#include char* _sbrk(int incr) { extern char heap_low; // Defined by the linker extern char heap_top; static char *heap_end; char *prev_heap_end; if (heap_end == 0) { heap_end = &heap_low; } prev_heap_end = heap_end; if (heap_end + incr > &heap_top) { return 0; } heap_end += incr; return (char*) prev_heap_end; } int _isatty(int fd) { return 1; } int _close(int fd) { return 0; } int _open(int fd) { return 0; } int _fstat(void) { return 0; } int _lseek(void) { return 0; } int _read(void) { return 0; } int _write(int fd, const void *buf, int count) { uart_send_array((char*)buf, count); return count; }