Compile OpenCV with TBB on a Raspberry Pi 2
I tried to build OpenCV on Raspberry Pi 2 with TBB, I installed TBB from source on the Pi, I specified the path to TBB libs for cmake config, but I get the error:
/home/mihai/tbb43_20150316oss/include/tbb/machine/gcc_armv7.h:31:2: error: #error compilation requires ARMv7-a architecture.
I think the error is because in the OpenCV makefile I have to enable the flag for ARMv7
-DTBB_USE_GCC_BUILTINS = 1 -D__TBB_64BIT_ATOMICS = 0
The problem is, I don't know where to turn it on. Has anyone had this problem and would like to share a solution?
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I solved it: D. For those who have this problem, follow these steps:
1.Go for file gcc_armv7.h line 31 and comment lines
30 31 32
2. Next, in the same gcc_armv7.h file, go to line 56 and replace it with
For those who want to explain how I did it, after the first step I get the following errors:
/tmp/ccnkbkfd.s:313: Error: selected processor does not support ARM mode `dmb ish' /tmp/ccnkbkfd.s:386: Error: selected processor does not support ARM mode `dmb ish' /tmp/ccnkbkfd.s:533: Error: selected processor does not support ARM mode `dmb ish' /tmp/ccnkbkfd.s:562: Error: selected processor does not support ARM mode `dmb ish'
After I searched on google and found this:
The alternative for using dmb is to call the Linux kernel __kuser_memory_barrier the __kuser_memory_barrier helper operation is found in all ARM kernels 2.6.15 and later and provide a way to issue a memory barrier that will work across all ARM arch.__kuser_memory_barrier helper function found at address 0xffff0fa0
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