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/arch/mips/ddb5xxx/common/prom.c

https://bitbucket.org/evzijst/gittest
C | 142 lines | 84 code | 19 blank | 39 comment | 11 complexity | df94fef671d6e83438fa8442d304b4fa MD5 | raw file
  1/*
  2 * Copyright 2001 MontaVista Software Inc.
  3 * Author: jsun@mvista.com or jsun@junsun.net
  4 *
  5 * This program is free software; you can redistribute  it and/or modify it
  6 * under  the terms of  the GNU General  Public License as published by the
  7 * Free Software Foundation;  either version 2 of the  License, or (at your
  8 * option) any later version.
  9 */
 10#include <linux/config.h>
 11#include <linux/init.h>
 12#include <linux/mm.h>
 13#include <linux/sched.h>
 14#include <linux/bootmem.h>
 15
 16#include <asm/addrspace.h>
 17#include <asm/bootinfo.h>
 18#include <asm/ddb5xxx/ddb5xxx.h>
 19#include <asm/debug.h>
 20
 21const char *get_system_type(void)
 22{
 23	switch (mips_machtype) {
 24	case MACH_NEC_DDB5074:		return "NEC DDB Vrc-5074";
 25	case MACH_NEC_DDB5476:		return "NEC DDB Vrc-5476";
 26	case MACH_NEC_DDB5477:		return "NEC DDB Vrc-5477";
 27	case MACH_NEC_ROCKHOPPER:	return "NEC Rockhopper";
 28	case MACH_NEC_ROCKHOPPERII:     return "NEC RockhopperII";
 29	default:			return "Unknown NEC board";
 30	}
 31}
 32
 33#if defined(CONFIG_DDB5477)
 34void ddb5477_runtime_detection(void);
 35#endif
 36
 37/* [jsun@junsun.net] PMON passes arguments in C main() style */
 38void __init prom_init(void)
 39{
 40	int argc = fw_arg0;
 41	char **arg = (char**) fw_arg1;
 42	int i;
 43
 44	/* if user passes kernel args, ignore the default one */
 45	if (argc > 1)
 46		arcs_cmdline[0] = '\0';
 47
 48	/* arg[0] is "g", the rest is boot parameters */
 49	for (i = 1; i < argc; i++) {
 50		if (strlen(arcs_cmdline) + strlen(arg[i] + 1)
 51		    >= sizeof(arcs_cmdline))
 52			break;
 53		strcat(arcs_cmdline, arg[i]);
 54		strcat(arcs_cmdline, " ");
 55	}
 56
 57	mips_machgroup = MACH_GROUP_NEC_DDB;
 58
 59#if defined(CONFIG_DDB5074)
 60	mips_machtype = MACH_NEC_DDB5074;
 61	add_memory_region(0, DDB_SDRAM_SIZE, BOOT_MEM_RAM);
 62#elif defined(CONFIG_DDB5476)
 63	mips_machtype = MACH_NEC_DDB5476;
 64	add_memory_region(0, DDB_SDRAM_SIZE, BOOT_MEM_RAM);
 65#elif defined(CONFIG_DDB5477)
 66	ddb5477_runtime_detection();
 67	add_memory_region(0, board_ram_size, BOOT_MEM_RAM);
 68#endif
 69}
 70
 71unsigned long __init prom_free_prom_memory(void)
 72{
 73	return 0;
 74}
 75
 76#if defined(CONFIG_DDB5477)
 77
 78#define DEFAULT_LCS1_BASE 0x19000000
 79#define TESTVAL1 'K'
 80#define TESTVAL2 'S'
 81
 82int board_ram_size;
 83void ddb5477_runtime_detection(void)
 84{
 85	volatile char *test_offset;
 86	char saved_test_byte;
 87
 88        /* Determine if this is a DDB5477 board, or a BSB-VR0300
 89           base board.  We can tell by checking for the location of
 90           the NVRAM.  It lives at the beginning of LCS1 on the DDB5477,
 91           and the beginning of LCS1 on the BSB-VR0300 is flash memory.
 92           The first 2K of the NVRAM are reserved, so don't we'll poke
 93           around just after that.
 94         */
 95
 96	/* We can only use the PCI bus to distinquish between
 97	   the Rockhopper and RockhopperII backplanes and this must
 98	   wait until ddb5477_board_init() in setup.c after the 5477
 99	   is initialized.  So, until then handle
100	   both Rockhopper and RockhopperII backplanes as Rockhopper 1
101	 */
102
103        test_offset = (char *)KSEG1ADDR(DEFAULT_LCS1_BASE + 0x800);
104        saved_test_byte = *test_offset;
105
106        *test_offset = TESTVAL1;
107        if (*test_offset != TESTVAL1) {
108                /* We couldn't set our test value, so it must not be NVRAM,
109                   so it's a BSB_VR0300 */
110		mips_machtype = MACH_NEC_ROCKHOPPER;
111        } else {
112                /* We may have gotten lucky, and the TESTVAL1 was already
113                   stored at the test location, so we must check a second
114                   test value */
115                *test_offset = TESTVAL2;
116                if (*test_offset != TESTVAL2) {
117                        /* OK, we couldn't set this value either, so it must
118                           definately be a BSB_VR0300 */
119			mips_machtype = MACH_NEC_ROCKHOPPER;
120                } else {
121                        /* We could change the value twice, so it must be
122                        NVRAM, so it's a DDB_VRC5477 */
123			mips_machtype = MACH_NEC_DDB5477;
124                }
125        }
126        /* Restore the original byte */
127        *test_offset = saved_test_byte;
128
129	/* before we know a better way, we will trust PMON for getting
130	 * RAM size
131	 */
132	board_ram_size = 1 << (36 - (ddb_in32(DDB_SDRAM0) & 0xf));
133
134	db_run(printk("DDB run-time detection : %s, %d MB RAM\n",
135				mips_machtype == MACH_NEC_DDB5477 ?
136				"DDB5477" : "Rockhopper",
137				board_ram_size >> 20));
138
139	/* we can't handle ram size > 128 MB */
140	db_assert(board_ram_size <= (128 << 20));
141}
142#endif