Square

Makefile

@@ -24,6 +24,7 @@ CFLAGS += -fno-common#			# Do not use common sections
 CFLAGS += -march=rv64i#			# Use RV64I ISA, i.e., integer only
 CFLAGS += -mabi=lp64#			# Use LP64 ABI, i.e., 64-bit longs and pointers, 32-bit ints
 CFLAGS += -Os#					# Optimize for size
+CFLAGS += -Wall -Wunused -O2
 
 LDFLAGS += -T link.ld			# Use the linker script
 LDFLAGS += --no-dynamic-linker
@@ -61,7 +62,7 @@ all: $(OBJS)
 	@echo "CC $<"
 
 # Run the binary in QEMU
-run: all	
+run: all
 	@echo "To exit: Ctrl+A, X"
 	@$(QEMU) $(QEMU_FLAGS) -bios $(TARGET)
 

link.ld

@@ -5,7 +5,7 @@ MEMORY {
 
 SECTIONS {
     .text : {
-        main.o(.text.*)
+        *(.text)
         *(.text)
         . = ALIGN(4);
     } > DRAM

main.s

@@ -25,7 +25,7 @@ test_routine:
     ret
 
 # Prints "hello" manually
-hello_manual:	
+hello_manual:
     addi a0, x0, 0x68
 	li a1, 0x10000000
 	sb a0, (a1) # 'h'

square.h

@@ -0,0 +1 @@
+int square(int, int);

square.s

@@ -0,0 +1,15 @@
+square:
+        addi    sp,sp,-32
+        sd      ra,24(sp)
+        sd      s0,16(sp)
+        addi    s0,sp,32
+        mv      a5,a0
+        sw      a5,-20(s0)
+        lw      a5,-20(s0)
+        mulw    a5,a5,a5
+        sext.w  a5,a5
+        mv      a0,a5
+        ld      ra,24(sp)
+        ld      s0,16(sp)
+        addi    sp,sp,32
+        jr      ra