diff --git a/hex_free_size.py b/hex_free_size.py
new file mode 100644
index 0000000..cde49c9
--- /dev/null
+++ b/hex_free_size.py
@@ -0,0 +1,39 @@
+#-------------------------------------------------------------------------------
+# hex_free_space
+# 02/05/2022
+# tool script used to estimate the free space left in a µP based on the number
+# of 0xFF bytes in the hex file. This methode only works for filled hex files.
+#
+# usage ex: python hex_free_size somehexfile.hex somemorehexfile.hex
+#-------------------------------------------------------------------------------
+
+import fileinput
+import re
+
+free_space = 0
+free_threshold = 16
+
+p = re.compile(r':[0-9A-F]{8,8}([0-9A-F]{32,32})')
+for line in fileinput.input():
+    val = re.search(p, line)
+    if val:
+        data = val.group(0)
+        count = 0
+        for char in data:
+            if char == 'F':
+                count += 1
+        if count <= free_threshold:
+            continue
+
+        for char in data:
+            if char == 'F':
+                if first:
+                    first = False
+                else:
+                    first = True
+                    free_space += 1
+            else:
+                first = True
+
+print("estimated free space: " + str(free_space))
+
diff --git a/lst_diff.py b/lst_diff.py
new file mode 100644
index 0000000..2b8420b
--- /dev/null
+++ b/lst_diff.py
@@ -0,0 +1,49 @@
+#-------------------------------------------------------------------------------
+# lst_diff
+# 22/03/2022
+# tool script used to summarize the code size of a list of .lst, which display
+# the size of segment CODE in their last lines
+#
+# usage ex: find lst_folder -name *.lst | python lst_diff.py > output.txt
+# the output can then be compared using diff
+#-------------------------------------------------------------------------------
+
+import fileinput
+import re
+
+code_size = 0
+
+p_code = re.compile("CODE")
+# list of input lst files
+for lst_file in fileinput.input():
+    
+    lst = lst_file.rstrip('\n')
+    i = 0
+    buff = []
+
+    # get 3 lines containing code size infos
+    for line in reversed(list(open(lst, encoding="latin-1"))):
+        i += 1
+        if i > 3 and i < 7:
+            buff.append(line)
+        elif i >= 7:
+            break
+
+    #parse lines
+    for line in buff:
+        if re.search(p_code, line):
+            toks = line.split()
+            size = 0
+            try:
+                size += int(toks[1])
+            except:
+                pass
+            if size != 0:
+                size += 1000 * int(toks[0])
+            else:
+                size += int(toks[0])
+            code_size += size 
+            print(lst.split('/').pop() + ": " + str(size))
+
+print("total: " + str(code_size))
+
diff --git a/map_diff.py b/map_diff.py
new file mode 100644
index 0000000..8ea5707
--- /dev/null
+++ b/map_diff.py
@@ -0,0 +1,32 @@
+#-------------------------------------------------------------------------------
+# map_diff
+# 22/03/2022
+# tool script used to easily compare diffs of (IAR) .map files
+#
+# usage ex: diff -hu file1.map file2.map | python map_diff.py
+#-------------------------------------------------------------------------------
+
+import fileinput
+import re
+
+old_size = 0x0
+new_size = 0x0
+prev_line = ""
+total_diff = 0
+
+p = re.compile('0x\w+ ')
+for line in fileinput.input():
+    val = re.search(p, line)
+    if val:
+        if line[0] == '-':
+            old_size = int(val.group(0), base=16)
+            prev_line = line
+        else:
+            new_size = int(val.group(0), base=16)
+            if new_size != old_size:
+                diff = new_size-old_size
+                total_diff += diff
+                print(prev_line + line + "diff: " + str(diff))
+
+print("total diff: " + str(total_diff))
+
diff --git a/utils.py b/utils.py
new file mode 100644
index 0000000..ec51774
--- /dev/null
+++ b/utils.py
@@ -0,0 +1,6 @@
+def twos_complement(hexstr,bits):
+    value = int(hexstr,16)
+    if value & (1 << (bits-1)):
+        value -= 1 << bits
+    return value
+