arch/sparc/prom/bootstr.c

   1 /*
   2  * bootstr.c:  Boot string/argument acquisition from the PROM.
   3  *
   4  * Copyright(C) 1995 David S. Miller (davem@caip.rutgers.edu)
   5  */
   6
   7 #include <linux/string.h>
   8 #include <asm/oplib.h>
   9 #include <asm/sun4prom.h>
  10 #include <linux/init.h>
  11
  12 #define BARG_LEN  256
  13 static char barg_buf[BARG_LEN] = { 0 };
  14 static char fetched __initdata = 0;
  15
  16 extern linux_sun4_romvec *sun4_romvec;
  17
  18 char * __init
  19 prom_getbootargs(void)
  20 {
  21         int iter;
  22         char *cp, *arg;
  23
  24         /* This check saves us from a panic when bootfd patches args. */
  25         if (fetched) {
  26                 return barg_buf;
  27         }
  28
  29         switch(prom_vers) {
  30         case PROM_V0:
  31         case PROM_SUN4:
  32                 cp = barg_buf;
  33                 /* Start from 1 and go over fd(0,0,0)kernel */
  34                 for(iter = 1; iter < 8; iter++) {
  35                         arg = (*(romvec->pv_v0bootargs))->argv[iter];
  36                         if(arg == 0) break;
  37                         while(*arg != 0) {
  38                                 /* Leave place for space and null. */
  39                                 if(cp >= barg_buf + BARG_LEN-2){
  40                                         /* We might issue a warning here. */
  41                                         break;
  42                                 }
  43                                 *cp++ = *arg++;
  44                         }
  45                         *cp++ = ' ';
  46                 }
  47                 *cp = 0;
  48                 break;
  49         case PROM_V2:
  50         case PROM_V3:
  51                 /*
  52                  * V3 PROM cannot supply as with more than 128 bytes
  53                  * of an argument. But a smart bootstrap loader can.
  54                  */
  55                 strlcpy(barg_buf, *romvec->pv_v2bootargs.bootargs, sizeof(barg_buf));
  56                 break;
  57         default:
  58                 break;
  59         }
  60
  61         fetched = 1;
  62         return barg_buf;
  63 }