add simple debug test for riscv-none-elf-gdb

tests/debug/simple/Makefile

@@ -0,0 +1,15 @@
+TARGET = simple
+
+$(TARGET).objdump: $(TARGET)
+	riscv64-unknown-elf-objdump -S -D $(TARGET) > $(TARGET).objdump
+	spike $(TARGET)
+    
+$(TARGET): $(TARGET).c Makefile
+	riscv64-unknown-elf-gcc -o $(TARGET) -g\
+	  -march=rv64gc -mabi=lp64d -mcmodel=medany \
+	  -nostdlib -static -lm -fno-tree-loop-distribute-patterns \
+	  -T../../../examples/C/common/test.ld -I../../../examples/C/common/ \
+	  $(TARGET).c ../../../examples/C/common/crt.S ../../../examples/C/common/syscalls.c
+
+clean:
+	rm -f $(TARGET) $(TARGET).objdump

tests/debug/simple/simple.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+
+int main() {
+
+  // This is just random simple instructions
+  // to test the RISC-V debug gdb
+  asm("li a0, 0x1000");
+  asm("addi a1, a0, 0x100");
+  asm("addi a2, a1, 0x200");
+  asm("li a3, 0x4000000");
+  asm("sw a0, 0(a3)");
+  asm("sw a1, 4(a3)");
+  asm("lw a4, 0(a3)");
+  asm("lw a5, 4(a3)");
+  asm("lw a5, 4(a3)");
+  asm("nop");
+  while(1);
+
+}