(joint with Luchezar Georgiev): add extra low disk buffer to avoid HMA

problems with certain device driver. Add an extra space for the device
driver command line and point to a correct environment for
INSTALL= (fixes problems with xmsdsk).


git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@636 6ac86273-5f31-0410-b378-82cca8765d1b

hdr/lol.h

@@ -26,6 +26,8 @@
 /* Boston, MA  02111-1307  USA.                                 */
 /****************************************************************/
 
+enum {LOC_CONV=0, LOC_HMA=1};
+
 /* note: we start at DOSDS:0, but the "official" list of lists starts a
    little later at DOSDS:26 (this is what is returned by int21/ah=52) */
 
@@ -60,7 +62,7 @@ struct lol {
   struct buffer far *lookahead;/* 4d pointer to lookahead buffer          */
   unsigned short slookahead;   /* 51 number of lookahead sectors          */
   unsigned char bufloc;        /* 53 BUFFERS loc (1=HMA)                  */
-  struct buffer far *deblock;  /* 54 pointer to workspace buffer          */
+  char far *deblock_buf;       /* 54 pointer to workspace buffer          */
   char filler2[5];             /* 58 ???/unused                           */
   unsigned char int24fail;     /* 5d int24 fail while making i/o stat call*/
   unsigned char memstrat;      /* 5e memory allocation strat during exec  */

kernel/blockio.c

@@ -291,7 +291,7 @@ STATIC BOOL flush1(struct buffer FAR * bp)
 
   UWORD result;                 /* BER 9/4/00 */
 
-  if ((bp->b_flag & BFR_VALID) && (bp->b_flag & BFR_DIRTY))
+  if ((bp->b_flag & (BFR_VALID | BFR_DIRTY)) == (BFR_VALID | BFR_DIRTY))
   {
     /* BER 9/4/00  */
     result = dskxfer(bp->b_unit, bp->b_blkno, bp->b_buffer, 1, DSKWRITE);
@@ -405,7 +405,6 @@ UWORD dskxfer(COUNT dsk, ULONG blkno, VOID FAR * buf, UWORD numblocks,
 
     IoReqHdr.r_status = 0;
     IoReqHdr.r_meddesc = dpbp->dpb_mdb;
-    IoReqHdr.r_trans = (BYTE FAR *) buf;
     IoReqHdr.r_count = numblocks;
     if (blkno >= MAXSHORT)
     {
@@ -414,8 +413,26 @@ UWORD dskxfer(COUNT dsk, ULONG blkno, VOID FAR * buf, UWORD numblocks,
     }
     else
       IoReqHdr.r_start = blkno;
-    execrh((request FAR *) & IoReqHdr, dpbp->dpb_device);
+    /*
-    if (!(IoReqHdr.r_status & S_ERROR) && (IoReqHdr.r_status & S_DONE))
+     * Some drivers normalise transfer address so HMA transfers are disastrous!
+     * Then transfer block through xferbuf (DiskTransferBuffer doesn't work!)
+     * (But this won't work for multi-block HMA transfers... are there any?)
+     */
+    if (FP_SEG(buf) >= 0xa000 && numblocks == 1 && bufloc != LOC_CONV)
+    {
+      IoReqHdr.r_trans = deblock_buf;
+      if (mode == DSKWRITE)
+        fmemcpy(deblock_buf, buf, SEC_SIZE);
+      execrh((request FAR *) & IoReqHdr, dpbp->dpb_device);
+      if (mode == DSKREAD)
+        fmemcpy(buf, deblock_buf, SEC_SIZE);
+    }
+    else
+    {
+      IoReqHdr.r_trans = (BYTE FAR *) buf;
+      execrh((request FAR *) & IoReqHdr, dpbp->dpb_device);
+    }
+    if ((IoReqHdr.r_status & (S_ERROR | S_DONE)) == S_DONE)
       break;
 
     /* INT25/26 (_SEEMS_ TO) return immediately with 0x8002,

kernel/config.c

@@ -226,20 +226,6 @@ BYTE HMAState = 0;
 #define HMA_DONE 2              /* Moved kernel to HMA */
 #define HMA_LOW 3               /* Definitely LOW */
 
-STATIC void FAR* ConfigAlloc(COUNT bytes, char type)
-{
-  VOID FAR *p;
-
-  p = HMAalloc(bytes);
-
-  if (p == NULL)
-    p = KernelAlloc(bytes, type, 0);
-
-  /* printf("ConfigAlloc %d at %p\n", bytes, p); */
-
-  return p;
-}
-
 /* Do first time initialization.  Store last so that we can reset it    */
 /* later.                                                               */
 void PreConfig(void)
@@ -1242,7 +1228,7 @@ STATIC BOOL LoadDevice(BYTE * pLine, char FAR *top, COUNT mode)
    */
 
   /* add \r\n to the command line */
-  strcat(szBuf, "\r\n");
+  strcat(szBuf, " \r\n");
 
   dhp = MK_FP(base, 0);
 
@@ -1639,9 +1625,23 @@ VOID config_init_buffers(COUNT anzBuffers)
   lpTop = lpOldTop;
 
   LoL->inforecptr = &LoL->firstbuf;
-  LoL->firstbuf = ConfigAlloc(sizeof(struct buffer) * anzBuffers, 'B');
+  
+  {
+    size_t bytes = sizeof(struct buffer) * anzBuffers;
+    pbuffer = HMAalloc(bytes);
 
-  pbuffer = LoL->firstbuf;
+    if (pbuffer == NULL)
+    {
+      pbuffer = KernelAlloc(bytes, 'B', 0);
+    }
+    else
+    {
+      LoL->bufloc = LOC_HMA;
+      LoL->deblock_buf = KernelAlloc(SEC_SIZE, 'B', 0);
+    }
+  }
+
+  LoL->firstbuf = pbuffer;
 
   DebugPrintf(("init_buffers (size %u) at", sizeof(struct buffer)));
   DebugPrintf((" (%p)", LoL->firstbuf));

kernel/globals.h

@@ -247,6 +247,9 @@ FAR * ASM clock,                    /* CLOCK$ device                        */
 extern WORD ASM maxbksize;          /* Number of Drives in system           */
 extern struct buffer
 FAR *ASM firstbuf;                  /* head of buffers linked list          */
+enum {LOC_CONV=0, LOC_HMA=1};
+extern unsigned char ASM bufloc;    /* 0=conv, 1=HMA                        */
+extern void far * ASM deblock_buf;  /* pointer to workspace buffer      */
 GLOBAL char FAR *firstAvailableBuf;
 extern struct cds FAR * ASM CDSp;   /* Current Directory Structure          */
 extern

kernel/inthndlr.c

@@ -89,6 +89,7 @@ VOID ASMCFUNC int21_syscall(iregs FAR * irp)
             irp->DL = break_ena;
             break_ena = tmp != 0;
           }
+          break;
 
           /* Get Boot Drive                                       */
         case 0x05:

kernel/kernel.asm

@@ -318,8 +318,10 @@ _firstbuf       dd      0               ; 0047 disk buffer chain
                 dw      0               ; 004B Number of dirty buffers
                 dd      0               ; 004D pre-read buffer
                 dw      0               ; 0051 number of look-ahead buffers
-                db      0               ; 0053 00=conv 01=HMA
+		global	_bufloc
-deblock_buf     dd      0               ; 0054 deblock buffer
+_bufloc         db      0               ; 0053 00=conv 01=HMA
+		global	_deblock_buf
+_deblock_buf    dd      0               ; 0054 deblock buffer
                 times 3 db 0            ; 0058 unknown
                 dw      0               ; 005B unknown
                 db      0, 0FFh, 0      ; 005D unknown

kernel/main.c

@@ -219,6 +219,7 @@ STATIC void init_kernel(void)
   set_DTA(MK_FP(DOS_PSP, 0x80));
   init_PSPSet(DOS_PSP);
   init_PSPInit(DOS_PSP);
+  ((psp far *)MK_FP(DOS_PSP, 0))->ps_environ = DOS_PSP + 8;
 
   Init_clk_driver();
 
@@ -531,7 +532,7 @@ BOOL init_device(struct dhdr FAR * dhp, char *cmdLine, COUNT mode,
 /*
  *  Added needed Error handle
  */
-  if (rq.r_status & S_ERROR)
+  if ((rq.r_status & (S_ERROR | S_DONE)) == S_ERROR)
     return TRUE;
 
   if (cmdLine)