Updated readme & Makefile fix

Author: jackctj117

test/Makefile

@@ -262,9 +262,13 @@ coverage:
 	$(MAKE) clean
 	$(MAKE) COVERAGE=1 DEBUG=1
 	@echo "Running tests..."
+	@if [ ! -f $(BUILD_DIR)/$(BIN).elf ]; then \
+		echo "Error: $(BUILD_DIR)/$(BIN).elf not found. Build failed."; \
+		exit 1; \
+	fi
 	$(BUILD_DIR)/$(BIN).elf
 	@echo "Generating coverage report..."
-	cd .. && gcovr --root . \
+	cd .. && mkdir -p coverage && gcovr --root . \
 		--filter 'src/.*' \
 		--filter 'wolfhsm/.*' \
 		--html-details coverage/index.html \

test/README.md

@@ -102,12 +102,9 @@ IMG_MGR RSA2048 Test completed successfully!
 
 The test suite supports code coverage analysis using gcovr. To generate coverage reports:
 
-### Prerequisites
-Install gcovr if not already installed:
+**Note**: The coverage directory must exist before generating reports. The `make coverage` target creates this automatically, but if running gcovr manually, create it first with:
 ```bash
-pip install gcovr
-# or
-pip3 install gcovr
+mkdir -p ../coverage
 ```
 
 ### Running Coverage
@@ -137,8 +134,9 @@ make COVERAGE=1 DEBUG=1
 # Run tests
 make run
 
-# Generate coverage report (from repository root)
+# Create coverage directory and generate report (from repository root)
 cd ..
+mkdir -p coverage
 gcovr --root . \
       --filter 'src/.*' \
       --filter 'wolfhsm/.*' \