fix(daplink_bridge): Address review on portability and venv staleness.

Three issues raised on PR #387:

1. Toolchain download was hard-coded to x86_64-linux. Detect uname and pick
   the matching ARM-published archive (Linux x86_64, Linux aarch64, Intel
   macOS). Fail with a clear message — and a pointer to the dev container —
   on Apple Silicon and Windows, where 10.3-2021.10 is not published.

2. Deprecated `deploy-pyocd` / `deploy-openocd` advertised non-existent
   `daplink-deploy-pyocd` / `daplink-deploy-openocd` targets. Suggest only
   the `micropython-` variant until the SWD-based DAPLink targets land
   (tracked in #388).

3. The DAPLink venv was created once and never refreshed, so a
   `daplink-update` that bumped requirements.txt would silently reuse stale
   dependencies. Replace the manual check with a sentinel file that depends
   on requirements.txt, so pip install re-runs whenever upstream bumps a dep.

Also document the platform constraint in CONTRIBUTING.md.

Author: nedseb

CONTRIBUTING.md

@@ -119,8 +119,9 @@ For local development (without dev container):
 
 * Python 3.10+
 * Node.js 22+ (for husky, commitlint, lint-staged, semantic-release)
-* `arm-none-eabi-gcc` toolchain (for `make micropython-firmware` and `make daplink-firmware`)
+* `arm-none-eabi-gcc` toolchain (for `make micropython-firmware`; `make daplink-firmware` ignores the system toolchain and downloads its own pinned 10.3-2021.10 build)
 * `ccache` and `ninja-build` (for `make daplink-firmware`)
+* For `make daplink-firmware`: Linux x86_64, Linux aarch64, or Intel macOS only (the pinned toolchain is not published for Apple Silicon or Windows — use the dev container on those platforms)
 * `pyocd` (for `make micropython-deploy`, installed via `pip install -e ".[flash]"`)
 * OpenOCD (optional, for `make micropython-deploy-openocd`)
 * `mpremote` (installed via `pip install -e ".[test]"`)

Makefile

@@ -147,7 +147,15 @@ micropython-deploy-usb: $(MPY_DIR) ## Flash MicroPython firmware via DAPLink USB
 define DEPRECATED_FIRMWARE
 @echo "Error: 'make $(1)' is ambiguous. Use one of:"; \
 echo "  make micropython-$(2)   (MicroPython firmware)"; \
-echo "  make daplink-$(2)       (DAPLink firmware, see #377)"; \
+echo "  make daplink-$(2)       (DAPLink firmware)"; \
+exit 1
+endef
+
+# Variant for short names whose DAPLink counterpart does not exist yet
+# (daplink-deploy-pyocd / daplink-deploy-openocd are tracked in #388).
+define DEPRECATED_MICROPYTHON_ONLY
+@echo "Error: 'make $(1)' has been renamed. Use:"; \
+echo "  make micropython-$(2)   (MicroPython firmware)"; \
 exit 1
 endef
 
@@ -161,9 +169,9 @@ firmware-clean:
 deploy:
 	$(call DEPRECATED_FIRMWARE,deploy,deploy)
 deploy-pyocd:
-	$(call DEPRECATED_FIRMWARE,deploy-pyocd,deploy-pyocd)
+	$(call DEPRECATED_MICROPYTHON_ONLY,deploy-pyocd,deploy-pyocd)
 deploy-openocd:
-	$(call DEPRECATED_FIRMWARE,deploy-openocd,deploy-openocd)
+	$(call DEPRECATED_MICROPYTHON_ONLY,deploy-openocd,deploy-openocd)
 deploy-usb:
 	$(call DEPRECATED_FIRMWARE,deploy-usb,deploy-usb)
 
@@ -206,20 +214,32 @@ $(DAPLINK_DIR):
 	git clone --branch $(DAPLINK_BRANCH) $(DAPLINK_REPO) $(CURDIR)/$(DAPLINK_DIR)
 
 $(DAPLINK_GCC_DIR)/bin/arm-none-eabi-gcc:
-	@echo "Downloading gcc-arm-none-eabi $(DAPLINK_GCC_VERSION) for DAPLink..."
+	@set -e
+	@if [ -z "$(DAPLINK_GCC_ARCHIVE)" ]; then \
+		echo "Error: no prebuilt gcc-arm-none-eabi $(DAPLINK_GCC_VERSION) for $(DAPLINK_GCC_HOST_OS)/$(DAPLINK_GCC_HOST_ARCH)."; \
+		echo "Supported by this target: Linux x86_64, Linux aarch64, macOS Intel."; \
+		echo "Other platforms: install the toolchain manually and override DAPLINK_GCC_DIR,"; \
+		echo "or build inside the dev container."; \
+		exit 1; \
+	fi
+	@echo "Downloading gcc-arm-none-eabi $(DAPLINK_GCC_VERSION) for $(DAPLINK_GCC_HOST_OS)/$(DAPLINK_GCC_HOST_ARCH)..."
 	@mkdir -p $(BUILD_DIR)
 	curl -fL -o $(BUILD_DIR)/gcc-arm-none-eabi.tar.bz2 "$(DAPLINK_GCC_URL)"
 	tar -xjf $(BUILD_DIR)/gcc-arm-none-eabi.tar.bz2 -C $(BUILD_DIR)
 	rm -f $(BUILD_DIR)/gcc-arm-none-eabi.tar.bz2
 
-.PHONY: daplink-firmware
-daplink-firmware: $(DAPLINK_DIR) $(DAPLINK_GCC_DIR)/bin/arm-none-eabi-gcc ## Build DAPLink interface firmware for the STeaMi STM32F103
-	@set -e
-	@if [ ! -d "$(DAPLINK_DIR)/venv" ]; then \
-		echo "Setting up DAPLink Python virtualenv..."; \
+# Sentinel: re-runs pip install whenever DAPLink's requirements.txt changes
+# (e.g. after `make daplink-update`).
+$(DAPLINK_DIR)/venv/.installed: $(DAPLINK_DIR)/requirements.txt
+	@echo "Setting up DAPLink Python virtualenv..."
+	@if [ ! -x "$(DAPLINK_DIR)/venv/bin/python" ]; then \
 		$(PYTHON) -m venv $(DAPLINK_DIR)/venv; \
-		$(DAPLINK_DIR)/venv/bin/pip install -r $(DAPLINK_DIR)/requirements.txt; \
 	fi
+	$(DAPLINK_DIR)/venv/bin/pip install -r $(DAPLINK_DIR)/requirements.txt
+	@touch $@
+
+.PHONY: daplink-firmware
+daplink-firmware: $(DAPLINK_DIR) $(DAPLINK_GCC_DIR)/bin/arm-none-eabi-gcc $(DAPLINK_DIR)/venv/.installed ## Build DAPLink interface firmware for the STeaMi STM32F103
 	@echo "Building DAPLink target $(DAPLINK_TARGET) with gcc-arm-none-eabi $(DAPLINK_GCC_VERSION)..."
 	cd $(CURDIR)/$(DAPLINK_DIR) && \
 		PATH="$(CURDIR)/$(DAPLINK_GCC_DIR)/bin:$(CURDIR)/$(DAPLINK_DIR)/venv/bin:$$PATH" \

env.mk

@@ -20,6 +20,25 @@ DAPLINK_BUILD_DIR ?= $(DAPLINK_DIR)/projectfiles/make_gcc_arm/$(DAPLINK_TARGET)/
 # DAPLink requires gcc-arm-none-eabi 10.3-2021.10. System toolchains >= 11.3
 # produce code that overflows m_text (see DAPLink docs/DEVELOPERS-GUIDE.md and
 # ARMmbed/DAPLink#1043). The toolchain is downloaded once into BUILD_DIR.
+#
+# ARM publishes 10.3-2021.10 binaries for: x86_64 Linux, aarch64 Linux, and
+# Intel macOS. Apple Silicon and Windows are NOT supported by this target —
+# users on those platforms must install the toolchain manually and override
+# DAPLINK_GCC_DIR / DAPLINK_GCC_URL, or build inside the dev container.
 DAPLINK_GCC_VERSION ?= 10.3-2021.10
 DAPLINK_GCC_DIR ?= $(BUILD_DIR)/gcc-arm-none-eabi-$(DAPLINK_GCC_VERSION)
-DAPLINK_GCC_URL ?= https://developer.arm.com/-/media/Files/downloads/gnu-rm/$(DAPLINK_GCC_VERSION)/gcc-arm-none-eabi-$(DAPLINK_GCC_VERSION)-x86_64-linux.tar.bz2
+
+DAPLINK_GCC_HOST_OS := $(shell uname -s)
+DAPLINK_GCC_HOST_ARCH := $(shell uname -m)
+ifeq ($(DAPLINK_GCC_HOST_OS),Linux)
+    ifeq ($(DAPLINK_GCC_HOST_ARCH),x86_64)
+        DAPLINK_GCC_ARCHIVE ?= gcc-arm-none-eabi-$(DAPLINK_GCC_VERSION)-x86_64-linux.tar.bz2
+    else ifeq ($(DAPLINK_GCC_HOST_ARCH),aarch64)
+        DAPLINK_GCC_ARCHIVE ?= gcc-arm-none-eabi-$(DAPLINK_GCC_VERSION)-aarch64-linux.tar.bz2
+    endif
+else ifeq ($(DAPLINK_GCC_HOST_OS),Darwin)
+    ifeq ($(DAPLINK_GCC_HOST_ARCH),x86_64)
+        DAPLINK_GCC_ARCHIVE ?= gcc-arm-none-eabi-$(DAPLINK_GCC_VERSION)-mac.tar.bz2
+    endif
+endif
+DAPLINK_GCC_URL ?= https://developer.arm.com/-/media/Files/downloads/gnu-rm/$(DAPLINK_GCC_VERSION)/$(DAPLINK_GCC_ARCHIVE)