sparc/prom/bootstr_32.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * bootstr.c:  Boot string/argument acquisition from the PROM.
0004  *
0005  * Copyright(C) 1995 David S. Miller (davem@caip.rutgers.edu)
0006  */
0007
0008 #include <linux/string.h>
0009 #include <asm/oplib.h>
0010 #include <linux/init.h>
0011
0012 #define BARG_LEN  256
0013 static char barg_buf[BARG_LEN] = { 0 };
0014 static char fetched __initdata = 0;
0015
0016 char * __init
0017 prom_getbootargs(void)
0018 {
0019     int iter;
0020     char *cp, *arg;
0021
0022     /* This check saves us from a panic when bootfd patches args. */
0023     if (fetched) {
0024         return barg_buf;
0025     }
0026
0027     switch (prom_vers) {
0028     case PROM_V0:
0029         cp = barg_buf;
0030         /* Start from 1 and go over fd(0,0,0)kernel */
0031         for (iter = 1; iter < 8; iter++) {
0032             arg = (*(romvec->pv_v0bootargs))->argv[iter];
0033             if (arg == NULL)
0034                 break;
0035             while (*arg != 0) {
0036                 /* Leave place for space and null. */
0037                 if (cp >= barg_buf + BARG_LEN - 2)
0038                     /* We might issue a warning here. */
0039                     break;
0040                 *cp++ = *arg++;
0041             }
0042             *cp++ = ' ';
0043             if (cp >= barg_buf + BARG_LEN - 1)
0044                 /* We might issue a warning here. */
0045                 break;
0046         }
0047         *cp = 0;
0048         break;
0049     case PROM_V2:
0050     case PROM_V3:
0051         /*
0052          * V3 PROM cannot supply as with more than 128 bytes
0053          * of an argument. But a smart bootstrap loader can.
0054          */
0055         strlcpy(barg_buf, *romvec->pv_v2bootargs.bootargs, sizeof(barg_buf));
0056         break;
0057     default:
0058         break;
0059     }
0060
0061     fetched = 1;
0062     return barg_buf;
0063 }