FreeDOS/kernel/main.c

/****************************************************************/
/*                                                              */
/*                           main.c                             */
/*                            DOS-C                             */
/*                                                              */
/*                    Main Kernel Functions                     */
/*                                                              */
/*                   Copyright (c) 1995, 1996                   */
/*                      Pasquale J. Villani                     */
/*                      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.             */
/*                                                              */
/* You should have received a copy of the GNU General Public    */
/* License along with DOS-C; see the file COPYING.  If not,     */
/* write to the Free Software Foundation, 675 Mass Ave,         */
/* Cambridge, MA 02139, USA.                                    */
/****************************************************************/

#include "portab.h"
#include "init-mod.h"

/*
  These are the far variables from the DOS data segment that we need here. The
  init procedure uses a different default DS data segment, which is discarded
  after use. I hope to clean this up to use the DOS List of List and Swappable
  Data Area obtained via INT21.

  -- Bart
 */
extern UBYTE FAR nblkdev,
    FAR lastdrive;                    /* value of last drive                  */

GLOBAL BYTE
    FAR os_major,                     /* major version number                 */
    FAR os_minor,                     /* minor version number                 */
    FAR dosidle_flag,
    FAR BootDrive,                    /* Drive we came up from                */
    FAR default_drive;                /* default drive for dos                */

GLOBAL BYTE FAR os_release[];
GLOBAL BYTE FAR copyright[];
GLOBAL seg FAR RootPsp;               /* Root process -- do not abort         */

extern struct dpb FAR * FAR DPBp; /* First drive Parameter Block          */
extern cdstbl FAR * FAR CDSp; /* Current Directory Structure          */

extern struct dhdr FAR * FAR clock,           /* CLOCK$ device                        */
                   FAR * FAR syscon;          /* console device                       */
extern struct dhdr FAR con_dev,               /* console device drive                 */
                   FAR clk_dev,               /* Clock device driver                  */
                   FAR blk_dev;               /* Block device (Disk) driver           */
extern UWORD
    FAR ram_top;                      /* How much ram in Kbytes               */

extern iregs FAR * FAR user_r;        /* User registers for int 21h call      */

#ifdef VERSION_STRINGS
static BYTE *mainRcsId = "$Id$";
#endif

/*
 * $Log$
 * Revision 1.19  2001/07/22 01:58:58  bartoldeman
 * Support for Brian's FORMAT, DJGPP libc compilation, cleanups, MSCDEX
 *
 * Revision 1.18  2001/07/09 22:19:33  bartoldeman
 * LBA/FCB/FAT/SYS/Ctrl-C/ioctl fixes + memory savings
 *
 * Revision 1.17  2001/06/03 14:16:18  bartoldeman
 * BUFFERS tuning and misc bug fixes/cleanups (2024c).
 *
 * Revision 1.16  2001/04/29 17:34:40  bartoldeman
 * A new SYS.COM/config.sys single stepping/console output/misc fixes.
 *
 * Revision 1.15  2001/04/21 22:32:53  bartoldeman
 * Init DS=Init CS, fixed stack overflow problems and misc bugs.
 *
 * Revision 1.14  2001/04/16 01:45:26  bartoldeman
 * Fixed handles, config.sys drivers, warnings. Enabled INT21/AH=6C, printf %S/%Fs
 *
 * Revision 1.13  2001/04/15 03:21:50  bartoldeman
 * See history.txt for the list of fixes.
 *
 * Revision 1.12  2001/03/30 22:27:42  bartoldeman
 * Saner lastdrive handling.
 *
 * Revision 1.10  2001/03/30 19:30:06  bartoldeman
 * Misc fixes and implementation of SHELLHIGH. See history.txt for details.
 *
 * Revision 1.9  2001/03/25 17:11:54  bartoldeman
 * Fixed sys.com compilation. Updated to 2023. Also: see history.txt.
 *
 * Revision 1.8  2001/03/21 02:56:26  bartoldeman
 * See history.txt for changes. Bug fixes and HMA support are the main ones.
 *
 * Revision 1.7  2000/08/06 05:50:17  jimtabor
 * Add new files and update cvs with patches and changes
 *
 * Revision 1.6  2000/06/21 18:16:46  jimtabor
 * Add UMB code, patch, and code fixes
 *
 * Revision 1.5  2000/05/26 19:25:19  jimtabor
 * Read History file for Change info
 *
 * Revision 1.4  2000/05/25 20:56:21  jimtabor
 * Fixed project history
 *
 * Revision 1.3  2000/05/17 19:15:12  jimtabor
 * Cleanup, add and fix source.
 *
 * Revision 1.2  2000/05/08 04:30:00  jimtabor
 * Update CVS to 2020
 *
 * Revision 1.1.1.1  2000/05/06 19:34:53  jhall1
 * The FreeDOS Kernel.  A DOS kernel that aims to be 100% compatible with
 * MS-DOS.  Distributed under the GNU GPL.
 *
 * Revision 1.14  2000/03/31 05:40:09  jtabor
 * Added Eric W. Biederman Patches
 *
 * Revision 1.13  2000/03/09 06:07:11  kernel
 * 2017f updates by James Tabor
 *
 * Revision 1.12  1999/09/23 04:40:48  jprice
 * *** empty log message ***
 *
 * Revision 1.10  1999/08/25 03:18:09  jprice
 * ror4 patches to allow TC 2.01 compile.
 *
 * Revision 1.9  1999/04/16 21:43:40  jprice
 * ror4 multi-sector IO
 *
 * Revision 1.8  1999/04/16 12:21:22  jprice
 * Steffen c-break handler changes
 *
 * Revision 1.7  1999/04/16 00:53:33  jprice
 * Optimized FAT handling
 *
 * Revision 1.6  1999/04/12 03:21:17  jprice
 * more ror4 patches.  Changes for multi-block IO
 *
 * Revision 1.5  1999/04/11 04:33:39  jprice
 * ror4 patches
 *
 * Revision 1.3  1999/04/04 22:57:47  jprice
 * no message
 *
 * Revision 1.2  1999/04/04 18:51:43  jprice
 * no message
 *
 * Revision 1.1.1.1  1999/03/29 15:41:18  jprice
 * New version without IPL.SYS
 *
 * Revision 1.5  1999/02/08 05:55:57  jprice
 * Added Pat's 1937 kernel patches
 *
 * Revision 1.4  1999/02/01 01:48:41  jprice
 * Clean up; Now you can use hex numbers in config.sys. added config.sys screen function to change screen mode (28 or 43/50 lines)
 *
 * Revision 1.3  1999/01/30 08:28:12  jprice
 * Clean up; Fixed bug with set attribute function.
 *
 * Revision 1.2  1999/01/22 04:13:26  jprice
 * Formating
 *
 * Revision 1.1.1.1  1999/01/20 05:51:01  jprice
 * Imported sources
 *
 *
 *    Rev 1.12   06 Dec 1998  8:45:30   patv
 * Changed due to new I/O subsystem.
 *
 *    Rev 1.11   22 Jan 1998  4:09:24   patv
 * Fixed pointer problems affecting SDA
 *
 *    Rev 1.10   04 Jan 1998 23:15:20   patv
 * Changed Log for strip utility
 *
 *    Rev 1.9   04 Jan 1998 17:26:16   patv
 * Corrected subdirectory bug
 *
 *    Rev 1.8   03 Jan 1998  8:36:48   patv
 * Converted data area to SDA format
 *
 *    Rev 1.7   06 Feb 1997 21:35:46   patv
 * Modified to support new version format and changed debug message to
 * output drive letter instead of number.
 *
 *    Rev 1.6   22 Jan 1997 13:05:02   patv
 * Now does correct default drive initialization.
 *
 *    Rev 1.5   16 Jan 1997 12:47:00   patv
 * pre-Release 0.92 feature additions
 *
 *    Rev 1.3   29 May 1996 21:03:32   patv
 * bug fixes for v0.91a
 *
 *    Rev 1.2   19 Feb 1996  3:21:36   patv
 * Added NLS, int2f and config.sys processing
 *
 *    Rev 1.1   01 Sep 1995 17:54:18   patv
 * First GPL release.
 *
 *    Rev 1.0   02 Jul 1995  8:33:18   patv
 * Initial revision.
 */

extern WORD days[2][13];
extern BYTE FAR * lpBase;
extern BYTE FAR * upBase;
extern BYTE _ib_start[], _ib_end[]; 

INIT VOID configDone(VOID);
INIT static void InitIO(void);

INIT static VOID update_dcb(struct dhdr FAR *);
INIT static VOID init_kernel(VOID);
INIT static VOID signon(VOID);
INIT VOID kernel(VOID);
INIT VOID FsConfig(VOID);

INIT VOID main(void)
{
    setvec(0, int0_handler);        /* zero divide */
    setvec(1, empty_handler);       /* single step */
    setvec(3, empty_handler);       /* debug breakpoint */
    setvec(6, empty_handler);       /* invalid opcode */
    
    /* clear the Init BSS area (what normally the RTL does */
    memset(_ib_start, 0, _ib_end - _ib_start);
    
  init_kernel();

#ifdef DEBUG
  /* Non-portable message kludge alert!   */
  printf("KERNEL: Boot drive = %c\n", 'A' + BootDrive - 1);
#endif
  signon();
  kernel();
}

/*
    InitializeAllBPBs()
    
    or MakeNortonDiskEditorHappy()

    it has been determined, that FDOS's BPB tables are initialized,
    only when used (like DIR H:).
    at least one known utility (norton DE) seems to access them directly.
    ok, so we access for all drives, that the stuff gets build
*/
void InitializeAllBPBs(VOID)
{
  static char filename[] = "A:-@JUNK@-.TMP";
  int drive,fileno;
  for (drive = 'C'; drive < 'A'+nblkdev; drive++)
    {
      filename[0] = drive;
      if ((fileno = open(filename, O_RDONLY)) >= 0)
        close(fileno);
    }
}    

INIT void init_kernel(void)
{
  COUNT i;
  
  os_major = MAJOR_RELEASE;
  os_minor = MINOR_RELEASE;

  /* Init oem hook - returns memory size in KB    */
  ram_top = init_oem();

/* Fake int 21h stack frame */
  user_r = (iregs FAR *) DOS_PSP + 0xD0;

#ifndef KDB
  for (i = 0x20; i <= 0x3f; i++)
    setvec(i, empty_handler);
#endif

  /* Initialize IO subsystem                                      */
  InitIO();

#ifndef KDB
  /* set interrupt vectors                                        */
  setvec(0x1b, got_cbreak);
  setvec(0x20, int20_handler);
  setvec(0x21, int21_handler);
  setvec(0x22, int22_handler);
  setvec(0x23, empty_handler);
  setvec(0x24, int24_handler);
  setvec(0x25, low_int25_handler);
  setvec(0x26, low_int26_handler);
  setvec(0x27, int27_handler);
  setvec(0x28, int28_handler);
  setvec(0x2a, int2a_handler);
  setvec(0x2f, int2f_handler);
#endif

  init_PSPSet(DOS_PSP);
  init_PSPInit(DOS_PSP);

  /* Do first initialization of system variable buffers so that   */
  /* we can read config.sys later.  */
  lastdrive = Config.cfgLastdrive;

  PreConfig();

  /*  init_device((struct dhdr FAR *)&blk_dev, NULL, NULL, ram_top); */
  blk_dev.dh_name[0] = dsk_init();
  /* Number of units */
  if (blk_dev.dh_name[0] > 0)
      update_dcb(&blk_dev);

  /* Now config the temporary file system */
  FsConfig();

#ifndef KDB
  /* Now process CONFIG.SYS     */
  DoConfig();

  /* Close all (device) files */
  for (i = 0; i < lastdrive; i++)
    close(i);
  
  /* and do final buffer allocation. */
  PostConfig();
  nblkdev = 0;
  update_dcb(&blk_dev);

  /* Init the file system one more time     */
  FsConfig();

  /* and process CONFIG.SYS one last time to load device drivers. */
  DoConfig();
  configDone();

  /* Close all (device) files */
  for (i = 0; i < lastdrive; i++)
    close(i);
  
  /* Now config the final file system     */
  FsConfig();

#endif
  InitializeAllBPBs();
}

INIT VOID FsConfig(VOID)
{
  REG COUNT i;
  struct dpb FAR *dpb;

  /* The system file tables need special handling and are "hand   */
  /* built. Included is the stdin, stdout, stdaux and stdprn. */

  /* 0 is /dev/con (stdin) */
  open("CON", O_RDWR);

  /* 1 is /dev/con (stdout)     */
  dup2(STDIN, STDOUT);

  /* 2 is /dev/con (stderr)     */
  dup2(STDIN, STDERR);

  /* 3 is /dev/aux                                                */
  open("AUX", O_RDWR);

  /* 4 is /dev/prn                                                */
  open("PRN", O_WRONLY);

  /* Log-in the default drive.  */
  /* Get the boot drive from the ipl and use it for default.  */
  default_drive = BootDrive - 1;
  dpb = DPBp;

  /* Initialize the current directory structures    */
  for (i = 0; i < lastdrive  ; i++)
  {
  	struct cds FAR *pcds_table = &CDSp->cds_table[i];

    fbcopy((VOID FAR *) "A:\\\0",
           (VOID FAR *) pcds_table->cdsCurrentPath, 4);

    pcds_table->cdsCurrentPath[0] += i;

    if (i < nblkdev && (ULONG)dpb != 0xffffffffl)
    {
      pcds_table->cdsDpb = dpb;
      pcds_table->cdsFlags = CDSPHYSDRV;
      dpb = dpb->dpb_next;
    }
    else
    {
      pcds_table->cdsFlags = 0;
    }
    pcds_table->cdsStrtClst = 0xffff;
    pcds_table->cdsParam = 0xffff;
    pcds_table->cdsStoreUData = 0xffff;
    pcds_table->cdsJoinOffset = 2;
  }

  /* Initialize the disk buffer management functions */
  /* init_call_init_buffers(); done from CONFIG.C   */
}

INIT VOID signon()
{
  BYTE tmp_or[81]; /* ugly constant, but this string should fit on one line */

  printf("\nFreeDOS Kernel compatibility %d.%d\n%S\n",
         os_major, os_minor, copyright);
  fmemcpy(tmp_or, os_release, 81);
  printf(tmp_or,
         REVISION_MAJOR, REVISION_MINOR, REVISION_SEQ,
         BUILD);
}

INIT void kernel()
{
#if 0    
  BYTE FAR *ep,
   *sp;
#endif  
  exec_blk exb;
  CommandTail Cmd;
  int rc;

#ifndef KDB
  static BYTE master_env[] = "PATH=.\0\0\0\0\0";
/*  static BYTE *path = "PATH=.";*/
#endif

#ifdef KDB
  kdb();
#else
#if 0
  /* create the master environment area   */
  
  if (allocmem(0x2, &exb.exec.env_seg))
    init_fatal("cannot allocate master environment space");

  /* populate it with the minimum environment */
  ++exb.exec.env_seg;
  ep = MK_FP(exb.exec.env_seg, 0);

  for (sp = path; *sp != 0;)
    *ep++ = *sp++;

  *ep++ = '\0';
  *ep++ = '\0';
  *((int FAR *)ep) = 0;
  ep += sizeof(int);
#else
  exb.exec.env_seg = DOS_PSP+8;
  fmemcpy(MK_FP(exb.exec.env_seg, 0), master_env, sizeof(master_env));
#endif  
#endif  

  
  RootPsp = ~0;

 

  /* process 0       */
  /* Execute command.com /P from the drive we just booted from    */
  fstrncpy(Cmd.ctBuffer, Config.cfgInitTail, 
                    sizeof(Config.cfgInitTail)-1);

  for (Cmd.ctCount = 0; Cmd.ctCount < 127; Cmd.ctCount++)
    if (Cmd.ctBuffer[Cmd.ctCount] == '\r')
      break;




  /* if stepping CONFIG.SYS (F5/F8), tell COMMAND.COM about it */  

  if (Cmd.ctCount < 127 - 3)
  {      
      extern int singleStep   ;
      extern int SkipAllConfig;
      char *insertString = NULL;

      if (singleStep) insertString = " /Y"; /* single step AUTOEXEC */
      
      if (SkipAllConfig)  insertString = " /D"; /* disable AUTOEXEC */
      
      if (insertString)
      {
        
                                     /* insert /D, /Y as first argument */
        int cmdEnd,i,slen = strlen(insertString);
        
        for (cmdEnd = 0;cmdEnd < 127; cmdEnd++)
        {
            if (Cmd.ctBuffer[cmdEnd] == ' ' ||
                Cmd.ctBuffer[cmdEnd] == '\t' ||
                Cmd.ctBuffer[cmdEnd] == '\r')
            {
                for (i = 127 - slen; i >= cmdEnd; i--)
                    Cmd.ctBuffer[i+slen] = Cmd.ctBuffer[i];
                    
                fmemcpy(&Cmd.ctBuffer[cmdEnd], insertString,slen);

                Cmd.ctCount += slen;

                break;
            }
        }
      }  
  }

      

  exb.exec.cmd_line = (CommandTail FAR *) & Cmd;
  exb.exec.fcb_1 = exb.exec.fcb_2 = (fcb FAR *) 0;

#ifdef DEBUG
  printf("Process 0 starting: %s\n\n", Config.cfgInit);
#endif

  while ((rc = init_DosExec(Config.cfgP_0_startmode, &exb, Config.cfgInit)) != SUCCESS)
  {
    BYTE *pLine;
    printf("\nBad or missing Command Interpreter: %d - %s\n", rc, Cmd.ctBuffer);
    printf("\nPlease enter the correct location (for example C:\\COMMAND.COM):\n");
    rc = read(STDIN, Cmd.ctBuffer, sizeof(Cmd.ctBuffer)-1);
    Cmd.ctBuffer[rc]='\0';

    /* Get the string argument that represents the new init pgm     */
    pLine = GetStringArg(Cmd.ctBuffer, Config.cfgInit);

    /* Now take whatever tail is left and add it on as a single     */
    /* string.                                                      */
    strcpy(Cmd.ctBuffer, pLine);

    /* and add a DOS new line just to be safe                       */
    strcat(Cmd.ctBuffer, "\r\n");
    
    Cmd.ctCount =  rc-(pLine-Cmd.ctBuffer);

#ifdef DEBUG
    printf("Process 0 starting: %s\n\n", Config.cfgInit);
#endif
  }
  printf("\nSystem shutdown complete\nReboot now.\n");
  for (;;) ;
}

/* check for a block device and update  device control block    */
static VOID update_dcb(struct dhdr FAR * dhp)
{
  REG COUNT Index;
  COUNT nunits = dhp->dh_name[0];
  struct dpb FAR *dpb;

  if (nblkdev==0)
    dpb = DPBp;
  else {
    for (dpb = DPBp; (ULONG)dpb->dpb_next != 0xffffffffl; dpb = dpb->dpb_next)
      ;
    dpb = dpb->dpb_next = (struct dpb FAR *)KernelAlloc(nunits*sizeof(struct dpb));
  }

  for(Index = 0; Index < nunits; Index++)
  {      
    dpb->dpb_next = dpb+1;
    dpb->dpb_unit = nblkdev;
    dpb->dpb_subunit = Index;
    dpb->dpb_device = dhp;
    dpb->dpb_flags = M_CHANGED;
    if ((CDSp != 0) && (nblkdev < lastdrive))
    {
      CDSp->cds_table[nblkdev].cdsDpb = dpb;
      CDSp->cds_table[nblkdev].cdsFlags = CDSPHYSDRV;
    }
    ++dpb;
    ++nblkdev;
  }
  (dpb-1)->dpb_next = (void FAR *)0xFFFFFFFFl;
}


/* If cmdLine is NULL, this is an internal driver */

BOOL init_device(struct dhdr FAR * dhp, BYTE FAR * cmdLine, COUNT mode, COUNT r_top)
{
  request rq;

  UCOUNT maxmem = ((UCOUNT)r_top << 6) - FP_SEG(dhp);

  if (maxmem >= 0x1000)
    maxmem = 0xFFFF;
  else
    maxmem <<= 4;

  rq.r_unit = 0;
  rq.r_status = 0;
  rq.r_command = C_INIT;
  rq.r_length = sizeof(request);
  rq.r_endaddr = MK_FP(FP_SEG(dhp), maxmem);
  rq.r_bpbptr = (void FAR *)(cmdLine ? cmdLine : "\n");
  rq.r_firstunit = nblkdev;

  execrh((request FAR *) & rq, dhp);

/*
 *  Added needed Error handle
 */
  if (rq.r_status & S_ERROR)
    return TRUE;

  if(cmdLine){
    if (mode)
    {
      /* Don't link in device drivers which do not take up memory */
      if (rq.r_endaddr == (BYTE FAR *)dhp)
        return TRUE;
      else
        upBase = rq.r_endaddr;
    }
    else
    {
      if (rq.r_endaddr == (BYTE FAR *)dhp)
        return TRUE;
      else
        lpBase = rq.r_endaddr;
    }
  }

  if (!(dhp->dh_attr & ATTR_CHAR) && (rq.r_nunits != 0)) {
    dhp->dh_name[0] = rq.r_nunits;
    update_dcb(dhp);
  }

  if (dhp->dh_attr & ATTR_CONIN)
    syscon = dhp;
  else if (dhp->dh_attr & ATTR_CLOCK)
    clock = dhp;

  return FALSE;
}


INIT static void InitIO(void)
{
  /* Initialize driver chain                                      */

  setvec(0x29, int29_handler);  /* Requires Fast Con Driver     */
  init_device(&con_dev, NULL, NULL, ram_top);
  init_device(&clk_dev, NULL, NULL, ram_top);
}

/* issue an internal error message                              */
VOID init_fatal(BYTE * err_msg)
{
  printf("\nInternal kernel error - %s\nSystem halted\n", err_msg);
  for (;;) ;
}