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 } 60