feat: change for arm to use clcok_gettime

installation_procedure.txt

@@ -1,7 +1,7 @@
 Reminder: this is for linux setup
 
 1. Install flexpret by following it's instructions. Use branch gametime-support. Can use instructions of master branch.
-        ***Remember to export PATH=$PATH:/home/c/Desktop/research/lf/code/flexpret/emulator*** USE ABS PATH
+        ***Remember to export PATH=$PATH:/Users/abdallaeltayeb/Desktop/Gamtime_project/flexpret/emulator*** USE ABS PATH
                         export PATH=$PATH:/opt/riscv/bin
 
 2. Pull the lastest Gametime.
@@ -30,3 +30,4 @@ apt-get install -qqy --no-install-recommends \
 7. Install KLEE and pycparser. Place pycparser in same directory as gametime to ensure it can find the stubs.
 
 7. To regenerate documentation: install sphinx and numpydoc. Then run: make html; sphinx-build -b html ./ build/ -v
+export PATH="/opt/homebrew/opt/llvm@14/bin:$PATH"

src/backend/arm_backend/arm_backend.py

@@ -13,9 +13,10 @@
 class ArmBackend(Backend):
     timing_func = """
 static inline unsigned long long read_cycle_count() {
-    unsigned long long val;
-    asm volatile("mrs %0, PMCCNTR_EL0" : "=r" (val));
-    return val;
+    struct timespec time;
+    clock_gettime(CLOCK_MONOTONIC, &time);
+    unsigned long long nanoTime = time.tv_sec * 1000000000L + time.tv_nsec;
+    return nanoTime;
 }
 """    
 

src/backend/generate_executable.py

@@ -427,7 +427,9 @@ def generate_executable(input_file, input_folder, function_name, hex_values_file
 
     # This must be included in we want to run flexpret backend (for printf)
     if include_flexpret:
-        original_c_content = "#include <flexpret.h> \n" + original_c_content
+        original_c_content = "#include <flexpret.h> \n" +  original_c_content
+    else:
+        original_c_content = "#include <time.h> \n" +  original_c_content
 
     #TODO: generate global variables, add the global timing function
     original_c_content += timing_function_body