STM32 profiler using openocd

ocd_sampler.py

#!/usr/bin/python3

# original https://gist.github.com/ynsta/7df418cb27b908391f86, adapted for python3

# 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,16)

        return 0


    def initSymbols(self, elf, readelf='arm-none-eabi-readelf'):
        proc = subprocess.Popen([readelf, '-s', elf], stdout=subprocess.PIPE)
        for line in iter(proc.stdout.readline, b''):
            field = line.decode('ascii').split()
            try:
                if field[3] == 'FUNC':
                    addr = int(field[1], 16)
                    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 = { }
    start = time.time()

    try:
        while True:
            func, addr = sampler.func((sampler.getpc()))

            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))
                start = cur
                print ()

    except KeyboardInterrupt:
        pass