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Rev 453 Rev 454
Line 37... Line 37...
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struct rmod_props far *rmod_install(unsigned short envsize) {
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struct rmod_props far *rmod_install(unsigned short envsize) {
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  char far *myptr, far *mcb;
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  char far *myptr, far *mcb;
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  unsigned short far *owner;
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  unsigned short far *owner;
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  const unsigned short sizeof_rmodandprops_paras = rmod_len + sizeof(struct rmod_props) + 15 / 16;
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  const unsigned short sizeof_rmodandprops_paras = rmod_len + sizeof(struct rmod_props) + 15 / 16;
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  unsigned short rmodseg = 0xffff;
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  unsigned short rmodseg = 0xffff;
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  unsigned short envseg = 0, origenvseg = 0;
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  unsigned short envseg, origenvseg;
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  struct rmod_props far *res = NULL;
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  struct rmod_props far *res = NULL;
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  /* read my current env segment from PSP and save it */
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  /* read my current env segment from PSP and save it */
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  _asm {
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    push ax
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    push bx
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    mov bx, 0x2c
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  envseg = *((unsigned short *)0x2c);
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    mov ax, [bx]
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    mov envseg, ax
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    mov origenvseg, ax
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  origenvseg = envseg;
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    pop bx
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    pop ax
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  }
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  /* printf("original (PSP) env buffer at %04X\r\n", envseg); */
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  /* printf("original (PSP) env buffer at %04X\r\n", envseg); */
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  /* if envseg is zero, then enforce our own one (MSDOS 5 does not provide a default env) */
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  /* if envseg is zero, then enforce our own one (MSDOS 5 does not provide a default env) */
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  if ((envseg == 0) && (envsize == 0)) envsize = 256;
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  if ((envseg == 0) && (envsize == 0)) envsize = 256;
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  if (envsize != 0) {
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  if (envsize != 0) {
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    envsize += 15;
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    envsize += 15;
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    envsize /= 16;
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    envsize /= 16;
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  }
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  }
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 - 
 
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  _asm {
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  _asm {
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    /* link in the UMB memory chain for enabling high-memory allocation (and save initial status on stack) */
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    /* link in the UMB memory chain for enabling high-memory allocation (and save initial status on stack) */
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    mov ax, 0x5802  /* GET UMB LINK STATE */
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    mov ax, 0x5802  /* GET UMB LINK STATE */
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    int 0x21
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    int 0x21
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    xor ah, ah
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    xor ah, ah
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  /* save my original parent in rmod's memory */
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  /* save my original parent in rmod's memory */
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  res->origparent = *((unsigned long *)0x0a); /* original parent seg:off is at 0x0a of my PSP */
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  res->origparent = *((unsigned long *)0x0a); /* original parent seg:off is at 0x0a of my PSP */
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  /* set the int22 handler in my PSP to rmod so DOS jumps to rmod after I
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  /* set the int22 handler in my PSP to rmod so DOS jumps to rmod after I
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   * terminate and save the original handler in rmod's memory */
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   * terminate and save the original handler in rmod's memory */
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  _asm {
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  {
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    push ax
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    push bx
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    push si
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    push di
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    push es
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    mov bx, 0x0a                   /* int22 handler is at 0x0A of the PSP */
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    unsigned short *ptr = (void *)0x0a; /* int22 handler is at 0x0A of the PSP */
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    mov ax, RMOD_OFFSET_ROUTINE
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    ptr[0] = RMOD_OFFSET_ROUTINE;
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    mov [bx], ax                   /* int handler offset */
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    mov ax, rmodseg
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    ptr[1] = rmodseg;
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    mov [bx+2], ax                 /* int handler segment */
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    pop es
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    pop di
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    pop si
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    pop bx
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    pop ax
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  }
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  }
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  return(res);
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  return(res);
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}
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}
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