1 files changed, 7 insertions, 1 deletions

diff --git a/include/linux/fd.h b/include/linux/fd.h
index b6bd41d2b460..f5d194af07a8 100644
--- a/include/linux/fd.h
+++ b/include/linux/fd.h
@@ -15,10 +15,16 @@ struct floppy_struct {
                         sect,           /* sectors per track */
                         head,           /* nr of heads */
                         track,          /* nr of tracks */
-                        stretch;        /* !=0 means double track steps */
+                        stretch;        /* bit 0 !=0 means double track steps */
+                                        /* bit 1 != 0 means swap sides */
+                                        /* bits 2..9 give the first sector */
+                                        /*  number (the LSB is flipped) */
 #define FD_STRETCH 1
 #define FD_SWAPSIDES 2
 #define FD_ZEROBASED 4
+#define FD_SECTBASEMASK 0x3FC
+#define FD_MKSECTBASE(s) (((s) ^ 1) << 2)
+#define FD_SECTBASE(floppy) ((((floppy)->stretch & FD_SECTBASEMASK) >> 2) ^ 1)
 
         unsigned char   gap,            /* gap1 size */