fixup! tests/periph_rtt: test for periph_rtc_mem

tests/periph_rtt/main.c

@@ -49,25 +49,51 @@ void cb(void *arg)
 }
 
 #ifdef MODULE_PERIPH_RTC_MEM
+static const uint8_t riot_msg_offset = 1;
 static const char riot_msg[] = "RIOT";
 static void _set_rtc_mem(void)
 {
-    rtc_mem_write(1, riot_msg, 4);
+    /* first fill the whole memory */
+    uint8_t size = rtc_mem_size();
+    while (size--) {
+        rtc_mem_write(size, &size, sizeof(size));
+    }
+
+    /* write test data */
+    rtc_mem_write(riot_msg_offset, riot_msg, sizeof(riot_msg) - 1);
 }
 
 static void _get_rtc_mem(void)
 {
     char buf[4];
-    rtc_mem_read(1, buf, 4);
+    rtc_mem_read(riot_msg_offset, buf, sizeof(buf));
 
-    if (memcmp(buf, riot_msg, 4)) {
+    if (memcmp(buf, riot_msg, sizeof(buf))) {
         puts("RTC mem content does not match");
         for (unsigned i = 0; i < sizeof(buf); ++i) {
             printf("%02x - %02x\n", riot_msg[i], buf[i]);
         }
-    } else {
-        puts("RTC mem OK");
+        return;
+    }
+
+    uint8_t size = rtc_mem_size();
+    while (size--) {
+        uint8_t data;
+
+        if (size >= riot_msg_offset &&
+            size < riot_msg_offset + sizeof(riot_msg)) {
+            continue;
+        }
+
+        rtc_mem_read(size, &data, 1);
+        if (data != size) {
+            puts("RTC mem content does not match");
+            printf("%0x2: %0x2\n", size, data);
+        }
     }
+
+
+    puts("RTC mem OK");
 }
 #else
 static inline void _set_rtc_mem(void) {}