WebSVN – SvarDOS – Diff – /svarcom/trunk/command.c

 /* DR-DOS specific boot processing: check for F5/F8 boot key presses and reset
  * the wild pointer to DR-DOS kernel (CONFIG.SYS) environment because it is not
  * allocated memory hence will be overwritten soon.
  * details: https://github.com/SvarDOS/edrdos/issues/83
  * this function returns 0, FLAG_SKIP_AUTOEXEC or FLAG_STEPBYSTEP */
-static unsigned char drdos_init(void) {
+static void drdos_init(struct config *cfg) {
   unsigned short kernenvseg = 0;
   unsigned char far *e;
   unsigned short far *scancode;
   /* If I am init then query kernel's private data via INT 21,4458 (DR-DOS).
     /* if DR-DOS env is at seg 0x60 then overwrite my own env in PSP with this.
      * Seg 0x60 is used since https://github.com/SvarDOS/edrdos/issues/88 and
      * it is safe to be used as it won't be overwritten */
     cmp ax, 0x60
-    ja FAIL
+    jne FAIL
     mov bx, 0x2C         /* environment segment field in my PSP */
     mov [bx], ax
     FAIL:
     pop es
     pop bx
     pop ax
+  }
-  if (kernenvseg == 0) return(0); /* either not DR-DOS, or kern env was read already or something failed */
+  if (kernenvseg == 0) return; /* either not DR-DOS, or kern env was read already or something failed */
+  /* now I know that 1) I am running under (E)DR-DOS and 2) I am init, so /P implied */
+  cfg->flags |= FLAG_PERMANENT;
+  /* DR-DOS kernel environment present: make sure to ask SvarCOM to alloc its
+   * own environment, because the kernel's environment might vanish eventually */
+  if (cfg->envsiz < 256) cfg->envsiz = 256;
   e = MK_FP(kernenvseg, 0);
   /* move forward until the DRDOS' environment 1Ah terminator is found */
   while (*e != 0x1A) e++;
   e++;
   /* next I have the boot key press scancode: either 0x0000, 0x3F00 or 0x4200
    * 0x3F00 means "F5 was pressed" while 0x4200 is for F8 */
   scancode = (void far *)e;
+  if (*scancode == 0x3F00) {
-  if (*scancode == 0x3F00) return(FLAG_SKIP_AUTOEXEC);
+    cfg->flags |= FLAG_SKIP_AUTOEXEC;
+  } else if (*scancode == 0x4200) {
-  if (*scancode == 0x4200) return(FLAG_STEPBYSTEP);
+    cfg->flags |= FLAG_STEPBYSTEP;
+  }
 /*
   printf("kernel env seg is at %04X and starts with bytes 0x%02X 0x%02X 0x%02X 0x%02X\r\n", kernenvseg, e[0], e[1], e[2], e[3]);
+  {
     int i;
       printf("%02X ", e[i]);
+    }
     printf("\r\n=== DUMP ENDS ===\r\n");
+  }
 */
-  return(0);
+}
 /* parses command line the hard way (directly from PSP) */
 static void parse_argv(struct config *cfg) {
     /* DR-DOS specific: if I am the init shell (zeroed env seg) then detect F5/F8 now
      * This must be done BEFORE rmod_install() because DR-DOS's boot environment
      * is located at an unallocated memory location that is likely to be overwritten
      * by rmod_install(). */
-    cfg.flags |= drdos_init();
+    drdos_init(&cfg);
-    rmod = rmod_install(cfg.envsiz, BUFFER, BUFFER_len);
+    rmod = rmod_install(cfg.envsiz, BUFFER, BUFFER_len, &(cfg.flags));
     if (rmod == NULL) {
       nls_outputnl_err(2,1); /* "FATAL ERROR: rmod_install() failed" */
       return(1);
+    }
     /* copy flags to rmod's storage (and enable ECHO) */
     rmod->flags = cfg.flags | FLAG_ECHOFLAG;
     /* printf("rmod installed at %Fp\r\n", rmod); */
     rmod->version = BYTE_VERSION;
-    /* if my environment seg was zeroed, then I am the init process (under DR-DOS and MS-DOS 5 at least) */
-    if (rmod->origenvseg == 0) {
-      cfg.flags |= FLAG_PERMANENT; /* imply /P so AUTOEXEC.BAT is executed */
-    }
   } else {
     /* printf("rmod found at %Fp\r\n", rmod); */
     /* if I was spawned by rmod and FLAG_EXEC_AND_QUIT is set, then I should
      * die asap, because the command has been executed already, so I no longer
      * have a purpose in life, UNLESS I still have a batch file to run or

Subversion Repositories SvarDOS

(root)/svarcom/trunk/command.c @ 467 – Rev 1865 → 1877