diff --git a/components/esp8266/include/esp_libc.h b/components/esp8266/include/esp_libc.h
index 525bbb67..123bff35 100644
--- a/components/esp8266/include/esp_libc.h
+++ b/components/esp8266/include/esp_libc.h
@@ -73,11 +73,7 @@ unsigned long os_random(void);
 int os_get_random(unsigned char *buf, size_t len);
 
 #ifndef os_printf
-/* NOTE: don't use printf_opt in irq handler, for test */
-#define os_printf(fmt, ...) do {    \
-        static const char flash_str[] ICACHE_RODATA_ATTR STORE_ATTR = fmt;  \
-        printf(flash_str, ##__VA_ARGS__);   \
-    } while(0)
+#define os_printf   printf
 #endif
 
 /* Note: check_memleak_debug_enable is a weak function inside SDK.
diff --git a/components/lwip/include/lwip/apps/multi-threads/sockets_mt.h b/components/lwip/include/lwip/apps/multi-threads/sockets_mt.h
index 02a41121..d6c8390a 100644
--- a/components/lwip/include/lwip/apps/multi-threads/sockets_mt.h
+++ b/components/lwip/include/lwip/apps/multi-threads/sockets_mt.h
@@ -36,23 +36,23 @@ int lwip_trace_tcp(int s, int cmd, void *arg);
 
 #ifdef SOCKETS_MT_DBUG
 
-#define accept(a,b,c)         lwip_accept_mt(a,b,c); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define bind(a,b,c)           lwip_bind_mt(a,b,c); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define shutdown(a,b)         lwip_shutdown_mt(a,b); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define closesocket(s)        lwip_close_mt(s); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define connect(a,b,c)        lwip_connect_mt(a,b,c); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define getsockname(a,b,c)    lwip_getsockname_mt(a,b,c); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define getpeername(a,b,c)    lwip_getpeername_mt(a,b,c); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define setsockopt(a,b,c,d,e) lwip_setsockopt_mt(a,b,c,d,e); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define getsockopt(a,b,c,d,e) lwip_getsockopt_mt(a,b,c,d,e); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define listen(a,b)           lwip_listen_mt(a,b); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define recv(a,b,c,d)         lwip_recv_mt(a,b,c,d); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define recvfrom(a,b,c,d,e,f) lwip_recvfrom_mt(a,b,c,d,e,f); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define send(a,b,c,d)         lwip_send_mt(a,b,c,d); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define sendto(a,b,c,d,e,f)   lwip_sendto_mt(a,b,c,d,e,f); os_printf("%s %d\n", __FUNCTION__, __LINE__);
-#define socket(a,b,c)         lwip_socket_mt(a,b,c); os_printf("%s %d\n", __FUNCTION__, __LINE__);
+#define accept(a,b,c)         lwip_accept_mt(a,b,c); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define bind(a,b,c)           lwip_bind_mt(a,b,c); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define shutdown(a,b)         lwip_shutdown_mt(a,b); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define closesocket(s)        lwip_close_mt(s); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define connect(a,b,c)        lwip_connect_mt(a,b,c); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define getsockname(a,b,c)    lwip_getsockname_mt(a,b,c); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define getpeername(a,b,c)    lwip_getpeername_mt(a,b,c); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define setsockopt(a,b,c,d,e) lwip_setsockopt_mt(a,b,c,d,e); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define getsockopt(a,b,c,d,e) lwip_getsockopt_mt(a,b,c,d,e); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define listen(a,b)           lwip_listen_mt(a,b); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define recv(a,b,c,d)         lwip_recv_mt(a,b,c,d); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define recvfrom(a,b,c,d,e,f) lwip_recvfrom_mt(a,b,c,d,e,f); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define send(a,b,c,d)         lwip_send_mt(a,b,c,d); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define sendto(a,b,c,d,e,f)   lwip_sendto_mt(a,b,c,d,e,f); printf("%s %d\n", __FUNCTION__, __LINE__);
+#define socket(a,b,c)         lwip_socket_mt(a,b,c); printf("%s %d\n", __FUNCTION__, __LINE__);
 #define select(a,b,c,d,e)     lwip_select_mt(a,b,c,d,e)
-#define ioctlsocket(a,b,c)    lwip_ioctl_mt(a,b,c) ; os_printf("%s %d\n", __FUNCTION__, __LINE__);
+#define ioctlsocket(a,b,c)    lwip_ioctl_mt(a,b,c) ; printf("%s %d\n", __FUNCTION__, __LINE__);
 
 #if LWIP_POSIX_SOCKETS_IO_NAMES
 #define read(a,b,c)           lwip_read_mt(a,b,c)
diff --git a/components/lwip/port/esp8266/include/arch/cc.h b/components/lwip/port/esp8266/include/arch/cc.h
index a54d6fd9..fc12ca0a 100644
--- a/components/lwip/port/esp8266/include/arch/cc.h
+++ b/components/lwip/port/esp8266/include/arch/cc.h
@@ -64,16 +64,9 @@ typedef int sys_prot_t;
 
 #include <stdio.h>
 
-#ifndef os_printf
-#define os_printf(fmt, ...) do {    \
-    static const char flash_str[] ICACHE_RODATA_ATTR STORE_ATTR = fmt;  \
-    printf(flash_str, ##__VA_ARGS__);   \
-    } while(0)
-#endif
-
 #ifdef LWIP_DEBUG
-#define LWIP_PLATFORM_DIAG(x)   do {os_printf x;} while(0)
-#define LWIP_PLATFORM_ASSERT(x) do {os_printf(x); sys_arch_assert(__FILE__, __LINE__);} while(0)
+#define LWIP_PLATFORM_DIAG(x)   do {printf x;} while(0)
+#define LWIP_PLATFORM_ASSERT(x) do {printf(x); sys_arch_assert(__FILE__, __LINE__);} while(0)
 #else
 #define LWIP_PLATFORM_DIAG(x)
 #define LWIP_PLATFORM_ASSERT(x)
diff --git a/components/ssl/axtls/include/ssl/ssl_os_port.h b/components/ssl/axtls/include/ssl/ssl_os_port.h
index a636c0ae..5af79a8d 100644
--- a/components/ssl/axtls/include/ssl/ssl_os_port.h
+++ b/components/ssl/axtls/include/ssl/ssl_os_port.h
@@ -44,7 +44,7 @@ extern "C" {
 #include "esp_common.h"
 
 #if 0
-#define ssl_printf(fmt, args...) os_printf(fmt,## args)
+#define ssl_printf(fmt, args...) printf(fmt,## args)
 #else
 #define ssl_printf(fmt, args...)
 #endif
diff --git a/components/ssl/mbedtls/port/openssl/include/platform/ssl_port.h b/components/ssl/mbedtls/port/openssl/include/platform/ssl_port.h
index 4403c420..77ac7478 100644
--- a/components/ssl/mbedtls/port/openssl/include/platform/ssl_port.h
+++ b/components/ssl/mbedtls/port/openssl/include/platform/ssl_port.h
@@ -63,14 +63,7 @@ extern void vPortFree(void *pv);
 #define ssl_speed_up_enter() system_update_cpu_freq(SYS_CPU_160MHZ)
 #define ssl_speed_up_exit()  system_update_cpu_freq(SYS_CPU_80MHZ)
 
-#ifndef os_printf
-#define os_printf(fmt, ...) do {    \
-        static const char flash_str[] ICACHE_RODATA_ATTR STORE_ATTR = fmt;  \
-        printf(flash_str, ##__VA_ARGS__);   \
-    } while(0)
-#endif
-
-#define SSL_DEBUG_LOG os_printf
+#define SSL_DEBUG_LOG printf
 
 #define LOCAL_ATRR ICACHE_RODATA_ATTR STORE_ATTR
 
diff --git a/examples/storage/spiffs_test/main/testrunner.h b/examples/storage/spiffs_test/main/testrunner.h
index 25819ea2..ed965687 100644
--- a/examples/storage/spiffs_test/main/testrunner.h
+++ b/examples/storage/spiffs_test/main/testrunner.h
@@ -122,7 +122,7 @@ typedef struct test_res_s {
   goto __fail_assert; \
 }
 
-#define DBGT(...) os_printf(__VA_ARGS__)
+#define DBGT(...) printf(__VA_ARGS__)
 
 #define str(s) #s