fix: stub getentropy and mkdir

Author: johnyob

newlib/libc/sys/hermit/crt0.c

@@ -31,6 +31,7 @@
 #include <reent.h>
 #include "syscall.h"
 
+
 extern int main(int argc, char** argv);
 extern void __libc_init_array(void);
 extern void __libc_fini_array (void);
@@ -86,6 +87,12 @@ void _free_r(struct _reent* r, void* ptr) {
    }
 }
 
+int getentropy(void *ptr, __size_t n) { return -1; };
+
+int32_t mkdir(const char *name, uint32_t mode) {
+   return sys_mkdir(name, mode);
+}
+
 void runtime_entry(int argc, char** argv, char** env)
 {
    int ret;

newlib/libc/sys/hermit/syscall.h

@@ -159,6 +159,8 @@ int swapcontext(ucontext_t *oucp, const ucontext_t *ucp);
 int getcontext(ucontext_t *ucp);
 int setcontext(ucontext_t *ucp);
 
+int32_t sys_mkdir(const char *name, uint32_t mode);
+
 #define __NR_exit 		0
 #define __NR_write		1
 #define __NR_open		2