add cpu detection so memdisk args supported in 8086 build

git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@1705 6ac86273-5f31-0410-b378-82cca8765d1b

docs/history.txt

@@ -20,6 +20,7 @@ Changelog items can list SVN revision rNUMBER and bugzilla bug NUMBER.
       during booting when forcing LBA mode option set
     * r1702 improve handling for sectors not 512 bytes in size 
       (up to 2048 bytes, larger sizes not yet working)
+    * r1705 add cpu detection so memdisk args supported in 8086 build
 	
 + Changes Bart
 	* r?

hdr/lol.h

@@ -55,7 +55,7 @@ struct lol {
   unsigned short nbuffers;     /* 3f Number of buffers                    */
   unsigned short nlookahead;   /* 41 Number of lookahead buffers          */
   unsigned char BootDrive;     /* 43 bootdrive (1=A:)                     */
-  unsigned char dwordmoves;    /* 44 use dword moves (unused)             */
+  unsigned char cpu;           /* 44 CPU family [was unused dword moves]  */
   unsigned short xmssize;      /* 45 extended memory size in KB           */ 
   struct buffer far *firstbuf; /* 47 head of buffers linked list          */
   unsigned short dirtybuf;     /* 4b number of dirty buffers              */

kernel/config.c

@@ -599,13 +599,6 @@ STATIC void umb_init(void)
   }
 }
 
-/* we require 386, so only supported for 386+ compiled kernels */
-#if defined(MEMDISK_ARGS)
-#ifndef I386
-#undef MEMDISK_ARGS
-#endif
-#endif
-
 #ifdef MEMDISK_ARGS
 struct memdiskinfo {
   UWORD bytes;               /* Total size of this structure, value >= 26 */
@@ -638,8 +631,12 @@ VOID DoConfig(int nPass)
   /* check if MEMDISK used for LoL->BootDrive, if so check for special appended arguments */
   struct memdiskinfo FAR *mdsk;
   BYTE FAR *mdsk_cfg = NULL;
-  UBYTE drv = (LoL->BootDrive < 3)?0x0:0x80; /* 1=A,2=B,3=C */
+  /* memdisk check & usage requires 386+, DO NOT invoke if less than 386 */
-  mdsk = query_memdisk(drv);
+  if (LoL->cpu >= 3)
+  {
+    UBYTE drv = (LoL->BootDrive < 3)?0x0:0x80; /* 1=A,2=B,3=C */
+    mdsk = query_memdisk(drv);
+  }
 #endif
 
   if (nPass==0)

kernel/cpu.asm

@@ -0,0 +1,74 @@
+; File:
+;                         cpu.asm
+; Description:
+;                   Query basic CPU running on
+;
+;                            DOS-C
+;                   Copyright (c) 2012
+;                        FreeDOS
+;                      All Rights Reserved
+;
+; This file is part of DOS-C.
+;
+; DOS-C is free software; you can redistribute it and/or
+; modify it under the terms of the GNU General Public License
+; as published by the Free Software Foundation; either version
+; 2, or (at your option) any later version.
+;
+; DOS-C is distributed in the hope that it will be useful, but
+; WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+; the GNU General Public License for more details.
+;
+;
+
+%include "segs.inc"
+segment INIT_TEXT
+
+CPU 386
+;*********************************************************************
+;
+; UWORD query_cpu() based on Eric Auer's public domain cpulevel.asm
+; input: none
+; output: ax = cpu, 0=8086/8088, 1=186/188, 2=286, 3=386+ 
+    global _query_cpu
+    _query_cpu:
+        ; save registers, assumes enough space on stack & valid stack frame setup
+        ;push ax - no need to save, return value saved here
+        push bx
+        push cx
+        pushf       ; save flags
+
+        ; begin check, assume x86 unless later family detected
+        xor  bx, bx ; 808x or 186  highest detected family stored in bx
+        push bx
+        popf        ; try to clear all flag bits
+        pushf       ; copy flags to ax so we can test if clear succeeded
+        pop  ax
+        and  ax, 0f000h
+        cmp  ax, 0f000h
+        jnz  is286  ; no the 4 msb stuck set to 1, so is a 808x or 8018x
+        mov  ax,1   ; determine if 8086 or 186
+        mov  cl,64  ; try to shift further than size of ax
+        shr  ax,cl
+        or   ax,ax
+        jz   is086  ; 186 ignores the upper bits of cl
+        mov  bx, 1  ; 186: above 808x, below 286
+is086:  jmp  short cleanup
+is286:  mov  bx, 2  ; at least 286
+        mov  ax, 0f000h
+        push ax
+        popf        ; try to set 4 msb of flags
+        pushf       ; copy flags to ax so we can test if clear succeeded
+        pop  ax
+        test ax, 0f000h
+        jz cleanup  ; 4 msb stuck to 0: 80286
+        mov bx, 3   ; at least 386
+        
+    cleanup:
+        mov  ax, bx ; return CPU family
+        popf
+        pop  cx
+        pop  bx
+        retn
+

kernel/globals.h

@@ -326,6 +326,7 @@ extern BYTE ASM verify_ena,         /* verify enabled flag                  */
 extern UWORD ASM return_code;       /* Process termination rets             */
 
 extern UBYTE ASM BootDrive,         /* Drive we came up from                */
+  ASM CPULevel,                     /* CPU family, 0=8086, 1=186, ...       */
   ASM scr_pos;                      /* screen position for bs, ht, etc      */
 /*extern WORD
   NumFloppies; !!*//* How many floppies we have            */

kernel/inthndlr.c

@@ -39,7 +39,7 @@ BYTE *RcsId =
 
 #ifdef TSC
 STATIC VOID StartTrace(VOID);
-static bTraceNext = FALSE;
+STATIC bTraceNext = FALSE;
 #endif
 
 #if 0                           /* Very suspicious, passing structure by value??
@@ -81,7 +81,7 @@ VOID ASMCFUNC int21_syscall(iregs FAR * irp)
           /* Set Ctrl-C flag; returns dl = break_ena              */
         case 0x01:
           break_ena = irp->DL & 1;
-          /* fall through */
+          /* fall through so DL only low bit (as in MS-DOS) */
 
           /* Get Ctrl-C flag                                      */
         case 0x00:
@@ -105,19 +105,26 @@ VOID ASMCFUNC int21_syscall(iregs FAR * irp)
         case 0x06:
           irp->BL = os_major;
           irp->BH = os_minor;
-          irp->DL = rev_number;
+          irp->DL = 0;                  /* lower 3 bits revision #, remaining should be 0 */
           irp->DH = version_flags;      /* bit3:runs in ROM,bit 4: runs in HMA */
           break;
 
-        case 0x03:             /* DOS 7 does not set AL */
+     /* case 0x03: */          /* DOS 7 does not set AL */
-        case 0x07:             /* neither here */
+     /* case 0x07: */          /* neither here */
 
         default:               /* set AL=0xFF as error, NOT carry */
           irp->AL = 0xff;
           break;
 
-          /* set FreeDOS returned version for int 21.30 from BX */
+        /* the remaining are FreeDOS extensions */
-        case 0xfc:             /* 0xfc ... 0xff are FreeDOS extensions */
+
+          /* return CPU family */
+        case 0xfa:
+          irp->AL = CPULevel;
+          break;
+					
+           /* set FreeDOS returned version for int 21.30 from BX */
+        case 0xfc:
           os_setver_major = irp->BL;
           os_setver_minor = irp->BH;
           break;
@@ -724,9 +731,12 @@ dispatch:
 
       /* Get (editable) DOS Version                                   */
     case 0x30:
+      if (lr.AL == 1) /* from RBIL, if AL=1 then return version_flags */
+          lr.BH = version_flags;
+      else
+          lr.BH = OEM_ID;
       lr.AL = os_setver_major;
       lr.AH = os_setver_minor;
-      lr.BH = OEM_ID;
       lr.BL = REVISION_SEQ;
       lr.CX = 0; /* do not set this to a serial number!
                     32RTM won't like non-zero values   */
@@ -943,6 +953,33 @@ dispatch:
           lr.AX = lr.CX;
           break;
 
+#if 0
+        case 0x02:
+            /* get compressed size -> compression not support returns size in clusters */
+            /* rc = DosGetClusterCnt((BYTE FAR *) FP_DS_DX); */
+          goto error_invalid;
+#endif
+
+        case 0xff: /* DOS 7.20 (w98) extended name (128 char length) functions */
+        {
+          switch(lr.CL)
+          {
+                /* Dos Create Directory                                         */
+                case 0x39:
+                /* Dos Remove Directory                                         */
+                case 0x3a:
+                rc = DosMkRmdir(FP_DS_DX, lr.AH);
+                goto short_check;
+
+                /* Dos rename file */
+                case 0x56:
+                rc = DosRename(FP_DS_DX, FP_ES_DI);
+                goto short_check;
+
+              /* fall through to goto error_invaid */
+          }
+        }
+
         default:
           goto error_invalid;
       }

kernel/kernel.asm

@@ -103,6 +103,7 @@ beyond_entry:   resb    256-(beyond_entry-entry)
 segment INIT_TEXT
 
                 extern  _FreeDOSmain
+                extern  _query_cpu
                 
                 ;
                 ; kernel start-up
@@ -190,6 +191,10 @@ cont:           ; Now set up call frame
 ;!!             inc     al
 ;!!                mov     byte [_NumFloppies],al ; and how many
 
+                call _query_cpu
+                mov     byte [_CPULevel],al
+                ; TODO display error if built for 386 running on 8086 etc
+                
                 mov     ax,ss
                 mov     ds,ax
                 mov     es,ax
@@ -335,11 +340,11 @@ _LoL_nbuffers   dw      1               ; 003F number of buffers
                 global  _BootDrive
 _BootDrive      db      1               ; 0043 drive we booted from   
 
-%IF XCPU < 386
+                global  _CPULevel
-                db      0               ; 0044 cpu type (1 if >=386)
+_CPULevel       db      0               ; 0044 cpu type (MSDOS >0 indicates dword moves ok, ie 386+)
-%ELSE                
+                                        ; unless compatibility issues arise FD uses
-                db      1               ; 0044 cpu type (1 if >=386)
+                                        ; 0=808x, 1=18x, 2=286, 3=386+
-%ENDIF
+                                        ; see cpu.asm, use >= as may add checks for 486 ...
 
                 dw      0               ; 0045 Extended memory in KBytes
 buf_info:               
@@ -379,7 +384,6 @@ _os_setver_major        db      5
 _os_minor       db      0
                 global  _os_major              
 _os_major       db      5
-                global  _rev_number
 _rev_number     db      0
                 global  _version_flags         
 _version_flags  db      0

kernel/makefile

@@ -22,7 +22,7 @@ inthndlr.obj
 OBJS5=ioctl.obj memmgr.obj task.obj newstuff.obj nls.obj network.obj
 OBJS6=prf.obj misc.obj strings.obj syspack.obj lfnapi.obj iasmsupt.obj memdisk.obj
 OBJS7=main.obj config.obj initoem.obj inithma.obj dyninit.obj iprf.obj \
-initdisk.obj initclk.obj
+initdisk.obj initclk.obj cpu.obj
 OBJS=$(OBJS1) $(OBJS2) $(OBJS3) $(OBJS4) $(OBJS5) $(OBJS6) $(OBJS7)
 
 #               *Explicit Rules*
@@ -71,6 +71,7 @@ $(TARGET).lnk: turboc.cfg makefile ../mkfiles/generic.mak ../mkfiles/$(COMPILER)
 apisupt.obj:	apisupt.asm segs.inc			$(TARGET).lnk
 asmsupt.obj:	asmsupt.asm segs.inc			$(TARGET).lnk
 console.obj:	console.asm io.inc			$(TARGET).lnk
+cpu.obj:	cpu.asm  segs.inc $(TARGET).lnk
 dosidle.obj:	dosidle.asm segs.inc			$(TARGET).lnk
 entry.obj:	entry.asm   segs.inc $(HDR)stacks.inc	$(TARGET).lnk
 execrh.obj:	execrh.asm  segs.inc 			$(TARGET).lnk

kernel/memdisk.asm

@@ -22,7 +22,7 @@
 ;
 ;
 
-%if XCPU == 386       ; requires 386+ registers, until CPU check implemented only allow for 386 builds
+; requires 386+ registers, check LoL->CPU >=3 prior to calling (or use 386 build)
 
 %include "segs.inc"
 segment INIT_TEXT
@@ -77,5 +77,3 @@ CPU 386
 		pop di
 		pop es
 		retn
-
-%endif