With this you can launch a test in gdb with:

  cd $(BUILD)/tests
  make -f $(SRC)/tests/tcg/Makefile gdb-$(TEST_NAME)

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 tests/tcg/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/tcg/Makefile b/tests/tcg/Makefile
index d26a36df61..8dfd1a76b9 100644
--- a/tests/tcg/Makefile
+++ b/tests/tcg/Makefile
@@ -128,6 +128,9 @@ run-%: %
 	  "$< on $(TARGET_NAME)")
 endif
 
+gdb-%: %
+	gdb --args $(QEMU) $(QEMU_OPTS) $<
+
 .PHONY: run
 run: $(RUN_TESTS)
 
-- 
2.20.1