diff --git a/cores/esp8266/StackThunk.c b/cores/esp8266/StackThunk.cpp
similarity index 96%
rename from cores/esp8266/StackThunk.c
rename to cores/esp8266/StackThunk.cpp
index 23f4374082..4d86875c97 100644
--- a/cores/esp8266/StackThunk.c
+++ b/cores/esp8266/StackThunk.cpp
@@ -27,6 +27,9 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include "StackThunk.h"
+#include <ets_sys.h>
+
+extern "C" {
 
 uint32_t *stack_thunk_ptr = NULL;
 uint32_t *stack_thunk_top = NULL;
@@ -115,8 +118,10 @@ void stack_thunk_dump_stack()
   }
   ets_printf(">>>stack>>>\n");
   while (pos < stack_thunk_ptr) {
-    ets_printf("%08x:  %08x %08x %08x %08x\n", pos, pos[0], pos[1], pos[2], pos[3]);
+    ets_printf("%08x:  %08x %08x %08x %08x\n", (int32_t)pos, pos[0], pos[1], pos[2], pos[3]);
     pos += 4;
   }
   ets_printf("<<<stack<<<\n");
 }
+
+};
diff --git a/cores/esp8266/cont_util.c b/cores/esp8266/cont_util.cpp
similarity index 99%
rename from cores/esp8266/cont_util.c
rename to cores/esp8266/cont_util.cpp
index 2d5d2b1eac..66ebd06ac7 100644
--- a/cores/esp8266/cont_util.c
+++ b/cores/esp8266/cont_util.cpp
@@ -23,6 +23,7 @@
 #include <string.h>
 #include "ets_sys.h"
 
+extern "C" {
 
 #define CONT_STACKGUARD 0xfeefeffe
 
@@ -80,3 +81,5 @@ void cont_repaint_stack(cont_t *cont)
         cont->stack[pos] = CONT_STACKGUARD;
     }
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_eboot_command.c b/cores/esp8266/core_esp8266_eboot_command.cpp
similarity index 93%
rename from cores/esp8266/core_esp8266_eboot_command.c
rename to cores/esp8266/core_esp8266_eboot_command.cpp
index ee3ccb4809..44d65a8c3e 100644
--- a/cores/esp8266/core_esp8266_eboot_command.c
+++ b/cores/esp8266/core_esp8266_eboot_command.cpp
@@ -23,7 +23,9 @@
 #include <stdbool.h>
 #include "eboot_command.h"
 
-uint32_t crc_update(uint32_t crc, const uint8_t *data, size_t length)
+extern "C" {
+
+static uint32_t crc_update(uint32_t crc, const uint8_t *data, size_t length)
 {
     uint32_t i;
     bool bit;
@@ -45,7 +47,7 @@ uint32_t crc_update(uint32_t crc, const uint8_t *data, size_t length)
     return crc;
 }
 
-uint32_t eboot_command_calculate_crc32(const struct eboot_command* cmd)
+static uint32_t eboot_command_calculate_crc32(const struct eboot_command* cmd)
 {
     return crc_update(0xffffffff, (const uint8_t*) cmd, 
                       offsetof(struct eboot_command, crc32));
@@ -86,3 +88,4 @@ void eboot_command_clear()
     RTC_MEM[offsetof(struct eboot_command, crc32) / sizeof(uint32_t)] = 0;
 }
 
+};
diff --git a/cores/esp8266/core_esp8266_flash_utils.c b/cores/esp8266/core_esp8266_flash_utils.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_flash_utils.c
rename to cores/esp8266/core_esp8266_flash_utils.cpp
index 0713998a6a..9abd23c110 100644
--- a/cores/esp8266/core_esp8266_flash_utils.c
+++ b/cores/esp8266/core_esp8266_flash_utils.cpp
@@ -25,6 +25,7 @@
 #include <stdbool.h>
 #include "flash_utils.h"
 
+extern "C" {
 
 int SPIEraseAreaEx(const uint32_t start, const uint32_t size)
 {
@@ -62,3 +63,4 @@ int SPIEraseAreaEx(const uint32_t start, const uint32_t size)
     return 0;
 }
 
+};
diff --git a/cores/esp8266/core_esp8266_i2s.c b/cores/esp8266/core_esp8266_i2s.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_i2s.c
rename to cores/esp8266/core_esp8266_i2s.cpp
index 7c8b4b73ac..005d1f4652 100644
--- a/cores/esp8266/core_esp8266_i2s.c
+++ b/cores/esp8266/core_esp8266_i2s.cpp
@@ -23,11 +23,11 @@
 #include "Arduino.h"
 #include "osapi.h"
 #include "ets_sys.h"
-
-
 #include "i2s_reg.h"
 #include "i2s.h"
 
+extern "C" {
+
 #define SLC_BUF_CNT (8)  // Number of buffers in the I2S circular buffer
 #define SLC_BUF_LEN (64) // Length of one buffer, in 32-bit words.
 
@@ -573,3 +573,5 @@ void i2s_end() {
     rx = NULL;
   }
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_noniso.c b/cores/esp8266/core_esp8266_noniso.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_noniso.c
rename to cores/esp8266/core_esp8266_noniso.cpp
index c499c1bcf3..b39edbb288 100644
--- a/cores/esp8266/core_esp8266_noniso.c
+++ b/cores/esp8266/core_esp8266_noniso.cpp
@@ -29,6 +29,8 @@
 #include <math.h>
 #include "stdlib_noniso.h"
 
+extern "C" {
+
 char* ltoa(long value, char* result, int base) {
     return itoa((int)value, result, base);
 }
@@ -109,3 +111,5 @@ char * dtostrf(double number, signed char width, unsigned char prec, char *s) {
     *out = 0;
     return s;
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_phy.c b/cores/esp8266/core_esp8266_phy.cpp
similarity index 63%
rename from cores/esp8266/core_esp8266_phy.c
rename to cores/esp8266/core_esp8266_phy.cpp
index d15b6830b1..3fb027f4fb 100644
--- a/cores/esp8266/core_esp8266_phy.c
+++ b/cores/esp8266/core_esp8266_phy.cpp
@@ -19,88 +19,90 @@
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <string.h>
+#include "c_types.h"
+#include "ets_sys.h"
+#include "spi_flash.h"
+#include "user_interface.h"
 
- #include <stdint.h>
- #include <stddef.h>
- #include <stdbool.h>
- #include <string.h>
- #include "c_types.h"
- #include "ets_sys.h"
- #include "spi_flash.h"
+extern "C" {
 
 static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
 {
-    [0] = 5,  // Reserved, do not change
-    [1] = 8,  // Reserved, do not change
-    [2] = 4,  // Reserved, do not change
-    [3] = 2,  // Reserved, do not change
-    [4] = 5,  // Reserved, do not change
-    [5] = 5,  // Reserved, do not change
-    [6] = 5,  // Reserved, do not change
-    [7] = 2,  // Reserved, do not change
-    [8] = 5,  // Reserved, do not change
-    [9] = 0,  // Reserved, do not change
-    [10] = 4,  // Reserved, do not change
-    [11] = 5,  // Reserved, do not change
-    [12] = 5,  // Reserved, do not change
-    [13] = 4,  // Reserved, do not change
-    [14] = 5,  // Reserved, do not change
-    [15] = 5,  // Reserved, do not change
-    [16] = 4,  // Reserved, do not change
-    [17] = -2, // Reserved, do not change
-    [18] = -3, // Reserved, do not change
-    [19] = -1, // Reserved, do not change
-    [20] = -16, // Reserved, do not change
-    [21] = -16, // Reserved, do not change
-    [22] = -16, // Reserved, do not change
-    [23] = -32, // Reserved, do not change
-    [24] = -32, // Reserved, do not change
-    [25] = -32, // Reserved, do not change
-
-    [26] = 225, // spur_freq_cfg, spur_freq=spur_freq_cfg/spur_freq_cfg_div
-    [27] = 10,  // spur_freq_cfg_div
+    /*[0] =*/ 5,  // Reserved, do not change
+    /*[1] =*/ 8,  // Reserved, do not change
+    /*[2] =*/ 4,  // Reserved, do not change
+    /*[3] =*/ 2,  // Reserved, do not change
+    /*[4] =*/ 5,  // Reserved, do not change
+    /*[5] =*/ 5,  // Reserved, do not change
+    /*[6] =*/ 5,  // Reserved, do not change
+    /*[7] =*/ 2,  // Reserved, do not change
+    /*[8] =*/ 5,  // Reserved, do not change
+    /*[9] =*/ 0,  // Reserved, do not change
+    /*[10] =*/ 4,  // Reserved, do not change
+    /*[11] =*/ 5,  // Reserved, do not change
+    /*[12] =*/ 5,  // Reserved, do not change
+    /*[13] =*/ 4,  // Reserved, do not change
+    /*[14] =*/ 5,  // Reserved, do not change
+    /*[15] =*/ 5,  // Reserved, do not change
+    /*[16] =*/ 4,  // Reserved, do not change
+    /*[17] =*/ (uint8_t)-2, // Reserved, do not change
+    /*[18] =*/ (uint8_t)-3, // Reserved, do not change
+    /*[19] =*/ (uint8_t)-1, // Reserved, do not change
+    /*[20] =*/ (uint8_t)-16, // Reserved, do not change
+    /*[21] =*/ (uint8_t)-16, // Reserved, do not change
+    /*[22] =*/ (uint8_t)-16, // Reserved, do not change
+    /*[23] =*/ (uint8_t)-32, // Reserved, do not change
+    /*[24] =*/ (uint8_t)-32, // Reserved, do not change
+    /*[25] =*/ (uint8_t)-32, // Reserved, do not change
+
+    /*[26] =*/ 225, // spur_freq_cfg, spur_freq=spur_freq_cfg/spur_freq_cfg_div
+    /*[27] =*/ 10,  // spur_freq_cfg_div
     // each bit for 1 channel, 1 to select the spur_freq if in band, else 40
-    [28] = 0xff,   // spur_freq_en_h
-    [29] = 0xff,   // spur_freq_en_l
-
-    [30] = 0xf8, // Reserved, do not change
-    [31] = 0,    // Reserved, do not change
-    [32] = 0xf8, // Reserved, do not change
-    [33] = 0xf8, // Reserved, do not change
-
-    [34] = 78, // target_power_qdb_0, target power is 78/4=19.5dbm
-    [35] = 74, // target_power_qdb_1, target power is 74/4=18.5dbm
-    [36] = 70, // target_power_qdb_2, target power is 70/4=17.5dbm
-    [37] = 64, // target_power_qdb_3, target power is 64/4=16dbm
-    [38] = 60, // target_power_qdb_4, target power is 60/4=15dbm
-    [39] = 56, // target_power_qdb_5, target power is 56/4=14dbm
-
-    [40] = 0, // target_power_index_mcs0
-    [41] = 0, // target_power_index_mcs1
-    [42] = 1, // target_power_index_mcs2
-    [43] = 1, // target_power_index_mcs3
-    [44] = 2, // target_power_index_mcs4
-    [45] = 3, // target_power_index_mcs5
-    [46] = 4, // target_power_index_mcs6
-    [47] = 5, // target_power_index_mcs7
+    /*[28] =*/ 0xff,   // spur_freq_en_h
+    /*[29] =*/ 0xff,   // spur_freq_en_l
+
+    /*[30] =*/ 0xf8, // Reserved, do not change
+    /*[31] =*/ 0,    // Reserved, do not change
+    /*[32] =*/ 0xf8, // Reserved, do not change
+    /*[33] =*/ 0xf8, // Reserved, do not change
+
+    /*[34] =*/ 78, // target_power_qdb_0, target power is 78/4=19.5dbm
+    /*[35] =*/ 74, // target_power_qdb_1, target power is 74/4=18.5dbm
+    /*[36] =*/ 70, // target_power_qdb_2, target power is 70/4=17.5dbm
+    /*[37] =*/ 64, // target_power_qdb_3, target power is 64/4=16dbm
+    /*[38] =*/ 60, // target_power_qdb_4, target power is 60/4=15dbm
+    /*[39] =*/ 56, // target_power_qdb_5, target power is 56/4=14dbm
+
+    /*[40] =*/ 0, // target_power_index_mcs0
+    /*[41] =*/ 0, // target_power_index_mcs1
+    /*[42] =*/ 1, // target_power_index_mcs2
+    /*[43] =*/ 1, // target_power_index_mcs3
+    /*[44] =*/ 2, // target_power_index_mcs4
+    /*[45] =*/ 3, // target_power_index_mcs5
+    /*[46] =*/ 4, // target_power_index_mcs6
+    /*[47] =*/ 5, // target_power_index_mcs7
 
     // crystal_26m_en
     // 0: 40MHz
     // 1: 26MHz
     // 2: 24MHz
     #if F_CRYSTAL == 40000000
-      [48] = 0,
+      /*[48] =*/ 0,
     #else
-      [48] = 1,
+      /*[48] =*/ 1,
     #endif
 
-
+    /*[49] =*/ 0,
 
     // sdio_configure
     // 0: Auto by pin strapping
     // 1: SDIO dataoutput is at negative edges (SDIO V1.1)
     // 2: SDIO dataoutput is at positive edges (SDIO V2.0)
-    [50] = 0,
+    /*[50] =*/ 0,
 
     // bt_configure
     // 0: None,no bluetooth
@@ -113,7 +115,7 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     //    MTMS -> BT_PRIORITY
     //    MTCK  -> BT_ACTIVE
     //    U0RXD -> ANT_SEL_BT
-    [51] = 0,
+    /*[51] =*/ 0,
 
     // bt_protocol
     // 0: WiFi-BT are not enabled. Antenna is for WiFi
@@ -122,16 +124,16 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     // 3: WiFi-BT 3-wire are enabled, (when BT_ACTIVE = 0, BT_PRIORITY must be 0), independent ant
     // 4: WiFi-BT 2-wire are enabled, (only use BT_ACTIVE), share ant
     // 5: WiFi-BT 3-wire are enabled, (when BT_ACTIVE = 0, BT_PRIORITY must be 0), share ant
-    [52] = 0,
+    /*[52] =*/ 0,
 
     // dual_ant_configure
     // 0: None
     // 1: dual_ant (antenna diversity for WiFi-only): GPIO0 + U0RXD
     // 2: T/R switch for External PA/LNA:  GPIO0 is high and U0RXD is low during Tx
     // 3: T/R switch for External PA/LNA:  GPIO0 is low and U0RXD is high during Tx
-    [53] = 0,
+    /*[53] =*/ 0,
 
-    [54] = 2, // Reserved, do not change
+    /*[54] =*/ 2, // Reserved, do not change
 
     // share_xtal
     // This option is to share crystal clock for BT
@@ -140,28 +142,53 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     // 1: Forcely On
     // 2: Automatically On according to XPD_DCDC
     // 3: Automatically On according to GPIO2
-    [55] = 0,
-
-    [64] = 225, // spur_freq_cfg_2, spur_freq_2=spur_freq_cfg_2/spur_freq_cfg_div_2
-    [65] = 10,  // spur_freq_cfg_div_2
-    [66] = 0,   // spur_freq_en_h_2
-    [67] = 0,   // spur_freq_en_l_2
-    [68] = 0,   // spur_freq_cfg_msb
-    [69] = 0,   // spur_freq_cfg_2_msb
-    [70] = 0,   // spur_freq_cfg_3_low
-    [71] = 0,   // spur_freq_cfg_3_high
-    [72] = 0,   // spur_freq_cfg_4_low
-    [73] = 0,   // spur_freq_cfg_4_high
-
-    [74] = 1,   // Reserved, do not change
-    [75] = 0x93,   // Reserved, do not change
-    [76] = 0x43,   // Reserved, do not change
-    [77] = 0x00,   // Reserved, do not change
+    /*[55] =*/ 0,
+
+    /*[56] =*/ 0,
+    /*[57] =*/ 0,
+    /*[58] =*/ 0,
+    /*[59] =*/ 0,
+    /*[60] =*/ 0,
+    /*[61] =*/ 0,
+    /*[62] =*/ 0,
+    /*[63] =*/ 0,
+
+    /*[64] =*/ 225, // spur_freq_cfg_2, spur_freq_2=spur_freq_cfg_2/spur_freq_cfg_div_2
+    /*[65] =*/ 10,  // spur_freq_cfg_div_2
+    /*[66] =*/ 0,   // spur_freq_en_h_2
+    /*[67] =*/ 0,   // spur_freq_en_l_2
+    /*[68] =*/ 0,   // spur_freq_cfg_msb
+    /*[69] =*/ 0,   // spur_freq_cfg_2_msb
+    /*[70] =*/ 0,   // spur_freq_cfg_3_low
+    /*[71] =*/ 0,   // spur_freq_cfg_3_high
+    /*[72] =*/ 0,   // spur_freq_cfg_4_low
+    /*[73] =*/ 0,   // spur_freq_cfg_4_high
+
+    /*[74] =*/ 1,   // Reserved, do not change
+    /*[75] =*/ 0x93,   // Reserved, do not change
+    /*[76] =*/ 0x43,   // Reserved, do not change
+    /*[77] =*/ 0x00,   // Reserved, do not change
+
+    /*[78] =*/ 0,
+    /*[79] =*/ 0,
+    /*[80] =*/ 0,
+    /*[81] =*/ 0,
+    /*[82] =*/ 0,
+    /*[83] =*/ 0,
+    /*[84] =*/ 0,
+    /*[85] =*/ 0,
+    /*[86] =*/ 0,
+    /*[87] =*/ 0,
+    /*[88] =*/ 0,
+    /*[89] =*/ 0,
+    /*[90] =*/ 0,
+    /*[91] =*/ 0,
+    /*[92] =*/ 0,
 
     // low_power_en
     // 0: disable low power mode
     // 1: enable low power mode
-    [93] = 0,
+    /*[93] =*/ 0,
 
     // lp_rf_stg10
     // the attenuation of RF gain stage 0 and 1,
@@ -173,7 +200,7 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     // 0x8: -14db,
     // 0x4: -17.5,
     // 0x0: -23
-    [94] = 0x00,
+    /*[94] =*/ 0x00,
 
 
     // lp_bb_att_ext
@@ -188,20 +215,29 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     // 7: -1.75db,
     // 8: -2db
     // max valve is 24(-6db)
-    [95] = 0,
+    /*[95] =*/ 0,
 
     // pwr_ind_11b_en
     // 0: 11b power is same as mcs0 and 6m
     // 1: enable 11b power different with ofdm
-    [96] = 0,
+    /*[96] =*/ 0,
 
     // pwr_ind_11b_0
     // 1m, 2m power index [0~5]
-    [97] = 0,
+    /*[97] =*/ 0,
 
     // pwr_ind_11b_1
     // 5.5m, 11m power index [0~5]
-    [98] = 0,
+    /*[98] =*/ 0,
+
+    /*[99] =*/ 0,
+    /*[100] =*/ 0,
+    /*[101] =*/ 0,
+    /*[102] =*/ 0,
+    /*[103] =*/ 0,
+    /*[104] =*/ 0,
+    /*[105] =*/ 0,
+    /*[106] =*/ 0,
 
     // vdd33_const
     // the voltage of PA_VDD
@@ -220,10 +256,14 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     // getVcc function (system_get_vdd33):
     // is only available when TOUT pin17 is suspended (floating), this function measure the power voltage of VDD3P3 pin 3 and 4
     // For this function the vdd33_const must be set to 255 (0xFF).
-    [107] = 33,
+    /*[107] =*/ 33,
 
     // disable RF calibration for certain number of times
-    [108] = 0,
+    /*[108] =*/ 0,
+
+    /*[109] =*/ 0,
+    /*[110] =*/ 0,
+    /*[111] =*/ 0,
 
     // freq_correct_en
     // bit[0]:0->do not correct frequency offset, 1->correct frequency offset.
@@ -234,20 +274,21 @@ static const uint8_t ICACHE_FLASH_ATTR phy_init_data[128] =
     // 3: auto measure frequency offset and correct it,  bbpll is 160M, it only can correct + frequency offset.
     // 5: use 113 byte force_freq_offset to correct frequency offset, bbpll is 168M, it can correct + and - frequency offset.
     // 7: use 113 byte force_freq_offset to correct frequency offset, bbpll is 160M , it only can correct + frequency offset.
-    [112] = 0,
+    /*[112] =*/ 0,
 
     // force_freq_offset
     // signed, unit is 8kHz
-    [113] = 0,
+    /*[113] =*/ 0,
 
     // rf_cal_use_flash
     // 0: RF init no RF CAL, using all RF CAL data in flash, it takes about 2ms for RF init
     // 1: RF init only do TX power control CAL, others using RF CAL data in flash, it takes about 20ms for RF init
     // 2: RF init no RF CAL, using all RF CAL data in flash, it takes about 2ms for RF init  (same as 0?!)
     // 3: RF init do all RF CAL, it takes about 200ms for RF init
-    [114] = 1
+    /*[114] =*/ 1
 };
 
+
 // These functions will be overriden from C++ code.
 // Unfortunately, we can't use extern "C" because Arduino preprocessor
 // doesn't generate forward declarations for extern "C" functions correctly,
@@ -260,6 +301,7 @@ static bool spoof_init_data = false;
 
 extern int __real_spi_flash_read(uint32_t addr, uint32_t* dst, size_t size);
 extern int ICACHE_RAM_ATTR __wrap_spi_flash_read(uint32_t addr, uint32_t* dst, size_t size);
+extern int __get_adc_mode();
 
 extern int ICACHE_RAM_ATTR __wrap_spi_flash_read(uint32_t addr, uint32_t* dst, size_t size)
 {
@@ -313,3 +355,5 @@ void user_rf_pre_init()
 
 
 void ICACHE_RAM_ATTR user_spi_flash_dio_to_qio_pre_init() {}
+
+};
diff --git a/cores/esp8266/core_esp8266_postmortem.c b/cores/esp8266/core_esp8266_postmortem.cpp
similarity index 96%
rename from cores/esp8266/core_esp8266_postmortem.c
rename to cores/esp8266/core_esp8266_postmortem.cpp
index 67ceac0127..f18dcfe53b 100644
--- a/cores/esp8266/core_esp8266_postmortem.c
+++ b/cores/esp8266/core_esp8266_postmortem.cpp
@@ -22,6 +22,8 @@
 #include <stdint.h>
 #include <stddef.h>
 #include <stdbool.h>
+#include <stdio.h>
+#include <stdarg.h>
 #include "debug.h"
 #include "ets_sys.h"
 #include "user_interface.h"
@@ -31,6 +33,8 @@
 #include "gdb_hooks.h"
 #include "StackThunk.h"
 
+extern "C" {
+
 extern void __real_system_restart_local();
 
 // These will be pointers to PROGMEM const strings
@@ -91,7 +95,8 @@ void __wrap_system_restart_local() {
         raise_exception();
     }
 
-    struct rst_info rst_info = {0};
+    struct rst_info rst_info;
+    memset(&rst_info, 0, sizeof(rst_info));
     system_rtc_mem_read(0, &rst_info, sizeof(rst_info));
     if (rst_info.reason != REASON_SOFT_WDT_RST &&
         rst_info.reason != REASON_EXCEPTION_RST &&
@@ -100,7 +105,8 @@ void __wrap_system_restart_local() {
         return;
     }
 
-    ets_install_putc1(&uart_write_char_d);
+    // TODO:  ets_install_putc1 definition is wrong in ets_sys.h, need cast
+    ets_install_putc1((void *)&uart_write_char_d);
 
     if (s_panic_line) {
         ets_printf_P(PSTR("\nPanic %S:%d %S"), s_panic_file, s_panic_line, s_panic_func);
@@ -175,7 +181,7 @@ void __wrap_system_restart_local() {
 
     custom_crash_callback( &rst_info, sp_dump + offset, stack_end );
 
-    delayMicroseconds(10000);
+    ets_delay_us(10000);
     __real_system_restart_local();
 }
 
@@ -248,3 +254,4 @@ void __panic_func(const char* file, int line, const char* func) {
     raise_exception();
 }
 
+};
diff --git a/cores/esp8266/core_esp8266_si2c.c b/cores/esp8266/core_esp8266_si2c.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_si2c.c
rename to cores/esp8266/core_esp8266_si2c.cpp
index 549273a1ad..6f6cd58971 100644
--- a/cores/esp8266/core_esp8266_si2c.c
+++ b/cores/esp8266/core_esp8266_si2c.cpp
@@ -23,6 +23,8 @@
 #include "pins_arduino.h"
 #include "wiring_private.h"
 
+extern "C" {
+
 unsigned int preferred_si2c_clock = 100000;
 #include "twi_util.h"
 
@@ -99,7 +101,7 @@ static void onSdaChange(void);
 static ETSEvent eventTaskQueue[EVENTTASK_QUEUE_SIZE];
 static void eventTask(ETSEvent *e);
 static ETSTimer timer;
-static void onTimer();
+static void onTimer(void *unused);
 
 #define SDA_LOW()   (GPES = (1 << twi_sda)) //Enable SDA (becomes output and since GPO is 0 for the pin, it will pull the line low)
 #define SDA_HIGH()  (GPEC = (1 << twi_sda)) //Disable SDA (becomes input and since it has pullup it will go high)
@@ -179,6 +181,7 @@ static void ICACHE_RAM_ATTR twi_delay(unsigned char v){
   for (i = 0; i < v; i++) {
     reg = GPI;
   }
+  (void)reg;
 #pragma GCC diagnostic pop
 }
 
@@ -478,8 +481,9 @@ void ICACHE_RAM_ATTR twi_onTwipEvent(uint8_t status)
   }
 }
 
-void ICACHE_RAM_ATTR onTimer()
+void ICACHE_RAM_ATTR onTimer(void *unused)
 {
+	(void)unused;
 	twi_releaseBus();
 	twip_status = TW_BUS_ERROR;
 	twi_onTwipEvent(twip_status);
@@ -781,3 +785,5 @@ void ICACHE_RAM_ATTR onSdaChange(void)
 			break;
 	}
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_sigma_delta.c b/cores/esp8266/core_esp8266_sigma_delta.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_sigma_delta.c
rename to cores/esp8266/core_esp8266_sigma_delta.cpp
index d101401c2e..68fc589e24 100644
--- a/cores/esp8266/core_esp8266_sigma_delta.c
+++ b/cores/esp8266/core_esp8266_sigma_delta.cpp
@@ -21,6 +21,8 @@
 
 #include "Arduino.h" // using pinMode
 
+extern "C" {
+
 // definitions in esp8266_peri.h style
 #define GPSD  ESP8266_REG(0x368) // GPIO_SIGMA_DELTA register @ 0x600000368
 #define GPSDT 0  // target, 8 bits
@@ -172,3 +174,5 @@ uint8_t ICACHE_FLASH_ATTR sigmaDeltaGetPrescaler(void)
 {
   return (uint8_t)((GPSD >> GPSDP) & 0xFF);
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_timer.c b/cores/esp8266/core_esp8266_timer.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_timer.c
rename to cores/esp8266/core_esp8266_timer.cpp
index 1b18861ae4..a2bce55003 100644
--- a/cores/esp8266/core_esp8266_timer.c
+++ b/cores/esp8266/core_esp8266_timer.cpp
@@ -24,6 +24,8 @@
 #include "c_types.h"
 #include "ets_sys.h"
 
+extern "C" {
+
 // ------------------------------------------------------------------ -
 // timer 1
 
@@ -101,3 +103,5 @@ void ICACHE_RAM_ATTR timer0_detachInterrupt() {
     timer0_user_cb = NULL;
     ETS_CCOMPARE0_DISABLE();
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_waveform.c b/cores/esp8266/core_esp8266_waveform.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_waveform.c
rename to cores/esp8266/core_esp8266_waveform.cpp
index e443102db7..59fce8695e 100644
--- a/cores/esp8266/core_esp8266_waveform.c
+++ b/cores/esp8266/core_esp8266_waveform.cpp
@@ -41,6 +41,8 @@
 #include "ets_sys.h"
 #include "core_esp8266_waveform.h"
 
+extern "C" {
+
 // Maximum delay between IRQs
 #define MAXIRQUS (10000)
 
@@ -303,3 +305,5 @@ static ICACHE_RAM_ATTR void timer1Interrupt() {
 #endif
   TEIE |= TEIE1; // Edge int enable
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_wiring.c b/cores/esp8266/core_esp8266_wiring.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_wiring.c
rename to cores/esp8266/core_esp8266_wiring.cpp
index 3d91043d34..247a02bbda 100644
--- a/cores/esp8266/core_esp8266_wiring.c
+++ b/cores/esp8266/core_esp8266_wiring.cpp
@@ -25,6 +25,9 @@
 #include "user_interface.h"
 #include "cont.h"
 
+extern "C" {
+
+extern void ets_delay_us(uint32_t us);
 extern void esp_schedule();
 extern void esp_yield();
 
@@ -210,3 +213,5 @@ void init() {
     os_timer_setfn(&micros_overflow_timer, (os_timer_func_t*) &micros_overflow_tick, 0);
     os_timer_arm(&micros_overflow_timer, 60000, REPEAT);
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_wiring_analog.c b/cores/esp8266/core_esp8266_wiring_analog.cpp
similarity index 96%
rename from cores/esp8266/core_esp8266_wiring_analog.c
rename to cores/esp8266/core_esp8266_wiring_analog.cpp
index 1ff1d264de..27c98ff3f0 100644
--- a/cores/esp8266/core_esp8266_wiring_analog.c
+++ b/cores/esp8266/core_esp8266_wiring_analog.cpp
@@ -24,7 +24,9 @@
 
 #include "wiring_private.h"
 #include "pins_arduino.h"
+#include "user_interface.h"
 
+extern "C" {
 
 extern int __analogRead(uint8_t pin)
 {
@@ -36,3 +38,5 @@ extern int __analogRead(uint8_t pin)
 }
 
 extern int analogRead(uint8_t pin) __attribute__ ((weak, alias("__analogRead")));
+
+};
diff --git a/cores/esp8266/core_esp8266_wiring_digital.c b/cores/esp8266/core_esp8266_wiring_digital.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_wiring_digital.c
rename to cores/esp8266/core_esp8266_wiring_digital.cpp
index 1954b3a1a2..28af409169 100644
--- a/cores/esp8266/core_esp8266_wiring_digital.c
+++ b/cores/esp8266/core_esp8266_wiring_digital.cpp
@@ -24,8 +24,11 @@
 #include "c_types.h"
 #include "eagle_soc.h"
 #include "ets_sys.h"
+#include "user_interface.h"
 #include "core_esp8266_waveform.h"
 
+extern "C" {
+
 uint8_t esp8266_gpioToFn[16] = {0x34, 0x18, 0x38, 0x14, 0x3C, 0x40, 0x1C, 0x20, 0x24, 0x28, 0x2C, 0x30, 0x04, 0x08, 0x0C, 0x10};
 
 extern void __pinMode(uint8_t pin, uint8_t mode) {
@@ -232,3 +235,4 @@ extern int digitalRead(uint8_t pin) __attribute__ ((weak, alias("__digitalRead")
 extern void attachInterrupt(uint8_t pin, voidFuncPtr handler, int mode) __attribute__ ((weak, alias("__attachInterrupt")));
 extern void detachInterrupt(uint8_t pin) __attribute__ ((weak, alias("__detachInterrupt")));
 
+};
diff --git a/cores/esp8266/core_esp8266_wiring_pulse.c b/cores/esp8266/core_esp8266_wiring_pulse.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_wiring_pulse.c
rename to cores/esp8266/core_esp8266_wiring_pulse.cpp
index ddcd8b9cd5..8e124ac312 100644
--- a/cores/esp8266/core_esp8266_wiring_pulse.c
+++ b/cores/esp8266/core_esp8266_wiring_pulse.cpp
@@ -22,6 +22,7 @@
 #include "wiring_private.h"
 #include "pins_arduino.h"
 
+extern "C" {
 
 extern uint32_t xthal_get_ccount();
 
@@ -53,3 +54,5 @@ unsigned long pulseInLong(uint8_t pin, uint8_t state, unsigned long timeout)
 {
     return pulseIn(pin, state, timeout);
 }
+
+};
diff --git a/cores/esp8266/core_esp8266_wiring_pwm.c b/cores/esp8266/core_esp8266_wiring_pwm.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_wiring_pwm.c
rename to cores/esp8266/core_esp8266_wiring_pwm.cpp
index 744a3e4c84..5a3481bbd8 100644
--- a/cores/esp8266/core_esp8266_wiring_pwm.c
+++ b/cores/esp8266/core_esp8266_wiring_pwm.cpp
@@ -24,6 +24,7 @@
 #include <Arduino.h>
 #include "core_esp8266_waveform.h"
 
+extern "C" {
 
 static uint32_t analogMap = 0;
 static int32_t analogScale = PWMRANGE;
@@ -76,3 +77,5 @@ extern void __analogWrite(uint8_t pin, int val) {
 extern void analogWrite(uint8_t pin, int val) __attribute__((weak, alias("__analogWrite")));
 extern void analogWriteFreq(uint32_t freq) __attribute__((weak, alias("__analogWriteFreq")));
 extern void analogWriteRange(uint32_t range) __attribute__((weak, alias("__analogWriteRange")));
+
+};
diff --git a/cores/esp8266/core_esp8266_wiring_shift.c b/cores/esp8266/core_esp8266_wiring_shift.cpp
similarity index 99%
rename from cores/esp8266/core_esp8266_wiring_shift.c
rename to cores/esp8266/core_esp8266_wiring_shift.cpp
index 673db90641..a5675c44f4 100644
--- a/cores/esp8266/core_esp8266_wiring_shift.c
+++ b/cores/esp8266/core_esp8266_wiring_shift.cpp
@@ -26,6 +26,7 @@
  */
 
 #include "wiring_private.h"
+extern "C" {
 
 uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder) {
     uint8_t value = 0;
@@ -55,3 +56,5 @@ void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val)
         digitalWrite(clockPin, LOW);
     }
 }
+
+};
diff --git a/cores/esp8266/esp8266_peri.h b/cores/esp8266/esp8266_peri.h
index 01f2a417cd..15a596aa6c 100644
--- a/cores/esp8266/esp8266_peri.h
+++ b/cores/esp8266/esp8266_peri.h
@@ -22,6 +22,7 @@
 #define ESP8266_PERI_H_INCLUDED
 
 #include "c_types.h"
+#include "esp8266_undocumented.h"
 
 #define ESP8266_REG(addr) *((volatile uint32_t *)(0x60000000+(addr)))
 #define ESP8266_DREG(addr) *((volatile uint32_t *)(0x3FF00000+(addr)))
diff --git a/cores/esp8266/esp8266_undocumented.h b/cores/esp8266/esp8266_undocumented.h
new file mode 100644
index 0000000000..dc84e2f57e
--- /dev/null
+++ b/cores/esp8266/esp8266_undocumented.h
@@ -0,0 +1,18 @@
+// ROM and blob calls without official headers available
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// ROM
+
+extern void rom_i2c_writeReg_Mask(int, int, int, int, int, int);
+extern int rom_i2c_readReg_Mask(int, int, int, int, int);
+
+extern int uart_baudrate_detect(int, int);
+
+extern void ets_delay_us(uint32_t us);
+
+#ifdef __cplusplus
+};
+#endif
diff --git a/cores/esp8266/gdb_hooks.c b/cores/esp8266/gdb_hooks.cpp
similarity index 99%
rename from cores/esp8266/gdb_hooks.c
rename to cores/esp8266/gdb_hooks.cpp
index 26aa6b0dfb..3516712c9f 100644
--- a/cores/esp8266/gdb_hooks.c
+++ b/cores/esp8266/gdb_hooks.cpp
@@ -24,6 +24,7 @@
 /* gdb_init and gdb_do_break do not return anything, but since the return
    value is in register, it doesn't hurt to return a bool, so that the
    same stub can be used for gdb_present. */
+extern "C" {
 
 static bool ICACHE_RAM_ATTR __gdb_no_op()
 {
@@ -40,3 +41,4 @@ void gdbstub_set_uart_isr_callback(void (*func)(void*, uint8_t), void* arg) __at
 void gdbstub_write_char(char c) __attribute__ ((weak, alias("__gdb_no_op")));
 void gdbstub_write(const char* buf, size_t size) __attribute__ ((weak, alias("__gdb_no_op")));
 
+};
diff --git a/cores/esp8266/heap.c b/cores/esp8266/heap.cpp
similarity index 99%
rename from cores/esp8266/heap.c
rename to cores/esp8266/heap.cpp
index d11525671c..b0bd908614 100644
--- a/cores/esp8266/heap.c
+++ b/cores/esp8266/heap.cpp
@@ -8,6 +8,8 @@
 #include <c_types.h>
 #include <sys/reent.h>
 
+extern "C" {
+
 // Debugging helper, last allocation which returned NULL
 void *umm_last_fail_alloc_addr = NULL;
 int umm_last_fail_alloc_size = 0;
@@ -189,3 +191,5 @@ void system_show_malloc(void)
 {
     umm_info(NULL, 1);
 }
+
+};
diff --git a/cores/esp8266/libb64/cdecode.c b/cores/esp8266/libb64/cdecode.cpp
similarity index 90%
rename from cores/esp8266/libb64/cdecode.c
rename to cores/esp8266/libb64/cdecode.cpp
index aa84ef60a8..fcd6f0401a 100755
--- a/cores/esp8266/libb64/cdecode.c
+++ b/cores/esp8266/libb64/cdecode.cpp
@@ -5,15 +5,18 @@ This is part of the libb64 project, and has been placed in the public domain.
 For details, see http://sourceforge.net/projects/libb64
 */
 
-#include "cdecode.h"
+#include <pgmspace.h>
 #include <stdint.h>
+#include "cdecode.h"
+
+extern "C" {
 
 static int base64_decode_value_signed(int8_t value_in){
-  static const int8_t decoding[] = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51};
+  static const int8_t decoding[] PROGMEM  = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51};
   static const int8_t decoding_size = sizeof(decoding);
   value_in -= 43;
   if (value_in < 0 || value_in > decoding_size) return -1;
-  return decoding[(int)value_in];
+  return pgm_read_byte( &decoding[(int)value_in] );
 }
 
 void base64_init_decodestate(base64_decodestate* state_in){
@@ -97,3 +100,5 @@ int base64_decode_block(const char* code_in, const int length_in, char* plaintex
 int base64_decode_chars(const char* code_in, const int length_in, char* plaintext_out){
   return base64_decode_chars_signed((int8_t *) code_in, length_in, (int8_t *) plaintext_out);
 }
+
+};
diff --git a/cores/esp8266/libb64/cencode.c b/cores/esp8266/libb64/cencode.cpp
similarity index 93%
rename from cores/esp8266/libb64/cencode.c
rename to cores/esp8266/libb64/cencode.cpp
index 4b902997de..69272faeca 100755
--- a/cores/esp8266/libb64/cencode.c
+++ b/cores/esp8266/libb64/cencode.cpp
@@ -5,8 +5,11 @@ This is part of the libb64 project, and has been placed in the public domain.
 For details, see http://sourceforge.net/projects/libb64
 */
 
+#include <pgmspace.h>
 #include "cencode.h"
 
+extern "C" {
+
 void base64_init_encodestate(base64_encodestate* state_in){
   state_in->step = step_A;
   state_in->result = 0;
@@ -21,9 +24,9 @@ void base64_init_encodestate_nonewlines(base64_encodestate* state_in){
 }
 
 char base64_encode_value(char value_in){
-  static const char* encoding = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+  static const char encoding[] PROGMEM = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
   if (value_in > 63) return '=';
-  return encoding[(int)value_in];
+  return pgm_read_byte( &encoding[(int)value_in] );
 }
 
 int base64_encode_block(const char* plaintext_in, int length_in, char* code_out, base64_encodestate* state_in){
@@ -107,3 +110,5 @@ int base64_encode_chars(const char* plaintext_in, int length_in, char* code_out)
   int len = base64_encode_block(plaintext_in, length_in, code_out, &_state);
   return len + base64_encode_blockend((code_out + len), &_state);
 }
+
+};
diff --git a/cores/esp8266/libc_replacements.c b/cores/esp8266/libc_replacements.cpp
similarity index 99%
rename from cores/esp8266/libc_replacements.c
rename to cores/esp8266/libc_replacements.cpp
index be55e49d3d..1d591abf0c 100644
--- a/cores/esp8266/libc_replacements.c
+++ b/cores/esp8266/libc_replacements.cpp
@@ -45,6 +45,7 @@
 #include "user_interface.h"
 #include "debug.h"
 
+extern "C" {
 
 int ICACHE_RAM_ATTR _open_r (struct _reent* unused, const char *ptr, int mode) {
     (void)unused;
@@ -128,4 +129,6 @@ void _exit(int status) {
 int atexit(void (*func)()) {
     (void) func;
     return 0;
-}
\ No newline at end of file
+}
+
+};
diff --git a/cores/esp8266/sntp-lwip2.c b/cores/esp8266/sntp-lwip2.cpp
similarity index 99%
rename from cores/esp8266/sntp-lwip2.c
rename to cores/esp8266/sntp-lwip2.cpp
index 2eabf12412..50b10bc5da 100644
--- a/cores/esp8266/sntp-lwip2.c
+++ b/cores/esp8266/sntp-lwip2.cpp
@@ -43,6 +43,8 @@
 #include <os_type.h>
 #include "coredecls.h"
 
+extern "C" {
+
 static void (*_settimeofday_cb)(void) = NULL;
 
 void settimeofday_cb (void (*cb)(void))
@@ -55,6 +57,8 @@ void settimeofday_cb (void (*cb)(void))
 #include <pgmspace.h>
 
 static const char stod14[] PROGMEM = "settimeofday() can't set time!\n";
+bool sntp_set_timezone(sint8 timezone);
+void sntp_set_daylight(int daylight);
 
 int settimeofday(const struct timeval* tv, const struct timezone* tz)
 {
@@ -461,3 +465,5 @@ int settimeofday(const struct timeval* tv, const struct timezone* tz)
 }
 
 #endif // lwip2 only
+
+};
diff --git a/cores/esp8266/spiffs/spiffs_cache.c b/cores/esp8266/spiffs/spiffs_cache.cpp
similarity index 99%
rename from cores/esp8266/spiffs/spiffs_cache.c
rename to cores/esp8266/spiffs/spiffs_cache.cpp
index e7cd4b7376..7640ac6dd5 100644
--- a/cores/esp8266/spiffs/spiffs_cache.c
+++ b/cores/esp8266/spiffs/spiffs_cache.cpp
@@ -10,6 +10,8 @@
 
 #if SPIFFS_CACHE
 
+extern "C" {
+
 // returns cached page for give page index, or null if no such cached page
 static spiffs_cache_page *spiffs_cache_page_get(spiffs *fs, spiffs_page_ix pix) {
   spiffs_cache *cache = spiffs_get_cache(fs);
@@ -316,4 +318,5 @@ void spiffs_cache_init(spiffs *fs) {
   }
 }
 
+};
 #endif // SPIFFS_CACHE
diff --git a/cores/esp8266/spiffs/spiffs_check.c b/cores/esp8266/spiffs/spiffs_check.cpp
similarity index 99%
rename from cores/esp8266/spiffs/spiffs_check.c
rename to cores/esp8266/spiffs/spiffs_check.cpp
index dde85eff3c..c17deef414 100644
--- a/cores/esp8266/spiffs/spiffs_check.c
+++ b/cores/esp8266/spiffs/spiffs_check.cpp
@@ -37,6 +37,8 @@
   } while (0)
 #endif
 
+extern "C" {
+
 //---------------------------------------
 // Look up consistency
 
@@ -925,7 +927,7 @@ static s32_t spiffs_object_index_consistency_check_v(spiffs *fs, spiffs_obj_id o
     } else { // span index
       // objix page, see if header can be found
       int r = spiffs_object_index_search(fs, obj_id);
-      u8_t delete = 0;
+      u8_t _delete = 0;
       if (r == -1) {
         // not in temporary index, try finding it
         spiffs_page_ix objix_hdr_pix;
@@ -936,7 +938,7 @@ static s32_t spiffs_object_index_consistency_check_v(spiffs *fs, spiffs_obj_id o
           obj_table[*log_ix] = obj_id & ~SPIFFS_OBJ_ID_IX_FLAG;
         } else if (res == SPIFFS_ERR_NOT_FOUND) {
           // not found, register as unreachable
-          delete = 1;
+          _delete = 1;
           obj_table[*log_ix] = obj_id | SPIFFS_OBJ_ID_IX_FLAG;
         } else {
           SPIFFS_CHECK_RES(res);
@@ -949,11 +951,11 @@ static s32_t spiffs_object_index_consistency_check_v(spiffs *fs, spiffs_obj_id o
         // in temporary index, check reachable flag
         if ((obj_table[r] & SPIFFS_OBJ_ID_IX_FLAG)) {
           // registered as unreachable
-          delete = 1;
+          _delete = 1;
         }
       }
 
-      if (delete) {
+      if (_delete) {
         SPIFFS_CHECK_DBG("IX: FIXUP: pix "_SPIPRIpg", obj id:"_SPIPRIid" spix:"_SPIPRIsp" is orphan index - deleting\n",
             cur_pix, obj_id, p_hdr.span_ix);
         CHECK_CB(fs, SPIFFS_CHECK_INDEX, SPIFFS_CHECK_DELETE_ORPHANED_INDEX, cur_pix, obj_id);
@@ -992,4 +994,6 @@ s32_t spiffs_object_index_consistency_check(spiffs *fs) {
   return res;
 }
 
+};
+
 #endif // !SPIFFS_READ_ONLY
diff --git a/cores/esp8266/spiffs/spiffs_gc.c b/cores/esp8266/spiffs/spiffs_gc.cpp
similarity index 99%
rename from cores/esp8266/spiffs/spiffs_gc.c
rename to cores/esp8266/spiffs/spiffs_gc.cpp
index db1af4ccf6..32d863ec3a 100644
--- a/cores/esp8266/spiffs/spiffs_gc.c
+++ b/cores/esp8266/spiffs/spiffs_gc.cpp
@@ -3,6 +3,8 @@
 
 #if !SPIFFS_READ_ONLY
 
+extern "C" {
+
 // Erases a logical block and updates the erase counter.
 // If cache is enabled, all pages that might be cached in this block
 // is dropped.
@@ -603,4 +605,6 @@ s32_t spiffs_gc_clean(spiffs *fs, spiffs_block_ix bix) {
   return res;
 }
 
+};
+
 #endif // !SPIFFS_READ_ONLY
diff --git a/cores/esp8266/spiffs/spiffs_hydrogen.c b/cores/esp8266/spiffs/spiffs_hydrogen.cpp
similarity index 98%
rename from cores/esp8266/spiffs/spiffs_hydrogen.c
rename to cores/esp8266/spiffs/spiffs_hydrogen.cpp
index 18c8bb4148..c4efa4f726 100644
--- a/cores/esp8266/spiffs/spiffs_hydrogen.c
+++ b/cores/esp8266/spiffs/spiffs_hydrogen.cpp
@@ -8,6 +8,8 @@
 #include "spiffs.h"
 #include "spiffs_nucleus.h"
 
+extern "C" {
+
 #if SPIFFS_CACHE == 1
 static s32_t spiffs_fflush_cache(spiffs *fs, spiffs_file fh);
 #endif
@@ -1429,7 +1431,7 @@ s32_t SPIFFS_vis(spiffs *fs) {
     SPIFFS_CHECK_RES(res);
 
     if (erase_count != (spiffs_obj_id)-1) {
-      spiffs_printf("\tera_cnt: "_SPIPRIi"\n", erase_count);
+      spiffs_printf("\tera_cnt: " _SPIPRIi "\n", erase_count);
     } else {
       spiffs_printf("\tera_cnt: N/A\n");
     }
@@ -1437,16 +1439,18 @@ s32_t SPIFFS_vis(spiffs *fs) {
     bix++;
   } // per block
 
-  spiffs_printf("era_cnt_max: "_SPIPRIi"\n", fs->max_erase_count);
-  spiffs_printf("last_errno:  "_SPIPRIi"\n", fs->err_code);
-  spiffs_printf("blocks:      "_SPIPRIi"\n", fs->block_count);
-  spiffs_printf("free_blocks: "_SPIPRIi"\n", fs->free_blocks);
-  spiffs_printf("page_alloc:  "_SPIPRIi"\n", fs->stats_p_allocated);
-  spiffs_printf("page_delet:  "_SPIPRIi"\n", fs->stats_p_deleted);
+  spiffs_printf("era_cnt_max: " _SPIPRIi "\n", fs->max_erase_count);
+  spiffs_printf("last_errno:  " _SPIPRIi "\n", fs->err_code);
+  spiffs_printf("blocks:      " _SPIPRIi "\n", fs->block_count);
+  spiffs_printf("free_blocks: " _SPIPRIi "\n", fs->free_blocks);
+  spiffs_printf("page_alloc:  " _SPIPRIi "\n", fs->stats_p_allocated);
+  spiffs_printf("page_delet:  " _SPIPRIi "\n", fs->stats_p_deleted);
   SPIFFS_UNLOCK(fs);
   u32_t total, used;
   SPIFFS_info(fs, &total, &used);
-  spiffs_printf("used:        "_SPIPRIi" of "_SPIPRIi"\n", used, total);
+  spiffs_printf("used:        " _SPIPRIi " of " _SPIPRIi "\n", used, total);
   return res;
 }
 #endif
+
+};
diff --git a/cores/esp8266/spiffs/spiffs_nucleus.c b/cores/esp8266/spiffs/spiffs_nucleus.cpp
similarity index 90%
rename from cores/esp8266/spiffs/spiffs_nucleus.c
rename to cores/esp8266/spiffs/spiffs_nucleus.cpp
index 27ecdff2a6..35238f351b 100644
--- a/cores/esp8266/spiffs/spiffs_nucleus.c
+++ b/cores/esp8266/spiffs/spiffs_nucleus.cpp
@@ -1,6 +1,8 @@
 #include "spiffs.h"
 #include "spiffs_nucleus.h"
 
+extern "C" {
+
 static s32_t spiffs_page_data_check(spiffs *fs, spiffs_fd *fd, spiffs_page_ix pix, spiffs_span_ix spix) {
   s32_t res = SPIFFS_OK;
   if (pix == (spiffs_page_ix)-1) {
@@ -232,7 +234,7 @@ s32_t spiffs_erase_block(
 
   // here we ignore res, just try erasing the block
   while (size > 0) {
-    SPIFFS_DBG("erase "_SPIPRIad":"_SPIPRIi"\n", addr,  SPIFFS_CFG_PHYS_ERASE_SZ(fs));
+    SPIFFS_DBG("erase " _SPIPRIad ":" _SPIPRIi "\n", addr,  SPIFFS_CFG_PHYS_ERASE_SZ(fs));
     SPIFFS_HAL_ERASE(fs, addr, SPIFFS_CFG_PHYS_ERASE_SZ(fs));
 
     addr += SPIFFS_CFG_PHYS_ERASE_SZ(fs);
@@ -407,7 +409,7 @@ s32_t spiffs_obj_lu_scan(
 #if SPIFFS_USE_MAGIC
   if (unerased_bix != (spiffs_block_ix)-1) {
     // found one unerased block, remedy
-    SPIFFS_DBG("mount: erase block "_SPIPRIbl"\n", bix);
+    SPIFFS_DBG("mount: erase block " _SPIPRIbl "\n", bix);
 #if SPIFFS_READ_ONLY
     res = SPIFFS_ERR_RO_ABORTED_OPERATION;
 #else
@@ -645,7 +647,7 @@ static void spiffs_update_ix_map(spiffs *fs,
     }
 
     map->map_buf[map_spix - map->start_spix] = objix_data_pix;
-    SPIFFS_DBG("map "_SPIPRIid":"_SPIPRIsp" ("_SPIPRIsp"--"_SPIPRIsp") objix.spix:"_SPIPRIsp" to pix "_SPIPRIpg"\n",
+    SPIFFS_DBG("map " _SPIPRIid ":" _SPIPRIsp " (" _SPIPRIsp "--" _SPIPRIsp ") objix.spix:" _SPIPRIsp " to pix " _SPIPRIpg "\n",
         fd->obj_id, map_spix - map->start_spix,
         map->start_spix, map->end_spix,
         objix->p_hdr.span_ix,
@@ -696,7 +698,7 @@ static s32_t spiffs_populate_ix_map_v(
     spiffs_update_ix_map(fs, state->fd, objix->p_hdr.span_ix, objix);
 
     state->remaining_objix_pages_to_visit--;
-    SPIFFS_DBG("map "_SPIPRIid" ("_SPIPRIsp"--"_SPIPRIsp") remaining objix pages "_SPIPRIi"\n",
+    SPIFFS_DBG("map " _SPIPRIid " (" _SPIPRIsp "--" _SPIPRIsp ") remaining objix pages " _SPIPRIi "\n",
         state->fd->obj_id,
         state->fd->ix_map->start_spix, state->fd->ix_map->end_spix,
         state->remaining_objix_pages_to_visit);
@@ -924,7 +926,7 @@ s32_t spiffs_object_create(
   // find free entry
   res = spiffs_obj_lu_find_free(fs, fs->free_cursor_block_ix, fs->free_cursor_obj_lu_entry, &bix, &entry);
   SPIFFS_CHECK_RES(res);
-  SPIFFS_DBG("create: found free page @ "_SPIPRIpg" bix:"_SPIPRIbl" entry:"_SPIPRIsp"\n", (spiffs_page_ix)SPIFFS_OBJ_LOOKUP_ENTRY_TO_PIX(fs, bix, entry), bix, entry);
+  SPIFFS_DBG("create: found free page @ " _SPIPRIpg " bix:" _SPIPRIbl " entry:" _SPIPRIsp "\n", (spiffs_page_ix)SPIFFS_OBJ_LOOKUP_ENTRY_TO_PIX(fs, bix, entry), bix, entry);
 
   // occupy page in object lookup
   res = _spiffs_wr(fs, SPIFFS_OP_T_OBJ_LU | SPIFFS_OP_C_UPDT,
@@ -1048,7 +1050,7 @@ void spiffs_cb_object_event(
   spiffs_obj_id obj_id = obj_id_raw & ~SPIFFS_OBJ_ID_IX_FLAG;
   u32_t i;
   spiffs_fd *fds = (spiffs_fd *)fs->fd_space;
-  SPIFFS_DBG("       CALLBACK  %s obj_id:"_SPIPRIid" spix:"_SPIPRIsp" npix:"_SPIPRIpg" nsz:"_SPIPRIi"\n", (const char *[]){"UPD", "NEW", "DEL", "MOV", "HUP","???"}[MIN(ev,5)],
+  SPIFFS_DBG("       CALLBACK  %s obj_id:" _SPIPRIid " spix:" _SPIPRIsp " npix:" _SPIPRIpg " nsz:" _SPIPRIi "\n", (const char *[]){"UPD", "NEW", "DEL", "MOV", "HUP","???"}[MIN(ev,5)],
       obj_id_raw, spix, new_pix, new_size);
   for (i = 0; i < fs->fd_count; i++) {
     spiffs_fd *cur_fd = &fds[i];
@@ -1061,7 +1063,7 @@ void spiffs_cb_object_event(
 #if SPIFFS_TEMPORAL_FD_CACHE
         if (cur_fd->score == 0) continue; // never used fd
 #endif
-        SPIFFS_DBG("       callback: setting fd "_SPIPRIfd":"_SPIPRIid"(fdoffs:"_SPIPRIi" offs:"_SPIPRIi") objix_hdr_pix to "_SPIPRIpg", size:"_SPIPRIi"\n",
+        SPIFFS_DBG("       callback: setting fd " _SPIPRIfd ":" _SPIPRIid "(fdoffs:" _SPIPRIi " offs:" _SPIPRIi ") objix_hdr_pix to " _SPIPRIpg ", size:" _SPIPRIi "\n",
             SPIFFS_FH_OFFS(fs, cur_fd->file_nbr), cur_fd->obj_id, cur_fd->fdoffset, cur_fd->offset, new_pix, new_size);
         cur_fd->objix_hdr_pix = new_pix;
         if (new_size != 0) {
@@ -1081,7 +1083,7 @@ void spiffs_cb_object_event(
           }
 #if SPIFFS_CACHE_WR
           if (cur_fd->cache_page && cur_fd->cache_page->offset > act_new_size+1) {
-            SPIFFS_CACHE_DBG("CACHE_DROP: file trunced, dropping cache page "_SPIPRIi", no writeback\n", cur_fd->cache_page->ix);
+            SPIFFS_CACHE_DBG("CACHE_DROP: file trunced, dropping cache page " _SPIPRIi ", no writeback\n", cur_fd->cache_page->ix);
             spiffs_cache_fd_release(fs, cur_fd->cache_page);
           }
 #endif
@@ -1090,18 +1092,18 @@ void spiffs_cb_object_event(
         // removing file
 #if SPIFFS_CACHE_WR
         if (cur_fd->file_nbr && cur_fd->cache_page) {
-          SPIFFS_CACHE_DBG("CACHE_DROP: file deleted, dropping cache page "_SPIPRIi", no writeback\n", cur_fd->cache_page->ix);
+          SPIFFS_CACHE_DBG("CACHE_DROP: file deleted, dropping cache page " _SPIPRIi ", no writeback\n", cur_fd->cache_page->ix);
           spiffs_cache_fd_release(fs, cur_fd->cache_page);
         }
 #endif
-        SPIFFS_DBG("       callback: release fd "_SPIPRIfd":"_SPIPRIid" span:"_SPIPRIsp" objix_pix to "_SPIPRIpg"\n", SPIFFS_FH_OFFS(fs, cur_fd->file_nbr), cur_fd->obj_id, spix, new_pix);
+        SPIFFS_DBG("       callback: release fd " _SPIPRIfd ":" _SPIPRIid " span:" _SPIPRIsp " objix_pix to " _SPIPRIpg "\n", SPIFFS_FH_OFFS(fs, cur_fd->file_nbr), cur_fd->obj_id, spix, new_pix);
         cur_fd->file_nbr = 0;
         cur_fd->obj_id = SPIFFS_OBJ_ID_DELETED;
       }
     } // object index header update
     if (cur_fd->cursor_objix_spix == spix) {
       if (ev != SPIFFS_EV_IX_DEL) {
-        SPIFFS_DBG("       callback: setting fd "_SPIPRIfd":"_SPIPRIid" span:"_SPIPRIsp" objix_pix to "_SPIPRIpg"\n", SPIFFS_FH_OFFS(fs, cur_fd->file_nbr), cur_fd->obj_id, spix, new_pix);
+        SPIFFS_DBG("       callback: setting fd " _SPIPRIfd ":" _SPIPRIid " span:" _SPIPRIsp " objix_pix to " _SPIPRIpg "\n", SPIFFS_FH_OFFS(fs, cur_fd->file_nbr), cur_fd->obj_id, spix, new_pix);
         cur_fd->cursor_objix_pix = new_pix;
       } else {
         cur_fd->cursor_objix_pix = 0;
@@ -1119,7 +1121,7 @@ void spiffs_cb_object_event(
       if (cur_fd->file_nbr == 0 ||
           cur_fd->ix_map == 0 ||
           (cur_fd->obj_id & ~SPIFFS_OBJ_ID_IX_FLAG) != obj_id) continue;
-      SPIFFS_DBG("       callback: map ix update fd "_SPIPRIfd":"_SPIPRIid" span:"_SPIPRIsp"\n", SPIFFS_FH_OFFS(fs, cur_fd->file_nbr), cur_fd->obj_id, spix);
+      SPIFFS_DBG("       callback: map ix update fd " _SPIPRIfd ":" _SPIPRIid " span:" _SPIPRIsp "\n", SPIFFS_FH_OFFS(fs, cur_fd->file_nbr), cur_fd->obj_id, spix);
       spiffs_update_ix_map(fs, cur_fd, spix, objix);
     }
   }
@@ -1138,7 +1140,7 @@ void spiffs_cb_object_event(
     } else if (ev == SPIFFS_EV_IX_DEL) {
       op = SPIFFS_CB_DELETED;
     } else {
-      SPIFFS_DBG("       callback: WARNING unknown callback event "_SPIPRIi"\n", ev);
+      SPIFFS_DBG("       callback: WARNING unknown callback event " _SPIPRIi "\n", ev);
       return; // bail out
     }
     fs->file_cb_f(fs, op, obj_id, new_pix);
@@ -1196,7 +1198,7 @@ s32_t spiffs_object_open_by_page(
 
   SPIFFS_VALIDATE_OBJIX(oix_hdr.p_hdr, fd->obj_id, 0);
 
-  SPIFFS_DBG("open: fd "_SPIPRIfd" is obj id "_SPIPRIid"\n", SPIFFS_FH_OFFS(fs, fd->file_nbr), fd->obj_id);
+  SPIFFS_DBG("open: fd " _SPIPRIfd " is obj id " _SPIPRIid "\n", SPIFFS_FH_OFFS(fs, fd->file_nbr), fd->obj_id);
 
   return res;
 }
@@ -1209,7 +1211,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
   s32_t res = SPIFFS_OK;
   u32_t written = 0;
 
-  SPIFFS_DBG("append: "_SPIPRIi" bytes @ offs "_SPIPRIi" of size "_SPIPRIi"\n", len, offset, fd->size);
+  SPIFFS_DBG("append: " _SPIPRIi " bytes @ offs " _SPIPRIi " of size " _SPIPRIi "\n", len, offset, fd->size);
 
   if (offset > fd->size) {
     SPIFFS_DBG("append: offset reversed to size\n");
@@ -1218,7 +1220,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
 
   res = spiffs_gc_check(fs, len + SPIFFS_DATA_PAGE_SIZE(fs)); // add an extra page of data worth for meta
   if (res != SPIFFS_OK) {
-    SPIFFS_DBG("append: gc check fail "_SPIPRIi"\n", res);
+    SPIFFS_DBG("append: gc check fail " _SPIPRIi "\n", res);
   }
   SPIFFS_CHECK_RES(res);
 
@@ -1246,7 +1248,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
       // within this clause we return directly if something fails, object index mess-up
       if (written > 0) {
         // store previous object index page, unless first pass
-        SPIFFS_DBG("append: "_SPIPRIid" store objix "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", fd->obj_id,
+        SPIFFS_DBG("append: " _SPIPRIid " store objix " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", fd->obj_id,
             cur_objix_pix, prev_objix_spix, written);
         if (prev_objix_spix == 0) {
           // this is an update to object index header page
@@ -1263,7 +1265,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
             res = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
                 fd->objix_hdr_pix, fs->work, 0, 0, offset+written, &new_objix_hdr_page);
             SPIFFS_CHECK_RES(res);
-            SPIFFS_DBG("append: "_SPIPRIid" store new objix_hdr, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", fd->obj_id,
+            SPIFFS_DBG("append: " _SPIPRIid " store new objix_hdr, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", fd->obj_id,
                 new_objix_hdr_page, 0, written);
           }
         } else {
@@ -1280,7 +1282,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
           res = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
               fd->objix_hdr_pix, 0, 0, 0, offset+written, &new_objix_hdr_page);
           SPIFFS_CHECK_RES(res);
-          SPIFFS_DBG("append: "_SPIPRIid" store new size I "_SPIPRIi" in objix_hdr, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", fd->obj_id,
+          SPIFFS_DBG("append: " _SPIPRIid " store new size I " _SPIPRIi " in objix_hdr, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", fd->obj_id,
               offset+written, new_objix_hdr_page, 0, written);
         }
         fd->size = offset+written;
@@ -1290,7 +1292,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
       // create or load new object index page
       if (cur_objix_spix == 0) {
         // load object index header page, must always exist
-        SPIFFS_DBG("append: "_SPIPRIid" load objixhdr page "_SPIPRIpg":"_SPIPRIsp"\n", fd->obj_id, cur_objix_pix, cur_objix_spix);
+        SPIFFS_DBG("append: " _SPIPRIid " load objixhdr page " _SPIPRIpg ":" _SPIPRIsp "\n", fd->obj_id, cur_objix_pix, cur_objix_spix);
         res = _spiffs_rd(fs, SPIFFS_OP_T_OBJ_IX | SPIFFS_OP_C_READ,
             fd->file_nbr, SPIFFS_PAGE_TO_PADDR(fs, cur_objix_pix), SPIFFS_CFG_LOG_PAGE_SZ(fs), fs->work);
         SPIFFS_CHECK_RES(res);
@@ -1310,19 +1312,19 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
           _SPIFFS_MEMCPY(fs->work, &p_hdr, sizeof(spiffs_page_header));
           spiffs_cb_object_event(fs, (spiffs_page_object_ix *)fs->work,
               SPIFFS_EV_IX_NEW, fd->obj_id, cur_objix_spix, cur_objix_pix, 0);
-          SPIFFS_DBG("append: "_SPIPRIid" create objix page, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", fd->obj_id
+          SPIFFS_DBG("append: " _SPIPRIid " create objix page, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", fd->obj_id
               , cur_objix_pix, cur_objix_spix, written);
         } else {
           // on first pass, we load existing object index page
           spiffs_page_ix pix;
-          SPIFFS_DBG("append: "_SPIPRIid" find objix span_ix:"_SPIPRIsp"\n", fd->obj_id, cur_objix_spix);
+          SPIFFS_DBG("append: " _SPIPRIid " find objix span_ix:" _SPIPRIsp "\n", fd->obj_id, cur_objix_spix);
           if (fd->cursor_objix_spix == cur_objix_spix) {
             pix = fd->cursor_objix_pix;
           } else {
             res = spiffs_obj_lu_find_id_and_span(fs, fd->obj_id | SPIFFS_OBJ_ID_IX_FLAG, cur_objix_spix, 0, &pix);
             SPIFFS_CHECK_RES(res);
           }
-          SPIFFS_DBG("append: "_SPIPRIid" found object index at page "_SPIPRIpg" [fd size "_SPIPRIi"]\n", fd->obj_id, pix, fd->size);
+          SPIFFS_DBG("append: " _SPIPRIid " found object index at page " _SPIPRIpg " [fd size " _SPIPRIi "]\n", fd->obj_id, pix, fd->size);
           res = _spiffs_rd(fs, SPIFFS_OP_T_OBJ_IX | SPIFFS_OP_C_READ,
               fd->file_nbr, SPIFFS_PAGE_TO_PADDR(fs, pix), SPIFFS_CFG_LOG_PAGE_SZ(fs), fs->work);
           SPIFFS_CHECK_RES(res);
@@ -1346,7 +1348,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
       p_hdr.flags = 0xff & ~(SPIFFS_PH_FLAG_FINAL);  // finalize immediately
       res = spiffs_page_allocate_data(fs, fd->obj_id & ~SPIFFS_OBJ_ID_IX_FLAG,
           &p_hdr, &data[written], to_write, page_offs, 1, &data_page);
-      SPIFFS_DBG("append: "_SPIPRIid" store new data page, "_SPIPRIpg":"_SPIPRIsp" offset:"_SPIPRIi", len "_SPIPRIi", written "_SPIPRIi"\n", fd->obj_id,
+      SPIFFS_DBG("append: " _SPIPRIid " store new data page, " _SPIPRIpg ":" _SPIPRIsp " offset:" _SPIPRIi ", len " _SPIPRIi ", written " _SPIPRIi "\n", fd->obj_id,
           data_page, data_spix, page_offs, to_write, written);
     } else {
       // append to existing page, fill out free data in existing page
@@ -1363,7 +1365,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
 
       res = _spiffs_wr(fs, SPIFFS_OP_T_OBJ_DA | SPIFFS_OP_C_UPDT,
           fd->file_nbr, SPIFFS_PAGE_TO_PADDR(fs, data_page) + sizeof(spiffs_page_header) + page_offs, to_write, &data[written]);
-      SPIFFS_DBG("append: "_SPIPRIid" store to existing data page, "_SPIPRIpg":"_SPIPRIsp" offset:"_SPIPRIi", len "_SPIPRIi", written "_SPIPRIi"\n", fd->obj_id
+      SPIFFS_DBG("append: " _SPIPRIid " store to existing data page, " _SPIPRIpg ":" _SPIPRIsp " offset:" _SPIPRIi ", len " _SPIPRIi ", written " _SPIPRIi "\n", fd->obj_id
           , data_page, data_spix, page_offs, to_write, written);
     }
 
@@ -1373,13 +1375,13 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
     if (cur_objix_spix == 0) {
       // update object index header page
       ((spiffs_page_ix*)((u8_t *)objix_hdr + sizeof(spiffs_page_object_ix_header)))[data_spix] = data_page;
-      SPIFFS_DBG("append: "_SPIPRIid" wrote page "_SPIPRIpg" to objix_hdr entry "_SPIPRIsp" in mem\n", fd->obj_id
+      SPIFFS_DBG("append: " _SPIPRIid " wrote page " _SPIPRIpg " to objix_hdr entry " _SPIPRIsp " in mem\n", fd->obj_id
           , data_page, data_spix);
       objix_hdr->size = offset+written;
     } else {
       // update object index page
       ((spiffs_page_ix*)((u8_t *)objix + sizeof(spiffs_page_object_ix)))[SPIFFS_OBJ_IX_ENTRY(fs, data_spix)] = data_page;
-      SPIFFS_DBG("append: "_SPIPRIid" wrote page "_SPIPRIpg" to objix entry "_SPIPRIsp" in mem\n", fd->obj_id
+      SPIFFS_DBG("append: " _SPIPRIid " wrote page " _SPIPRIpg " to objix entry " _SPIPRIsp " in mem\n", fd->obj_id
           , data_page, (spiffs_span_ix)SPIFFS_OBJ_IX_ENTRY(fs, data_spix));
     }
 
@@ -1399,7 +1401,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
   if (cur_objix_spix != 0) {
     // wrote beyond object index header page
     // write last modified object index page, unless object header index page
-    SPIFFS_DBG("append: "_SPIPRIid" store objix page, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", fd->obj_id,
+    SPIFFS_DBG("append: " _SPIPRIid " store objix page, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi"\n", fd->obj_id,
         cur_objix_pix, cur_objix_spix, written);
 
     res2 = spiffs_page_index_check(fs, fd, cur_objix_pix, cur_objix_spix);
@@ -1414,7 +1416,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
     // update size in object header index page
     res2 = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
         fd->objix_hdr_pix, 0, 0, 0, offset+written, &new_objix_hdr_page);
-    SPIFFS_DBG("append: "_SPIPRIid" store new size II "_SPIPRIi" in objix_hdr, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi", res "_SPIPRIi"\n", fd->obj_id
+    SPIFFS_DBG("append: " _SPIPRIid " store new size II " _SPIPRIi " in objix_hdr, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi ", res " _SPIPRIi "\n", fd->obj_id
         , offset+written, new_objix_hdr_page, 0, written, res2);
     SPIFFS_CHECK_RES(res2);
   } else {
@@ -1422,7 +1424,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
     if (offset == 0) {
       // wrote to empty object - simply update size and write whole page
       objix_hdr->size = offset+written;
-      SPIFFS_DBG("append: "_SPIPRIid" store fresh objix_hdr page, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", fd->obj_id
+      SPIFFS_DBG("append: " _SPIPRIid " store fresh objix_hdr page, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", fd->obj_id
           , cur_objix_pix, cur_objix_spix, written);
 
       res2 = spiffs_page_index_check(fs, fd, cur_objix_pix, cur_objix_spix);
@@ -1438,7 +1440,7 @@ s32_t spiffs_object_append(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
       // modifying object index header page, update size and make new copy
       res2 = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
           fd->objix_hdr_pix, fs->work, 0, 0, offset+written, &new_objix_hdr_page);
-      SPIFFS_DBG("append: "_SPIPRIid" store modified objix_hdr page, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", fd->obj_id
+      SPIFFS_DBG("append: " _SPIPRIid " store modified objix_hdr page, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", fd->obj_id
           , new_objix_hdr_page, 0, written);
       SPIFFS_CHECK_RES(res2);
     }
@@ -1488,7 +1490,7 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
           // store previous object index header page
           res = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
               fd->objix_hdr_pix, fs->work, 0, 0, 0, &new_objix_hdr_pix);
-          SPIFFS_DBG("modify: store modified objix_hdr page, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", new_objix_hdr_pix, 0, written);
+          SPIFFS_DBG("modify: store modified objix_hdr page, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", new_objix_hdr_pix, 0, written);
           SPIFFS_CHECK_RES(res);
         } else {
           // store new version of previous object index page
@@ -1498,7 +1500,7 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
           SPIFFS_CHECK_RES(res);
 
           res = spiffs_page_move(fs, fd->file_nbr, (u8_t*)objix, fd->obj_id, 0, cur_objix_pix, &new_objix_pix);
-          SPIFFS_DBG("modify: store previous modified objix page, "_SPIPRIid":"_SPIPRIsp", written "_SPIPRIi"\n", new_objix_pix, objix->p_hdr.span_ix, written);
+          SPIFFS_DBG("modify: store previous modified objix page, " _SPIPRIid ":" _SPIPRIsp ", written " _SPIPRIi "\n", new_objix_pix, objix->p_hdr.span_ix, written);
           SPIFFS_CHECK_RES(res);
           spiffs_cb_object_event(fs, (spiffs_page_object_ix *)objix,
               SPIFFS_EV_IX_UPD, fd->obj_id, objix->p_hdr.span_ix, new_objix_pix, 0);
@@ -1508,7 +1510,7 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
       // load next object index page
       if (cur_objix_spix == 0) {
         // load object index header page, must exist
-        SPIFFS_DBG("modify: load objixhdr page "_SPIPRIpg":"_SPIPRIsp"\n", cur_objix_pix, cur_objix_spix);
+        SPIFFS_DBG("modify: load objixhdr page " _SPIPRIpg ":" _SPIPRIsp "\n", cur_objix_pix, cur_objix_spix);
         res = _spiffs_rd(fs, SPIFFS_OP_T_OBJ_IX | SPIFFS_OP_C_READ,
             fd->file_nbr, SPIFFS_PAGE_TO_PADDR(fs, cur_objix_pix), SPIFFS_CFG_LOG_PAGE_SZ(fs), fs->work);
         SPIFFS_CHECK_RES(res);
@@ -1516,14 +1518,14 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
       } else {
         // load existing object index page on first pass
         spiffs_page_ix pix;
-        SPIFFS_DBG("modify: find objix span_ix:"_SPIPRIsp"\n", cur_objix_spix);
+        SPIFFS_DBG("modify: find objix span_ix:" _SPIPRIsp "\n", cur_objix_spix);
         if (fd->cursor_objix_spix == cur_objix_spix) {
           pix = fd->cursor_objix_pix;
         } else {
           res = spiffs_obj_lu_find_id_and_span(fs, fd->obj_id | SPIFFS_OBJ_ID_IX_FLAG, cur_objix_spix, 0, &pix);
           SPIFFS_CHECK_RES(res);
         }
-        SPIFFS_DBG("modify: found object index at page "_SPIPRIpg"\n", pix);
+        SPIFFS_DBG("modify: found object index at page " _SPIPRIpg "\n", pix);
         res = _spiffs_rd(fs, SPIFFS_OP_T_OBJ_IX | SPIFFS_OP_C_READ,
             fd->file_nbr, SPIFFS_PAGE_TO_PADDR(fs, pix), SPIFFS_CFG_LOG_PAGE_SZ(fs), fs->work);
         SPIFFS_CHECK_RES(res);
@@ -1554,7 +1556,7 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
       // a full page, allocate and write a new page of data
       res = spiffs_page_allocate_data(fs, fd->obj_id & ~SPIFFS_OBJ_ID_IX_FLAG,
           &p_hdr, &data[written], to_write, page_offs, 1, &data_pix);
-      SPIFFS_DBG("modify: store new data page, "_SPIPRIpg":"_SPIPRIsp" offset:"_SPIPRIi", len "_SPIPRIi", written "_SPIPRIi"\n", data_pix, data_spix, page_offs, to_write, written);
+      SPIFFS_DBG("modify: store new data page, " _SPIPRIpg ":" _SPIPRIsp " offset:" _SPIPRIi ", len " _SPIPRIi ", written " _SPIPRIi "\n", data_pix, data_spix, page_offs, to_write, written);
     } else {
       // write to existing page, allocate new and copy unmodified data
 
@@ -1595,7 +1597,7 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
           (u8_t *)&p_hdr.flags);
       if (res != SPIFFS_OK) break;
 
-      SPIFFS_DBG("modify: store to existing data page, src:"_SPIPRIpg", dst:"_SPIPRIpg":"_SPIPRIsp" offset:"_SPIPRIi", len "_SPIPRIi", written "_SPIPRIi"\n", orig_data_pix, data_pix, data_spix, page_offs, to_write, written);
+      SPIFFS_DBG("modify: store to existing data page, src:" _SPIPRIpg ", dst:" _SPIPRIpg ":" _SPIPRIsp " offset:" _SPIPRIi ", len " _SPIPRIi ", written " _SPIPRIi "\n", orig_data_pix, data_pix, data_spix, page_offs, to_write, written);
     }
 
     // delete original data page
@@ -1605,11 +1607,11 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
     if (cur_objix_spix == 0) {
       // update object index header page
       ((spiffs_page_ix*)((u8_t *)objix_hdr + sizeof(spiffs_page_object_ix_header)))[data_spix] = data_pix;
-      SPIFFS_DBG("modify: wrote page "_SPIPRIpg" to objix_hdr entry "_SPIPRIsp" in mem\n", data_pix, data_spix);
+      SPIFFS_DBG("modify: wrote page " _SPIPRIpg " to objix_hdr entry " _SPIPRIsp " in mem\n", data_pix, data_spix);
     } else {
       // update object index page
       ((spiffs_page_ix*)((u8_t *)objix + sizeof(spiffs_page_object_ix)))[SPIFFS_OBJ_IX_ENTRY(fs, data_spix)] = data_pix;
-      SPIFFS_DBG("modify: wrote page "_SPIPRIpg" to objix entry "_SPIPRIsp" in mem\n", data_pix, (spiffs_span_ix)SPIFFS_OBJ_IX_ENTRY(fs, data_spix));
+      SPIFFS_DBG("modify: wrote page " _SPIPRIpg " to objix entry " _SPIPRIsp " in mem\n", data_pix, (spiffs_span_ix)SPIFFS_OBJ_IX_ENTRY(fs, data_spix));
     }
 
     // update internals
@@ -1634,7 +1636,7 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
     SPIFFS_CHECK_RES(res2);
 
     res2 = spiffs_page_move(fs, fd->file_nbr, (u8_t*)objix, fd->obj_id, 0, cur_objix_pix, &new_objix_pix);
-    SPIFFS_DBG("modify: store modified objix page, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", new_objix_pix, cur_objix_spix, written);
+    SPIFFS_DBG("modify: store modified objix page, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", new_objix_pix, cur_objix_spix, written);
     fd->cursor_objix_pix = new_objix_pix;
     fd->cursor_objix_spix = cur_objix_spix;
     SPIFFS_CHECK_RES(res2);
@@ -1645,7 +1647,7 @@ s32_t spiffs_object_modify(spiffs_fd *fd, u32_t offset, u8_t *data, u32_t len) {
     // wrote within object index header page
     res2 = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
         fd->objix_hdr_pix, fs->work, 0, 0, 0, &new_objix_hdr_pix);
-    SPIFFS_DBG("modify: store modified objix_hdr page, "_SPIPRIpg":"_SPIPRIsp", written "_SPIPRIi"\n", new_objix_hdr_pix, 0, written);
+    SPIFFS_DBG("modify: store modified objix_hdr page, " _SPIPRIpg ":" _SPIPRIsp ", written " _SPIPRIi "\n", new_objix_hdr_pix, 0, written);
     SPIFFS_CHECK_RES(res2);
   }
 
@@ -1765,7 +1767,7 @@ s32_t spiffs_object_truncate(
     if (prev_objix_spix != cur_objix_spix) {
       if (prev_objix_spix != (spiffs_span_ix)-1) {
         // remove previous object index page
-        SPIFFS_DBG("truncate: delete objix page "_SPIPRIpg":"_SPIPRIsp"\n", objix_pix, prev_objix_spix);
+        SPIFFS_DBG("truncate: delete objix page " _SPIPRIpg ":" _SPIPRIsp "\n", objix_pix, prev_objix_spix);
 
         res = spiffs_page_index_check(fs, fd, objix_pix, prev_objix_spix);
         SPIFFS_CHECK_RES(res);
@@ -1782,7 +1784,7 @@ s32_t spiffs_object_truncate(
           // Hence, take the risk - if aborted, a file check would free the lost pages and mend things
           // as the file is marked as fully deleted in the beginning.
           if (remove_full == 0) {
-            SPIFFS_DBG("truncate: update objix hdr page "_SPIPRIpg":"_SPIPRIsp" to size "_SPIPRIi"\n", fd->objix_hdr_pix, prev_objix_spix, cur_size);
+            SPIFFS_DBG("truncate: update objix hdr page " _SPIPRIpg ":" _SPIPRIsp " to size " _SPIPRIi "\n", fd->objix_hdr_pix, prev_objix_spix, cur_size);
             res = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
                 fd->objix_hdr_pix, 0, 0, 0, cur_size, &new_objix_hdr_pix);
             SPIFFS_CHECK_RES(res);
@@ -1798,7 +1800,7 @@ s32_t spiffs_object_truncate(
         SPIFFS_CHECK_RES(res);
       }
 
-      SPIFFS_DBG("truncate: load objix page "_SPIPRIpg":"_SPIPRIsp" for data spix:"_SPIPRIsp"\n", objix_pix, cur_objix_spix, data_spix);
+      SPIFFS_DBG("truncate: load objix page " _SPIPRIpg ":" _SPIPRIsp " for data spix:" _SPIPRIsp "\n", objix_pix, cur_objix_spix, data_spix);
       res = _spiffs_rd(fs, SPIFFS_OP_T_OBJ_IX | SPIFFS_OP_C_READ,
           fd->file_nbr, SPIFFS_PAGE_TO_PADDR(fs, objix_pix), SPIFFS_CFG_LOG_PAGE_SZ(fs), fs->work);
       SPIFFS_CHECK_RES(res);
@@ -1820,20 +1822,20 @@ s32_t spiffs_object_truncate(
       ((spiffs_page_ix*)((u8_t *)objix + sizeof(spiffs_page_object_ix)))[SPIFFS_OBJ_IX_ENTRY(fs, data_spix)] = SPIFFS_OBJ_ID_FREE;
     }
 
-    SPIFFS_DBG("truncate: got data pix "_SPIPRIpg"\n", data_pix);
+    SPIFFS_DBG("truncate: got data pix " _SPIPRIpg "\n", data_pix);
 
     if (new_size == 0 || remove_full || cur_size - new_size >= SPIFFS_DATA_PAGE_SIZE(fs)) {
       // delete full data page
       res = spiffs_page_data_check(fs, fd, data_pix, data_spix);
       if (res != SPIFFS_ERR_DELETED && res != SPIFFS_OK && res != SPIFFS_ERR_INDEX_REF_FREE) {
-        SPIFFS_DBG("truncate: err validating data pix "_SPIPRIi"\n", res);
+        SPIFFS_DBG("truncate: err validating data pix " _SPIPRIi "\n", res);
         break;
       }
 
       if (res == SPIFFS_OK) {
         res = spiffs_page_delete(fs, data_pix);
         if (res != SPIFFS_OK) {
-          SPIFFS_DBG("truncate: err deleting data pix "_SPIPRIi"\n", res);
+          SPIFFS_DBG("truncate: err deleting data pix " _SPIPRIi "\n", res);
           break;
         }
       } else if (res == SPIFFS_ERR_DELETED || res == SPIFFS_ERR_INDEX_REF_FREE) {
@@ -1848,13 +1850,13 @@ s32_t spiffs_object_truncate(
       }
       fd->size = cur_size;
       fd->offset = cur_size;
-      SPIFFS_DBG("truncate: delete data page "_SPIPRIpg" for data spix:"_SPIPRIsp", cur_size:"_SPIPRIi"\n", data_pix, data_spix, cur_size);
+      SPIFFS_DBG("truncate: delete data page " _SPIPRIpg " for data spix:" _SPIPRIsp ", cur_size:" _SPIPRIi "\n", data_pix, data_spix, cur_size);
     } else {
       // delete last page, partially
       spiffs_page_header p_hdr;
       spiffs_page_ix new_data_pix;
       u32_t bytes_to_remove = SPIFFS_DATA_PAGE_SIZE(fs) - (new_size % SPIFFS_DATA_PAGE_SIZE(fs));
-      SPIFFS_DBG("truncate: delete "_SPIPRIi" bytes from data page "_SPIPRIpg" for data spix:"_SPIPRIsp", cur_size:"_SPIPRIi"\n", bytes_to_remove, data_pix, data_spix, cur_size);
+      SPIFFS_DBG("truncate: delete " _SPIPRIi " bytes from data page " _SPIPRIpg " for data spix:" _SPIPRIsp ", cur_size:" _SPIPRIi "\n", bytes_to_remove, data_pix, data_spix, cur_size);
 
       res = spiffs_page_data_check(fs, fd, data_pix, data_spix);
       if (res != SPIFFS_OK) break;
@@ -1886,11 +1888,11 @@ s32_t spiffs_object_truncate(
       if (cur_objix_spix == 0) {
         // update object index header page
         ((spiffs_page_ix*)((u8_t *)objix_hdr + sizeof(spiffs_page_object_ix_header)))[data_spix] = new_data_pix;
-        SPIFFS_DBG("truncate: wrote page "_SPIPRIpg" to objix_hdr entry "_SPIPRIsp" in mem\n", new_data_pix, (spiffs_span_ix)SPIFFS_OBJ_IX_ENTRY(fs, data_spix));
+        SPIFFS_DBG("truncate: wrote page " _SPIPRIpg " to objix_hdr entry " _SPIPRIsp " in mem\n", new_data_pix, (spiffs_span_ix)SPIFFS_OBJ_IX_ENTRY(fs, data_spix));
       } else {
         // update object index page
         ((spiffs_page_ix*)((u8_t *)objix + sizeof(spiffs_page_object_ix)))[SPIFFS_OBJ_IX_ENTRY(fs, data_spix)] = new_data_pix;
-        SPIFFS_DBG("truncate: wrote page "_SPIPRIpg" to objix entry "_SPIPRIsp" in mem\n", new_data_pix, (spiffs_span_ix)SPIFFS_OBJ_IX_ENTRY(fs, data_spix));
+        SPIFFS_DBG("truncate: wrote page " _SPIPRIpg " to objix entry " _SPIPRIsp " in mem\n", new_data_pix, (spiffs_span_ix)SPIFFS_OBJ_IX_ENTRY(fs, data_spix));
       }
       cur_size = new_size;
       fd->size = new_size;
@@ -1906,7 +1908,7 @@ s32_t spiffs_object_truncate(
     if (cur_size == 0) {
       if (remove_full) {
         // remove object altogether
-        SPIFFS_DBG("truncate: remove object index header page "_SPIPRIpg"\n", objix_pix);
+        SPIFFS_DBG("truncate: remove object index header page " _SPIPRIpg "\n", objix_pix);
 
         res = spiffs_page_index_check(fs, fd, objix_pix, 0);
         SPIFFS_CHECK_RES(res);
@@ -1917,7 +1919,7 @@ s32_t spiffs_object_truncate(
             SPIFFS_EV_IX_DEL, fd->obj_id, 0, objix_pix, 0);
       } else {
         // make uninitialized object
-        SPIFFS_DBG("truncate: reset objix_hdr page "_SPIPRIpg"\n", objix_pix);
+        SPIFFS_DBG("truncate: reset objix_hdr page " _SPIPRIpg "\n", objix_pix);
         memset(fs->work + sizeof(spiffs_page_object_ix_header), 0xff,
             SPIFFS_CFG_LOG_PAGE_SZ(fs) - sizeof(spiffs_page_object_ix_header));
         res = spiffs_object_update_index_hdr(fs, fd, fd->obj_id,
@@ -1943,7 +1945,7 @@ s32_t spiffs_object_truncate(
     SPIFFS_CHECK_RES(res);
     spiffs_cb_object_event(fs, (spiffs_page_object_ix *)objix_hdr,
         SPIFFS_EV_IX_UPD, fd->obj_id, objix->p_hdr.span_ix, new_objix_pix, 0);
-    SPIFFS_DBG("truncate: store modified objix page, "_SPIPRIpg":"_SPIPRIsp"\n", new_objix_pix, cur_objix_spix);
+    SPIFFS_DBG("truncate: store modified objix page, " _SPIPRIpg ":" _SPIPRIsp "\n", new_objix_pix, cur_objix_spix);
     fd->cursor_objix_pix = new_objix_pix;
     fd->cursor_objix_spix = cur_objix_spix;
     fd->offset = cur_size;
@@ -1989,7 +1991,7 @@ s32_t spiffs_object_read(
         if (cur_objix_spix == 0) {
           objix_pix = fd->objix_hdr_pix;
         } else {
-          SPIFFS_DBG("read: find objix "_SPIPRIid":"_SPIPRIsp"\n", fd->obj_id, cur_objix_spix);
+          SPIFFS_DBG("read: find objix " _SPIPRIid ":" _SPIPRIsp "\n", fd->obj_id, cur_objix_spix);
           if (fd->cursor_objix_spix == cur_objix_spix) {
             objix_pix = fd->cursor_objix_pix;
           } else {
@@ -1997,7 +1999,7 @@ s32_t spiffs_object_read(
             SPIFFS_CHECK_RES(res);
           }
         }
-        SPIFFS_DBG("read: load objix page "_SPIPRIpg":"_SPIPRIsp" for data spix:"_SPIPRIsp"\n", objix_pix, cur_objix_spix, data_spix);
+        SPIFFS_DBG("read: load objix page " _SPIPRIpg ":" _SPIPRIsp " for data spix:" _SPIPRIsp "\n", objix_pix, cur_objix_spix, data_spix);
         res = _spiffs_rd(fs, SPIFFS_OP_T_OBJ_IX | SPIFFS_OP_C_READ,
             fd->file_nbr, SPIFFS_PAGE_TO_PADDR(fs, objix_pix), SPIFFS_CFG_LOG_PAGE_SZ(fs), fs->work);
         SPIFFS_CHECK_RES(res);
@@ -2026,7 +2028,7 @@ s32_t spiffs_object_read(
     len_to_read = MIN(len_to_read, SPIFFS_DATA_PAGE_SIZE(fs) - (cur_offset % SPIFFS_DATA_PAGE_SIZE(fs)));
     // remaining data in file
     len_to_read = MIN(len_to_read, fd->size);
-    SPIFFS_DBG("read: offset:"_SPIPRIi" rd:"_SPIPRIi" data spix:"_SPIPRIsp" is data_pix:"_SPIPRIpg" addr:"_SPIPRIad"\n", cur_offset, len_to_read, data_spix, data_pix,
+    SPIFFS_DBG("read: offset:" _SPIPRIi " rd:" _SPIPRIi " data spix:" _SPIPRIsp " is data_pix:" _SPIPRIpg " addr:" _SPIPRIad "\n", cur_offset, len_to_read, data_spix, data_pix,
         (u32_t)(SPIFFS_PAGE_TO_PADDR(fs, data_pix) + sizeof(spiffs_page_header) + (cur_offset % SPIFFS_DATA_PAGE_SIZE(fs))));
     if (len_to_read <= 0) {
       res = SPIFFS_ERR_END_OF_OBJECT;
@@ -2113,7 +2115,7 @@ static s32_t spiffs_obj_lu_find_free_obj_id_compact_v(spiffs *fs, spiffs_obj_id
       if (id >= state->min_obj_id && id <= state->max_obj_id) {
         u8_t *map = (u8_t *)fs->work;
         int ix = (id - state->min_obj_id) / state->compaction;
-        //SPIFFS_DBG("free_obj_id: add ix "_SPIPRIi" for id "_SPIPRIid" min"_SPIPRIid" max"_SPIPRIid" comp:"_SPIPRIi"\n", ix, id, state->min_obj_id, state->max_obj_id, state->compaction);
+        //SPIFFS_DBG("free_obj_id: add ix " _SPIPRIi " for id " _SPIPRIid " min" _SPIPRIid " max" _SPIPRIid " comp:" _SPIPRIi "\n", ix, id, state->min_obj_id, state->max_obj_id, state->compaction);
         map[ix]++;
       }
     }
@@ -2141,7 +2143,7 @@ s32_t spiffs_obj_lu_find_free_obj_id(spiffs *fs, spiffs_obj_id *obj_id, const u8
     if (state.max_obj_id - state.min_obj_id <= (spiffs_obj_id)SPIFFS_CFG_LOG_PAGE_SZ(fs)*8) {
       // possible to represent in bitmap
       u32_t i, j;
-      SPIFFS_DBG("free_obj_id: BITM min:"_SPIPRIid" max:"_SPIPRIid"\n", state.min_obj_id, state.max_obj_id);
+      SPIFFS_DBG("free_obj_id: BITM min:" _SPIPRIid " max:" _SPIPRIid "\n", state.min_obj_id, state.max_obj_id);
 
       memset(fs->work, 0, SPIFFS_CFG_LOG_PAGE_SZ(fs));
       res = spiffs_obj_lu_find_entry_visitor(fs, 0, 0, 0, 0, spiffs_obj_lu_find_free_obj_id_bitmap_v,
@@ -2186,14 +2188,14 @@ s32_t spiffs_obj_lu_find_free_obj_id(spiffs *fs, spiffs_obj_id *obj_id, const u8
           return SPIFFS_ERR_FULL;
         }
 
-        SPIFFS_DBG("free_obj_id: COMP select index:"_SPIPRIi" min_count:"_SPIPRIi" min:"_SPIPRIid" max:"_SPIPRIid" compact:"_SPIPRIi"\n", min_i, min_count, state.min_obj_id, state.max_obj_id, state.compaction);
+        SPIFFS_DBG("free_obj_id: COMP select index:" _SPIPRIi " min_count:" _SPIPRIi " min:" _SPIPRIid " max:" _SPIPRIid " compact:" _SPIPRIi "\n", min_i, min_count, state.min_obj_id, state.max_obj_id, state.compaction);
 
         if (min_count == 0) {
           // no id in this range, skip compacting and use directly
           *obj_id = min_i * state.compaction + state.min_obj_id;
           return SPIFFS_OK;
         } else {
-          SPIFFS_DBG("free_obj_id: COMP SEL chunk:"_SPIPRIi" min:"_SPIPRIid" -> "_SPIPRIid"\n", state.compaction, state.min_obj_id, state.min_obj_id + min_i *  state.compaction);
+          SPIFFS_DBG("free_obj_id: COMP SEL chunk:" _SPIPRIi " min:" _SPIPRIid " -> " _SPIPRIid "\n", state.compaction, state.min_obj_id, state.min_obj_id + min_i *  state.compaction);
           state.min_obj_id += min_i *  state.compaction;
           state.max_obj_id = state.min_obj_id + state.compaction;
           // decrease compaction
@@ -2206,7 +2208,7 @@ s32_t spiffs_obj_lu_find_free_obj_id(spiffs *fs, spiffs_obj_id *obj_id, const u8
       // in a work memory of log_page_size bytes, we may fit in log_page_size ids
       // todo what if compaction is > 255 - then we cannot fit it in a byte
       state.compaction = (state.max_obj_id-state.min_obj_id) / ((SPIFFS_CFG_LOG_PAGE_SZ(fs) / sizeof(u8_t)));
-      SPIFFS_DBG("free_obj_id: COMP min:"_SPIPRIid" max:"_SPIPRIid" compact:"_SPIPRIi"\n", state.min_obj_id, state.max_obj_id, state.compaction);
+      SPIFFS_DBG("free_obj_id: COMP min:" _SPIPRIid " max:" _SPIPRIid " compact:" _SPIPRIi "\n", state.min_obj_id, state.max_obj_id, state.compaction);
 
       memset(fs->work, 0, SPIFFS_CFG_LOG_PAGE_SZ(fs));
       res = spiffs_obj_lu_find_entry_visitor(fs, 0, 0, 0, 0, spiffs_obj_lu_find_free_obj_id_compact_v, &state, 0, 0, 0);
@@ -2357,3 +2359,5 @@ void spiffs_fd_temporal_cache_rehash(
   }
 }
 #endif
+
+};
diff --git a/cores/esp8266/spiffs/spiffs_nucleus.h b/cores/esp8266/spiffs/spiffs_nucleus.h
index dd1c414bc7..cc195c7eca 100644
--- a/cores/esp8266/spiffs/spiffs_nucleus.h
+++ b/cores/esp8266/spiffs/spiffs_nucleus.h
@@ -110,6 +110,10 @@
 #ifndef SPIFFS_NUCLEUS_H_
 #define SPIFFS_NUCLEUS_H_
 
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 #define _SPIFFS_ERR_CHECK_FIRST         (SPIFFS_ERR_INTERNAL - 1)
 #define SPIFFS_ERR_CHECK_OBJ_ID_MISM    (SPIFFS_ERR_INTERNAL - 1)
 #define SPIFFS_ERR_CHECK_SPIX_MISM      (SPIFFS_ERR_INTERNAL - 2)
@@ -839,4 +843,8 @@ s32_t spiffs_object_index_consistency_check(
 #endif
 #endif //_SPIFFS_TEST
 
+#if defined(__cplusplus)
+};
+#endif
+
 #endif /* SPIFFS_NUCLEUS_H_ */
diff --git a/cores/esp8266/sqrt32.c b/cores/esp8266/sqrt32.cpp
similarity index 98%
rename from cores/esp8266/sqrt32.c
rename to cores/esp8266/sqrt32.cpp
index af6ffa495f..4dbb5d5df6 100644
--- a/cores/esp8266/sqrt32.c
+++ b/cores/esp8266/sqrt32.cpp
@@ -2,6 +2,8 @@
 #include <coredecls.h>
 #include <stdint.h>
 
+extern "C" {
+
 uint32_t sqrt32 (uint32_t n)
 {
     // http://www.codecodex.com/wiki/Calculate_an_integer_square_root#C
@@ -54,3 +56,5 @@ int main (void)
 
  *
  */
+
+};
diff --git a/cores/esp8266/time.c b/cores/esp8266/time.cpp
similarity index 97%
rename from cores/esp8266/time.c
rename to cores/esp8266/time.cpp
index 19b0dee522..d8391c420c 100644
--- a/cores/esp8266/time.c
+++ b/cores/esp8266/time.cpp
@@ -22,6 +22,8 @@
 #include "sntp.h"
 #include "coredecls.h"
 
+extern "C" {
+
 #ifndef _TIMEVAL_DEFINED
 #define _TIMEVAL_DEFINED
 struct timeval {
@@ -33,6 +35,7 @@ struct timeval {
 extern char* sntp_asctime(const struct tm *t);
 extern struct tm* sntp_localtime(const time_t *clock);
 extern uint64_t micros64();
+extern void sntp_set_daylight(int daylight);
 
 // time gap in seconds from 01.01.1900 (NTP time) to 01.01.1970 (UNIX time)
 #define DIFF1900TO1970 2208988800UL
@@ -101,3 +104,5 @@ int _gettimeofday_r(struct _reent* unused, struct timeval *tp, void *tzp)
     }
     return 0;
 }
+
+};
diff --git a/cores/esp8266/uart.c b/cores/esp8266/uart.cpp
similarity index 99%
rename from cores/esp8266/uart.c
rename to cores/esp8266/uart.cpp
index 88048cd363..3a27ff62f4 100644
--- a/cores/esp8266/uart.c
+++ b/cores/esp8266/uart.cpp
@@ -42,6 +42,7 @@
  */
 #include "Arduino.h"
 #include <pgmspace.h>
+#include "../../libraries/GDBStub/src/GDBStub.h"
 #include "uart.h"
 #include "esp8266_peri.h"
 #include "user_interface.h"
@@ -70,8 +71,9 @@
   kept running to enable GDB to do commands.
 */
 
-static int s_uart_debug_nr = UART0;
+extern "C" {
 
+static int s_uart_debug_nr = UART0;
 
 struct uart_rx_buffer_
 {
@@ -974,3 +976,5 @@ uart_detect_baudrate(int uart_nr)
 
     return default_rates[i];
 }
+
+};
diff --git a/cores/esp8266/umm_malloc/umm_malloc.c b/cores/esp8266/umm_malloc/umm_malloc.cpp
similarity index 99%
rename from cores/esp8266/umm_malloc/umm_malloc.c
rename to cores/esp8266/umm_malloc/umm_malloc.cpp
index 46b8578927..8314c5ec60 100644
--- a/cores/esp8266/umm_malloc/umm_malloc.c
+++ b/cores/esp8266/umm_malloc/umm_malloc.cpp
@@ -499,6 +499,8 @@
 
 #include "umm_malloc_cfg.h"   /* user-dependent */
 
+extern "C" {
+
 // From UMM, the last caller of a malloc/realloc/calloc which failed:
 extern void *umm_last_fail_alloc_addr;
 extern int umm_last_fail_alloc_size;
@@ -905,7 +907,8 @@ static int check_poison_all_blocks(void) {
  *
  * `size_w_poison` is a size of the whole block, including a poison.
  */
-static void *get_poisoned( unsigned char *ptr, size_t size_w_poison ) {
+static void *get_poisoned( void *vptr, size_t size_w_poison ) {
+  unsigned char *ptr = (unsigned char *)vptr;
   if (size_w_poison != 0 && ptr != NULL) {
 
     /* Put exact length of the user's chunk of memory */
@@ -930,7 +933,8 @@ static void *get_poisoned( unsigned char *ptr, size_t size_w_poison ) {
  *
  * Returns unpoisoned pointer, i.e. actual pointer to the allocated memory.
  */
-static void *get_unpoisoned( unsigned char *ptr ) {
+static void *get_unpoisoned( void *vptr ) {
+  unsigned char *ptr = (unsigned char *)vptr;
   if (ptr != NULL) {
     unsigned short int c;
 
@@ -1775,4 +1779,6 @@ size_t ICACHE_FLASH_ATTR umm_block_size( void ) {
   return sizeof(umm_block);
 }
 
+};
+
 /* ------------------------------------------------------------------------ */
diff --git a/tests/host/Makefile b/tests/host/Makefile
index 14b6dd11b8..38393f824b 100644
--- a/tests/host/Makefile
+++ b/tests/host/Makefile
@@ -56,17 +56,17 @@ CORE_CPP_FILES := $(addprefix $(CORE_PATH)/,\
 	FS.cpp \
 	spiffs_api.cpp \
 	MD5Builder.cpp \
+	core_esp8266_noniso.cpp \
+	spiffs/spiffs_cache.cpp \
+	spiffs/spiffs_check.cpp \
+	spiffs/spiffs_gc.cpp \
+	spiffs/spiffs_hydrogen.cpp \
+	spiffs/spiffs_nucleus.cpp \
+	libb64/cencode.cpp \
 	Schedule.cpp \
 )
 
 CORE_C_FILES := $(addprefix $(CORE_PATH)/,\
-	core_esp8266_noniso.c \
-	spiffs/spiffs_cache.c \
-	spiffs/spiffs_check.c \
-	spiffs/spiffs_gc.c \
-	spiffs/spiffs_hydrogen.c \
-	spiffs/spiffs_nucleus.c \
-	libb64/cencode.c \
 )
 
 MOCK_CPP_FILES_COMMON := $(addprefix common/,\