Add hex tests

sw/tests/test_main.c

@@ -1,7 +1,61 @@
 #include <stdio.h>
 
+#include "sevenseg.h"
+
 int main(void)
 {
-    printf("No test to run!\n");
-    return 0;
+    int retval = 0;
+
+    int i;
+
+    printf("\nStarting tests...\n\n");
+
+    printf("Testing hex_set_8...\n");
+    for (i = 0; i < 3; i++) {
+        if (hex_set_8(i+1, i)) {
+            printf("Failed to write to idx %d!\n", i);
+            retval++;
+        }
+        if (*(uint8_t*)0x7ff0+i != i+1) {
+            printf("Incorrect value at idx %d!\n", i);
+            retval++;
+        }
+    }
+
+    if (!hex_set_8(0xab, 3)) {
+        printf("Writing to idx 3 should fail!\n");
+        retval++;
+    }
+    printf("Done!\n\n");
+
+    printf("Testing hex_set_16...\n");
+    if (hex_set_16(0xabcd)){
+        printf("Failed to write!\n");
+    }
+    if (*(uint16_t*)0x7ff0 != 0xabcd) {
+        printf("Incorrect value!\n", i);
+        retval++;
+    }
+    printf("Done!\n\n");
+
+    printf("Testing hex_set_24...\n");
+    if (hex_set_24(0xabcdef)){
+        printf("Failed to write!\n");
+    }
+    if (*(uint16_t*)0x7ff0 != 0xcdef && *(uint8_t*)0x7ff2 != 0xab) {
+        printf("Incorrect value!\n", i);
+        retval++;
+    }
+    printf("Done!\n\n");
+
+    printf("Testing hex_enable...\n");
+    hex_enable(0xa5);
+    if (*(uint8_t*)0x7ff3 != 0xa5) {
+        printf("Incorrect value!\n", i);
+        retval++;
+    }
+    printf("Done!\n\n");
+
+
+    return retval != 0;
 }