diff --git a/resources/soft/func/inst/n105_playground.c b/resources/soft/func/inst/n105_playground.c
index 2ac8122..1be0cae 100644
--- a/resources/soft/func/inst/n105_playground.c
+++ b/resources/soft/func/inst/n105_playground.c
@@ -77,7 +77,7 @@ int n105_playground_test_cache() {
     // clear
     puts(PREFIX "cache: clear");
     for (volatile unsigned *ptr = cached_bgn; ptr < cached_end; ptr++)
-        *ptr = 0;
+        *ptr = 0x12345678;
 
     // cache
     puts(PREFIX "cache: blast clear");
diff --git a/resources/soft/func/inst/utils.c b/resources/soft/func/inst/utils.c
index c940d98..e61d4b7 100644
--- a/resources/soft/func/inst/utils.c
+++ b/resources/soft/func/inst/utils.c
@@ -86,12 +86,13 @@ void probe_pcache(void) {
     unsigned long icache_size;
     unsigned long dcache_size;
 
-    struct cpuinfo_mips *c = &current_cpu_data;
+    volatile struct cpuinfo_mips *c = &current_cpu_data;
     unsigned int config = read_c0_config();
     unsigned long config1;
     unsigned int lsize;
 
     puts("init: probing cache");
+    putstr("init: current_cpu_data: "), puthex((unsigned)c), putchar('\n');
 
     config1 = read_c0_config1();