[Qemu-devel] [RFC 06/10] fdc: add physical disk sizes

[John Snow]

2.88MB capable drives can accept 1.44MB floppies,
for instance. To rework the pick_geometry function,
we need to know if our current drive can even accept
the type of disks we're considering.

NB: This allows us to distinguish between all of the
"total sectors" collisions between 1.20MB and 1.44MB
diskette types.

Signed-off-by: John Snow <address@hidden>
---
 hw/block/fdc.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index 4004b98..6e5f87b 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -59,6 +59,11 @@ typedef enum FDriveRate {
     FDRIVE_RATE_1M   = 0x03,  /*   1 Mbps */
 } FDriveRate;
 
+typedef enum FDriveSize {
+    FDRIVE_SIZE_350,
+    FDRIVE_SIZE_525
+} FDriveSize;
+
 typedef struct FDFormat {
     FDriveType drive;
     uint8_t last_sect;
@@ -95,15 +100,15 @@ static const FDFormat fd_formats[] = {
     { FDRIVE_DRV_144, 14, 80, 1, FDRIVE_RATE_250K, },
     /* 1.2 MB 5"1/4 floppy disks */
     { FDRIVE_DRV_120, 15, 80, 1, FDRIVE_RATE_500K, },
-    { FDRIVE_DRV_120, 18, 80, 1, FDRIVE_RATE_500K, },
+    { FDRIVE_DRV_120, 18, 80, 1, FDRIVE_RATE_500K, }, /* conflicts w/ #0 */
     { FDRIVE_DRV_120, 18, 82, 1, FDRIVE_RATE_500K, },
     { FDRIVE_DRV_120, 18, 83, 1, FDRIVE_RATE_500K, },
-    { FDRIVE_DRV_120, 20, 80, 1, FDRIVE_RATE_500K, },
+    { FDRIVE_DRV_120, 20, 80, 1, FDRIVE_RATE_500K, }, /* conflicts w/ #1 */
     /* 720 kB 5"1/4 floppy disks */
-    { FDRIVE_DRV_120,  9, 80, 1, FDRIVE_RATE_250K, },
+    { FDRIVE_DRV_120,  9, 80, 1, FDRIVE_RATE_250K, }, /* conflicts w/ #13 */
     { FDRIVE_DRV_120, 11, 80, 1, FDRIVE_RATE_250K, },
     /* 360 kB 5"1/4 floppy disks */
-    { FDRIVE_DRV_120,  9, 40, 1, FDRIVE_RATE_300K, },
+    { FDRIVE_DRV_120,  9, 40, 1, FDRIVE_RATE_300K, }, /* conflicts w/ #32 */
     { FDRIVE_DRV_120,  9, 40, 0, FDRIVE_RATE_300K, },
     { FDRIVE_DRV_120, 10, 41, 1, FDRIVE_RATE_300K, },
     { FDRIVE_DRV_120, 10, 42, 1, FDRIVE_RATE_300K, },
@@ -116,6 +121,20 @@ static const FDFormat fd_formats[] = {
     { FDRIVE_DRV_NONE, -1, -1, 0, 0, },
 };
 
+__attribute__((__unused__))
+static FDriveSize drive_size(FDriveType drive)
+{
+    switch (drive) {
+    case FDRIVE_DRV_120:
+        return FDRIVE_SIZE_525;
+    case FDRIVE_DRV_144:
+    case FDRIVE_DRV_288:
+        return FDRIVE_SIZE_350;
+    default:
+        return -1;
+    }
+}
+
 #define GET_CUR_DRV(fdctrl) ((fdctrl)->cur_drv)
 #define SET_CUR_DRV(fdctrl, drive) ((fdctrl)->cur_drv = (drive))
 
-- 
2.1.0