*

Makerbase_ODrive/ODrive-fw-v0.5.1/Firmware/Board/v3/Src/syscalls.c

@@ -0,0 +1,61 @@
+/**
+  ******************************************************************************
+  * @file           : syscalls.c
+  * @brief          : This file implements printf functionality
+  ******************************************************************************
+*/
+
+#include <cmsis_os.h>
+#include <freertos_vars.h>
+#include <sys/unistd.h>
+#include <usart.h>
+#include <usbd_cdc_if.h>
+
+
+//int _read(int file, char *data, int len) {}
+//int _close(int file) {}
+//int _lseek(int file, int ptr, int dir) {}
+//int _fstat(int file, struct stat *st) {}
+//int _isatty(int file) {}
+
+extern char _end; // provided by the linker script: it's end of statically allocated section, which is where the heap starts.
+extern char _heap_end_max; // provided by the linker script
+void* _end_ptr = &_end;
+void* _heap_end_max_ptr = &_heap_end_max;
+void* heap_end_ptr = 0;
+
+/* @brief Increments the program break (aka heap end)
+*
+* This is called internally by malloc once it runs out
+* of heap space. Malloc might expect a contiguous heap,
+* so we don't call the FreeRTOS pvPortMalloc here.
+* If this function returns -1, malloc will return NULL.
+* Note that if this function returns NULL, malloc does not
+* consider this as an error and will return the pointer 0x8.
+*
+* You should still be careful with using malloc though,
+* as it does not guarantee thread safety.
+*
+* @return A pointer to the newly allocated block on success
+*         or -1 otherwise.
+*/
+intptr_t _sbrk(size_t size) {
+    intptr_t ptr;
+	vTaskSuspendAll();
+	{
+        if (!heap_end_ptr)
+            heap_end_ptr = _end_ptr;
+        if (heap_end_ptr + size > _heap_end_max_ptr) {
+            ptr = -1;
+        } else {
+            ptr = (intptr_t)heap_end_ptr;
+            heap_end_ptr += size;
+        }
+	}
+	(void)xTaskResumeAll();
+    return ptr;
+}
+
+// _write is defined in communication.cpp
+
+