ref: a80c579064560b4bcf8ed28ed857b6265dc5fd37
dir: /src/libc/syscall.h/
extern int _brk(void *); extern void _exit(int); extern int _close(int); extern int _open(const char *, int, int); extern int _read(int, void *, size_t); extern int _unlink(const char *); extern int _write(int, void *, size_t); extern int _access(const char *, int); extern long _lseek(int, long, int);