many fixes

runtime/include/vx_tex.h

@@ -1,14 +1,16 @@
-#ifndef VX_API_H
-#define VX_API_H
-
-#include <stdint.h>
-#include <stdio.h>
+#ifndef VX_TEX_H
+#define VX_TEX_H
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-int vx_tex(unsigned t, unsigned u, unsigned v, unsigned lod);
+unsigned vx_tex(unsigned unit, unsigned u, unsigned v, unsigned lod) {
+    unsigned result;
+    unsigned lod_unit = (unit << 24) | lod;
+    asm volatile (".insn r4 0x6b, 5, 0, %0, %1, %2, %3" : "=r"(result) : "r"(u), "r"(v), "r"(lod_unit));
+    return result;
+}
 
 #ifdef __cplusplus
 }