add the pc sampling profiler script

Firmware/sampler.py

@@ -0,0 +1,124 @@
+#!/usr/bin/python2
+
+# run openocd (0.9.0) with :
+# $ openocd -f stlink-v2-1.cfg -f stm32f4x.cfg &> /dev/null"
+# then run
+# $ python2 sampler.py path_to_myelf_with_symbols
+
+import sys
+import time
+import telnetlib
+import subprocess
+from bisect import bisect_right
+import operator
+
+class OpenOCDCMSampler(object):
+
+    def __init__(self, host='localhost', port=4444):
+
+        self.net = telnetlib.Telnet(host, port)
+        self.net.read_very_eager()
+
+        self.table = []
+        self.indexes = set()
+
+    def __del__(self):
+        self.net.write(b'exit\r\n')
+        self.net.read_until(b'exit\r\n', 1)
+        self.net.close()
+
+    def getpc(self):
+
+        self.net.write(b'mrw 0xE000101C\r\n')
+        res = self.net.read_until(b'\r\n\r> ', 1)
+
+        if res:
+            prefix = res[0:16]
+            num    = res[16:-5]
+            res    = res[-15:0]
+
+            if prefix == b'mrw 0xE000101C\r\n':
+                return int(num)
+
+        return 0
+
+
+    def initSymbols(self, elf, readelf='arm-none-eabi-readelf'):
+        proc = subprocess.Popen([readelf, '-s', elf], stdout=subprocess.PIPE)
+        for line in proc.stdout.readlines():
+            field = line.split()
+            # for i,txt in enumerate(field):
+            #     print("{}, {}".format(i, txt))
+            try:
+                if field[3] == b'FUNC':
+                    addr = int(field[1], 16) - 1 # For some reason readelf dumps the func addr off by 1
+                    func = field[7]
+                    size = int(field[2])
+                    if addr not in self.indexes:
+                        self.table.append((addr, func, size))
+                        self.indexes.add(addr)
+            except IndexError:
+                pass
+
+        self.table.sort()
+        self.addrs = [ x for (x, y, z) in self.table ]
+
+
+    def func(self, pc):
+
+        if pc == 0 or pc == 0xFFFFFFFF:
+            return ('', 0)
+
+        i = bisect_right(self.addrs, pc)
+        if i:
+            addr, symb, size = self.table[i-1]
+            if pc >= addr and pc <= addr + size:
+                return (symb, addr)
+
+        return ('', 0)
+
+
+if __name__ == '__main__':
+
+    sampler = OpenOCDCMSampler('localhost', 4444)
+    sampler.initSymbols(sys.argv[1])
+
+    total = 0
+    countmap = { }
+    pcmap = { }
+    start = time.time()
+
+    try:
+        while True:
+            pc = sampler.getpc()
+
+            if pc in pcmap:
+                pcmap[pc] += 1
+            else:
+                pcmap[pc] = 1
+
+            func, addr = sampler.func(pc)
+
+            if not addr:
+                continue
+
+            if func in countmap:
+                countmap[func] += 1
+                total += 1
+            else:
+                countmap[func] = 1
+                total += 1
+
+            cur = time.time()
+            if cur - start > 1.0:
+                tmp = sorted(countmap.items(), key=operator.itemgetter(1), reverse=True)
+                for k, v in tmp:
+                    # print('{:05.2f}% {}'.format((v * 100.) / total, k))
+                    print('{:06.2f} clocks : {}'.format((v * 8192) / total, k))
+                start = cur
+                print('{} Samples'.format(total))
+                print('')
+
+    except KeyboardInterrupt:
+        pcmap = sorted(pcmap.items(), key=operator.itemgetter(1), reverse=True)
+        pcmap = [(hex(addr), count) for addr, count in pcmap]