RAM Disk function using Mbed os5 standard library

Please refer following my Notebook page.
/users/kenjiArai/notebook/sd-card-control-new/#

Revision:
2:4c2328c61af7
Parent:
1:58fc0cbd9a41
Child:
3:c31e9e43554b
--- a/main.cpp	Thu Dec 26 05:29:38 2019 +0000
+++ b/main.cpp	Thu Dec 26 11:12:47 2019 +0000
@@ -32,7 +32,6 @@
 #define RAM_DISK_SIZE_512KB (1024 * 512)
 #define RAM_DISK_SIZE_128KB (256 * 512)
 #define RAM_DISK_SIZE_64KB  (128 * 512)
-#define RAM_DISK_SIZE_32KB  (64 * 512)
 
 #if defined(TARGET_NUCLEO_F401RE) || defined(TARGET_NUCLEO_F411RE) ||\
     defined(TARGET_NUCLEO_F446RE) || defined(TARGET_NUCLEO_L476RG) ||\
@@ -46,6 +45,7 @@
 #elif defined(TARGET_RZ_A1H)
     #define RAM_DISK_SIZE       RAM_DISK_SIZE_2MB
 #else
+    #warning "make sure disk size for your board!" 
     #define RAM_DISK_SIZE       RAM_DISK_SIZE_64KB
 #endif
 
@@ -146,7 +146,7 @@
         DBG("line:%3d\r\n", __LINE__);
         uint32_t time_sd = tmr.read_ms();
         pc.printf("time[ms]:%3d ,", time_sd);
-        Thread::wait(20);
+        ThisThread::sleep_for(20);
         if (user_sw == USER_SW_ON) {
             break;
         }
@@ -157,7 +157,7 @@
     }
     while(true) {
         mon();
-        NVIC_SystemReset();
+        system_reset();
     }
 }