(de)modulation problems gnuradio 3.7.3.also GRC FFT missing axis labels

GNU Radio
1

I successfully? installed gnuradio 3.7.3 from source on Ubuntu 12.04
using the gnuradio-build script, but am running into problems
demodulating anything from a R820T based SDR. GRC runs fine, but when I
attempt to execute any blocks that include an AM, NFM, or WBFM
demodulator I get a VOLK:Error allocating memory error. I also noticed
that if I just pipe the RTL-SDR source to a GUI FFT Sink (either QT or
WX) there are no axis labels on the graphs…

Attempting to receive WBFM using rtl_fm (per the examples on the rtl-sdr
OsmoSDR website) produce only static. It’s not a signal strength issue
per se as another radio can pick up the station, and the SDR hardware is
functional since I can receive WBFM with it normally via gqrx on a
different machine .

I’m wondering if there’s a fundamental problem somewhere that’s
preventing demod from happening. Any troubleshooting suggestions would
be appreciated.
Regards,
R

2

On Mon, Mar 17, 2014 at 11:49 PM, [email protected] wrote:

se as another radio can pick up the station, and the SDR hardware is
functional since I can receive WBFM with it normally via gqrx on a different
machine.

I’m wondering if there’s a fundamental problem somewhere that’s preventing
demod from happening. Any troubleshooting suggestions would be appreciated.
Regards,
R

Yes, these all sound like very low-level issues with your installation
or machine. You told us the OS you are using, but not the platform
(e.g., processor).

In the build directory of GNU Radio, you can run ‘ctest’ to see what
passes and what fails there. That might help clue us in. Also, you
should run volk_profile and make sure that completes without error
(that will take some time to complete).

Tom

3

Since the LastTests.log file was so large (150K) I extracted a few error
blocks from the file. I’m attempting to compile this on a PowerBook G4
(PowerPC architecture) running Ubuntu 12.04.

RUN_VOLK_TESTS: volk_32fc_s32fc_multiply_32fc(20462,1)
Volk warning: no arch found, returning generic impl
unknown location(0): fatal error in
“volk_32fc_s32fc_multiply_32fc_test”: memory access violation at
address: 0x105d6000: no mapping at fault address
/home/fisher/gnuradio/volk/lib/testqa.cc(88): last checkpoint

*** 1 failure detected in test suite “Master Test Suite”

Test time = 2.13 sec

Test Failed.
“qa_volk_test_all” end time: Mar 19 20:52 EDT
“qa_volk_test_all” time elapsed: 00:00:02

53/178 Testing: qa_add_mult_div_sub
53/178 Test: qa_add_mult_div_sub
Command: “/bin/sh”
“/home/fisher/gnuradio/build/gr-blocks/python/blocks/qa_add_mult_div_sub_test.sh”
Directory: /home/fisher/gnuradio/build/gr-blocks/python/blocks
“qa_add_mult_div_sub” start time: Mar 19 20:55 EDT
Output:

Segmentation fault (core dumped)

Test time = 3.47 sec

Test Failed.
“qa_add_mult_div_sub” end time: Mar 19 20:55 EDT
“qa_add_mult_div_sub” time elapsed: 00:00:03

53/178 Testing: qa_add_mult_div_sub
53/178 Test: qa_add_mult_div_sub
Command: “/bin/sh”
“/home/fisher/gnuradio/build/gr-blocks/python/blocks/qa_add_mult_div_sub_test.sh”
Directory: /home/fisher/gnuradio/build/gr-blocks/python/blocks
“qa_add_mult_div_sub” start time: Mar 19 20:55 EDT
Output:

Segmentation fault (core dumped)

Test time = 3.47 sec

Test Failed.
“qa_add_mult_div_sub” end time: Mar 19 20:55 EDT
“qa_add_mult_div_sub” time elapsed: 00:00:03

78/178 Testing: test_gr_filter
78/178 Test: test_gr_filter
Command: “/bin/sh”
“/home/fisher/gnuradio/build/gr-filter/lib/test_gr_filter_test.sh”
Directory: /home/fisher/gnuradio/build/gr-filter/lib
“test_gr_filter” start time: Mar 19 20:57 EDT
Output:

VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
Segmentation fault (core dumped)
…

Test time = 1.08 sec

Test Failed.
“test_gr_filter” end time: Mar 19 20:57 EDT
“test_gr_filter” time elapsed: 00:00:01

79/178 Testing: qa_interp_fir_filter
79/178 Test: qa_interp_fir_filter
Command: “/bin/sh”
“/home/fisher/gnuradio/build/gr-filter/python/filter/qa_interp_fir_filter_test.sh”
Directory: /home/fisher/gnuradio/build/gr-filter/python/filter
“qa_interp_fir_filter” start time: Mar 19 20:57 EDT
Output:

VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
Segmentation fault (core dumped)

Test time = 3.62 sec

Test Failed.
“qa_interp_fir_filter” end time: Mar 19 20:57 EDT
“qa_interp_fir_filter” time elapsed: 00:00:03

81/178 Testing: qa_freq_xlating_fir_filter
81/178 Test: qa_freq_xlating_fir_filter
Command: “/bin/sh”
“/home/fisher/gnuradio/build/gr-filter/python/filter/qa_freq_xlating_fir_filter_test.sh”
Directory: /home/fisher/gnuradio/build/gr-filter/python/filter
“qa_freq_xlating_fir_filter” start time: Mar 19 20:57 EDT
Output:

VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
VOLK: Error allocating memory (posix_memalign: 22)
Segmentation fault (core dumped)

Test time = 4.98 sec

Test Failed.
“qa_freq_xlating_fir_filter” end time: Mar 19 20:57 EDT
“qa_freq_xlating_fir_filter” time elapsed: 00:00:04

82/178 Testing: qa_fir_filter
82/178 Test: qa_fir_filter
Command: “/bin/sh”
“/home/fisher/gnuradio/build/gr-filter/python/filter/qa_fir_filter_test.sh”
Directory: /home/fisher/gnuradio/build/gr-filter/python/filter
“qa_fir_filter” start time: Mar 19 20:57 EDT
Output:

VOLK: Error allocating memory (posix_memalign: 22)
Segmentation fault (core dumped)

Test time = 5.68 sec

Test Failed.
“qa_fir_filter” end time: Mar 19 20:57 EDT
“qa_fir_filter” time elapsed: 00:00:05

85/178 Testing: qa_fractional_resampler
85/178 Test: qa_fractional_resampler
Command: “/bin/sh”
“/home/fisher/gnuradio/build/gr-filter/python/filter/qa_fractional_resampler_test.sh”
Directory: /home/fisher/gnuradio/build/gr-filter/python/filter
“qa_fractional_resampler” start time: Mar 19 20:57 EDT
Output:

VOLK: Error allocating memory (posix_memalign: 22)
Segmentation fault (core dumped)

Test time = 3.76 sec

Test Failed.
“qa_fractional_resampler” end time: Mar 19 20:57 EDT
“qa_fractional_resampler” time elapsed: 00:00:03

----- Original Message -----
From: “Tom R.” [email protected]
To: [email protected]
Cc: “GNURadio D.ion List” [email protected]
Sent: Wednesday, March 19, 2014 12:02:50 PM
Subject: Re: [Discuss-gnuradio] (de)modulation problems gnuradio
3.7.3…also GRC FFT missing axis labels

On Mon, Mar 17, 2014 at 11:49 PM, [email protected] wrote:

se as another radio can pick up the station, and the SDR hardware is
functional since I can receive WBFM with it normally via gqrx on a different
machine.

I’m wondering if there’s a fundamental problem somewhere that’s preventing
demod from happening. Any troubleshooting suggestions would be appreciated.
Regards,
R

Yes, these all sound like very low-level issues with your installation
or machine. You told us the OS you are using, but not the platform
(e.g., processor).

In the build directory of GNU Radio, you can run ‘ctest’ to see what
passes and what fails there. That might help clue us in. Also, you
should run volk_profile and make sure that completes without error
(that will take some time to complete).

Tom

4

Progress of sorts. Made the modification to volk_malloc.c and rebuilt
gnuradio. Ctest still returns some errors (LastTest log attached), but
using a (de)modulator no longer crashes with the volk memory error…so
that’s a plus. Oddly enough the FFT display still doesn’t show axis
labels…

----- Original Message -----
From: “Tom R.” [email protected]
To: “Robert Fisher” [email protected]
Cc: “GNURadio D.ion List” [email protected]
Sent: Wednesday, March 19, 2014 11:29:32 PM
Subject: Re: [Discuss-gnuradio] (de)modulation problems gnuradio
3.7.3…also GRC FFT missing axis labels

On Wed, Mar 19, 2014 at 10:25 PM, [email protected] wrote:

Since the LastTests.log file was so large (150K) I extracted a few error
blocks from the file. I’m attempting to compile this on a PowerBook G4
(PowerPC architecture) running Ubuntu 12.04.

Wow. Haven’t had anyone report using a PowerPC with GNU Radio for a
while. But I’m not surprised that there are VOLK related issues; a
fairly untested platform for us these days.

This is failing using volk_malloc, which looks to see if your system
is POSIX compliant and if so, use posix_malloc; otherwise, use an
internally developed way of allocating aligned memory. In your case,
posix_memalign is being called and throwing that warning, which is
strange.

If you can apply this diff (a one-line change) and rebuild, it will
disable using posix_memalign. It’ll be interesting to see if the
backup method will work for you.

Tom

diff --git a/volk/lib/volk_malloc.c b/volk/lib/volk_malloc.c
index b2b77dd…e913ffc 100644
— a/volk/lib/volk_malloc.c
+++ b/volk/lib/volk_malloc.c
@@ -54,7 +54,8 @@

// Otherwise, test if we are a POSIX or X/Open system
// This only has a restriction that alignment be a power of 2.
-#if _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
+//#if _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
+#if 0

void *volk_malloc(size_t size, size_t alignment)
{

5

On Wed, Mar 19, 2014 at 10:25 PM, [email protected] wrote:

Since the LastTests.log file was so large (150K) I extracted a few error
blocks from the file. I’m attempting to compile this on a PowerBook G4
(PowerPC architecture) running Ubuntu 12.04.

Wow. Haven’t had anyone report using a PowerPC with GNU Radio for a
while. But I’m not surprised that there are VOLK related issues; a
fairly untested platform for us these days.

This is failing using volk_malloc, which looks to see if your system
is POSIX compliant and if so, use posix_malloc; otherwise, use an
internally developed way of allocating aligned memory. In your case,
posix_memalign is being called and throwing that warning, which is
strange.

If you can apply this diff (a one-line change) and rebuild, it will
disable using posix_memalign. It’ll be interesting to see if the
backup method will work for you.

Tom

diff --git a/volk/lib/volk_malloc.c b/volk/lib/volk_malloc.c
index b2b77dd…e913ffc 100644
— a/volk/lib/volk_malloc.c
+++ b/volk/lib/volk_malloc.c
@@ -54,7 +54,8 @@

// Otherwise, test if we are a POSIX or X/Open system
// This only has a restriction that alignment be a power of 2.
-#if _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
+//#if _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600
+#if 0

void *volk_malloc(size_t size, size_t alignment)
{