Optional support for modifying CONFIG via memdisk args, requires MEMDISK_ARGS and 386 defined to be included.

git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@1634 6ac86273-5f31-0410-b378-82cca8765d1b

filelist

@@ -108,6 +108,7 @@
 */*/kernel/lfnapi.c
 */*/kernel/ludivmul.inc
 */*/kernel/main.c
+*/*/kernel/memdisk.asm
 */*/kernel/memmgr.c
 */*/kernel/misc.c
 */*/kernel/network.c

kernel/config.c

@@ -599,16 +599,99 @@ 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 */
+  UBYTE version_minor;       /* Memdisk minor version */
+  UBYTE version;             /* Memdisk major version */
+  UDWORD base;               /* Pointer to disk data in high memory */
+  UDWORD size;               /* Size of disk in 512 byte sectors */
+  char FAR * cmdline;        /* Command line */
+  ADDRESS oldint13;          /* Old INT 13h */
+  ADDRESS oldint15;          /* Old INT 15h */
+  UWORD olddosmem;           /* Amount of DOS memory before Memdisk loaded */
+  UBYTE boot_id;             /* major >= 3, boot loader ID */
+  UBYTE unused;
+  UWORD DPT_offset;          /* >= 3.71, ES based offset to installed DPT, +16 is Old INT 1Eh */
+};
+
+/* query_memdisk() based on similar subroutine in Eric Auer's public domain getargs.asm which is based on IFMEMDSK */
+struct memdiskinfo FAR * ASMCFUNC query_memdisk(UBYTE drive);
+#endif
+
+
 VOID DoConfig(int nPass)
 {
   COUNT nFileDesc;
   BYTE *pLine;
   BOOL bEof;
+  
+
+#ifdef MEMDISK_ARGS
+  /* 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 */
+  mdsk = query_memdisk(drv);
+#endif
+
   if (nPass==0)
+  {
     HaltCpuWhileIdle = 0; /* init to "no HLT while idle" */
 
+#ifdef MEMDISK_ARGS
+    if (mdsk != NULL)
+    {
+      printf("MEMDISK version %u.%02u  (%lu sectors)\n", mdsk->version, mdsk->version_minor, mdsk->size);
+      DebugPrintf(("MEMDISK args:{%S}  bootdrive=[%0Xh]\n", mdsk->cmdline, (unsigned int)drv));
+    }
+#endif
+  }
+
+#ifdef MEMDISK_ARGS
+  if (mdsk != NULL)
+  {
+    /* scan for FD= */
+    /* when done mdsk->cmdline points to { character or assume no valid CONFIG options */
+    for (mdsk_cfg=mdsk->cmdline; *mdsk_cfg; ++mdsk_cfg)
+    {
+      if (*mdsk_cfg != ' ') continue;
+      ++mdsk_cfg;
+      if (*mdsk_cfg != 'F') goto goback1;
+      ++mdsk_cfg;
+      if (*mdsk_cfg != 'D') goto goback2;
+      ++mdsk_cfg;
+      if (*mdsk_cfg != '=') goto goback3;
+      ++mdsk_cfg;
+      break;
+
+      goback3:
+        --mdsk_cfg;
+      goback2:
+        --mdsk_cfg;
+      goback1:
+        --mdsk_cfg;
+    }
+    /* if FD= was not found then flag as no extra CONFIG lines */
+    if (!*mdsk_cfg) mdsk_cfg = NULL;
+  }
+  else
+  {
+    DebugPrintf(("MEMDISK not detected! bootdrive=[%0Xh]\n", (unsigned int)drv));
+  }
+#endif
+
+
   /* Check to see if we have a config.sys file.  If not, just     */
-  /* exit since we don't force the user to have one.              */
+  /* exit since we don't force the user to have one (but 1st      */
+  /* also process MEMDISK passed config options if present).      */
   if ((nFileDesc = open("fdconfig.sys", 0)) >= 0)
   {
     DebugPrintf(("Reading FDCONFIG.SYS...\n"));
@@ -619,10 +702,18 @@ VOID DoConfig(int nPass)
     if ((nFileDesc = open("config.sys", 0)) < 0)
     {
       DebugPrintf(("CONFIG.SYS not found\n"));
+#ifdef MEMDISK_ARGS
+      if (mdsk_cfg != NULL)
+        bEof = TRUE;
+      else
+#endif
         return;
     }
+    else
+    {
       DebugPrintf(("Reading CONFIG.SYS...\n"));
     }
+  }
 
   /* Have one -- initialize.                                      */
   nCfgLine = 0;
@@ -633,12 +724,22 @@ VOID DoConfig(int nPass)
   /* do the table lookup and execute the handler for that         */
   /* function.                                                    */
 
+#ifdef MEMDISK_ARGS
+  for (; !bEof || (mdsk_cfg != NULL); nCfgLine++)
+#else
   for (; !bEof; nCfgLine++)
+#endif
   {
     struct table *pEntry;
 
     pLineStart = szLine;
 
+
+#ifdef MEMDISK_ARGS
+    if (!bEof)
+    {
+#endif
+        
     /* read in a single line, \n or ^Z terminated */
 
     for (pLine = szLine;;)
@@ -663,9 +764,47 @@ VOID DoConfig(int nPass)
         pLine++;
     }
 
+#ifdef MEMDISK_ARGS
+    }
+    else if (mdsk_cfg != NULL)
+    {
+        pLine = szLine;
+        /* copy data to near buffer skipping { and } */
+        if (*mdsk_cfg != '{') /* if not at start of line */
+        {
+            mdsk_cfg = NULL; /* no longer need data, so set to NULL to flag done */
+        }
+        else
+        {
+            for (pLine = szLine, mdsk_cfg++; *mdsk_cfg; mdsk_cfg++, pLine++)
+            {
+              /* copy character to near buffer */
+              *pLine = *mdsk_cfg;
+
+              /* ensure we don't copy too much, exceed our buffer size */
+              if (pLine >= szLine + sizeof(szLine) - 3)
+              {
+                CfgFailure(pLine);
+                printf("error - line overflow line %d \n", nCfgLine);
+                break;
+              }
+
+              /* if end of this simulated line is found, skip over EOL marker then proceed to process line */
+              if (*pLine == '}')
+              {
+                  mdsk_cfg++;
+                  break;
+              }
+            }
+        }
+    }
+#endif
+
     *pLine = 0;
     pLine = szLine;
 
+    DebugPrintf(("CONFIG=[%s]\n", pLine));
+
     /* Skip leading white space and get verb.               */
     pLine = scan(pLine, szBuf);
 

kernel/makefile

@@ -20,7 +20,7 @@ error.obj
 OBJS4=break.obj dosfns.obj fatdir.obj fatfs.obj fattab.obj fcbfns.obj \
 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
+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
 OBJS=$(OBJS1) $(OBJS2) $(OBJS3) $(OBJS4) $(OBJS5) $(OBJS6) $(OBJS7)
@@ -79,6 +79,7 @@ intr.obj:	intr.asm    segs.inc			$(TARGET).lnk
 io.obj:		io.asm	    segs.inc $(HDR)stacks.inc   $(TARGET).lnk
 irqstack.obj:   irqstack.asm segs.inc			$(TARGET).lnk
 kernel.obj:	kernel.asm  segs.inc ludivmul.inc 	$(TARGET).lnk
+memdisk.obj:	memdisk.asm  segs.inc $(TARGET).lnk
 nls_hc.obj:	nls_hc.asm  segs.inc			$(TARGET).lnk
 nlssupt.obj:	nlssupt.asm segs.inc $(HDR)stacks.inc   $(TARGET).lnk
 printer.obj:	printer.asm io.inc			$(TARGET).lnk

kernel/memdisk.asm

@@ -0,0 +1,81 @@
+; File:
+;                         memdisk.asm
+; Description:
+;                   Query for memdisk provided config.sys parameters
+;
+;                            DOS-C
+;                   Copyright (c) 2011
+;                        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.
+;
+;
+
+%if XCPU == 386       ; requires 386+ registers, until CPU check implemented only allow for 386 builds
+
+%include "segs.inc"
+segment INIT_TEXT
+
+CPU 386
+;*********************************************************************
+;
+; query_memdisk() based on similar subroutine in Eric Auer's public domain getargs.asm which is based on IFMEMDSK
+; input: drive (in AL) to query if memdisk provided disk
+; output: a far * to a memdiskinfo structure as defined by memdisk (see config.c) 
+; struct memdiskinfo FAR * query_memdisk(UBYTE drive);
+	global _query_memdisk
+	_query_memdisk:
+		; save registers, assumes enough space on stack & valid stack frame setup, ax & dx return values
+		push es
+		push di
+		push ebx
+		push ecx
+		push edx                ; we only care about high word
+		push eax                ; we only care about high word
+        mov dl, al              ; drive number (only argument, assumed to be in AL)
+        mov eax,454d0800h       ; magic1 + AH=8 (get geometry)
+        mov ecx,444d0000h       ; magic2
+        mov edx,53490000h       ; magic3 +
+        mov ebx,3f4b0000h       ; magic4
+        int 13h                 ; BIOS DISK API
+        shr eax,16              ; ignore AX
+        shr ebx,16              ; ignore BX
+        shr ecx,16              ; ignore CX (geometry C/S)
+        shr edx,16              ; ignore DX (geometry H in DH)
+        cmp ax,4d21h            ; magic5
+        jnz nomemdisk
+        cmp cx,4d45h            ; magic6
+        jnz nomemdisk
+        cmp dx,4944h            ; magic7
+        jnz nomemdisk
+        cmp bx,4b53h            ; magic8
+        jnz nomemdisk
+		jmp cleanup
+
+	nomemdisk:
+		xor di, di              ; return NULL;
+		mov es, di
+		
+	cleanup:
+		pop eax
+		pop edx
+		mov ax, di              ; return MK_FP(es, di);
+		mov dx, es
+		pop ecx
+		pop ebx
+		pop di
+		pop es
+		retn
+
+%endif