Update on assembly simple/spike

examples/C/simple/Makefile

@@ -10,7 +10,7 @@ $(TARGET): $(TARGET).c Makefile
 	  -static -nostdlib -nostartfiles -lm -lgcc -T../common/test.ld \
 	  -I../common \
 	  -O0 $(TARGET).c \
-	  ../common/crt.S ../common/syscalls.c
+	  ../common/crt.S ../common/syscalls.c comp1.s
 
 clean:
 	rm -f $(TARGET) $(TARGET).objdump

examples/C/simple/comp1.s

@@ -0,0 +1,10 @@
+.global _comp1
+_comp1:
+
+	li a0, 42
+	ret
+
+	
+	
+
+	

examples/C/simple/comp1.s~

@@ -0,0 +1,7 @@
+_comp1:
+
+	li a0, 1
+	ret
+	
+
+	

examples/C/simple/sim.s~

@@ -0,0 +1,6 @@
+_comp1:
+
+	li a0, 1
+	
+
+	

examples/C/simple/simple.c

@@ -5,31 +5,36 @@
 //#include <stdio.h>
 #include "util.h"
 extern int printf(const char* fmt, ...);
+extern int _comp1(void);
 
+/*
 long sum(long N) {
-/*   long result, i;
+   long result, i;
    result = 0;
    for (i=1; i<=N; i++) {
        result = result + i;
    }
-   return result; */
+   return result; 
 
    int a;
-//   asm volatile ("li s0, 10;");
+   asm volatile ("li s0, 10;");
+
    asm volatile(
-           "li %0, 10"
+	   "li %0, 3;"			
-//	       "csrrs %0, 0xF14, zero" //CSSRS rd, mhartid, 0
+	   //  "csrrs %0, 0xF14, zero" //CSSRS rd, mhartid, 0
-	       : "=r"(a) //output
+	   : "=r"(a) //output
-	       : //input
+	   : //input
-	       : //clobbered
+	   : //clobbered
 		);
    return a;
 }
+*/
 
 int main(void) {
     int s[1], expected[1];
-    s[0] = sum(4);
+    //    s[0] = sum(4);
+    s[0] = _comp1();
     printf("s = %d\n", s[0]);
-    expected[0] = 10;
+    expected[0] = 42;
     return verify(1, s, expected); // 0 means success
 }

examples/C/simple/simple_orig.c

@@ -0,0 +1,35 @@
+// simple.C
+// David_Harris@hmc.edu 24 December 2021
+// Simple illustration of compiling C code
+
+//#include <stdio.h>
+#include "util.h"
+extern int printf(const char* fmt, ...);
+
+long sum(long N) {
+/*   long result, i;
+   result = 0;
+   for (i=1; i<=N; i++) {
+       result = result + i;
+   }
+   return result; */
+
+   int a;
+//   asm volatile ("li s0, 10;");
+   asm volatile(
+           "li %0, 10"
+//	       "csrrs %0, 0xF14, zero" //CSSRS rd, mhartid, 0
+	       : "=r"(a) //output
+	       : //input
+	       : //clobbered
+		);
+   return a;
+}
+
+int main(void) {
+    int s[1], expected[1];
+    s[0] = sum(4);
+    printf("s = %d\n", s[0]);
+    expected[0] = 10;
+    return verify(1, s, expected); // 0 means success
+}