From 3dbcd6017f821edfe67fabc02120696704885ec3 Mon Sep 17 00:00:00 2001
From: "Nicholas H.Tollervey" <ntoll@ntoll.org>
Date: Thu, 11 May 2017 14:21:32 +0100
Subject: [PATCH] Convert to Python3. Use PEP8 naming conventions and
 formatting.

---
 utils/uf2conv.py | 108 ++++++++++++++++++++++++++---------------------
 1 file changed, 60 insertions(+), 48 deletions(-)

diff --git a/utils/uf2conv.py b/utils/uf2conv.py
index 3828284..8dadc09 100755
--- a/utils/uf2conv.py
+++ b/utils/uf2conv.py
@@ -1,5 +1,4 @@
-#!/usr/bin/python
-
+#!/usr/bin/env python3
 import sys
 import struct
 import subprocess
@@ -8,6 +7,7 @@
 import os.path
 import argparse
 
+
 UF2_MAGIC_START0 = 0x0A324655 # "UF2\n"
 UF2_MAGIC_START1 = 0x9E5D5157 # Randomly selected
 UF2_MAGIC_END    = 0x0AB16F30 # Ditto
@@ -16,20 +16,22 @@
 
 appstartaddr = 0x2000
 
-def isUF2(buf):
+
+def is_uf2(buf):
     w = struct.unpack("<II", buf[0:8])
     return w[0] == UF2_MAGIC_START0 and w[1] == UF2_MAGIC_START1
 
-def convertFromUF2(buf):
-    numblocks = len(buf) / 512
+
+def convert_from_uf2(buf):
+    numblocks = len(buf) // 512
     curraddr = None
-    outp = ""
-    for blockno in range(0, numblocks):
+    outp = b""
+    for blockno in range(numblocks):
         ptr = blockno * 512
         block = buf[ptr:ptr + 512]
-        hd = struct.unpack("<IIIIIIII", block[0:32])
+        hd = struct.unpack(b"<IIIIIIII", block[0:32])
         if hd[0] != UF2_MAGIC_START0 or hd[1] != UF2_MAGIC_START1:
-            print "Skipping block at " + ptr + "; bad magic"
+            print("Skipping block at " + ptr + "; bad magic")
             continue
         if hd[2] & 1:
             # NO-flash flag set; skip block
@@ -50,34 +52,38 @@ def convertFromUF2(buf):
             assert False, "Non-word padding size at " + ptr
         while padding > 0:
             padding -= 4
-            outp += "\x00\x00\x00\x00"
+            outp += b"\x00\x00\x00\x00"
         outp += block[32 : 32 + datalen]
         curraddr = newaddr + datalen
     return outp
 
-def convertToUF2(fileContent):
-    datapadding = ""
+
+def convert_to_uf2(file_content):
+    datapadding = b""
     while len(datapadding) < 512 - 256 - 32 - 4:
-        datapadding += "\x00\x00\x00\x00"
-    numblocks = (len(fileContent) + 255) / 256
-    outp = ""
-    for blockno in range(0, numblocks):
+        datapadding += b"\x00\x00\x00\x00"
+    numblocks = (len(file_content) + 255) // 256
+    outp = b""
+    for blockno in range(numblocks):
         ptr = 256 * blockno
-        chunk = fileContent[ptr:ptr + 256]
-        hd = struct.pack("<IIIIIIII",  
+        chunk = file_content[ptr:ptr + 256]
+        hd = struct.pack(b"<IIIIIIII",  
             UF2_MAGIC_START0, UF2_MAGIC_START1, 
             0, ptr + appstartaddr, 256, blockno, numblocks, 0)
         while len(chunk) < 256:
-            chunk += "\x00"
-        block = hd + chunk + datapadding + struct.pack("<I", UF2_MAGIC_END)
+            chunk += b"\x00"
+        block = hd + chunk + datapadding + struct.pack(b"<I", UF2_MAGIC_END)
         assert len(block) == 512
         outp += block
     return outp
 
-def getdrives():
+
+def get_drives():
     drives = []
     if sys.platform == "win32":
-        r = subprocess.check_output(["wmic", "PATH", "Win32_LogicalDisk", "get", "DeviceID,", "VolumeName,", "FileSystem,", "DriveType"])
+        r = subprocess.check_output(["wmic", "PATH", "Win32_LogicalDisk",
+                                     "get", "DeviceID,", "VolumeName,",
+                                     "FileSystem,", "DriveType"])
         for line in r.split('\n'):
             words = re.split('\s+', line)
             if len(words) >= 3 and words[1] == "2" and words[2] == "FAT":
@@ -92,33 +98,38 @@ def getdrives():
                 rootpath = tmp
         for d in os.listdir(rootpath):
             drives.append(os.path.join(rootpath, d))
-    
+
+
     def hasInfo(d):
         try:
             return os.path.isfile(d + INFO_FILE)
         except:
             return False
     
-    return filter(hasInfo, drives)
+    return list(filter(hasInfo, drives))
 
-def boardID(path):
+
+def board_id(path):
     with open(path + INFO_FILE, mode='r') as file:
-        fileContent = file.read()
-    return re.search("Board-ID: ([^\r\n]*)", fileContent).group(1)
- 
-def listdrives():
-    for d in getdrives():
-        print d, boardID(d)
-
-def writeFile(name, buf):
+        file_content = file.read()
+    return re.search("Board-ID: ([^\r\n]*)", file_content).group(1)
+
+
+def list_drives():
+    for d in get_drives():
+        print(d, boardID(d))
+
+
+def write_file(name, buf):
     with open(name, "wb") as f:
         f.write(buf)
-    print "Wrote %d bytes to %s." % (len(buf), name)
+    print("Wrote %d bytes to %s." % (len(buf), name))
+
 
 def main():
     global appstartaddr
     def error(msg):
-        print msg
+        print(msg)
         sys.exit(1)
     parser = argparse.ArgumentParser(description='Convert to UF2 or flash directly.')
     parser.add_argument('input', metavar='INPUT', type=str, nargs='?', 
@@ -137,36 +148,37 @@ def error(msg):
     args = parser.parse_args()
     appstartaddr = int(args.base, 0)
     if args.list:
-        listdrives()
+        list_drives()
     else:
         if not args.input:
             error("Need input file")
-        with open(args.input, mode='rb') as file:
-            inpbuf = file.read()
-        fromUF2 = isUF2(inpbuf)
+        with open(args.input, mode='rb') as f:
+            inpbuf = f.read()
+        from_uf2 = is_uf2(inpbuf)
         ext = "uf2"
-        if fromUF2:
-            outbuf = convertFromUF2(inpbuf)
+        if from_uf2:
+            outbuf = convert_from_uf2(inpbuf)
             ext = "bin"
         else:
-            outbuf = convertToUF2(inpbuf)
-        print "Converting to %s, output size: %d, start address: 0x%x" % (ext, len(outbuf), appstartaddr)
-
+            outbuf = convert_to_uf2(inpbuf)
+        print("Converting to %s, output size: %d, start address: 0x%x" %
+              (ext, len(outbuf), appstartaddr))
         if args.convert:
             drives = []
             if args.output == None:
                 args.output = "flash." + ext
         else:
-            drives = getdrives()
+            drives = get_drives()
         
         if args.output:
-            writeFile(args.output, outbuf)
+            write_file(args.output, outbuf)
         else:
             if len(drives) == 0:
                 error("No drive to deploy.")
         for d in drives:
-            print "Flashing %s (%s)" % (d, boardID(d))
-            writeFile(outbuf, d + "/NEW.UF2")
+            print("Flashing %s (%s)" % (d, boardID(d)))
+            write_file(outbuf, d + "/NEW.UF2")
+
 
 if __name__ == "__main__":
     main()