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How could I graphically display the memory layout from a .map file?

Posted by: admin November 30, 2017 Leave a comment


My gcc build toolchain produces a .map file. How do I display the memory map graphically?


Here’s the beginnings of a script in Python. It loads the map file into a list of Sections and Symbols (first half). It then renders the map using HTML (or do whatever you want with the sections and symbols lists).

You can control the script by modifying these lines:

with open('t.map') as f:
colors = ['9C9F84', 'A97D5D', 'F7DCB4', '5C755E']
total_height = 32.0


from __future__ import with_statement
import re

class Section:
    def __init__(self, address, size, segment, section):
        self.address = address
        self.size = size
        self.segment = segment
        self.section = section
    def __str__(self):
        return self.section+""

class Symbol:
    def __init__(self, address, size, file, name):
        self.address = address
        self.size = size
        self.file = file
        self.name = name
    def __str__(self):
        return self.name

# Load the Sections and Symbols
sections = []
symbols = []

with open('t.map') as f:
    in_sections = True
    for line in f:
        m = re.search('^([0-9A-Fx]+)\s+([0-9A-Fx]+)\s+((\[[ 0-9]+\])|\w+)\s+(.*?)\s*$', line)
        if m:
            if in_sections:
                sections.append(Section(eval(m.group(1)), eval(m.group(2)), m.group(3), m.group(5)))
                symbols.append(Symbol(eval(m.group(1)), eval(m.group(2)), m.group(3), m.group(5)))
            if len(sections) > 0:
                in_sections = False

# Gererate the HTML File

colors = ['9C9F84', 'A97D5D', 'F7DCB4', '5C755E']
total_height = 32.0

segments = set()
for s in sections: segments.add(s.segment)
segment_colors = dict()
i = 0
for s in segments:
    segment_colors[s] = colors[i % len(colors)]
    i += 1

total_size = 0
for s in symbols:
    total_size += s.size

sections.sort(lambda a,b: a.address - b.address)
symbols.sort(lambda a,b: a.address - b.address)

def section_from_address(addr):
    for s in sections:
        if addr >= s.address and addr < (s.address + s.size):
            return s
    return None

print "<html><head>"
print "  <style>a { color: black; text-decoration: none; font-family:monospace }</style>"
print "<body>"
print "<table cellspacing='1px'>"
for sym in symbols:
    section = section_from_address(sym.address)
    height = (total_height/total_size) * sym.size
    font_size = 1.0 if height > 1.0 else height
    print "<tr style='background-color:#%s;height:%gem;line-height:%gem;font-size:%gem'><td style='overflow:hidden'>" % \
        (segment_colors[section.segment], height, height, font_size)
    print "<a href='#%s'>%s</a>" % (sym.name, sym.name)
    print "</td></tr>"
print "</table>"
print "</body></html>"

And here’s a bad rendering of the HTML it outputs:



I’ve written a C# program to display the information in a Map file along with information not usually present in the map file (like static symbols provided you can use binutils). The code is available here. In short it parses the map file and also uses BINUTILS (if available) to gather more information. To run it you need to download the code and run the project under visual studio, browse to the map file path and click Analyze.

Note: Only works for GCC/LD map files