diff --git a/core/esp_timer.c b/core/esp_timer.c
index 2110948..473e617 100644
--- a/core/esp_timer.c
+++ b/core/esp_timer.c
@@ -18,7 +18,7 @@
 const static uint32_t IROM _TIMER_FREQS[] = { _FREQ_DIV1, _FREQ_DIV16, _FREQ_DIV256 };
 
 /* Timer divisor index to divisor value */
-const static uint32_t IROM _TIMER_DIV_VAL[] = { 1, 16, 256 };
+const static uint32_t IROM _TIMER_DIV_VAL[] __attribute__((unused)) = { 1, 16, 256 };
 
 void timer_set_interrupts(const timer_frc_t frc, bool enable)
 {
diff --git a/core/include/common_macros.h b/core/include/common_macros.h
index 7034787..4585c6c 100644
--- a/core/include/common_macros.h
+++ b/core/include/common_macros.h
@@ -39,11 +39,29 @@
 
 /* Set bits in reg with specified mask.
  */
+#ifdef __cplusplus
+constexpr inline auto SET_MASK_BITS(auto volatile& reg, auto mask) {
+    auto value = reg;
+    value |= mask;
+    reg = value;
+    return reg;
+}
+#else
 #define SET_MASK_BITS(reg, mask) (reg) |= (mask)
+#endif
 
 /* Clear bits in reg with specified mask
  */
+#ifdef __cplusplus
+constexpr inline auto CLEAR_MASK_BITS(auto volatile& reg, auto mask) {
+    auto value = reg;
+    value &= ~mask;
+    reg = value;
+    return reg;
+}
+#else
 #define CLEAR_MASK_BITS(reg, mask) (reg) &= ~(mask)
+#endif
 
 /* Use the IRAM macro to place functions into Instruction RAM (IRAM)
    instead of flash (aka irom).
diff --git a/core/include/debug_dumps.h b/core/include/debug_dumps.h
index 8b82b84..4f739e5 100644
--- a/core/include/debug_dumps.h
+++ b/core/include/debug_dumps.h
@@ -21,7 +21,7 @@ void dump_heapinfo(void);
    Probably not useful to be called in other contexts.
 */
 void __attribute__((noreturn)) fatal_exception_handler(uint32_t *sp, bool registers_saved_on_stack);
-void __attribute__((weak, alias("fatal_exception_handler")))
+void __attribute__((noreturn)) __attribute__((weak, alias("fatal_exception_handler")))
 	debug_exception_handler(uint32_t *sp, bool registers_saved_on_stack);
 
 #endif
diff --git a/core/include/esp/gpio.h b/core/include/esp/gpio.h
index 85842aa..376d4c6 100644
--- a/core/include/esp/gpio.h
+++ b/core/include/esp/gpio.h
@@ -48,7 +48,13 @@ void gpio_set_pullup(uint8_t gpio_num, bool enabled, bool enabled_during_sleep);
 static inline void gpio_disable(const uint8_t gpio_num)
 {
     GPIO.ENABLE_OUT_CLEAR = BIT(gpio_num);
+#ifdef __cplusplus
+    auto value = *gpio_iomux_reg(gpio_num);
+    value &= ~IOMUX_PIN_OUTPUT_ENABLE;
+    *gpio_iomux_reg(gpio_num) = value;
+#else
     *gpio_iomux_reg(gpio_num) &= ~IOMUX_PIN_OUTPUT_ENABLE;
+#endif
 }
 
 /* Set whether the specified pin continues to drive its output when the ESP8266
@@ -61,9 +67,21 @@ static inline void gpio_disable(const uint8_t gpio_num)
 static inline void gpio_set_output_on_sleep(const uint8_t gpio_num, bool enabled)
 {
     if (enabled) {
+#ifdef __cplusplus
+        auto value = IOMUX.PIN[gpio_to_iomux(gpio_num)];
+        value |= IOMUX_PIN_OUTPUT_ENABLE_SLEEP;
+        IOMUX.PIN[gpio_to_iomux(gpio_num)] = value;
+#else
         IOMUX.PIN[gpio_to_iomux(gpio_num)] |= IOMUX_PIN_OUTPUT_ENABLE_SLEEP;
+#endif
     } else {
+#ifdef __cplusplus
+        auto value = IOMUX.PIN[gpio_to_iomux(gpio_num)];
+        value &= ~IOMUX_PIN_OUTPUT_ENABLE_SLEEP;
+        IOMUX.PIN[gpio_to_iomux(gpio_num)] = value;
+#else
         IOMUX.PIN[gpio_to_iomux(gpio_num)] &= ~IOMUX_PIN_OUTPUT_ENABLE_SLEEP;
+#endif
     }
 }
 
diff --git a/core/include/esp/timer.h b/core/include/esp/timer.h
index fc74992..df52373 100644
--- a/core/include/esp/timer.h
+++ b/core/include/esp/timer.h
@@ -65,10 +65,23 @@ void timer_set_interrupts(const timer_frc_t frc, bool enable);
 /* Turn the timer on or off */
 static inline void timer_set_run(const timer_frc_t frc, const bool run)
 {
-    if (run)
+    if (run) {
+#ifdef __cplusplus
+        auto value = TIMER(frc).CTRL;
+        value |= TIMER_CTRL_RUN;
+        TIMER(frc).CTRL = value;
+#else
         TIMER(frc).CTRL |= TIMER_CTRL_RUN;
-    else
+#endif
+    } else {
+#ifdef __cplusplus
+        auto value = TIMER(frc).CTRL;
+        value &= ~TIMER_CTRL_RUN;
+        TIMER(frc).CTRL = value;
+#else
         TIMER(frc).CTRL &= ~TIMER_CTRL_RUN;
+#endif
+    }
 }
 
 /* Get the run state of the timer (on or off) */
@@ -80,10 +93,23 @@ static inline bool timer_get_run(const timer_frc_t frc)
 /* Set timer auto-reload on or off */
 static inline void timer_set_reload(const timer_frc_t frc, const bool reload)
 {
-    if (reload)
+    if (reload) {
+#ifdef __cplusplus
+        auto value = TIMER(frc).CTRL;
+        value |= TIMER_CTRL_RELOAD;
+        TIMER(frc).CTRL = value;
+#else
         TIMER(frc).CTRL |= TIMER_CTRL_RELOAD;
-    else
+#endif
+    } else {
+#ifdef __cplusplus
+        auto value = TIMER(frc).CTRL;
+        value &= ~TIMER_CTRL_RELOAD;
+        TIMER(frc).CTRL = value;
+#else
         TIMER(frc).CTRL &= ~TIMER_CTRL_RELOAD;
+#endif
+    }
 }
 
 /* Get the auto-reload state of the timer (on or off) */
diff --git a/core/newlib_syscalls.c b/core/newlib_syscalls.c
index 50d0d30..cf83c76 100644
--- a/core/newlib_syscalls.c
+++ b/core/newlib_syscalls.c
@@ -29,6 +29,11 @@
 #if LWIP_SOCKET_OFFSET < 3
 #error Expecting a LWIP_SOCKET_OFFSET >= 3, to allow room for the standard I/O descriptors.
 #endif
+
+extern ssize_t lwip_read(int s, void *mem, size_t len);
+extern ssize_t lwip_write(int s, const void *mem, size_t len);
+extern int lwip_close(int s);
+
 #define FILE_DESCRIPTOR_OFFSET (LWIP_SOCKET_OFFSET + MEMP_NUM_NETCONN)
 #if FILE_DESCRIPTOR_OFFSET > FD_SETSIZE
 #error Too many lwip sockets for the FD_SETSIZE.
@@ -175,31 +180,6 @@ __attribute__((weak)) int _close_r(struct _reent *r, int fd)
     return -1;
 }
 
-/* Stub syscall implementations follow, to allow compiling newlib functions that
-   pull these in via various codepaths
-*/
-__attribute__((weak, alias("syscall_returns_enosys"))) 
-int _open_r(struct _reent *r, const char *pathname, int flags, int mode);
-
-__attribute__((weak, alias("syscall_returns_enosys"))) 
-int _unlink_r(struct _reent *r, const char *path);
-
-__attribute__((weak, alias("syscall_returns_enosys"))) 
-int _fstat_r(struct _reent *r, int fd, struct stat *buf);
-
-__attribute__((weak, alias("syscall_returns_enosys"))) 
-int _stat_r(struct _reent *r, const char *pathname, struct stat *buf);
-
-__attribute__((weak, alias("syscall_returns_enosys"))) 
-off_t _lseek_r(struct _reent *r, int fd, off_t offset, int whence);
-
-__attribute__((weak, alias("_gettimeofday_r")))
-int _gettimeofday_r (struct _reent *ptr, struct timeval *ptimeval, void *ptimezone) {
-  ptimeval->tv_sec = 0;
-  ptimeval->tv_usec = 0;
-  errno = ENOSYS;
-  return -1;
-}
 
 /* Generic stub for any newlib syscall that fails with errno ENOSYS
    ("Function not implemented") and a return value equivalent to
@@ -209,6 +189,31 @@ static int syscall_returns_enosys(struct _reent *r)
     r->_errno=ENOSYS;
     return -1;
 }
+/* Stub syscall implementations follow, to allow compiling newlib functions that
+   pull these in via various codepaths
+*/
+__attribute__((weak))
+int _open_r(struct _reent *r, const char *pathname, int flags, int mode) { return syscall_returns_enosys(r); }
+
+__attribute__((weak))
+int _unlink_r(struct _reent *r, const char *path) { return syscall_returns_enosys(r); }
+
+__attribute__((weak))
+int _fstat_r(struct _reent *r, int fd, struct stat *buf) { return syscall_returns_enosys(r); }
+
+__attribute__((weak))
+int _stat_r(struct _reent *r, const char *pathname, struct stat *buf) { return syscall_returns_enosys(r); }
+
+__attribute__((weak))
+off_t _lseek_r(struct _reent *r, int fd, off_t offset, int whence) { return syscall_returns_enosys(r); }
+
+__attribute__((weak))
+int _gettimeofday_r (struct _reent *ptr, struct timeval *ptimeval, void *ptimezone) {
+  ptimeval->tv_sec = 0;
+  ptimeval->tv_usec = 0;
+  errno = ENOSYS;
+  return -1;
+}
 
 int getentropy(void *ptr, size_t n)
 {
diff --git a/include/espressif/phy_info.h b/include/espressif/phy_info.h
index bda23ea..f9d33e8 100644
--- a/include/espressif/phy_info.h
+++ b/include/espressif/phy_info.h
@@ -174,8 +174,13 @@
 /* Run full RF CAL routine. RF init takes approx 200ms. */
 #define RF_CAL_MODE_FULL 3
 
-/* Data structure that maps to the phy_info configuration block */
-typedef struct __attribute__((packed)) {
+/* Data structure that maps to the phy_info configuration block.
+ * This was originally attributed with the ((packed)) attribute,
+ * but I don't currently see a reason why it needs to be. The
+ * structure uses only u8, so there shouldn't be any padding
+ * inserted.
+ */
+typedef struct {
     uint8_t _reserved00[0x05]; /* 0x00 - 0x04 */
 
     /* This "version" field was set to 5 in the SDK phy_info,
diff --git a/libc/xtensa-lx106-elf/include/stdlib.h b/libc/xtensa-lx106-elf/include/stdlib.h
index 5417ac0..238ed7b 100644
--- a/libc/xtensa-lx106-elf/include/stdlib.h
+++ b/libc/xtensa-lx106-elf/include/stdlib.h
@@ -144,8 +144,12 @@ void	qsort (void *__base, size_t __nmemb, size_t __size, __compar_fn_t _compar);
 int	rand (void);
 void *	realloc (void *__r, size_t __size) _NOTHROW;
 #if __BSD_VISIBLE
+#if 0
 void	*reallocarray(void *, size_t, size_t) __result_use_check __alloc_size(2)
 	    __alloc_size(3);
+#else
+void	*reallocarray(void *, size_t, size_t) __result_use_check __attribute__((alloc_size(2, 3)));
+#endif
 void *	reallocf (void *__r, size_t __size);
 #endif
 #if __BSD_VISIBLE || __XSI_VISIBLE >= 4
diff --git a/libc/xtensa-lx106-elf/include/sys/reent.h b/libc/xtensa-lx106-elf/include/sys/reent.h
index 0f21c68..c0c847b 100644
--- a/libc/xtensa-lx106-elf/include/sys/reent.h
+++ b/libc/xtensa-lx106-elf/include/sys/reent.h
@@ -404,7 +404,7 @@ struct _reent
   char *_asctime_buf;
 
   /* signal info */
-  void (**(_sig_func))(int);
+  void (**_sig_func)(int);
 
 # ifndef _REENT_GLOBAL_ATEXIT
   /* atexit stuff */
diff --git a/open_esplibs/libpp/pp.c b/open_esplibs/libpp/pp.c
index 4439c5a..cb58424 100644
--- a/open_esplibs/libpp/pp.c
+++ b/open_esplibs/libpp/pp.c
@@ -18,7 +18,7 @@
 static const uint32_t pp_zeros[8];
 void *_ppz20(size_t n)
 {
-    return &pp_zeros;
+    return (void*)&pp_zeros;
 }
 
 #if OPEN_LIBPP_PP