Update PlatformIO build scripts (#7200)

This update includes the following:

- Implemented an additional build step that produces an adjusted bootloader image with updated headers
  according to  selected flash mode and size values. This step is only executed for debugging or uploading
  via debug probes.

- Implemented a basic mechanism to dynamically add an extra UF2 bootloader image if corresponding
  partition is selected (e.g. for Adafruit targets)

- Minor code formatting

tools/platformio-build.py

@@ -24,7 +24,7 @@ http://arduino.cc/en/Reference/HomePage
 
 # Extends: https://github.com/platformio/platform-espressif32/blob/develop/builder/main.py
 
-from os.path import abspath, isdir, isfile, join
+from os.path import abspath, basename, isdir, isfile, join
 
 from SCons.Script import DefaultEnvironment, SConscript
 
@@ -32,6 +32,9 @@ env = DefaultEnvironment()
 platform = env.PioPlatform()
 board_config = env.BoardConfig()
 build_mcu = board_config.get("build.mcu", "").lower()
+partitions_name = board_config.get(
+    "build.partitions", board_config.get("build.arduino.partitions", "")
+)
 
 FRAMEWORK_DIR = platform.get_package_dir("framework-arduinoespressif32")
 assert isdir(FRAMEWORK_DIR)
@@ -41,25 +44,23 @@ assert isdir(FRAMEWORK_DIR)
 # Helpers
 #
 
+
 def get_partition_table_csv(variants_dir):
     fwpartitions_dir = join(FRAMEWORK_DIR, "tools", "partitions")
+    variant_partitions_dir = join(variants_dir, board_config.get("build.variant", ""))
 
-    custom_partition = board_config.get(
+    if partitions_name:
-        "build.partitions", board_config.get("build.arduino.partitions", "")
+        # A custom partitions file is selected
-    )
+        if isfile(join(variant_partitions_dir, partitions_name)):
+            return join(variant_partitions_dir, partitions_name)
 
-    if custom_partition:
-        partitions_csv = board_config.get("build.partitions", board_config.get(
-            "build.arduino.partitions", "default.csv"))
         return abspath(
-            join(fwpartitions_dir, partitions_csv)
+            join(fwpartitions_dir, partitions_name)
-            if isfile(join(fwpartitions_dir, partitions_csv))
+            if isfile(join(fwpartitions_dir, partitions_name))
-            else partitions_csv
+            else partitions_name
         )
 
-    variant_partitions = join(
+    variant_partitions = join(variant_partitions_dir, "partitions.csv")
-        variants_dir, board_config.get("build.variant", ""), "partitions.csv"
-    )
     return (
         variant_partitions
         if isfile(variant_partitions)
@@ -68,9 +69,16 @@ def get_partition_table_csv(variants_dir):
 
 
 def get_bootloader_image(variants_dir):
+    bootloader_image_file = "bootloader.bin"
+    if partitions_name.endswith("tinyuf2.csv"):
+        bootloader_image_file = "bootloader-tinyuf2.bin"
+
     variant_bootloader = join(
-        variants_dir, board_config.get("build.variant", ""), "bootloader.bin"
+        variants_dir,
+        board_config.get("build.variant", ""),
+        board_config.get("build.arduino.custom_bootloader", bootloader_image_file),
     )
+
     return (
         variant_bootloader
         if isfile(variant_bootloader)
@@ -85,6 +93,76 @@ def get_bootloader_image(variants_dir):
     )
 
 
+def get_patched_bootloader_image(original_bootloader_image, bootloader_offset):
+    patched_bootloader_image = join(env.subst("$BUILD_DIR"), "patched_bootloader.bin")
+    bootloader_cmd = env.Command(
+        patched_bootloader_image,
+        original_bootloader_image,
+        env.VerboseAction(
+            " ".join(
+                [
+                    '"$PYTHONEXE"',
+                    join(
+                        platform.get_package_dir("tool-esptoolpy") or "", "esptool.py"
+                    ),
+                    "--chip",
+                    build_mcu,
+                    "merge_bin",
+                    "-o",
+                    "$TARGET",
+                    "--flash_mode",
+                    "${__get_board_flash_mode(__env__)}",
+                    "--flash_size",
+                    board_config.get("upload.flash_size", "4MB"),
+                    "--target-offset",
+                    bootloader_offset,
+                    bootloader_offset,
+                    "$SOURCE",
+                ]
+            ),
+            "Updating bootloader headers",
+        ),
+    )
+    env.Depends("$BUILD_DIR/$PROGNAME$PROGSUFFIX", bootloader_cmd)
+
+    return patched_bootloader_image
+
+
+def add_tinyuf2_extra_image():
+    tinuf2_image = board_config.get(
+        "upload.arduino.tinyuf2_image",
+        join(variants_dir, board_config.get("build.variant", ""), "tinyuf2.bin"),
+    )
+
+    # Add the UF2 image only if it exists and it's not already added
+    if not isfile(tinuf2_image):
+        print("Warning! The `%s` UF2 bootloader image doesn't exist" % tinuf2_image)
+        return
+
+    if any(
+        "tinyuf2.bin" == basename(extra_image[1])
+        for extra_image in env.get("FLASH_EXTRA_IMAGES", [])
+    ):
+        print("Warning! An extra UF2 bootloader image is already added!")
+        return
+
+    env.Append(
+        FLASH_EXTRA_IMAGES=[
+            (
+                board_config.get(
+                    "upload.arduino.uf2_bootloader_offset",
+                    (
+                        "0x2d0000"
+                        if env.subst("$BOARD").startswith("adafruit")
+                        else "0x410000"
+                    ),
+                ),
+                tinuf2_image,
+            ),
+        ]
+    )
+
+
 #
 # Run target-specific script to populate the environment with proper build flags
 #
@@ -99,32 +177,6 @@ SConscript(
     )
 )
 
-#
-# Process framework extra images
-#
-
-env.Append(
-    LIBSOURCE_DIRS=[
-        join(FRAMEWORK_DIR, "libraries")
-    ],
-
-    FLASH_EXTRA_IMAGES=[
-        (
-            "0x1000" if build_mcu in ("esp32", "esp32s2") else "0x0000",
-            get_bootloader_image(board_config.get(
-                "build.variants_dir", join(FRAMEWORK_DIR, "variants")))
-        ),
-        ("0x8000", join(env.subst("$BUILD_DIR"), "partitions.bin")),
-        ("0xe000", join(FRAMEWORK_DIR, "tools", "partitions", "boot_app0.bin"))
-    ]
-    + [
-        (offset, join(FRAMEWORK_DIR, img))
-        for offset, img in board_config.get(
-            "upload.arduino.flash_extra_images", []
-        )
-    ],
-)
-
 #
 # Target: Build Core Library
 #
@@ -137,23 +189,68 @@ if "build.variants_dir" in board_config:
     variants_dir = join("$PROJECT_DIR", board_config.get("build.variants_dir"))
 
 if "build.variant" in board_config:
-    env.Append(
+    env.Append(CPPPATH=[join(variants_dir, board_config.get("build.variant"))])
-        CPPPATH=[
-            join(variants_dir, board_config.get("build.variant"))
-        ]
-    )
     env.BuildSources(
         join("$BUILD_DIR", "FrameworkArduinoVariant"),
-        join(variants_dir, board_config.get("build.variant"))
+        join(variants_dir, board_config.get("build.variant")),
     )
 
-libs.append(env.BuildLibrary(
+libs.append(
+    env.BuildLibrary(
         join("$BUILD_DIR", "FrameworkArduino"),
-    join(FRAMEWORK_DIR, "cores", board_config.get("build.core"))
+        join(FRAMEWORK_DIR, "cores", board_config.get("build.core")),
-))
+    )
+)
 
 env.Prepend(LIBS=libs)
 
+#
+# Process framework extra images
+#
+
+# Starting with v2.0.4 the Arduino core contains updated bootloader images that have
+# innacurate default headers. This results in bootloops if firmware is flashed via
+# OpenOCD (e.g. debugging or uploading via debug tools). For this reason, before
+# uploading or debugging we need to adjust the bootloader binary according to
+# the values of the --flash-size and --flash-mode arguments.
+# Note: This behavior doesn't occur if uploading is done via esptoolpy, as esptoolpy
+# overrides the binary image headers before flashing.
+
+bootloader_patch_required = bool(
+    env.get("PIOFRAMEWORK", []) == ["arduino"]
+    and (
+        "debug" in env.GetBuildType()
+        or env.subst("$UPLOAD_PROTOCOL") in board_config.get("debug.tools", {})
+        or env.IsIntegrationDump()
+    )
+)
+
+bootloader_image_path = get_bootloader_image(variants_dir)
+bootloader_offset = "0x1000" if build_mcu in ("esp32", "esp32s2") else "0x0000"
+if bootloader_patch_required:
+    bootloader_image_path = get_patched_bootloader_image(
+        bootloader_image_path, bootloader_offset
+    )
+
+env.Append(
+    LIBSOURCE_DIRS=[join(FRAMEWORK_DIR, "libraries")],
+    FLASH_EXTRA_IMAGES=[
+        (bootloader_offset, bootloader_image_path),
+        ("0x8000", join(env.subst("$BUILD_DIR"), "partitions.bin")),
+        ("0xe000", join(FRAMEWORK_DIR, "tools", "partitions", "boot_app0.bin")),
+    ]
+    + [
+        (offset, join(FRAMEWORK_DIR, img))
+        for offset, img in board_config.get("upload.arduino.flash_extra_images", [])
+    ],
+)
+
+# Add an extra UF2 image if the 'TinyUF2' partition is selected
+if partitions_name.endswith("tinyuf2.csv") or board_config.get(
+    "upload.arduino.tinyuf2_image", ""
+):
+    add_tinyuf2_extra_image()
+
 #
 # Generate partition table
 #