release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sparc/prom/bootstr_32.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 <linux/init.h>
  10
  11 #define BARG_LEN  256
  12 static char barg_buf[BARG_LEN] = { 0 };
  13 static char fetched __initdata = 0;
  14
  15 char * __init
  16 prom_getbootargs(void)
  17 {
  18         int iter;
  19         char *cp, *arg;
  20
  21         /* This check saves us from a panic when bootfd patches args. */
  22         if (fetched) {
  23                 return barg_buf;
  24         }
  25
  26         switch(prom_vers) {
  27         case PROM_V0:
  28                 cp = barg_buf;
  29                 /* Start from 1 and go over fd(0,0,0)kernel */
  30                 for(iter = 1; iter < 8; iter++) {
  31                         arg = (*(romvec->pv_v0bootargs))->argv[iter];
  32                         if(arg == 0) break;
  33                         while(*arg != 0) {
  34                                 /* Leave place for space and null. */
  35                                 if(cp >= barg_buf + BARG_LEN-2){
  36                                         /* We might issue a warning here. */
  37                                         break;
  38                                 }
  39                                 *cp++ = *arg++;
  40                         }
  41                         *cp++ = ' ';
  42                 }
  43                 *cp = 0;
  44                 break;
  45         case PROM_V2:
  46         case PROM_V3:
  47                 /*
  48                  * V3 PROM cannot supply as with more than 128 bytes
  49                  * of an argument. But a smart bootstrap loader can.
  50                  */
  51                 strlcpy(barg_buf, *romvec->pv_v2bootargs.bootargs, sizeof(barg_buf));
  52                 break;
  53         default:
  54                 break;
  55         }
  56
  57         fetched = 1;
  58         return barg_buf;
  59 }