VAX/vax780_fload.c

   1 /* vax780_fload.c: VAX780 FLOAD command
   2
   3    Copyright (c) 2006-2008, Robert M Supnik
   4
   5    Permission is hereby granted, free of charge, to any person obtaining a
   6    copy of this software and associated documentation files (the "Software"),
   7    to deal in the Software without restriction, including without limitation
   8    the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9    and/or sell copies of the Software, and to permit persons to whom the
  10    Software is furnished to do so, subject to the following conditions:
  11
  12    The above copyright notice and this permission notice shall be included in
  13    all copies or substantial portions of the Software.
  14
  15    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18    ROBERT M SUPNIK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
  19    IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  20    CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21
  22    Except as contained in this notice, the name of Robert M Supnik shall not be
  23    used in advertising or otherwise to promote the sale, use or other dealings
  24    in this Software without prior written authorization from Robert M Supnik.
  25
  26    This code is based on the CP/M RT11 utility, which bears the following
  27    copyrights:
  28
  29     copyright (c) 1980, William C. Colley, III
  30
  31     Rev. 1.2 -- Craig Davenport - Incitec Ltd      (Feb 1984)
  32                                   P O Box 140
  33                                   Morningside,
  34                                   Qld 4170,
  35                                   Australia.
  36              -- Modified for Digital Research C compiler under CP/M-86
  37              -- Assebmbly language routines added for BIOS calls etc.
  38
  39    Thanks to Phil Budne for the original adaptation of RT11 to SimH.
  40
  41    28-May-08    RMS     Inlined physical memory routines
  42 */
  43
  44 #include "vax_defs.h"
  45 #include <ctype.h>
  46
  47 #define BLK_SIZE        256                             /* RT11 block size */
  48
  49 /* Floppy disk parameters */
  50
  51 #define BPT             26                              /* blocks/track */
  52 #define NTRACKS         77
  53 #define SECTOR_SKEW     2
  54 #define TRACK_SKEW      6
  55 #define TRACK_OFFSET    1                               /* track 0 unused */
  56
  57 /* RT11 directory segment (2 blocks = 512 16b words) */
  58
  59 #define DS_TOTAL        0                               /* segments available */
  60 #define  DS_MAX         31                              /* segment max */
  61 #define DS_NEXT         1                               /* zero for last segment */
  62 #define DS_HIGHEST      2                               /* only in 1st segment */
  63 #define DS_EXTRA        3                               /* extra bytes/entry */
  64 #define DS_FIRST        4                               /* first block */
  65 #define DS_ENTRIES      5                               /* start of entries */
  66 #define DS_SIZE         (2 * BLK_SIZE)                  /* segment size, words */
  67
  68 /* RT11 directory entry offsets */
  69
  70 #define DE_STATUS       0                               /* status (odd byte) */
  71 #define  TENTAT          001                            /* tentative */
  72 #define  EMPTY           002
  73 #define  PERM            004
  74 #define  ENDSEG          010                            /* end of segment */
  75 #define DE_NAME         1                               /* file name */
  76 #define DE_FLNT         4                               /* file length */
  77 #define DE_SIZE         7                               /* entry size in words */
  78 #define DE_GET_STAT(x)  (((x) >> 8) & 0377)
  79
  80 extern UNIT cpu_unit;
  81 extern UNIT fl_unit;
  82
  83 t_bool rtfile_parse (char *pntr, uint16 *file_name);
  84 uint32 rtfile_lookup (uint16 *file_name, uint32 *start);
  85 uint32 rtfile_ator50 (uint32 ascii);
  86 t_bool rtfile_read (uint32 block, uint32 count, uint16 *buffer);
  87 uint32 rtfile_find (uint32 block, uint32 sector);
  88
  89 /* FLOAD file_name {file_origin} */
  90
  91 t_stat vax780_fload (int flag, char *cptr)
  92 {
  93 char gbuf[CBUFSIZE];
  94 uint16 file_name[3], blkbuf[BLK_SIZE];
  95 t_stat r;
  96 uint32 i, j, start, size, origin;
  97
  98 if ((fl_unit.flags & UNIT_ATT) == 0)                    /* floppy attached? */
  99     return SCPE_UNATT;
 100 if (*cptr == 0) return SCPE_2FARG;
 101 cptr = get_glyph (cptr, gbuf, 0);                       /* get file name */
 102 if (!rtfile_parse (gbuf, file_name))                    /* legal file name? */
 103     return SCPE_ARG;
 104 if ((size = rtfile_lookup (file_name, &start)) == 0)    /* file on floppy? */
 105     return SCPE_ARG;
 106 if (*cptr) {                                            /* origin? */
 107     origin = (uint32) get_uint (cptr, 16, MEMSIZE, &r);
 108     if ((r != SCPE_OK) || (origin & 1))                 /* must be even */
 109         return SCPE_ARG;
 110     }
 111 else origin = 512;                                      /* no, use default */
 112
 113 for (i = 0; i < size; i++) {                            /* loop thru blocks */
 114     if (!rtfile_read (start + i, 1, blkbuf))            /* read block */
 115         return SCPE_FMT;
 116     for (j = 0; j < BLK_SIZE; j++) {                    /* loop thru words */
 117         if (ADDR_IS_MEM (origin))
 118             WriteW (origin, blkbuf[j]);
 119         else return SCPE_NXM;
 120         origin = origin + 2;
 121         }
 122     }
 123 return SCPE_OK;
 124 }
 125
 126 /* Parse an RT11 file name and convert it to radix-50 */
 127
 128 t_bool rtfile_parse (char *pntr, uint16 *file_name)
 129 {
 130 char c;
 131 uint16 d;
 132 uint32 i, j;
 133
 134 file_name[0] = file_name[1] = file_name[2] = 0;         /* zero file name */
 135 for (i = 0; i < 2; i++) {                               /* 6 characters */
 136     for (j = 0; j < 3; j++) {
 137         c = *pntr;
 138         if ((c == '.') || (c == 0)) d = 0;              /* fill if . or end */
 139         else {
 140             if ((d = rtfile_ator50 (c)) == 0) return FALSE;
 141             pntr++;
 142             }
 143         file_name[i] = (file_name[i] * 050) + d;        /* merge into name */
 144         }
 145     }
 146 if (file_name[0] == 0) return FALSE;                    /* no name? lose */
 147 while ((c = *pntr++) != '.') {                          /* scan for . */
 148     if (c == 0) return TRUE;                            /* end? done */
 149     }
 150 for (i = 0; i < 3; i++) {                               /* 3 characters */
 151     c = *pntr;
 152     if (c == 0) d = 0;                                  /* fill if end */
 153     else {
 154         if ((d = rtfile_ator50 (c)) == 0) return FALSE;
 155         pntr++;
 156         }
 157     file_name[2] = (file_name[2] * 050) + d;            /* merge into ext */
 158     }
 159 return TRUE;
 160 }
 161
 162 /* ASCII to radix-50 conversion */
 163
 164 uint32 rtfile_ator50 (uint32 ascii)
 165 {
 166 static char *r50 = " ABCDEFGHIJKLMNOPQRSTUVWXYZ$._0123456789";
 167 char *fptr;
 168
 169 ascii = toupper (ascii);
 170 if ((fptr = strchr (r50, toupper (ascii))) != NULL)
 171     return ((uint32) (fptr - r50));
 172 else return 0;
 173 }
 174
 175 /* Lookup an RT11 file name in the directory */
 176
 177 uint32 rtfile_lookup (uint16 *file_name, uint32 *start)
 178 {
 179 uint16 dirseg[DS_SIZE];
 180 uint32 segnum, dirent;
 181
 182 for (segnum = 1;                                        /* loop thru segments */
 183      (segnum != 0) && (segnum <= DS_MAX);
 184      segnum = dirseg[DS_NEXT]) {
 185     if (!rtfile_read ((segnum * 2) + 4, 2, dirseg))     /* read segment */
 186         return 0;                                       /* error? */
 187     *start = dirseg[DS_FIRST];                          /* init file start */
 188     for (dirent = DS_ENTRIES;                           /* loop thru entries */
 189          (dirent < DS_SIZE) &&
 190          (DE_GET_STAT (dirseg[dirent + DE_STATUS]) != ENDSEG);
 191          dirent += DE_SIZE + (dirseg[DS_EXTRA] / 2)) {
 192         if ((DE_GET_STAT (dirseg[dirent + DE_STATUS]) == PERM) &&
 193             (dirseg[dirent + DE_NAME + 0] == file_name[0]) &&
 194             (dirseg[dirent + DE_NAME + 1] == file_name[1]) &&
 195             (dirseg[dirent + DE_NAME + 2] == file_name[2]))
 196             return dirseg[dirent + DE_FLNT];
 197         *start += dirseg[dirent + DE_FLNT];             /* incr file start */
 198         }
 199     }
 200 return 0;
 201 }
 202
 203 /* Read blocks */
 204
 205 t_stat rtfile_read (uint32 block, uint32 count, uint16 *buffer)
 206 {
 207 uint32 i, j;
 208 uint32 pos;
 209 uint8 *fbuf = fl_unit.filebuf;
 210
 211 for (; count > 0; count--, block++) {
 212     for (i = 0; i < 4; i++) {                           /* 4 sectors/block */
 213         pos = rtfile_find (block, i);                   /* position */
 214         if ((pos + 128) >= (uint32) fl_unit.capac)      /* off end of disk? */
 215             return FALSE;
 216         for (j = 0; j < 128; j = j + 2)                 /* copy 128 bytes */
 217             *buffer++ = (((uint16) fbuf[pos + j + 1]) << 8) |
 218                 ((uint16) fbuf[pos + j]);
 219         }
 220     }
 221 return TRUE;
 222 }
 223
 224 /* Map an RT-11 block number to a physical byte number */
 225
 226 uint32 rtfile_find (uint32 block, uint32 sector)
 227 {
 228 uint32 ls, lt, pt, ps;
 229 uint32 off, bb;
 230
 231 /* get logical block, track & sector */
 232
 233 bb = (block * 4) + sector;
 234
 235 lt = bb / BPT;
 236 ls = bb % BPT;
 237
 238 /* logic from 4.3BSD rx.c
 239  * calculate phys track & sector
 240  * 2:1 skew, 6 sector skew for each track
 241  */
 242
 243 pt = lt + TRACK_OFFSET;
 244 ps = ((ls * SECTOR_SKEW) + (ls / (BPT / SECTOR_SKEW)) + (TRACK_SKEW * lt)) % BPT;
 245
 246 /* byte offset in logical disk */
 247
 248 off = (pt * BPT + ps) * 128;
 249 return off;
 250 }