diff --git a/core/app_main.c b/core/app_main.c
index 88ac743..a710c77 100644
--- a/core/app_main.c
+++ b/core/app_main.c
@@ -16,8 +16,8 @@
 #include "common_macros.h"
 #include "xtensa_ops.h"
 #include "esp/rom.h"
+#include "esp/uart.h"
 #include "esp/iomux_regs.h"
-#include "esp/uart_regs.h"
 #include "esp/spi_regs.h"
 #include "esp/dport_regs.h"
 #include "esp/wdev_regs.h"
@@ -30,7 +30,6 @@
 
 void user_init(void);
 
-#define UART_DIVISOR 1068  // 74906 bps (yeah, I don't understand it either)
 #define BOOT_INFO_SIZE 28
 //TODO: phy_info should probably be a struct (no idea about its organization, though)
 #define PHY_INFO_SIZE 128
@@ -82,8 +81,6 @@ xTaskHandle sdk_xWatchDogTaskHandle;
 
 static void IRAM get_otp_mac_address(uint8_t *buf);
 static void IRAM set_spi0_divisor(uint32_t divisor);
-static int IRAM default_putc(char c);
-static void IRAM default_putc1(char c);
 static void zero_bss(void);
 static void init_networking(uint8_t *phy_info, uint8_t *mac_addr);
 static void init_g_ic(void);
@@ -160,27 +157,15 @@ void IRAM sdk_user_fatal_exception_handler(void) {
     Cache_Read_Disable();
     Cache_Read_Enable(0, 0, 1);
     dump_excinfo();
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(0).STATUS)) {}
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(1).STATUS)) {}
+    uart_flush_txfifo(0);
+    uart_flush_txfifo(1);
     sdk_system_restart_in_nmi();
     halt();
 }
 
-// .Lfunc003 -- .text+0x1d0
-static int IRAM default_putc(char c) {
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(0).STATUS) > 125) {}
-    UART(0).FIFO = c;
-    return 0;
-}
 
-// .Lfunc004 -- .text+0x1f4
-static void IRAM default_putc1(char c) {
-    if (c == '\n') {
-        default_putc('\r');
-    } else if (c == '\r') {
-        return;
-    }
-    default_putc(c);
+static void IRAM default_putc(char c) {
+    uart_putc(0, c);
 }
 
 // .text+0x258
@@ -247,7 +232,7 @@ void IRAM sdk_user_start(void) {
     sdk_SPIRead(ic_flash_addr, buf32, sizeof(struct sdk_g_ic_saved_st));
     Cache_Read_Enable(0, 0, 1);
     zero_bss();
-    sdk_os_install_putc1(default_putc1);
+    sdk_os_install_putc1(default_putc);
     if (cksum_magic == 0xffffffff) {
         // No checksum required
     } else if ((cksum_magic == 0x55aa55aa) &&
@@ -293,8 +278,8 @@ static void init_networking(uint8_t *phy_info, uint8_t *mac_addr) {
         printf("FATAL: sdk_register_chipv6_phy failed");
         halt();
     }
-    sdk_uart_div_modify(0, UART_DIVISOR);
-    sdk_uart_div_modify(1, UART_DIVISOR);
+    uart_set_baud(0, 74906);
+    uart_set_baud(1, 74906);
     sdk_phy_disable_agc();
     sdk_ieee80211_phy_init(sdk_g_ic.s.phy_mode);
     sdk_lmacInit();
@@ -378,15 +363,6 @@ static void dump_excinfo(void) {
     sdk_system_rtc_mem_write(0, excinfo, 32);
 }
 
-// .irom0.text+0x368
-int sdk_uart_rx_one_char(char *buf) {
-    if (FIELD2VAL(UART_STATUS_RXFIFO_COUNT, UART(0).STATUS)) {
-        *buf = UART(0).FIFO;
-        return 0;
-    }
-    return 1;
-}
-
 // .irom0.text+0x398
 void sdk_wdt_init(void) {
     WDT.CTRL &= ~WDT_CTRL_ENABLE;
@@ -455,9 +431,11 @@ static void user_start_phase2(void) {
     phy_info = malloc(PHY_INFO_SIZE);
     sdk_spi_flash_read(sdk_flashchip.chip_size - sdk_flashchip.sector_size * 4, (uint32_t *)phy_info, PHY_INFO_SIZE);
 
+    // Disable default buffering on stdout
+    setbuf(stdout, NULL);
     // Wait for UARTs to finish sending anything in their queues.
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(0).STATUS) > 0) {}
-    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(1).STATUS) > 0) {}
+    uart_flush_txfifo(0);
+    uart_flush_txfifo(1);
 
     if (phy_info[0] != 5) {
         // Bad version byte.  Discard what we read and use default values
diff --git a/core/include/esp/uart.h b/core/include/esp/uart.h
new file mode 100644
index 0000000..9d72dc3
--- /dev/null
+++ b/core/include/esp/uart.h
@@ -0,0 +1,127 @@
+/** esp/uart.h
+ *
+ * Utility routines for working with UARTs
+ *
+ * Part of esp-open-rtos
+ * Copyright (C) 2015 Superhouse Automation Pty Ltd
+ * BSD Licensed as described in the file LICENSE
+ */
+#ifndef _ESP_UART_H
+#define _ESP_UART_H
+
+#include "esp/types.h"
+#include "esp/uart_regs.h"
+#include "esp/clocks.h"
+
+#define UART_FIFO_MAX 127
+
+/* Wait for at least `min_count` bytes of data to be available in the UART's
+ * receive FIFO
+ *
+ * Returns the number of bytes actually available for reading.
+ */
+static inline int uart_rxfifo_wait(int uart_num, int min_count) {
+    int count;
+    do {
+        count = FIELD2VAL(UART_STATUS_RXFIFO_COUNT, UART(uart_num).STATUS);
+    } while (count < min_count);
+    return count;
+}
+
+/* Wait for at least `min_count` bytes of space to be available in the UART's
+ * transmit FIFO
+ *
+ * Returns the number of bytes actually available in the write buffer.
+ */
+static inline int uart_txfifo_wait(int uart_num, int min_count) {
+    int count;
+    do {
+        count = UART_FIFO_MAX - FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(uart_num).STATUS);
+    } while (count < min_count);
+    return count;
+}
+
+/* Read a character from the UART.  Block until a character is available for
+ * reading.
+ *
+ * Returns the character read.
+ */
+static inline int uart_getc(int uart_num) {
+    uart_rxfifo_wait(uart_num, 1);
+    return UART(uart_num).FIFO;
+}
+
+/* Read a character from the UART.  Does not block.
+ *
+ * Returns the read character on success.  If the RX FIFO is currently empty
+ * (nothing to read), returns -1.
+ */
+static inline int uart_getc_nowait(int uart_num) {
+    if (FIELD2VAL(UART_STATUS_RXFIFO_COUNT, UART(uart_num).STATUS)) {
+        return UART(uart_num).FIFO;
+    }
+    return -1;
+}
+
+/* Write a character to the UART.  Blocks if necessary until there is space in
+ * the TX FIFO.
+ */
+static inline void uart_putc(int uart_num, char c) {
+    uart_txfifo_wait(uart_num, 1);
+    UART(uart_num).FIFO = c;
+}
+
+/* Write a character to the UART.  Does not block.
+ *
+ * Returns 0 on success.  If there is no space currently in the TX FIFO,
+ * returns -1.
+ */
+static inline int uart_putc_nowait(int uart_num, char c) {
+    if (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(uart_num).STATUS) < UART_FIFO_MAX) {
+        UART(uart_num).FIFO = c;
+        return 0;
+    }
+    return -1;
+}
+
+/* Clear (discard) all pending write data in the TX FIFO */
+static inline void uart_clear_txfifo(int uart_num) {
+    uint32_t conf = UART(uart_num).CONF0;
+    UART(uart_num).CONF0 = conf | UART_CONF0_TXFIFO_RESET;
+    UART(uart_num).CONF0 = conf & ~UART_CONF0_TXFIFO_RESET;
+}
+
+/* Clear (discard) all pending read data in the RX FIFO */
+static inline void uart_clear_rxfifo(int uart_num) {
+    uint32_t conf = UART(uart_num).CONF0;
+    UART(uart_num).CONF0 = conf | UART_CONF0_RXFIFO_RESET;
+    UART(uart_num).CONF0 = conf & ~UART_CONF0_RXFIFO_RESET;
+}
+
+/* Wait until all pending output in the UART's TX FIFO has been sent out the
+ * serial port. */
+static inline void uart_flush_txfifo(int uart_num) {
+    while (FIELD2VAL(UART_STATUS_TXFIFO_COUNT, UART(uart_num).STATUS) != 0) {}
+}
+
+/* Flush all pending input in the UART's RX FIFO
+ * (this is just another name for uart_clear_rxfifo)
+ */
+static inline void uart_flush_rxfifo(int uart_num) {
+    uart_clear_rxfifo(uart_num);
+}
+
+/* Set uart baud rate to the desired value */
+static inline void uart_set_baud(int uart_num, int bps)
+{
+    uint32_t divider = APB_CLK_FREQ / bps;
+    UART(uart_num).CLOCK_DIVIDER = divider;
+}
+
+/* Returns the current baud rate for the UART */
+static inline int uart_get_baud(int uart_num)
+{
+    return APB_CLK_FREQ / FIELD2VAL(UART_CLOCK_DIVIDER_VALUE, UART(uart_num).CLOCK_DIVIDER);
+}
+
+#endif /* _ESP_UART_H */
diff --git a/core/newlib_syscalls.c b/core/newlib_syscalls.c
index 767dd2d..ae15aff 100644
--- a/core/newlib_syscalls.c
+++ b/core/newlib_syscalls.c
@@ -9,6 +9,7 @@
 #include <sys/errno.h>
 #include <espressif/sdk_private.h>
 #include <common_macros.h>
+#include <esp/uart.h>
 #include <stdlib.h>
 
 IRAM caddr_t _sbrk_r (struct _reent *r, int incr)
@@ -32,37 +33,40 @@ IRAM caddr_t _sbrk_r (struct _reent *r, int incr)
     return (caddr_t) prev_heap_end;
 }
 
-/* syscall implementation for stdio write to UART
-
-   at the moment UART functionality is all still in the binary SDK
- */
+/* syscall implementation for stdio write to UART */
 long _write_r(struct _reent *r, int fd, const char *ptr, int len )
 {
     if(fd != r->_stdout->_file) {
         r->_errno = EBADF;
         return -1;
     }
-    for(int i = 0; i < len; i++)
-	sdk_os_putc(ptr[i]);
+    for(int i = 0; i < len; i++) {
+        /* Auto convert CR to CRLF, ignore other LFs (compatible with Espressif SDK behaviour) */
+        if(ptr[i] == '\r')
+            continue;
+        if(ptr[i] == '\n')
+            uart_putc(0, '\r');
+        uart_putc(0, ptr[i]);
+    }
     return len;
 }
 
-/* syscall implementation for stdio read from UART
-
-   at the moment UART functionality is all still in the binary SDK
- */
+/* syscall implementation for stdio read from UART */
 long _read_r( struct _reent *r, int fd, char *ptr, int len )
 {
+    int ch, i;
+
     if(fd != r->_stdin->_file) {
         r->_errno = EBADF;
         return -1;
     }
-    for(int i = 0; i < len; i++) {
-        char ch;
-        while (sdk_uart_rx_one_char(&ch)) ;
+    uart_rxfifo_wait(0, 1);
+    for(i = 0; i < len; i++) {
+        ch = uart_getc_nowait(0);
+        if (ch < 0) break;
         ptr[i] = ch;
     }
-    return len;
+    return i;
 }
 
 /* Stub syscall implementations follow, to allow compiling newlib functions that
diff --git a/core/sdk_compat.c b/core/sdk_compat.c
index b6bb6b3..b0d6789 100644
--- a/core/sdk_compat.c
+++ b/core/sdk_compat.c
@@ -1,5 +1,5 @@
 /*
- * Wrappers for functions called by binary espressif libraries
+ * Compatibility routines for the Espressif SDK and its API
  *
  * Part of esp-open-rtos
  * Copyright (C) 2015 Superhouse Automation Pty Ltd
@@ -10,6 +10,8 @@
 #include <stdio.h>
 #include <common_macros.h>
 
+#include <esp/uart.h>
+
 void IRAM *zalloc(size_t nbytes)
 {
     return calloc(1, nbytes);
@@ -18,9 +20,8 @@ void IRAM *zalloc(size_t nbytes)
 extern void (*__init_array_start)(void);
 extern void (*__init_array_end)(void);
 
-/* Do things which should be done as part of the startup code, but aren't.
-
-   Can be replaced with _start() once we have open source startup code.
+/* Do things which should be done as part of the SDK startup code, but aren't.
+   TODO: Move into app_main.c
 */
 void sdk_compat_initialise()
 {
@@ -29,3 +30,15 @@ void sdk_compat_initialise()
     for ( p = &__init_array_start; p != &__init_array_end; ++p)
         (*p)();
 }
+
+/* UART RX function from Espressif SDK internals.
+ *
+ * Not part of published API.
+ */
+int sdk_uart_rx_one_char(char *buf) {
+    int c = uart_getc_nowait(0);
+    if(c < 0)
+        return 1;
+    *buf = (char)c;
+    return 0;
+}
diff --git a/examples/blink/blink.c b/examples/blink/blink.c
index 52d69a5..00388b5 100644
--- a/examples/blink/blink.c
+++ b/examples/blink/blink.c
@@ -3,7 +3,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -53,7 +53,7 @@ void blinkenRegisterTask(void *pvParameters)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     xTaskCreate(blinkenTask, (signed char *)"blinkenTask", 256, NULL, 2, NULL);
     //xTaskCreate(blinkenRegisterTask, (signed char *)"blinkenRegisterTask", 256, NULL, 2, NULL);
 }
diff --git a/examples/blink_timers/blink_timers.c b/examples/blink_timers/blink_timers.c
index 5b6b7a2..177cff3 100644
--- a/examples/blink_timers/blink_timers.c
+++ b/examples/blink_timers/blink_timers.c
@@ -3,7 +3,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -33,7 +33,7 @@ void frc2_interrupt_handler(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     /* configure GPIOs */
     gpio_enable(gpio_frc1, GPIO_OUTPUT);
diff --git a/examples/bmp180_i2c/bmp180_i2c.c b/examples/bmp180_i2c/bmp180_i2c.c
index 578db67..64ee961 100644
--- a/examples/bmp180_i2c/bmp180_i2c.c
+++ b/examples/bmp180_i2c/bmp180_i2c.c
@@ -3,7 +3,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 
 #include "FreeRTOS.h"
 #include "task.h"
@@ -87,7 +87,7 @@ void bmp180_task(void *pvParameters)
 void user_setup(void)
 {
     // Set UART Parameter
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     // Give the UART some time to settle
     sdk_os_delay_us(500);
diff --git a/examples/button/button.c b/examples/button/button.c
index e197ffc..0b0784d 100644
--- a/examples/button/button.c
+++ b/examples/button/button.c
@@ -6,7 +6,7 @@
  * This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
@@ -75,7 +75,7 @@ void GPIO_HANDLER(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     gpio_enable(gpio, GPIO_INPUT);
 
     tsqueue = xQueueCreate(2, sizeof(uint32_t));
diff --git a/examples/cpp_01_tasks/cpp_tasks.cpp b/examples/cpp_01_tasks/cpp_tasks.cpp
index 9e381b9..1a54129 100644
--- a/examples/cpp_01_tasks/cpp_tasks.cpp
+++ b/examples/cpp_01_tasks/cpp_tasks.cpp
@@ -31,6 +31,8 @@
 
 #include "espressif/esp_common.h"
 
+#include "esp/uart.h"
+
 /******************************************************************************************************************
  * task_1_t
  *
@@ -94,8 +96,8 @@ esp_open_rtos::thread::queue_t<uint32_t> MyQueue;
  */
 extern "C" void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
-	
+    uart_set_baud(0, 115200);
+    
     MyQueue.queue_create(10);
     
     task_1.queue = MyQueue;
diff --git a/examples/experiments/timers/timers.c b/examples/experiments/timers/timers.c
index 2a11bec..d5a2f50 100644
--- a/examples/experiments/timers/timers.c
+++ b/examples/experiments/timers/timers.c
@@ -7,7 +7,7 @@
  * This experimental reverse engineering code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -118,7 +118,7 @@ void frc2_handler(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     xTaskCreate(timerRegTask, (signed char *)"timerRegTask", 1024, NULL, 2, NULL);
 
     TIMER(0).CTRL = VAL2FIELD(TIMER_CTRL_CLKDIV, TIMER_CLKDIV_256) | TIMER_CTRL_RELOAD;
diff --git a/examples/experiments/unaligned_load/unaligned_load.c b/examples/experiments/unaligned_load/unaligned_load.c
index 1574172..48016af 100644
--- a/examples/experiments/unaligned_load/unaligned_load.c
+++ b/examples/experiments/unaligned_load/unaligned_load.c
@@ -3,7 +3,7 @@
 #include "esp/rom.h"
 #include "esp/timer.h"
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
@@ -214,7 +214,7 @@ void sanity_tests(void);
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     gpio_enable(2, GPIO_OUTPUT); /* used for LED debug */
     gpio_write(2, 1); /* active low */
diff --git a/examples/http_get/http_get.c b/examples/http_get/http_get.c
index 408b462..b90abdf 100644
--- a/examples/http_get/http_get.c
+++ b/examples/http_get/http_get.c
@@ -5,7 +5,7 @@
  * This sample code is in the public domain.,
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 
 #include <string.h>
 
@@ -114,7 +114,7 @@ void http_get_task(void *pvParameters)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
 
     struct sdk_station_config config = {
diff --git a/examples/http_get_mbedtls/http_get_mbedtls.c b/examples/http_get_mbedtls/http_get_mbedtls.c
index d1fbf0d..f45fd54 100644
--- a/examples/http_get_mbedtls/http_get_mbedtls.c
+++ b/examples/http_get_mbedtls/http_get_mbedtls.c
@@ -10,7 +10,7 @@
  * Additions Copyright (C) 2015 Angus Gratton, Apache 2.0 License.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 
 #include <string.h>
 
@@ -80,7 +80,6 @@ static void my_debug(void *ctx, int level,
         file = file_sep+1;
 
     printf("%s:%04d: %s", file, line, str);
-    fflush(stdout);
 }
 #endif
 
@@ -107,7 +106,6 @@ void http_get_task(void *pvParameters)
     mbedtls_x509_crt_init(&cacert);
     mbedtls_ctr_drbg_init(&ctr_drbg);
     printf("\n  . Seeding the random number generator...");
-    fflush(stdout);
 
     mbedtls_ssl_config_init(&conf);
 
@@ -126,7 +124,6 @@ void http_get_task(void *pvParameters)
      * 0. Initialize certificates
      */
     printf("  . Loading the CA root certificate ...");
-    fflush(stdout);
 
     ret = mbedtls_x509_crt_parse(&cacert, (uint8_t*)server_root_cert, strlen(server_root_cert)+1);
     if(ret < 0)
@@ -148,7 +145,6 @@ void http_get_task(void *pvParameters)
      * 2. Setup stuff
      */
     printf("  . Setting up the SSL/TLS structure...");
-    fflush(stdout);
 
     if((ret = mbedtls_ssl_config_defaults(&conf,
                                           MBEDTLS_SSL_IS_CLIENT,
@@ -182,7 +178,6 @@ void http_get_task(void *pvParameters)
        our network is probably working...
     */
     printf("Waiting for server DNS to resolve... ");
-    fflush(stdout);
     err_t dns_err;
     ip_addr_t host_ip;
     do {
@@ -198,7 +193,6 @@ void http_get_task(void *pvParameters)
          * 1. Start the connection
          */
         printf("  . Connecting to %s:%s...", WEB_SERVER, WEB_PORT);
-        fflush(stdout);
 
         if((ret = mbedtls_net_connect(&server_fd, WEB_SERVER,
                                       WEB_PORT, MBEDTLS_NET_PROTO_TCP)) != 0)
@@ -215,7 +209,6 @@ void http_get_task(void *pvParameters)
          * 4. Handshake
          */
         printf("  . Performing the SSL/TLS handshake...");
-        fflush(stdout);
 
         while((ret = mbedtls_ssl_handshake(&ssl)) != 0)
         {
@@ -251,7 +244,6 @@ void http_get_task(void *pvParameters)
          * 3. Write the GET request
          */
         printf("  > Write to server:");
-        fflush(stdout);
 
         int len = sprintf((char *) buf, GET_REQUEST);
 
@@ -271,7 +263,6 @@ void http_get_task(void *pvParameters)
          * 7. Read the HTTP response
          */
         printf("  < Read from server:");
-        fflush(stdout);
 
         do
         {
@@ -322,7 +313,6 @@ void http_get_task(void *pvParameters)
         printf("\n\nsuccesses = %d failures = %d\n", successes, failures);
         for(int countdown = successes ? 10 : 5; countdown >= 0; countdown--) {
             printf("%d... ", countdown);
-            fflush(stdout);
             vTaskDelay(1000 / portTICK_RATE_MS);
         }
         printf("\nStarting again!\n");
@@ -331,7 +321,7 @@ void http_get_task(void *pvParameters)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
 
     struct sdk_station_config config = {
diff --git a/examples/ota_basic/ota_basic.c b/examples/ota_basic/ota_basic.c
index 69751d0..a6d354d 100644
--- a/examples/ota_basic/ota_basic.c
+++ b/examples/ota_basic/ota_basic.c
@@ -7,7 +7,7 @@
  * NOT SUITABLE TO PUT ON THE INTERNET OR INTO A PRODUCTION ENVIRONMENT!!!!
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "esp8266.h"
@@ -18,7 +18,7 @@
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     rboot_config_t conf = rboot_get_config();
     printf("\r\n\r\nOTA Basic demo.\r\nCurrently running on flash slot %d / %d.\r\n\r\n",
diff --git a/examples/serial_echo/Makefile b/examples/serial_echo/Makefile
new file mode 100644
index 0000000..2b34c0e
--- /dev/null
+++ b/examples/serial_echo/Makefile
@@ -0,0 +1,3 @@
+# Simple makefile for serial_echo example
+PROGRAM=serial_echo
+include ../../common.mk
diff --git a/examples/serial_echo/serial_echo.c b/examples/serial_echo/serial_echo.c
new file mode 100644
index 0000000..5be9ff4
--- /dev/null
+++ b/examples/serial_echo/serial_echo.c
@@ -0,0 +1,42 @@
+/* Extremely simple example that just reads from stdin and echoes back on stdout
+ *
+ * Has an easter egg, which is if you type "QUACK" it'll quack 3 times back at you.
+ *
+ * This example code is in the public domain
+ */
+#include "espressif/esp_common.h"
+#include <esp/uart.h>
+#include <string.h>
+
+void user_init(void)
+{
+    uart_set_baud(0, 115200);
+    printf("SDK version:%s\n", sdk_system_get_sdk_version());
+    printf("Going into echo mode...\n");
+
+    /* By default stdout is line-buffered, so you only see output
+       after a newline is sent. This is helpful in a multithreaded
+       environment so output doesn't get chopped up within a line.
+
+       Here we want to see the echo immediately, so disable buffering.
+    */
+    setbuf(stdout, NULL);
+
+    while(1) {
+        int c = getchar();
+        if(c != EOF)
+            putchar(c);
+
+        /* Easter egg: check for a quack! */
+        static int quack;
+        if(c == "QUACK"[quack]) {
+            quack++;
+            if(quack == strlen("QUACK")) {
+                printf("\nQUACK\nQUACK\n");
+                quack = 0;
+            }
+        } else {
+            quack = 0;
+        }
+    }
+}
diff --git a/examples/simple/simple.c b/examples/simple/simple.c
index 98e4ada..d95a040 100644
--- a/examples/simple/simple.c
+++ b/examples/simple/simple.c
@@ -1,7 +1,7 @@
 /* Very basic example that just demonstrates we can run at all!
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
@@ -36,7 +36,7 @@ static xQueueHandle mainqueue;
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
     mainqueue = xQueueCreate(10, sizeof(uint32_t));
     xTaskCreate(task1, (signed char *)"tsk1", 256, &mainqueue, 2, NULL);
diff --git a/examples/simple_cplusplus/simple.cpp b/examples/simple_cplusplus/simple.cpp
index 1826499..dec286d 100644
--- a/examples/simple_cplusplus/simple.cpp
+++ b/examples/simple_cplusplus/simple.cpp
@@ -3,11 +3,12 @@
    This sample code is in the public domain.
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
 #include "FreeRTOS.h"
 #include "task.h"
 #include "queue.h"
 
+#include <esp/uart.h>
+
 class Counter
 {
 private:
@@ -58,7 +59,7 @@ void task1(void *pvParameters)
 
 extern "C" void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
     xTaskCreate(task1, (signed char *)"tsk1", 256, NULL, 2, NULL);
 }
diff --git a/examples/tests/hmac_test_vectors/hmac_test_vectors.c b/examples/tests/hmac_test_vectors/hmac_test_vectors.c
index a6a20f9..d0ed1de 100644
--- a/examples/tests/hmac_test_vectors/hmac_test_vectors.c
+++ b/examples/tests/hmac_test_vectors/hmac_test_vectors.c
@@ -8,7 +8,7 @@
  * This sample code is in the public domain.,
  */
 #include "espressif/esp_common.h"
-#include "espressif/sdk_private.h"
+#include "esp/uart.h"
 #include "FreeRTOS.h"
 #include "mbedtls/md.h"
 
@@ -130,7 +130,7 @@ static void test_md5(void)
 
 void user_init(void)
 {
-    sdk_uart_div_modify(0, UART_CLK_FREQ / 115200);
+    uart_set_baud(0, 115200);
 
     test_md5();
 
diff --git a/libc/xtensa-lx106-elf/include/newlib.h b/libc/xtensa-lx106-elf/include/newlib.h
index 7ea84d4..e9bf566 100644
--- a/libc/xtensa-lx106-elf/include/newlib.h
+++ b/libc/xtensa-lx106-elf/include/newlib.h
@@ -31,7 +31,7 @@
 
 /* Optional reentrant struct support.  Used mostly on platforms with
    very restricted storage.  */
-/* #undef _WANT_REENT_SMALL */
+#define _WANT_REENT_SMALL 1
 
 /* Multibyte supported */
 /* #undef _MB_CAPABLE */
diff --git a/libc/xtensa-lx106-elf/include/sys/config.h b/libc/xtensa-lx106-elf/include/sys/config.h
index ee9d3b7..f6f923e 100644
--- a/libc/xtensa-lx106-elf/include/sys/config.h
+++ b/libc/xtensa-lx106-elf/include/sys/config.h
@@ -188,6 +188,8 @@
 #ifdef __XTENSA__
 #include <xtensa/config/core-isa.h>
 #define MALLOC_ALIGNMENT ((XCHAL_DATA_WIDTH) < 16 ? 16 : (XCHAL_DATA_WIDTH))
+/* esp8266-specific: shrink the default fd buffer size */
+#define __BUFSIZ__ 128
 #endif
 
 /* This block should be kept in sync with GCC's limits.h.  The point
diff --git a/libc/xtensa-lx106-elf/lib/libc.a b/libc/xtensa-lx106-elf/lib/libc.a
index 33cfced..a166b9e 100644
Binary files a/libc/xtensa-lx106-elf/lib/libc.a and b/libc/xtensa-lx106-elf/lib/libc.a differ
diff --git a/libc/xtensa-lx106-elf/lib/libg.a b/libc/xtensa-lx106-elf/lib/libg.a
index 33cfced..a166b9e 100644
Binary files a/libc/xtensa-lx106-elf/lib/libg.a and b/libc/xtensa-lx106-elf/lib/libg.a differ
diff --git a/libc/xtensa-lx106-elf/lib/libm.a b/libc/xtensa-lx106-elf/lib/libm.a
index 7a2455b..be41436 100644
Binary files a/libc/xtensa-lx106-elf/lib/libm.a and b/libc/xtensa-lx106-elf/lib/libm.a differ