Set development environment with UART debug output for aarch64

Makefile

@@ -6,14 +6,13 @@ AARCH64_TOOLCHAIN ?= aarch64-linux-gnu
 # Shortcuts
 
 CC=clang --target=aarch64-none-elf -mcpu=cortex-a57
-# CC=$(AARCH64_TOOLCHAIN)-gcc
-LD=$(AARCH64_TOOLCHAIN)-ld
+LD=ld.lld
 OBJCOPY=$(AARCH64_TOOLCHAIN)-objcopy --target elf64-littleaarch64
 
 CFLAGS += -O0
 CFLAGS += -g
-CFLAGS += -nostdlib
-CFLAGS += -march=armv8-a
+#CFLAGS += -nostdlib
+#CFLAGS += -march=armv8-a
 #CFLAGS += -std=c99
 #CFLAGS += -pedantic
 #CFLAGS += -Wall
@@ -26,7 +25,7 @@ BUILD_DIR=build
 
 # Files
 
-KERNEL_MEMMAP = sys/memmap
+KERNEL_MEMMAP = aarch64/memmap
 
 KERNEL_SOURCES = \
   aarch64/boot.s \
@@ -45,7 +44,7 @@ kernel: $(BUILD_DIR)/kernel.elf # $(BUILD_DIR)/kernel.sym
 
 $(BUILD_DIR)/kernel.elf: $(KERNEL_OBJS)
 	$(info linking target: $@)
-	$(LD) -T$(KERNEL_MEMMAP) $^ -o $@
+	$(LD) -T$(KERNEL_MEMMAP) -nostdlib $^ -o $@
 	$(info done: $@)
 
 $(BUILD_DIR)/kernel.bin: $(BUILD_DIR)/kernel.elf
@@ -66,14 +65,15 @@ $(BUILD_DIR)/%.o: %
 # helpers
 QEMU_CMD = \
   qemu-system-aarch64 \
+    -M virt \
     -cpu cortex-a57 \
-    -machine type=virt \
     -nographic \
     -smp 4 \
-    -m 4098 \
+    -m 4096 \
     -kernel build/kernel.elf \
     -serial stdio \
-    -monitor none
+    -monitor none \
+
 
 clean:
 	rm -Rf ./$(BUILD_DIR)/*
@@ -83,4 +83,8 @@ run: kernel
 
 
 debug: kernel
-	$(QEMU_CMD) -gdb tcp::1234 -S
+	$(QEMU_CMD) -S -gdb tcp::1234 & \
+  gdb-multiarch -q \
+  -ex 'file build/kernel.elf' \
+  -ex 'target remote localhost:1234'
+	kill %1