From fba50f1c195dae984bb8a180a3330594f1f95173 Mon Sep 17 00:00:00 2001
From: Kenneth J Davis <PerditionC@gmail.com>
Date: Sun, 9 Jan 2005 11:25:44 +0000
Subject: [PATCH] fix bug 1789 and add some extra debug prints

git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/branches/UNSTABLE@1089 6ac86273-5f31-0410-b378-82cca8765d1b
---
 kernel/dsk.c      | 13 +++++++++++--
 kernel/initdisk.c | 10 +++++++++-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/kernel/dsk.c b/kernel/dsk.c
index 2b65b24..e7e03be 100644
--- a/kernel/dsk.c
+++ b/kernel/dsk.c
@@ -673,6 +673,8 @@ STATIC WORD Genblkdev(rqptr rp, ddt * pddt)
         struct gblkio FAR *gblp = rp->r_io;
         bpb *pbpb;
 
+        DebugPrintf(("get params entry: spec=%X, type=%X, devattr=%X\n", gblp->gbio_spcfunbit,pddt->ddt_type,descflags));
+
         gblp->gbio_devtype = pddt->ddt_type;
         gblp->gbio_devattrib = descflags & 3;
         /* 360 kb disk in 1.2 MB drive */
@@ -680,18 +682,25 @@ STATIC WORD Genblkdev(rqptr rp, ddt * pddt)
         gblp->gbio_ncyl = pddt->ddt_ncyl;
         /* use default dpb or current bpb? */
         pbpb = (gblp->gbio_spcfunbit & 1) ? &pddt->ddt_bpb : &pddt->ddt_defbpb;
+        /* Note: last 6 bytes of standard BPB may not be copied for
+           0x60 when rp->r_cat==8 in some versions of DOS eg MSDOS5,see rbil */
 #ifdef WITHFAT32
+        if (rp->r_cat == 0x08) copy_size -= 6;
         fmemcpy(&gblp->gbio_bpb, pbpb, copy_size);
 #else
-        fmemcpy(&gblp->gbio_bpb, pbpb, sizeof(gblp->gbio_bpb));
+        fmemcpy(&gblp->gbio_bpb, pbpb, sizeof(gblp->gbio_bpb)-6);
 #endif
         /*gblp->gbio_nsecs = pbpb->bpb_nsector;*/
+        DebugPrintf(("get params dev spec=%X, type=%X, attrib=%X, media=%X, ncyl=%X\n", 
+                      gblp->gbio_spcfunbit, gblp->gbio_devtype, gblp->gbio_devattrib, gblp->gbio_media, gblp->gbio_ncyl));
         break;
       }
     case 0x61:                 /* read track */
       {
         struct gblkrw FAR *rw = rp->r_rw;
-        int ret = Genblockio(pddt, LBA_READ, rw->gbrw_head, rw->gbrw_cyl,
+        int ret;
+        DebugPrintf(("read track: head=%X, cyl=%X, sect=%X, nsecs=%X\n", rw->gbrw_head, rw->gbrw_cyl,rw->gbrw_sector, rw->gbrw_nsecs));
+        /*int*/ ret = Genblockio(pddt, LBA_READ, rw->gbrw_head, rw->gbrw_cyl,
                              rw->gbrw_sector, rw->gbrw_nsecs, rw->gbrw_buffer);
         if (ret)
           return ret;
diff --git a/kernel/initdisk.c b/kernel/initdisk.c
index a4430aa..9307ad4 100644
--- a/kernel/initdisk.c
+++ b/kernel/initdisk.c
@@ -306,6 +306,7 @@ COUNT init_getdriveparm(UBYTE drive, bpb * pbpbarray)
     return 5;
   regs.a.b.h = 0x08;
   regs.d.b.l = drive;
+  /* Note: RBIL suggests setting ES:DI to 0:0 to guard against BIOS bugs */
   init_call_intr(0x13, &regs);
   type = regs.b.b.l - 1;
   if (regs.flags & FLG_CARRY)
@@ -316,6 +317,8 @@ COUNT init_getdriveparm(UBYTE drive, bpb * pbpbarray)
     type = 4;                   /* 5 and 4 are both 2.88 MB */
 
   memcpy(pbpbarray, &floppy_bpbs[type & 7], sizeof(floppy_bpb));
+  ((bpb *)pbpbarray)->bpb_hidden = 0;  /* very important to init to 0, see bug#1789 */
+  ((bpb *)pbpbarray)->bpb_huge = 0;
 
   if (type == 3)
     return 7;                   /* 1.44 MB */
@@ -597,12 +600,17 @@ void DosDefinePartition(struct DriveParamS *driveParam,
   pddt->ddt_defbpb.bpb_mdesc = 0xf8;
   pddt->ddt_defbpb.bpb_nheads = driveParam->chs.Head;
   pddt->ddt_defbpb.bpb_nsecs = driveParam->chs.Sector;
-  pddt->ddt_defbpb.bpb_nsize = 0;
   pddt->ddt_defbpb.bpb_hidden = pEntry->RelSect;
   if (pEntry->NumSect > 0xffff)
+  {
+    pddt->ddt_defbpb.bpb_nsize = 0;
     pddt->ddt_defbpb.bpb_huge = pEntry->NumSect;
+  }
   else
+  {
     pddt->ddt_defbpb.bpb_nsize = (UWORD) (pEntry->NumSect);
+    pddt->ddt_defbpb.bpb_huge = 0;
+  }
 
   /* sectors per cluster, sectors per FAT etc. */
   CalculateFATData(pddt, pEntry->NumSect, pEntry->FileSystem);