C userspace programs

ulib/_premain.c

@@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <stddef.h>
+
+extern void main(void);
+
+extern uint8_t _bss_start[];
+extern uint8_t _bss_end[];
+
+void bss_clear(void) {
+  uint8_t *p = _bss_start;
+  while (p != _bss_end) {
+    *p = 0;
+    p++;
+  }
+}
+
+// ulib initialization goes here
+void _premain(void) {
+  bss_clear();
+  main();
+}
+