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 == NULL) 33 break; 34 while (*arg != 0) { 35 /* Leave place for space and null. */ 36 if (cp >= barg_buf + BARG_LEN - 2) 37 /* We might issue a warning here. */ 38 break; 39 *cp++ = *arg++; 40 } 41 *cp++ = ' '; 42 if (cp >= barg_buf + BARG_LEN - 1) 43 /* We might issue a warning here. */ 44 break; 45 } 46 *cp = 0; 47 break; 48 case PROM_V2: 49 case PROM_V3: 50 /* 51 * V3 PROM cannot supply as with more than 128 bytes 52 * of an argument. But a smart bootstrap loader can. 53 */ 54 strlcpy(barg_buf, *romvec->pv_v2bootargs.bootargs, sizeof(barg_buf)); 55 break; 56 default: 57 break; 58 } 59 60 fetched = 1; 61 return barg_buf; 62 } 63