LXR linux/arch/sparc/prom/bootstr

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * bootstr.c:  Boot string/argument acquisition from the PROM.
   4 *
   5 * Copyright(C) 1995 David S. Miller (davem@caip.rutgers.edu)
   6 */
   7
   8#include <linux/string.h>
   9#include <asm/oplib.h>
  10#include <linux/init.h>
  11
  12#define BARG_LEN  256
  13static char barg_buf[BARG_LEN] = { 0 };
  14static char fetched __initdata = 0;
  15
  16char * __init
  17prom_getbootargs(void)
  18{
  19        int iter;
  20        char *cp, *arg;
  21
  22        /* This check saves us from a panic when bootfd patches args. */
  23        if (fetched) {
  24                return barg_buf;
  25        }
  26
  27        switch (prom_vers) {
  28        case PROM_V0:
  29                cp = barg_buf;
  30                /* Start from 1 and go over fd(0,0,0)kernel */
  31                for (iter = 1; iter < 8; iter++) {
  32                        arg = (*(romvec->pv_v0bootargs))->argv[iter];
  33                        if (arg == NULL)
  34                                break;
  35                        while (*arg != 0) {
  36                                /* Leave place for space and null. */
  37                                if (cp >= barg_buf + BARG_LEN - 2)
  38                                        /* We might issue a warning here. */
  39                                        break;
  40                                *cp++ = *arg++;
  41                        }
  42                        *cp++ = ' ';
  43                        if (cp >= barg_buf + BARG_LEN - 1)
  44                                /* We might issue a warning here. */
  45                                break;
  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}
  64