Support some floppy image in Memdisk mode

INSTALL/grub/grub.cfg

@@ -1704,6 +1704,15 @@ function img_unsupport_tip {
     read vtInputKey 
 }
 
+function legacy_img_memdisk {
+    linux16   $vtoy_path/memdisk
+    echo "Loading img file to memory ..."
+    initrd16  "${1}${2}"
+    
+    ventoy_cli_console
+    boot
+}
+
 function img_common_menuentry {
     set ventoy_compatible=YES
     set ventoy_busybox_ver=32
@@ -1718,6 +1727,13 @@ function img_common_menuentry {
         return
     fi
 
+    if [ "$grub_platform" = "pc" ]; then
+        if vt_check_mode 0; then
+            legacy_img_memdisk $vtoy_iso_part "$vt_chosen_path"
+            return
+        fi
+    fi
+
     if [ -d (vtimghd)/ ]; then
         loopback -d vtimghd
     fi