errno: 2 flags: 0

I am interested in your opinions on the matter.

With regards,

freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"
(Continue reading)

Gerry Weaver | 29 Jul 05:55 2015

Custom point-to-point tunnel protocol

Hello All,

I need to create a secure point-to-point tunnel protocol for a project that I'm working on. I have several
questions related to the security aspect of that protocol. I'm looking for a place or resource where I can
ask those type of questions. Could anyone please recommend a good mailing list or other resource for this
kind of thing? I've checked this out on Google, but I haven't been able to find exactly what I'm looking for.

freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"

Raviprakash Darbha | 30 Jul 01:31 2015

getting a disk structure given a device name

Hello All 

I am trying to write a filter driver for the ata block on freebsd 6.2 to simulate failed reads and writes. For
this i would like to know if there is a call to convert a given device path (ex /dev/ad0)  to a disk structure
(adp->disk) which has the strategy function so that i could modify that and point it to my filter. 
There is a similar function in linux kernel blk_get_by_path and would like to know if there is something
similar on freebsd too.
The other option is to write  a function to traverse through the list of devs and return the disk which has the
disk->d_name as the given device path.This is a bit laborious but not sure if thats the only option. 

Any help is appreciated. 


freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"

Ali Mashtizadeh | 27 Jul 20:39 2015

SPEC CPU2006 Benchmarks

Hey Folks,

I was curious if anyone has been working with SPEC CPU2006 on FreeBSD 10?
Seems like several benchmarks crash or fail to build depending if you try
V1.1 or V1.2 of the benchmarks.

In version 1.2: perlbench coredumps, gcc exits prematurely, and dealII
fails to build.


Ali Mashtizadeh
freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"

deco33000 | 25 Jul 15:25 2015

Timekeeping between two hardclocks


I am learning the freebsd way to keep the time up to date.
I already read

I am mostly in sys/kern_tc.c 

We avoid to call hardware hardclock() every time we need a timestamp by applying some math (to improve
performance). I get the idea.

But, how do we know how far we are from the last hardclock(), at any given moment?
Are the updates to the "fake" timestamps occuring at a constant rate? Is there a feed somewhere I missed? I
don't see where in that case.

This is the last -and most important- point I don't get on the timer/clock subsystem.

I seriously need your help/pointers I guess.


freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"
HeTak | 25 Jul 10:54 2015

Kernel Debug Howto

Hi there,

I have recently started some developments on FreeBSD net section. But I am
kinda new to this field. My base interest is to first understand the
implementation structure via tracing the code and so.

 I have three major questions:
1-  how to debug changes made to FreeBSD kernel?
(You know, till some levels, I can even use uprintf or so, but, for example
inside radix.c (where I wanna understand how a route is checked to be
unique and then inserted to the tree) I can't do such checks..)

2- are there standards there for freebsd kernel developments of which I can
follow so my job gets a bit simplified?
(Any development guides or so?I prospect it to be some differences between
system developments and normal coding, but I don't have an idea on how to
get that).

3- what is the fastest way to apply changes to FreeBSD kernel?
(For now, I just follow the normal build & install kernel & reboot.)

Thanks in advance for your patience in answering an anxious newbie :)

-- HeTak
freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"

(Continue reading)

Pratik Singhal | 25 Jul 07:54 2015

How to interface AC'97 codec driver with kernel ?

Hello  all,

I am writing the driver for AC'97 controller present in Allwinner A10 SoC
as a part of my Google summer of code Project.  I have understood the
theoretical aspects of AC'97 and know "what" to code, but I am unable to
understand , how to interface the code with FreeBSD kernel.

For ex, when making changes in the mmc driver, it was very clear that the
high-level file sys/dev/mmc/mmc.c will call the methods defined in our
implementation of mmc driver,

In the case of AC'97, what all files should I look at ? I have so far
looked at sys/dev/sound/pcm/ directory, but can't seem to understand much
Also,how does FreeBSD control the AC-link , which will be used to control
various parameters related to AC'97 codec I/O ?

I am new to working with sound at this low level, so there might be some
trivial things which I may have missed.
Any help would be very valuable for timely completion of project

Pratik Singhal
freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"

Hunter Satterwhite | 23 Jul 02:19 2015

Cisco Virtual Interface Card (VIC) & FreeBSD

Does anyone have experience or knowledge around FreeBSD enic/vnic driver
support for Cisco's Virtual Interface Card? We are moving to Cisco FlexPod
and this has been raised as a concern. I for one have not been successful
in finding any information around this and do not have the necessary
hardware to test FreeBSD on.

Cisco does not offer one and of course there are no plans on supporting
FreeBSD in this capacity, which came straight from one of their Data Center

My team and I are heavily invested in FreeBSD and would like continue using
it as our first choice of operating system. Any help our insight in to this
would be greatly appreciated.


*Hunter Satterwhite*
WebAssign | Systems Engineer, Technical Operations
C 252.762.5177
Website <>
freebsd-hackers <at> mailing list
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe <at>"

Eric McCorkle | 17 Jul 17:32 2015

Interesting open laptop project

Hi folks,

I ran across this project last week:

While a bit pricey, it seems like the best shot at having a laptop that
actually really works.  My only concern lies with the graphics, as I'm
not sure what's going to be supported by the i915 driver updates.  Are
we likely to get Iris 6100 (Broadwell, if I'm not mistaken) support in
the near future?

BSDCon Brasil 2015 | 16 Jul 18:09 2015

BSDCon Brasil 2015: Apresentações / Talks

===== pt

Acompanhe as atualizações da conferência através do Twitter ou Facebook

Gostaria de patrocinar a BSDCon Brasil 2015? Entre em contato conosco
através das redes sociais ou mande-nos um email. Escreva para
patrocinio <at>

Conheça nossos patrocinadores:

===== en

Follow conference updates on Twitter or Facebook (

Would you like to become a sponsor? Please write to
sponsorship <at>

Meet our sponsors:


BSDCon Brasil 2015
freebsd-hackers <at> mailing list
(Continue reading)