Subversion Repositories SvarDOS

Rev

Rev 439 | Rev 449 | Go to most recent revision | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 439 Rev 448
Line 116... Line 116...
116 
  mcb = MK_FP(rmodseg - 1, 0);
 116 
  mcb = MK_FP(rmodseg - 1, 0);
117 
  owner = (void far *)(mcb + 1);
 117 
  owner = (void far *)(mcb + 1);
118 
  *owner = rmodseg;
 118 
  *owner = rmodseg;
119 
  _fmemcpy(mcb + 8, "SVARCOM", 8);
 119 
  _fmemcpy(mcb + 8, "SVARCOM", 8);
120 
 
 120 
 
121 
  /* mark env memory as "self owned" */
 121 
  /* mark env memory as "owned by rmod" */
122 
  mcb = MK_FP(envseg - 1, 0);
 122 
  mcb = MK_FP(envseg - 1, 0);
123 
  owner = (void far *)(mcb + 1);
 123 
  owner = (void far *)(mcb + 1);
124 
  *owner = rmodseg;
 124 
  *owner = rmodseg;
125 
  _fmemcpy(mcb + 8, "SVARENV", 8);
 125 
  _fmemcpy(mcb + 8, "SVARENV", 8);
126 
 
 126 
 
Line 147... Line 147...
147 
    pop dx
 147 
    pop dx
148 
    pop bx
 148 
    pop bx
149 
    pop ax
 149 
    pop ax
150 
  }
 150 
  }
151 
 
 151 
 
152 
  /* set the int22 handler in my PSP to rmod so DOS jumps to rmod after I terminate */
 152 
  /* set the int22 handler in my PSP to rmod so DOS jumps to rmod after I
- 
 
 153 
   * terminate and save the original handler in rmod's memory */
153 
  _asm {
 154 
  _asm {
154 
    push ax
 155 
    push ax
155 
    push bx
 156 
    push bx
- 
 
 157 
    push si
- 
 
 158 
    push di
- 
 
 159 
    push es
- 
 
 160 
 
- 
 
 161 
    /* save my original parent in rmod's memory */
- 
 
 162 
    mov es, [rmodseg]
- 
 
 163 
    mov si, 0x0a
- 
 
 164 
    mov di, RMOD_OFFSET_ORIGPARENT
- 
 
 165 
    cld
- 
 
 166 
    movsw  /* mov ES:[DI], DS:[SI] and SI += 2 and DI += 2 */
- 
 
 167 
    movsw
- 
 
 168 
 
156 
    mov bx, 0x0a                   /* int22 handler is at 0x0A of the PSP */
 169 
    mov bx, 0x0a                   /* int22 handler is at 0x0A of the PSP */
157 
    mov ax, RMOD_OFFSET_ROUTINE
 170 
    mov ax, RMOD_OFFSET_ROUTINE
158 
    mov [bx], ax                   /* int handler offset */
 171 
    mov [bx], ax                   /* int handler offset */
159 
    mov ax, rmodseg
 172 
    mov ax, rmodseg
160 
    mov [bx+2], ax                 /* int handler segment */
 173 
    mov [bx+2], ax                 /* int handler segment */
- 
 
 174 
 
- 
 
 175 
    pop es
- 
 
 176 
    pop di
- 
 
 177 
    pop si
161 
    pop bx
 178 
    pop bx
162 
    pop ax
 179 
    pop ax
163 
  }
 180 
  }
164 
 
 181 
 
165 
  return(rmodseg);
 182 
  return(rmodseg);
166 
}
 183 
}
167 
 
 184 
 
168 
 
 185 
 
169 
/* scan memory for rmod, returns its segment if found, 0xffff otherwise */
 186 
/* look up my parent: if it's rmod then return its segment,
- 
 
 187 
 * otherwise return 0xffff */
170 
unsigned short rmod_find(void) {
 188 
unsigned short rmod_find(void) {
171 
  unsigned short i;
 - 
 
172 
  unsigned short far *ptrword;
 189 
  unsigned short *parent = (void *)0x0C; /* parent's seg in PSP[Ch] ("prev. int22 handler") */
173 
  unsigned char far *ptrbyte;
 190 
  unsigned short far *ptr;
174 
 
 - 
 
175 
  /* iterate over all paragraphs, looking for my signature */
 191 
  const unsigned short sig[] = {0x1983, 0x1985, 0x2017, 0x2019};
176 
  for (i = 1; i != 65535; i++) {
 - 
 
177 
    ptrword = MK_FP(i, 0);
 192 
  unsigned char i;
178 
    if (ptrword[0] != 0x1983) continue;
 - 
 
179 
    if (ptrword[1] != 0x1985) continue;
 - 
 
180 
    if (ptrword[2] != 0x2017) continue;
 - 
 
181 
    if (ptrword[3] != 0x2019) continue;
 - 
 
182 
    /* extra check: make sure the paragraph before is an MCB block and that it
- 
 
183 
     * belongs to itself. otherwise I could find the rmod code embedded inside
- 
 
184 
     * the command.com binary... */
 193 
  /* is it rmod? */
185 
    ptrbyte = MK_FP(i - 1, 0);
 194 
  ptr = MK_FP(*parent, 0);
186 
    if ((*ptrbyte != 'M') && (*ptrbyte != 'Z')) continue; /* not an MCB */
 195 
  for (i = 0; i < 4; i++) if (ptr[i] != sig[i]) return(0xffff);
187 
    ptrword = MK_FP(i - 1, 1);
 - 
 
188 
    if (*ptrword != i) continue; /* not belonging to self */
 196 
  /* match successfull (rmod is my parent) */
189 
    return(i);
 - 
 
190 
  }
 - 
 
191 
  return(0xffff);
 197 
  return(*parent);
192 
}
 198 
}
193 
 
 199 
 
194 
 
 200 
 
195 
/* update rmod's pointer to comspec */
 201 
/* update rmod's pointer to comspec */
196 
void rmod_updatecomspecptr(unsigned short rmod_seg, unsigned short env_seg) {
 202 
void rmod_updatecomspecptr(unsigned short rmod_seg, unsigned short env_seg) {