#!/usr/bin/env python3

# Microsoft UF2
#
# The MIT License (MIT)
#
# Copyright (c) Microsoft Corporation
#
# All rights reserved.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import sys
import struct
import subprocess
import re
import os
import os.path
import argparse


UF2_MAGIC_START0 = 0x0A324655 # "UF2\n"
UF2_MAGIC_START1 = 0x9E5D5157 # Randomly selected
UF2_MAGIC_END = 0x0AB16F30 # Ditto

families = {
 "SAMD21": 0x68ED2B88,
 "SAMD51": 0x55114460,
 "NRF52": 0x1B57745F,
 "STM32F1": 0x5EE21072,
 "STM32F4": 0x57755A57,
 "ATMEGA32": 0x16573617,
}

INFO_FILE = "/INFO_UF2.TXT"

appstartaddr = 0x2000
familyid = 0x0


def is_uf2(buf):
 w = struct.unpack("<II", buf[0:8])
 return w[0] == UF2_MAGIC_START0 and w[1] == UF2_MAGIC_START1


def is_hex(buf):
 try:
 w = buf[0:30].decode("utf-8")
 except UnicodeDecodeError:
 return False
 if w[0] == ":" and re.match(b"^[:0-9a-fA-F\r\n]+$", buf):
 return True
 return False


def convert_from_uf2(buf):
 global appstartaddr
 numblocks = len(buf) // 512
 curraddr = None
 outp = b""
 for blockno in range(numblocks):
 ptr = blockno * 512
 block = buf[ptr : ptr + 512]
 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")
 continue
 if hd[2] & 1:
 # NO-flash flag set; skip block
 continue
 datalen = hd[4]
 if datalen > 476:
 assert False, "Invalid UF2 data size at " + ptr
 newaddr = hd[3]
 if curraddr == None:
 appstartaddr = newaddr
 curraddr = newaddr
 padding = newaddr - curraddr
 if padding < 0:
 assert False, "Block out of order at " + ptr
 if padding > 10 * 1024 * 1024:
 assert False, "More than 10M of padding needed at " + ptr
 if padding % 4 != 0:
 assert False, "Non-word padding size at " + ptr
 while padding > 0:
 padding -= 4
 outp += b"\x00\x00\x00\x00"
 outp += block[32 : 32 + datalen]
 curraddr = newaddr + datalen
 return outp


def convert_to_carray(file_content):
 outp = "const unsigned char bindata[] __attribute__((aligned(16))) = {"
 for i in range(len(file_content)):
 if i % 16 == 0:
 outp += "\n"
 outp += "0x%02x, " % ord(file_content[i])
 outp += "\n};\n"
 return outp


def convert_to_uf2(file_content):
 global familyid
 datapadding = b""
 while len(datapadding) < 512 - 256 - 32 - 4:
 datapadding += b"\x00\x00\x00\x00"
 numblocks = (len(file_content) + 255) // 256
 outp = b""
 for blockno in range(numblocks):
 ptr = 256 * blockno
 chunk = file_content[ptr : ptr + 256]
 flags = 0x0
 if familyid:
 flags |= 0x2000
 hd = struct.pack(
 b"<IIIIIIII",
 UF2_MAGIC_START0,
 UF2_MAGIC_START1,
 flags,
 ptr + appstartaddr,
 256,
 blockno,
 numblocks,
 familyid,
 )
 while len(chunk) < 256:
 chunk += b"\x00"
 block = hd + chunk + datapadding + struct.pack(b"<I", UF2_MAGIC_END)
 assert len(block) == 512
 outp += block
 return outp


class Block:
 def __init__(self, addr):
 self.addr = addr
 self.bytes = bytearray(256)

 def encode(self, blockno, numblocks):
 global familyid
 flags = 0x0
 if familyid:
 flags |= 0x2000
 hd = struct.pack(
 "<IIIIIIII",
 UF2_MAGIC_START0,
 UF2_MAGIC_START1,
 flags,
 self.addr,
 256,
 blockno,
 numblocks,
 familyid,
 )
 hd += self.bytes[0:256]
 while len(hd) < 512 - 4:
 hd += b"\x00"
 hd += struct.pack("<I", UF2_MAGIC_END)
 return hd


def convert_from_hex_to_uf2(buf):
 global appstartaddr
 appstartaddr = None
 upper = 0
 currblock = None
 blocks = []
 for line in buf.split("\n"):
 if line[0] != ":":
 continue
 i = 1
 rec = []
 while i < len(line) - 1:
 rec.append(int(line[i : i + 2], 16))
 i += 2
 tp = rec[3]
 if tp == 4:
 upper = ((rec[4] << 8) | rec[5]) << 16
 elif tp == 2:
 upper = ((rec[4] << 8) | rec[5]) << 4
 assert (upper & 0xFFFF) == 0
 elif tp == 1:
 break
 elif tp == 0:
 addr = upper | (rec[1] << 8) | rec[2]
 if appstartaddr == None:
 appstartaddr = addr
 i = 4
 while i < len(rec) - 1:
 if not currblock or currblock.addr & ~0xFF != addr & ~0xFF:
 currblock = Block(addr & ~0xFF)
 blocks.append(currblock)
 currblock.bytes[addr & 0xFF] = rec[i]
 addr += 1
 i += 1
 numblocks = len(blocks)
 resfile = b""
 for i in range(0, numblocks):
 resfile += blocks[i].encode(i, numblocks)
 return resfile


def get_drives():
 drives = []
 if sys.platform == "win32":
 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":
 drives.append(words[0])
 else:
 rootpath = "/media"
 if sys.platform == "darwin":
 rootpath = "/Volumes"
 elif sys.platform == "linux":
 tmp = rootpath + "/" + os.environ["USER"]
 if os.path.isdir(tmp):
 rootpath = tmp
 for d in os.listdir(rootpath):
 drives.append(os.path.join(rootpath, d))

 def has_info(d):
 try:
 return os.path.isfile(d + INFO_FILE)
 except:
 return False

 return list(filter(has_info, drives))


def board_id(path):
 with open(path + INFO_FILE, mode="r") as file:
 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, board_id(d))


def write_file(name, buf):
 with open(name, "wb") as f:
 f.write(buf)
 print("Wrote %d bytes to %s." % (len(buf), name))


def main():
 global appstartaddr, familyid

 def error(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="?", help="input file (HEX, BIN or UF2)"
 )
 parser.add_argument(
 "-b",
 "--base",
 dest="base",
 type=str,
 default="0x2000",
 help="set base address of application for BIN format (default: 0x2000)",
 )
 parser.add_argument(
 "-o",
 "--output",
 metavar="FILE",
 dest="output",
 type=str,
 help='write output to named file; defaults to "flash.uf2" or "flash.bin" where sensible',
 )
 parser.add_argument("-d", "--device", dest="device_path", help="select a device path to flash")
 parser.add_argument("-l", "--list", action="store_true", help="list connected devices")
 parser.add_argument("-c", "--convert", action="store_true", help="do not flash, just convert")
 parser.add_argument(
 "-f",
 "--family",
 dest="family",
 type=str,
 default="0x0",
 help="specify familyID - number or name (default: 0x0)",
 )
 parser.add_argument(
 "-C", "--carray", action="store_true", help="convert binary file to a C array, not UF2"
 )
 args = parser.parse_args()
 appstartaddr = int(args.base, 0)

 if args.family.upper() in families:
 familyid = families[args.family.upper()]
 else:
 try:
 familyid = int(args.family, 0)
 except ValueError:
 error("Family ID needs to be a number or one of: " + ", ".join(families.keys()))

 if args.list:
 list_drives()
 else:
 if not args.input:
 error("Need input file")
 with open(args.input, mode="rb") as f:
 inpbuf = f.read()
 from_uf2 = is_uf2(inpbuf)
 ext = "uf2"
 if from_uf2:
 outbuf = convert_from_uf2(inpbuf)
 ext = "bin"
 elif is_hex(inpbuf):
 outbuf = convert_from_hex_to_uf2(inpbuf.decode("utf-8"))
 elif args.carray:
 outbuf = convert_to_carray(inpbuf)
 ext = "h"
 else:
 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 = get_drives()

 if args.output:
 write_file(args.output, outbuf)
 else:
 if len(drives) == 0:
 error("No drive to deploy.")
 for d in drives:
 print("Flashing %s (%s)" % (d, board_id(d)))
 write_file(d + "/NEW.UF2", outbuf)


if __name__ == "__main__":
 main()