illegal Instructions

[yacoubhanna]

Hello,

I tried to compile Ascon on my PC using opt64/32 and it was working. However, when I try to compile it on RPI 3/4 using ARMV7 and ARMV6 architecture it doesn't work and it gives me an Illegal Instructions error. How can I compile Ascon on the RPI?

Also when I run lscpu command on RPI I'm getting that it is based on ARMV7.

Thank you for your help.

[mschlaeffer]

It does compile correctly on an RPI1.

Please provide the exact commands and outputs. Otherwise it's difficult to debug.

[yacoubhanna]

In my first trial, I ran the default commands on Raspberry Pi 4 using

mkdir build && cd build
cmake .. -DALG_LIST="ascon128;asconhash" -DIMPL_LIST="opt32;opt32_lowsize" -DTEST_LIST="getcycles"
cmake --build .
ctest

It build everything and when I try to execute the ./getcycles_crypto_aead_ascon128v12_opt32

I got that

pi@raspberrypi:~/Desktop/Ascon/ascon-c/build $ ./getcycles_crypto_aead_ascon128v12_opt32
Illegal instruction

In my second trial, I ran the commands using armv7

mkdir build && cd build
cmake .. -DALG_LIST="ascon128;asconhash" -DIMPL_LIST="armv7m;armv7m_lowsize" -DTEST_LIST="getcycles"
cmake --build .

I got the following errors

/tmp/ccW0KWFD.s: Assembler messages:
/tmp/ccW0KWFD.s:46: Error: selected processor does not support `orn r10,r2,r9' in ARM mode
/tmp/ccW0KWFD.s:49: Error: selected processor does not support `orn fp,lr,r2' in ARM mode
/tmp/ccW0KWFD.s:62: Error: selected processor does not support `orn r10,r3,r8' in ARM mode
/tmp/ccW0KWFD.s:65: Error: selected processor does not support `orn fp,ip,r3' in ARM mode
make[2]: *** [CMakeFiles/crypto_hash_asconhashv12_armv7m_lowsize.dir/build.make:76: CMakeFiles/crypto_hash_asconhashv12_armv7m_lowsize.dir/crypto_hash/asconhashv12/armv7m_lowsize/permutations.c.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:90: CMakeFiles/crypto_hash_asconhashv12_armv7m_lowsize.dir/all] Error 2
make: *** [Makefile:95: all] Error 2

Thank you for your time.

[yacoubhanna]

Also when I tried to run

cmake .. -DCMAKE_C_COMPILER="arm-linux-gnueabi-gcc" \
         -DREL_FLAGS="-O2;-fomit-frame-pointer;-march=armv7;-mtune=cortex-m4" \
         -DEMULATOR="qemu-arm;-L;/usr/arm-linux-gnueabi" \
         -DALG_LIST="ascon128;ascon128a" -DIMPL_LIST="armv7m;bi32_armv7m"

I got

cmake .. -DCMAKE_C_COMPILER="arm-linux-gnueabi-gcc" -DREL_FLAGS="-O2;-fomit-frame-pointer;-march=armv7;-mtune=cortex-m4" -DEMULATOR="qemu-arm;-L;/usr/arm-linux-gnueabi" -DALG_LIST="ascon128;ascon128a" -DIMPL_LIST="armv7m;bi32_armv7m"
-- The C compiler identification is unknown
-- The ASM compiler identification is unknown
-- Didn't find assembler
CMake Error at CMakeLists.txt:2 (project):
  The CMAKE_C_COMPILER:

    arm-linux-gnueabi-gcc

  is not a full path and was not found in the PATH.

  Tell CMake where to find the compiler by setting either the environment
  variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
  the compiler, or to the compiler name if it is in the PATH.

CMake Error at CMakeLists.txt:2 (project):
  No CMAKE_ASM_COMPILER could be found.

  Tell CMake where to find the compiler by setting either the environment
  variable "ASM" or the CMake cache entry CMAKE_ASM_COMPILER to the full path
  to the compiler, or to the compiler name if it is in the PATH.

-- Warning: Did not find file Compiler/-ASM
-- Configuring incomplete, errors occurred!
See also "/home/pi/Desktop/Ascon-2/ascon-c/build/CMakeFiles/CMakeOutput.log".
See also "/home/pi/Desktop/Ascon-2/ascon-c/build/CMakeFiles/CMakeError.log".

[mschlaeffer]

Does building the genkat test work?

-DTEST_LIST="genkat"

I think the problem is that the cycle counter does not work for RPI 3/4. Maybe because the assembly instruction is different than for the RPI 1. Another reason could be that you did not compile/install/load the requested kernel module. There are instructions in the readme for RPI 1, but this is most likely different for RPI 3/4.

[mschlaeffer]

Regarding your second comment: These instructions are for cross-compiling and simulating using qemu. Not for compiling and running on an RPI.

[smuellerDD]

Perhaps https://github.com/ascon/ascon-c/issues/16 contains a hint to the issue?

[mschlaeffer]

The armv7m implementation of Ascon uses the T32 ORN instruction: https://developer.arm.com/documentation/dui0801/l/A32-and-T32-Instructions/ORN--T32-only-

This instruction is only available on 32-bit ARMv7-M, ARMv8-M and ARMv8-A CPUs, but not on ARMv7-A CPUs. The RPI3/4 are 64-bit Cortex-A53 and Cortex-A72 CPUs. The best option is to use the opt64 implementation of Ascon then.

If running in 32-bit mode, I assume the compiler uses ARMv7-A, where T32 ORN is not available. The best option is to use the armv6 implementation of Ascon, which is the same as armv7m with ORN replaced by MVN+ORR. Maybe armv6 should be called armv7a nowadays.