feat(save_mbr function done)

tpfs/vol.c

@@ -30,3 +30,22 @@ void load_mbr()
     mbr.magic = MBR_MAGIC;
     mbr.nb_vols = 0;
 }
+
+void save_mbr()
+{
+    int i;
+    unsigned char buffer[sizeof(mbr_t)];
+
+    buffer[0] = mbr.magic & 255;
+    buffer[1] = (mbr.magic >> 8) & 255;
+    buffer[2] = mbr.nb_vols;
+    for (i = 0; i < mbr.nb_vols; i++)
+    {
+        buffer[3 + (i * 4)] = mbr.vols[i].sector;
+        buffer[4 + (i * 4)] = mbr.vols[i].cylinder;
+        buffer[5 + (i * 4)] = mbr.vols[i].nb_sectors;
+        buffer[6 + (i * 4)] = mbr.vols[i].type;
+    }
+
+    write_sector(0, 0, buffer);
+}
\ No newline at end of file

tpfs/vol.h

@@ -30,4 +30,6 @@ typedef struct mbr_s
 
 void load_mbr(void);
 
+void save_mbr(void);
+
 #endif // VOL_H