Re: [casper] Question about FPGA Roach2

[Bob Stricklin]

Hi Grace,

If you are using a linux computer you can issue the command line instruction:

arp -a

You will see a list of devices active

If your have a windows computer open a CMD window and issue the same command 
and see the devices.


Hope this helps.

Bob

On Jul 12, 2022, at 3:38 PM, Michael D'Cruze 
mailto:michael.dcr...@postgrad.manchester.ac.uk>>
 wrote:

Hi Grace,

Some things to check:

-- are you definitely using the correct eth port on the roach?
-- are you using a crossover eth cable? you'll need a crossover to get it to 
talk straight to a PCI-E NIC, but if you can put a switch between them I think 
it'll work
-- to check the IP (unsure whether *.4.20 is correct) can you connect via 
Serial/Minicom using the USB? I've found this to be an essential route for 
diagnostics especially if something weird happens with the eth connection

Also, I recommend joining the casper Slack 
(casper-astro.slack.com), if you're not already 
on there. There's a dedicated roach2 channel and you might find your questions 
are answered already or may be answered a bit more quickly, especially out of 
hours.

Good luck!
Michael



From: casper@lists.berkeley.edu on behalf of 
Grace Chesmore
Sent: Tuesday, July 12, 2022 20:23
To: casper@lists.berkeley.edu
Cc: Sara M. Simon
Subject: [casper] Fwd: Question about FPGA Roach2

Hi casper team!

I’m Grace Chesmore, a graduate student working out at Fermi National Lab with 
Dr. Sara Simon (cc’d).

We’ve purchased a ROACH2 board and are setting it up.  We are plugging it into 
our computer using the Ethernet port on the ROACH2.  We can see that the 
computer is connecting to the IP port of the FPGA via the ethernet port.  We 
configured our ethernet port to be 192.168.4.1 (to be compatible with the 
ROACH2 IP address which I believe is 192.168.4.20 but tell me if I’m wrong).

Then, when I try to connect to the same FPGA via the casperfpga package in 
Python, it times out because it cannot connect (or find the IP address).  I am 
using the command:
fpga=casperfpga.Casperfpga(“192.168.4.20”)

Am I missing something in the setup? Do I need to first configure the FPGA some 
way? Maybe we can also set up a call to troubleshoot this, I’d really 
appreciate any help.

Thanks so much!
Grace

---
Grace Chesmore | she, her, hers
PhD Candidate
Department of Physics
University of Chicago
chesmore.github.io


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Re: [casper] Calculating Arctan on FPGA

[Bob Stricklin]

Consider making a lookup table. If your accuracy requirements and space will 
allow it. This is the way things use to be done before calculators and 
computers and it will work in a lot of cases.

Bob Stricklin

> On Dec 13, 2021, at 6:55 AM, baldwin  wrote:
> 
> Hi Guys,
> 
> Quick question; I'm just wondering what is the best way to calculate arctan 
> on the FPGA? I am currently using the Xilinx CORDIC block to take I and Q and 
> use them to calculate phase, but have found this to give unreliable data. 
> While it sometimes gives out the correct phase value, it often just gives 
> completely nonsensical results. Just wondering if anybody else has ever had 
> similar issues.
> 
> All the best,
> 
> Eoin.
> 
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Re: [casper] ROACH-2 Poor Sampling

[Bob Stricklin]

Hi Ben,

I found your issue interesting and took a look at your data. I notice your 
sample rate period is changing every  few samples. Could this be causing some 
aliasing in the data.

If the sample clock is being derived from a fractional n PLL this is normal 
behavior for the clock. If you change your sample rate to be an integer 
multiple of the reference clock in the system the sample periods will all be 
the same and the data should smooth out.

This may not be the issue you have but I thought I would mention it here. I 
normally just read along but  to pass this along.
I will be interested to see what you find.

Bob Stricklin

On Dec 9, 2021, at 9:49 PM, 'Benjamin Godfrey' via 
casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu> 
mailto:casper@lists.berkeley.edu>> wrote:

Hi Tony,
   I do not think there is a header. At least I am collecting as much data as I 
expect to collect, and there isn't anything obviously amiss at the start/end of 
the acquisition both from plotting the ADC-count spectrum and also looking 
through the start/end of the text file the ADC data is stored in.

- Ben

On Thu, Dec 9, 2021 at 7:35 PM Tony Goodson 
mailto:aggoods...@gmail.com>> wrote:
Hi Ben,

Does the data have a header that hasn't been removed?  An unremoved header will 
produce this effect.

--Tony Goodson

On Thu, Dec 9, 2021 at 6:52 PM 'Benjamin Godfrey' via 
casper@lists.berkeley.edu<mailto:casper@lists.berkeley.edu> 
mailto:casper@lists.berkeley.edu>> wrote:
Hi everyone,
I was hoping you could help me with a bit of a mystery. I'm working on an 
experiment looking for a Q~10^6 signal embedded in broad-spectrum noise. To 
this end, we are using a ROACH-2 board with a KatADC, to sample the incoming 
signal, and then offloading the data to a PC where a GPU performs a (large) FFT.
   I have been doing some basic tests recently, injecting a sine wave from a 
signal generator into the KatADC. Using a commercial swept analyzer, I have 
verified that the injected signal is spectrally pure. Looking at the data 
[2^(24) samples] sampled by the ROACH in the time domain, I see the following:

This looks a little modulated, but it could be a sampling effect. The FFT of 
the previous signal looks very odd though. The top image below shows the 
full-span view of the FFT of the same injected signal (-30 dBm at 120 MHz). The 
bottom two images below show zoom-ins around the central peak.



As you zoom in the FFT looks oddly modulated, and it becomes very difficult to 
make out much of a peak at all. I'm not windowing so I expect some scalloping 
loss, but this is way beyond what I would expect. I've confirmed that I'm not 
dropping packets by appending a timestamp to the end of each data frame so I'm 
not sure what is causing this. I'd greatly appreciate any input you have as to 
what may be behind this strange behavior.

Thanks,
Ben


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Re: [casper] System Verilog

[Bob Stricklin]

If you are still looking and can afford to pay for a pro trainer check out:

http://www.sunburst-design.com

His website is a little out of date but if Cliff Cummings is still training he 
has a complete course and he has trained hundreds of people. Cliff may have 
something you can tag along on at a lower cost to you.

Bob Stricklin

On Jun 24, 2021, at 8:30 PM, Brian Bradford 
mailto:bbradford...@gmail.com>> wrote:

Hey Jack,

A little late here but better late than never I suppose...

Papers worth a read:

  *   
https://sutherland-hdl.com/papers/2013-SNUG-SV_Synthesizable-SystemVerilog_paper.pdf
  *   
http://www.sunburst-design.com/papers/CummingsSNUG2003SJ_SystemVerilogFSM.pdf
  *   https://sutherland-hdl.com/papers/2007-SNUG-SanJose_gotcha_again_paper.pdf

Colleagues also recommended these Sutherland textbooks 
(https://www.sutherland-hdl.com/books_and_guides.html):

  *   RTL Modeling with SystemVerilog For Simulation and Synthesis
  *   SystemVerilog For Design (2nd edition)

Cheers,
Brian

On Friday, April 30, 2021 at 4:05:55 AM UTC-7 
jackh...@gmail.com<http://gmail.com> wrote:
Hi CASPERites,

Does anyone have any resources for learning System Verilog they've used and 
particularly like?

Cheers
Jack

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Re: [EXTERNAL] [casper] seeking high accuracy GPS disciplined time/frequency standards ?

[Bob Stricklin]

All,

Since you mostly have a nice radio telescope handy you could also calibrate 
your time standards by using a paticular pulsar and an agreed upon method.

Bob Stricklin

On Mar 13, 2019, at 1:23 AM, David MacMahon 
mailto:dav...@berkeley.edu>> wrote:

Hi, Dan,

Thanks for summarizing all the great suggestions from the collective wisdom of 
the CASPER mailing list!

I think getting super precise wrt some external time reference between multiple 
observatories is an admirable goal, but I think it's also important to keep the 
ultimate goal in mind: coincident detection of transient events at astronomical 
distances.  No matter how good you think you're doing with the external time 
reference synchronization, you will never really know you got it right until 
you can demonstrate coincident detection at multiple sites of a known 
astronomical transient event.  I'm not sure what kinds of events your 
instrument is sensitive to, but something like the occultation of a star by an 
asteroid or other solar system object would be very convincing.  Tracking the 
movement of the limb of the moon across your detector arrays would perhaps be 
another possibility.  Not only would these demonstrations be a very reassuring 
confirmation that you've nailed the time synchronization problem, they would 
also provide a nice way to measure/calibrate the residual errors.

Fun stuff!!!

Dave

On Mar 12, 2019, at 20:17, Dan Werthimer 
mailto:d...@ssl.berkeley.edu>> wrote:


dear casper time keepers,

thanks for all your good ideas on how to get a pair of time/freq standards 500 
km apart to agree to a few ns.

some of you suggested common view GPS, which can get clocks to agree to within 
about 2 or 3 ns:
https://www.nist.gov/pml/time-<https://www.nist.gov/pml/time-and-frequency-division/atomic-standards/common-view-gps-time-transfer>and-frequency-division/atomic-standards/common-view-gps-time-transfer<https://www.nist.gov/pml/time-and-frequency-division/atomic-standards/common-view-gps-time-transfer>
also see papers at the bottom of that page.

some suggested NIST TMAS service, (time-measurement and analysis service),
where you pay a monthly fee for NIST to keep your GPSDO to < 10ns RMS wrt 
NIST-UTC.
https://www.nist.gov/programs-projects/time-measurement-and-analysis-service-tmas

i like john's suggestion of letting the oscillator drift, rather than 
continually trying to correct it.
i think several observatories do that -  makes sense.

best wishes,

dan





From: John Ford mailto:jmfor...@gmail.com>>
Sent: Monday, March 11, 2019 9:41 AM
To: LIST mailto:casper@lists.berkeley.edu>>
Subject: Re: [EXTERNAL] [casper] seeking high accuracy GPS disciplined 
time/frequency standards ?

Hi Dan.  I've been thinking about this a bit over the weekend, and I think the 
problem can be solved by dividing the problem.  I think the frequency standard 
should not be coupled to GPS, rather a free-running rubidium or better 
oscillator could provide sufficient frequency stability and could also generate 
a local clock.  The CLOCK, then can be either referenced or calibrated somehow 
(postprocessed GPS time + ?) to UTC.  The local clocks at the N sites then 
would not be slaved to GPS, but rather to their own frequency standard, 
corrected as needed by filtered/corrected GPS time.

Green Bank does this to some extent, without closing the loop.  The hydrogen 
maser drives a counter, which provides 1 PPS.  But this one PPS is NOT slaved 
to GPS, but rather the GPS signal is used to measure the offset from GPS.  The 
offset is then supplied to the users for their calculations.  The system drifts 
some microseconds per year.  Eventually the time gets resynced to GPS, when 
someone decides it's time, or when something happens to force it.  Like a 
power/UPS outage.

I think you could build such a system that would be accurate to << 10 ns with 
respect to UTC using GPS and doing corrections to the GPS TIME after the fact, 
and feeding forward the errors into your clock.  The corrections would be a day 
late, but presumably you are not going to rely on raw GPS, rather on the 
time-corrected GPS time.  In the meantime your clock will freewheel with your 
oscillator, which will be extremely accurate anyway.

John



On Sat, Mar 9, 2019 at 3:08 PM Dan Werthimer 
mailto:d...@ssl.berkeley.edu>> wrote:

hi david,

i'm not an expert in atmospheric delay correction and gps,  but if you are 
interested,
i think there are several papers about what corrections gps can do and what it 
can't do.
some references are listed at the end of:
https://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System

the best GPSDO's on the market provide errors of around 10 ns RMS wrt UTC.
i think most of this error is due to variable atmospheric delays that can not 
be removed
(eg:  dispersion errors can be measured and removed, but other propogation 
delay errors can not be removed).

best wishes,

dan

Re: [EXTERNAL] [casper] seeking high accuracy GPS disciplined time/frequency standards ?

[Bob Stricklin]

Here is a link to an Analog Devices Ap note discussing an accurate timing 
reference. It may be a good reference to help you.

https://www.analog.com/media/en/technical-documentation/application-notes/AN-1002.pdf

Bob Stricklin



On Mar 8, 2019, at 8:04 PM, John Ford 
mailto:jmfor...@gmail.com>> wrote:

Hi Dan, all.

How about a combination of these techniques?  You could get an ultra-stable 
oscillator, possibly similar to what Bob Jarnot suggested, and then use the 
day-old-postprocessed GPS timing results to calibrate the 2 atomic clocks' time 
at different places on the earth.  Hopefully (to be borne out by 
testing/calculations!) your 2 oscillators would be stable enough that you could 
adjust them over time (days?) and get them precisely synced up and they would 
stay that way.

John


On Fri, Mar 8, 2019 at 2:55 PM Dan Werthimer 
mailto:d...@ssl.berkeley.edu>> wrote:

hi robert, randall,  dale and casperites,

thanks for your time/freq standard suggestions.

our problem to get accurate 1 PPS wrt UTC is not limited by internal oscillator 
stability.
the problem is mostly about GPS atmospheric delay corrections.
i don't thinks one needs an ultra stable oscillator in a GPSDO time/freq 
standard if one is only interested in 1 PPS accuracy wrt UTC.
there's no need for rubidium, hydrogen, or microsemi's atomic gizmo for 1 pps 
accuracy
--  an OXCO is fine.

the typical GPS disciplined oscillators (eg: srs and  trimble) output 1 PPS 
that have 100 ns errors from UTC.
the best ones we have found so far are made by endrun technologies (<  10 ns 
error wrt UTC).

endrun claims to have unique algorithms for GPS atmospheric correction.
although one can do next day GPS atmospheric correction for atmospheric delays
(the next day, there are correction tables available for the previous day that 
are location/satellite dependent),
endrun technologies can do some fairly accurate measurements and atmospheric 
delay corrections in near real time.
we'd prefer not to use next day correction tables in our application.

has anybody used GPSDO time/freq standards that have < 10 ns accuracy wrt UTC?
has anybody used the endrun technologies standards ?
has anybody used GPSDO products from microsemi?
https://www.microsemi.com/product-directory/clocks-frequency-references/3826-gps-disciplined-oscillators-gpsdo
the GPSDO's listed at the bottom of that page have 10 ns wrt utc.

best wishes,

dan



On Thu, Mar 7, 2019 at 8:57 AM Robert F. Jarnot 
mailto:robert.f.jar...@jpl.nasa.gov>> wrote:

Dan,

I looked into GPS disciplined oscillators for a project, and ended up using 
atomic clocks instead, as they are now very small, can be flown, and have 
remarkably low power consumption. We have 2 of them, $7500 each. See 
https://www.microsemi.com/product-directory/clocks-frequency-references/3824-chip-scale-atomic-clock-csac

I suspect that a good choice of GPS disciplined oscillators would work 
pretty much as well, and be cheaper.

Bob

On 3/7/19 8:51 AM, Dan Werthimer wrote:


in a somewhat related question.

can anybody give us advice about GPS disciplined oscillators time/freq 
standards that are very accurate wrt UTC?
we don't want to buy a hydrogen maser (too pricy).
we have been looking at a company called endrun technologies that sell 
time/freq standards accurate to about +-10 ns wrt UTC.
they might be able to match a pair of them that track each other +- 3ns RMS.
we need a pair of well matched time/freq standards for coincidence time 
stamping/correlation between two observatories for our panoseti experiment.
(the two optical/IR observatories are 500 km apart, and don't have masers).

thanks for any advice on this.

btw, we are using white rabbit for time/frequency distribution over 1 Gbe bidi 
fiber,
and we put the white rabbit hardware (VCO and DAC chips) and software on our 
FPGA boards for this project.
(we made our own FPGA boards with white rabbit and kintex7 because we need a 
few thousand boards)
white rabbit does sub-ns accuracy in timing distribution - some white rabbit 
users have measured 30 ps RMS.

best wishes,

dan


On Thu, Mar 7, 2019 at 12:05 AM Michael Inggs 
mailto:miki...@gmail.com>> wrote:
Hi Franco

Simon Lewis in the RRSG at UCT has White Rabbit hardware and expertise (PhD 
incubating). Snag is that it runs on 1GE Fibre. We also have a GPS version. The 
former gives sub ns precision, the latter about 4 ns rms. Send me a message off 
line and I can link you. We also have a scheme of aligning a trigger to both a 
local MHz clock and the 1 pps. This is all open source hardware and software.

Regards

On Thu, 7 Mar 2019 at 08:52, James Smith 
mailto:jsm...@ska.ac.za>> wrote:
Hello Franco,

As I understand it, PTP wasn't terribly useful in our application (though I 
wasn't involved with this directly). You can probably sync the little Linux 
instance that runs on the ROACH2, but getting the time information onto your 
FPGA may prove somewhat tricky.

Are

Re: [casper] Raspberry Pi 3 B+ Image Corrupt?

[Bob Stricklin]

Dave,

The SNAP image mentioned should be a unTARed as stated and be ready to burn on 
an SD card.


tar -xzvf rpi_snap.img.tar.gz

This command should give you a file rpi_snap.img ready to burn to an SD card.


Typically, after downloading a Pi image you copy the image directly to a mini 
SD card. You can do this using a linux computer or a Mac. If the SNAP image was 
created using the dd command it should be copied back to a SD card in the same 
manner.

First you have to make sure you know which disk the SD card is located on your 
system. The SD card should be formatted with a FAT filesystem and then be 
un-mounted.

You may use the Disk Utility on a Mac to format and umount the disk. There are 
other utilities in Linux to do this as well.

This command will copy the image from (if) to (of):

sudo dd bs=1m if=./Name_of_Image_Download.img of=/dev/diskX

You must be sure to only copy to the disk with the SD card or you may damage 
your file system. Make sure you know your disk assignments. Move to the 
directory that contains the image before running the dd command.

After copying the image to an SD card which takes a while (30 minutes to an 
hour estimate) you can put the card in the Pi and with it connected to a HDMI 
monitor power up the Pi and watch it boot up. With a standard Pi image use a 
USB keyboard and Mouse. You will then have to configure the pi. Typically allow 
ssh connections and install xrdp, set the time zone and allow vnc connections. 
IF you have a preconfigured SNAP image you may be able to skip this step.

Run ifconfig to determine the Pi ip address and mac address. You can set this 
to be static in the Pi or force it on your router.





Bob Stricklin


On Oct 19, 2018, at 1:20 PM, David Marsh 
mailto:davidmma...@gmail.com>> wrote:

Hello,

We are trying to setup the SNAP board using the instructions found at 
https://casper.berkeley.edu/wiki/SNAP_Bringup.

We are using a Raspberry Pi 3 B+ and we are trying to configure it using the Pi 
3 image. When we download the image we are unable to unzip the file and the 
extracted image is not valid. We were wondering if this was a corrupted image. 
Is there another working image? We tried unzipping the download on multiple 
machines/operating systems.

Thanks,
David



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Re: [casper] SNAP Board clocking for a low-frequency array

[Bob Stricklin]

For the time reference this one was suggested on an earlier discussion….

http://www.leobodnar.com/shop/index.php?main_page=index=107=468ab2632bba5b5ffe4d2fe7d8bb19e2

If you need to reduce cost even more you can find GPS based 1PPS sources on 
ebay.
https://www.ebay.com/itm/UBLOX-LEA-5T-high-precision-timing-GPS-module-dev-board-1PPS-USB-RS232-ntp-ser/263546760982?hash=item3d5c9c6f16:g:hbgAAOSwbsBXopDl:rk:19:pf:0

If you have a failure you should have a good plan for how you can obtain 
another time reference for the project before or after the failure. Also their 
can be some phase noise in a 1PPS signal. This phase noise can contribute to 
error in your system just like noise degrades RF reception.

I have not looked at the SNAP spec but it is stated here as 2.0V into a 50 ohm 
load or resistor. A LVTTL CMOS output would be the wrong voltage level and 
could not supply 40 mA. In this case you will need a buffer circuit to match 
the output conditions of the 1PPS reference selected and the input of SNAP. You 
could build this yourself. Typically there will be the need for many time 
reference lines. You must be sure not to create any phase delay as you fan out 
N time reference lines. So each circuit path and connecting cable will be the 
same type and length. You can see examples of this in other systems posted to 
this list.

Your circuit would interface the output and input with the proper voltage level 
and currents. Take a look at this link for some ideas of buffer interfaces…

http://www.ti.com/lit/an/scea035a/scea035a.pdf

I am a retired engineer that follows this list and offer these suggestions to 
hopefully help you in your efforts.


Bob Stricklin


On Oct 19, 2018, at 2:04 AM, Nitish Ragoomundun 
mailto:nitish.ragoomun...@gmail.com>> wrote:


Hi all,

We are building a low-frequency array for the observation of the deuterium 
hyperfine line at 327.4 MHz with a bandwidth of 250 kHz. We intend to use SNAPs 
for acquisition. The boards will operate at full 12 channels input, thus the 
ADCs at 250 MSps. We will subsequently decimate the data rate, as our working 
bandwidth is narrow.

Concerning the clock input for the SNAP,  https://casper.berkeley.edu/wiki/SNAP 
states the following:

Digital 1 PPS: 50 ohm single-ended LVTTL logic levels

  *   SMATP13
  *   Vin-high 2.0 to 3.3 Volts. Low current drive sources, such as typical 
LVTTL or CMOS gates, probably can not supply the 40mA required to supply the 
2.0V into the 50ohm load.
  *   Vin-low 0.0 to 0.8 Volts

Actually we considered buying the GPS-disciplined Meinberg M500 LANTIME 
(https://www.meinbergglobal.com/english/products/modular-railmount-ntp-server-ieee-1588-solution.htm),
 which is advertised to output 1 PPS TTL levels. Now, our first question is 
whether the SNAP can work with this? Also, the note about low current drive 
sources is a little confusing, can anyone shed some light here.

Secondly, we would like suggestions from anyone who has experience with 
clocking the SNAP. You see, we run a very tight budget and the M500 LANTIME 
clock is expensive. We would like to know if there is a less costly way to 
clock the SNAP and synchronise several boards.

Thanks.

Best regards,
Nitish Ragoomundun
Department of Physics
University of Mauritius


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Re: [casper] Timing distribution over fiber

[Bob Stricklin]

Hi Jack and John,

I wanted to add an input here…..

I am working on a 10 MHz GPS slaved reference for my personal use. I am working 
with a Analog Devices AD9548 Evaluation board (~$250) , GPS with 1 PPS, and a 
ovenized 10 MHz osc. I also plan to distribute this clock and have considered 
the Avago fiber product line. One of the older generation Avago fiber parts 
should work fine for $25 per channel. With careful control of lengths and 
delays it should be possible to maintain good phasing between channels. The 
analog devices chip is $50 so a custom solution should be $500/reference but 
with considerable development time.

Bob Stricklin


On May 4, 2015, at 10:02 PM, Jack Hickish 
jackhick...@gmail.commailto:jackhick...@gmail.com wrote:

Hi John,

Thanks for the info. I'll add Litelink to my list of suppliers to investigate.
We have no particular urge to multiplex the signals on to the fiber unless 
there's a particularly neat/cheap solution to do that. There's no great 
appetite to go custom. We've got about ~30 nodes, and my first stab at getting 
an off-the-shelf solution turned up at a few k$ / node, not including any 
cleanup electronics.

Thanks again,

Jack

On Mon, 4 May 2015 at 19:25 John Ford jf...@nrao.edumailto:jf...@nrao.edu 
wrote:
 Hi CASPERites,

 For HERA, we're looking at distributing timing signals (PPS  10Mhz ref or
 500 MHz clock) over O(100m) fibers to various digitization nodes.
 I figure some folks in CASPERland have experience with this kind of
 system?
 Did you use custom RF-over-fiber kit, or off-the-shelf PPS/10MHz
 solutions?
 Any words of wisdom/caution to share?

 Any responses much appreciated!

We have several different schemes for the different signals.  Are you
planning for one fiber per signal per node?  or one fiber with the signals
multiplexed on them?

If the signals are one per signal, you can use some off-the-shelf
solutions, but they are kind of pricey, and if you have a lot of nodes to
supply, it might be worth working on something custom.  We have used Math
Associates stuff for this kind of work.  Math Associates is now litelink,
and they tout the affordability of their stuff, so maybe it's
reasonable...


On the 10 MHz, we send the 10 MHz reference over fiber, and at the far end
use a crystal oscillator locked to the reference to clean up the noise
from the fiber electronics.  This is essential for interferometry, but
maybe not for single-dish use.

John


 Jack

Re: [casper] {Disarmed} Problem with ROACH2 netboot

[Bob Stricklin]

 VFS: Mounted root (nfs filesystem) readonly on device 0:11.

Note that your root is being mounted as read only.

Must have an issue in a config file on new machine or a file/directory is not 
configured for write/execute.

Use ls -l to review permissions.
Use chmod to change the permissions.
Review all conf files involved in the process. Make backups copies before you 
start making changes so you can get back when you find the root issue.

Bob



 On Feb 7, 2015, at 9:31 AM, John Ford jf...@nrao.edu wrote:
 
 Hi Andrea.
 
 Was the file system extracted from the archive as root to preserve the
 ownership and permissions?  Is the export of the file system allowing root
 access (norootsquash).
 
 The error is pretty clear that the init isn't executable and neither is
 the shell, so I suspect your file system that's being mounted isn't right,
 or is being mounted in such a way as to revoke root privileges.
 
 John
 
 
 Dear all,
 I get a problem when I try to boot our ROACH2 via netboot. The complete
 log
 message dumped on minicom during the boot procedure is reported at the end
 of this email.
 The same board successfully booted in the previous machine, so I'm pretty
 sure that the problem depends on the new machine configuration, but, to
 date, I'm not able to fix the problem by myself.
 
 The part where the boot fails is the following:
 
 [4.444359] Sending DHCP requests .., OK
 [7.232802] IP-Config: Got DHCP answer from 192.168.40.1, my address is
 192.168.40.93
 [7.240947] IP-Config: Complete:
 [7.244206]  device=eth0, hwaddr=02:44:01:02:08:25,
 ipaddr=192.168.40.93, mask=255.255.255.0, gw=255.255.255.255
 [7.254765]  host=192.168.40.93, domain=, nis-domain=(none)
 [7.260669]  bootserver=192.168.40.1, rootserver=192.168.40.1,
 rootpath=/home/nfs/roach2/current,nolock
 [7.270209]  nameserver0=192.168.40.1
 [7.283258] VFS: Mounted root (nfs filesystem) readonly on device 0:11.
 [7.290904] Freeing unused kernel memory: 300K (805a8000 - 805f3000)
 [7.298537] Starting init: /sbin/init exists but couldn't execute it
 (error -5)
 [7.308506] Starting init: /bin/sh exists but couldn't execute it
 (error
 -5)
 [7.315635] Kernel panic - not syncing: No working init found.  Try
 passing init= option to kernel. See Linux Documentation/init.txt for.
 [7.328715] CPU: 0 PID: 1 Comm: swapper Not tainted
 3.16.0-saska-03675-g1c70ffc #3
 [7.336250] Call Trace:
 [7.338716] [bf86de70] [80006bc0] show_stack+0x10c/0x1c0 (unreliable)
 [7.345176] [bf86dec0] [8041410c] dump_stack+0x24/0x34
 [7.350311] [bf86ded0] [80411d20] panic+0xd0/0x234
 [7.355107] [bf86df30] [80001f00] kernel_init+0xf0/0x108
 [7.360426] [bf86df40] [8000d470] ret_from_kernel_thread+0x5c/0x64
 
 The netboot procedure stops here but I do not understand the reason
 because
 both /sbin/init and /bin/sh are in the right place (I've downloaded the
 nfs
 image available on github, git clone git://
 github.com/ska-sa/roach2_nfs_uboot).
 The tftp, dnsmasq and nfs service seam configured in the proper way.
 
 Some infos about the system we are using:
 OS: Scientific Linux release 7.0 (Nitrogen)
 tftp: tftp-hpa 5.2, with readline
 dnsmasq: Dnsmasq version 2.66
 nfs: NFSv4, NFSv3, NFSv2 (NFSv4 disabled)
 
 The file system where the directory /home/nfs/roach2/current is located is
 xfs.
 
 In /var/log/messages i get the following message
 
 Feb  6 16:46:15 holmes0 dnsmasq-dhcp[21918]: DHCPDISCOVER(em2)
 02:44:01:02:08:25
 Feb  6 16:46:15 holmes0 dnsmasq-dhcp[21918]: DHCPOFFER(em2) 192.168.40.93
 02:44:01:02:08:25
 Feb  6 16:46:15 holmes0 dnsmasq-dhcp[21918]: DHCPREQUEST(em2)
 192.168.40.93
 02:44:01:02:08:25
 Feb  6 16:46:15 holmes0 dnsmasq-dhcp[21918]: DHCPACK(em2) 192.168.40.93
 02:44:01:02:08:25
 Feb  6 16:46:15 holmes0 rpc.mountd[32469]: authenticated mount request
 from
 192.168.40.93:1010 for /home/nfs/roach2/debian_stable_devel (/home/nfs)
 
 
 I would be grateful for any help you are able to provide,
 
 best,
 
 ag.
 
 
 
 
 
 
 U-Boot 2011.06-rc2-0-g2694c9d-dirty (Dec 04 2013 - 20:58:06)
 
 CPU:   AMCC PowerPC 440EPx Rev. A at 533.333 MHz (PLB=133 OPB=66 EBC=66)
   No Security/Kasumi support
   Bootstrap Option C - Boot ROM Location EBC (16 bits)
   32 kB I-Cache 32 kB D-Cache
 Board: ROACH2
 I2C:   ready
 DRAM:  512 MiB
 Flash: 128 MiB
 In:serial
 Out:   serial
 Err:   serial
 CPLD:  2.1
 USB:   Host(int phy)
 SN:ROACH2.2 batch=D#8#37 software fixups match
 MAC:   02:44:01:02:08:25
 DTT:   1 is 28 C
 DTT:   2 is 26 C
 Net:   ppc_4xx_eth0
 Sensors Config
 type run netboot to boot via dhcp+tftp+nfs
 type run soloboot to run from flash independent of network
 
 Hit any key to stop autoboot:  0
 Waiting for PHY auto negotiation to complete done
 ENET Speed is 1000 Mbps - FULL duplex connection (EMAC0)
 BOOTP broadcast 1
 *** Unhandled DHCP Option in OFFER/ACK: 28
 *** Unhandled DHCP Option in OFFER/ACK: 28
 DHCP client bound to address