1/* 2 * Based on Ocelot Linux port, which is 3 * Copyright 2001 MontaVista Software Inc. 4 * Author: jsun@mvista.com or jsun@junsun.net 5 * 6 * Copyright 2003 ICT CAS 7 * Author: Michael Guo <guoyi@ict.ac.cn> 8 * 9 * Copyright (C) 2007 Lemote Inc. & Insititute of Computing Technology 10 * Author: Fuxin Zhang, zhangfx@lemote.com 11 * 12 * Copyright (C) 2009 Lemote Inc. 13 * Author: Wu Zhangjin, wuzhangjin@gmail.com 14 * 15 * This program is free software; you can redistribute it and/or modify it 16 * under the terms of the GNU General Public License as published by the 17 * Free Software Foundation; either version 2 of the License, or (at your 18 * option) any later version. 19 */ 20#include <linux/module.h> 21 22#include <asm/bootinfo.h> 23 24#include <loongson.h> 25 26unsigned long cpu_clock_freq; 27EXPORT_SYMBOL(cpu_clock_freq); 28unsigned long memsize, highmemsize; 29 30#define parse_even_earlier(res, option, p) \ 31do { \ 32 unsigned int tmp __maybe_unused; \ 33 \ 34 if (strncmp(option, (char *)p, strlen(option)) == 0) \ 35 tmp = strict_strtol((char *)p + strlen(option"="), 10, &res); \ 36} while (0) 37 38void __init prom_init_env(void) 39{ 40 /* pmon passes arguments in 32bit pointers */ 41 int *_prom_envp; 42 unsigned long bus_clock; 43 unsigned int processor_id; 44 long l; 45 46 /* firmware arguments are initialized in head.S */ 47 _prom_envp = (int *)fw_arg2; 48 49 l = (long)*_prom_envp; 50 while (l != 0) { 51 parse_even_earlier(bus_clock, "busclock", l); 52 parse_even_earlier(cpu_clock_freq, "cpuclock", l); 53 parse_even_earlier(memsize, "memsize", l); 54 parse_even_earlier(highmemsize, "highmemsize", l); 55 _prom_envp++; 56 l = (long)*_prom_envp; 57 } 58 if (memsize == 0) 59 memsize = 256; 60 if (bus_clock == 0) 61 bus_clock = 66000000; 62 if (cpu_clock_freq == 0) { 63 processor_id = (¤t_cpu_data)->processor_id; 64 switch (processor_id & PRID_REV_MASK) { 65 case PRID_REV_LOONGSON2E: 66 cpu_clock_freq = 533080000; 67 break; 68 case PRID_REV_LOONGSON2F: 69 cpu_clock_freq = 797000000; 70 break; 71 default: 72 cpu_clock_freq = 100000000; 73 break; 74 } 75 } 76 77 pr_info("busclock=%ld, cpuclock=%ld, memsize=%ld, highmemsize=%ld\n", 78 bus_clock, cpu_clock_freq, memsize, highmemsize); 79} 80