From 4dc88ed87c3aeae13726aae7f8505eebec927f36 Mon Sep 17 00:00:00 2001
From: Mathieu Maret <mathieu.maret@gmail.com>
Date: Tue, 15 Mar 2022 20:56:42 +0100
Subject: [PATCH] Add debug target

---
 Makefile  | 15 +++++++++++----
 debug.gdb |  3 +++
 2 files changed, 14 insertions(+), 4 deletions(-)
 create mode 100644 debug.gdb

diff --git a/Makefile b/Makefile
index d2c8aaf..8559ad6 100644
--- a/Makefile
+++ b/Makefile
@@ -4,6 +4,7 @@ CROSS=aarch64-linux-gnu-
 CC=$(CROSS)gcc
 LD=$(CROSS)ld
 CFLAGS=-Wall -Wextra -ffreestanding -march=armv8-a+crc -mcpu=cortex-a53
+DEBUG_FLAGS += -g -Og -DDEBUG -fno-omit-frame-pointer -fno-inline
 LDSCRIPT=rpi3.ld
 
 OBJS=crt0.o uart.o hello.o
@@ -13,20 +14,26 @@ csrc=$(wildcard *.c)
 cobj=$(csrc:%.c=%.o)
 deps=$(csrc:%.c=%.d) $(gasmsrc:%.S=%.d)
 
-all:kernel.bin
+KERNEL=kernel.bin
+
+all:$(KERNEL)
 
 kernel.elf: $(cobj) $(gasmobj) $(LDSCRIPT)
-	$(LD) $(LDFLAGS) -o $@ $(cobj) $(gasmobj) -T$(LDSCRIPT) -Map kernel.map
+	$(LD) $(LDFLAGS) -o $@ $(gasmobj) $(cobj) -T$(LDSCRIPT) -Map kernel.map
 
-kernel.bin: kernel.elf
+$(KERNEL): kernel.elf
 	$(CROSS)objcopy -O binary $< $@
 
 clean:
 	rm -rf $(cobj) $(gasmobj) $(deps) *.bin *.elf *.map
 
-run: kernel.bin
+run: $(KERNEL)
 	qemu-system-aarch64 -machine raspi3b -kernel $<
 
+debug: CFLAGS += $(DEBUG_FLAGS)
+debug: CXXFLAGS += $(DEBUG_FLAGS)
+debug:$(KERNEL)
+	aarch64-linux-gnu-gdb -q -x debug.gdb
 
 
 ifneq ($(MAKECMDGOALS),clean)
diff --git a/debug.gdb b/debug.gdb
new file mode 100644
index 0000000..d63e10d
--- /dev/null
+++ b/debug.gdb
@@ -0,0 +1,3 @@
+#add-symbol-file kernel.map
+file kernel.elf
+target remote | qemu-system-aarch64 -machine raspi3b  -S -gdb stdio -kernel kernel.bin