feat: Support uploading hex file

Naive implementation, assuming the addresses start at 0 and increment.

pyproject.toml

@@ -31,6 +31,9 @@ classifiers = [
 dynamic = ["version"]
 
 [project.optional-dependencies]
+hex = [
+    "intelhex",
+]
 dev = [
     "wheel",
     "twine",

stm32loader/bootloader.py

@@ -101,6 +101,10 @@ class DataMismatchError(Stm32LoaderError):
     """Exception: data comparison failed."""
 
 
+class MissingDependencyError(Stm32LoaderError):
+    """Exception: required dependency is missing."""
+
+
 class ShowProgress:
     """
     Show progress through a progress bar, as a context manager.

stm32loader/hexfile.py

@@ -0,0 +1,30 @@
+"""Load binary data from a file in Intel hex format."""
+
+from stm32loader.bootloader import MissingDependencyError
+
+try:
+    import intelhex
+except ImportError:
+    intelhex = None
+
+
+def load_hex(file_path: str) -> bytes:
+    """
+    Return bytes from the given hex file.
+
+    Addresses should start at zero and always increment.
+    """
+    if intelhex is None:
+        raise MissingDependencyError(
+            "Please install package 'intelhex' in order to read .hex files."
+        )
+
+    hex_content = intelhex.IntelHex()
+    hex_content.loadhex(str(file_path))
+    hex_dict = hex_content.todict()
+
+    addresses = list(hex_dict.keys())
+    assert addresses[0] == 0
+    assert addresses[-1] == len(addresses) - 1
+
+    return bytes(hex_content.todict().values())

stm32loader/main.py

@@ -27,6 +27,7 @@
 import os
 import sys
 from types import SimpleNamespace
+from pathlib import Path
 
 try:
     from progress.bar import ChargingBar as progress_bar
@@ -35,6 +36,7 @@
 
 from stm32loader import __version__, bootloader
 from stm32loader.uart import SerialConnection
+from stm32loader.hexfile import load_hex
 
 DEFAULT_VERBOSITY = 5
 
@@ -323,8 +325,11 @@ def perform_commands(self):
         # pylint: disable=too-many-branches
         binary_data = None
         if self.configuration.write or self.configuration.verify:
-            with open(self.configuration.data_file, "rb") as read_file:
-                binary_data = bytearray(read_file.read())
+            data_file_path = Path(self.configuration.data_file)
+            if data_file_path.suffix == ".hex":
+                binary_data = load_hex(data_file_path)
+            else:
+                binary_data = data_file_path.read_bytes()
         if self.configuration.unprotect:
             try:
                 self.stm32.readout_unprotect()

tests/data/small.hex

@@ -0,0 +1,2 @@
+:10000000000102030405060708090A0B0C0D0E0F78
+:00000001FF

tests/unit/test_hexfile.py

@@ -0,0 +1,14 @@
+
+from pathlib import Path
+
+HERE = Path(__file__).parent
+DATA = HERE / "../data"
+
+
+from stm32loader.hexfile import load_hex
+
+
+def test_load_hex_delivers_bytes():
+    small_hex_path = DATA / "small.hex"
+    data = load_hex(small_hex_path)
+    assert data == bytes(range(16))