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 * Copyright(C) 1996,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz) 7 */ 8 9 #include <linux/string.h> 10 #include <linux/init.h> 11 #include <asm/oplib.h> 12 13 /* WARNING: The boot loader knows that these next three variables come one right 14 * after another in the .data section. Do not move this stuff into 15 * the .bss section or it will break things. 16 */ 17 18 /* We limit BARG_LEN to 1024 because this is the size of the 19 * 'barg_out' command line buffer in the SILO bootloader. 20 */ 21 #define BARG_LEN 1024 22 struct { 23 int bootstr_len; 24 int bootstr_valid; 25 char bootstr_buf[BARG_LEN]; 26 } bootstr_info = { 27 .bootstr_len = BARG_LEN, 28 #ifdef CONFIG_CMDLINE 29 .bootstr_valid = 1, 30 .bootstr_buf = CONFIG_CMDLINE, 31 #endif 32 }; 33 34 char * __init 35 prom_getbootargs(void) 36 { 37 /* This check saves us from a panic when bootfd patches args. */ 38 if (bootstr_info.bootstr_valid) 39 return bootstr_info.bootstr_buf; 40 prom_getstring(prom_chosen_node, "bootargs", 41 bootstr_info.bootstr_buf, BARG_LEN); 42 bootstr_info.bootstr_valid = 1; 43 return bootstr_info.bootstr_buf; 44 } 45