circuitpython/ports/esp8266/makeimg.py
2023-02-02 12:51:03 +11:00

54 lines
1.7 KiB
Python

import sys
import struct
import hashlib
# This region at the start of flash contains a small header and then segments
# containing .text, .data and .rodata, and so must be large enough to hold all
# of this. This data is loaded to the appropriate places in RAM by the ROM
# bootloader at boot. After this in flash comes .irom0.text, which must begin
# on a flash erase-page boundary.
SEGS_MAX_SIZE = 0x9000
assert len(sys.argv) == 4
md5 = hashlib.md5()
with open(sys.argv[3], "wb") as fout:
with open(sys.argv[1], "rb") as f:
data_flash = f.read()
fout.write(data_flash)
# First 4 bytes include flash size, etc. which may be changed
# by esptool.py, etc.
md5.update(data_flash[4:])
print("flash ", len(data_flash))
# Print info about segments in this first part of flash
num_segs = struct.unpack_from("<BBBBI", data_flash, 0)[1]
offset = 8
for seg_num in range(num_segs):
seg_name = [".text", ".data", ".rodata"][seg_num]
seg_offset, seg_size = struct.unpack_from("<II", data_flash, offset)
print(" {:7} {} at 0x{:x}".format(seg_name, seg_size, seg_offset))
offset += 8 + seg_size
with open(sys.argv[2], "rb") as f:
data_rom = f.read()
pad = b"\xff" * (SEGS_MAX_SIZE - len(data_flash))
assert len(pad) >= 4
fout.write(pad[:-4])
md5.update(pad[:-4])
len_data = struct.pack("I", SEGS_MAX_SIZE + len(data_rom))
fout.write(len_data)
md5.update(len_data)
print("padding ", len(pad))
fout.write(data_rom)
md5.update(data_rom)
print("irom0text", len(data_rom))
fout.write(md5.digest())
print("total ", SEGS_MAX_SIZE + len(data_rom))
print("md5 ", md5.hexdigest())