Update FDCReset

I have patched FDCReset to actually do its job correctly, switching it over to DOR-twiddling instead of the DSR method. I also allowed it to skip the interrupt checks if it gets a 0x80 byte back at any point.

1 files changed, 18 insertions, 6 deletions

diff --git a/Kernel/BlkDev/DskFDC.HC b/Kernel/BlkDev/DskFDC.HC
index 53cdccb..8a68b21 100644
--- a/Kernel/BlkDev/DskFDC.HC
+++ b/Kernel/BlkDev/DskFDC.HC
@@ -101,20 +101,32 @@ U0 FDCSendByte(CBlkDev *bd,U8 byte)
 U0 FDCReset(CBlkDev *bd)
 {
   // Reset the FDC
+  I64 i;
+  U64 dor;
 
+  // Prepare the int semaphore
   fdc_int_semaphore=FALSE;
 
-  // Twiddle the reset bit in the DSR
-  OutU8(bd->base0+FDC_MSR_DSR,0x80|bd->bps);
+  // Clear the reset and IRQ bits in the DOR
+  dor=InU8(bd->base0+FDC_DOR)&~(FDC_DOR_DMA+FDC_DOR_REST);
+  OutU8(bd->base0+FDC_DOR,dor);
+
+  // Wait for a few microseconds
+  for (i=0;i<4;i++) {
+    PortNop;
+  }
+  
+  // Set the bits back
+  dor=dor|(FDC_DOR_DMA+FDC_DOR_REST);
+  OutU8(bd->base0+FDC_DOR,dor);
 
   // Wait for the int
-  while (!fdc_int_semaphore)
-    Yield;
+  while (!fdc_int_semaphore) Yield;
 
-  // Send 4 SISes
+  // Send 4 SISes (or bail if we get 0x80)
   for (i=0,i<4,i++) {
     FDCSendByte(bd,FDC_SENSE_INTR)
-    FDCReadByte(bd);
+    if (FDCReadByte(bd)=0x80) break;
     FDCReadByte(bd);
   }