Swap memory management to FreeRTOS-style, fixed heap size

FreeRTOS/Source/portable/esp8266/sdk_compat.c

@@ -0,0 +1,80 @@
+/* this file provides function aliasing/etc that are needed for
+   compatibility with other binary espressif libraries */
+#include <stdlib.h>
+#include <string.h>
+#include "FreeRTOS.h"
+
+/* Enable/Disable Interrupts
+
+   Called from many of the linked libraries to protect critical sections.
+ */
+
+/*
+void vPortEnterCritical( void )
+{
+    portDISABLE_INTERRUPTS();
+}
+
+void vPortExitCritical( void )
+{
+    portEXIT_CRITICAL();
+}
+*/
+
+/* libc memory management functions.
+
+   Many of these are linked from the RTOS SDK blob libraries.
+
+   In esp_iot_rtos_sdk these are aliased to exception-safe versions of
+   the FreeRTOS functions. I think the rationale is that they're
+   sometimes called in exception contexts (ESPTODO: Verify this).
+
+   For now these are exception-safe wrappers to the FreeRTOS versions.
+ */
+
+void *malloc(size_t nbytes) {
+	void *res;
+	portENTER_CRITICAL();
+	res = pvPortMalloc(nbytes);
+	portEXIT_CRITICAL();
+	return res;
+}
+
+void *calloc(size_t count, size_t size) {
+	void *res;
+	size_t nbytes = count * size;
+	portENTER_CRITICAL();
+	res = pvPortMalloc(nbytes);
+	portEXIT_CRITICAL();
+	if(res) {
+		memset(res, 0, nbytes);
+	}
+	return res;
+}
+
+void *zalloc(size_t nbytes) {
+    return calloc(1, nbytes);
+}
+
+void *realloc(void *old, size_t newsize) {
+	void *new;
+	portENTER_CRITICAL();
+	if(newsize == 0) {
+		vPortFree(old);
+		return 0;
+	}
+	/* realloc implementation borrowed from esp_iot_rtos_sdk, could be better I think */
+	new = pvPortMalloc(newsize);
+	if (new) {
+		memcpy(new, old, newsize);
+		vPortFree(old);
+	}
+	portEXIT_CRITICAL();
+	return new;
+}
+
+void free(void *ptr) {
+    portENTER_CRITICAL();
+    vPortFree(ptr);
+    portEXIT_CRITICAL();
+}