qemu-arm/Makefile: Add support to run qemu in debugging mode.

dpgeorge · dpgeorge · commit 6128328c910f · 2024-09-03T12:07:13.000+10:00
Signed-off-by: Damien George &lt;damien@micropython.org&gt;
diff --git a/ports/qemu-arm/Makefile b/ports/qemu-arm/Makefile
@@ -28,6 +28,16 @@ include $(TOP)/extmod/extmod.mk
 
 QEMU_SYSTEM = qemu-system-$(QEMU_ARCH)
 QEMU_ARGS += -machine $(QEMU_MACHINE) -nographic -monitor null -semihosting
+QEMU_ARGS += $(QEMU_EXTRA)
+
+# `-gdb` command line parameters should go here (ie -gdb tcp::3333),
+# defaults to put gdb behind TCP port 1234
+
+# Specifying QEMU_DEBUG=1 will block qemu until a debugger is connected.
+ifeq ($(QEMU_DEBUG),1)
+QEMU_DEBUG_ARGS ?= -s
+QEMU_ARGS += -S $(QEMU_DEBUG_ARGS) $(QEMU_DEBUG_EXTRA)
+endif
 
 INC += -I.
 INC += -I$(TOP)
@@ -144,11 +154,6 @@ repl: $(BUILD)/firmware.elf
 run: $(BUILD)/firmware.elf
 	$(QEMU_SYSTEM) $(QEMU_ARGS) -serial pty -kernel $<
 
-# `make debug` will block QEMU until a debugger is connected to port 1234.
-.PHONY: debug
-debug: $(BUILD)/firmware.elf
-	$(QEMU_SYSTEM) $(QEMU_ARGS) -serial mon:stdio -S -s -kernel $<
-
 .PHONY: test
 test: $(BUILD)/firmware.elf
 	$(eval DIRNAME=ports/$(notdir $(CURDIR)))
diff --git a/ports/qemu-arm/README.md b/ports/qemu-arm/README.md
@@ -104,3 +104,9 @@ The following options can be specified on the `make` command line:
 - `CFLAGS_EXTRA`: pass in extra flags for the compiler.
 - `RUN_TESTS_EXTRA`: pass in extra flags for `run-tests.py` when invoked via
   `make test`.
+- `QEMU_DEBUG=1`: when running qemu (via `repl`, `run` or `test` target), qemu
+  will block until a debugger is connected.  By default it waits for a gdb connection
+  on TCP port 1234.
+- `QEMU_DEBUG_ARGS`: defaults to `-s` (gdb on TCP port 1234), but can be overridden
+  with different qemu gdb arguments.
+- `QEMU_DEBUG_EXTRA`: extra options to pass to qemu when `QEMU_DEBUG=1` is used.
