1 /***********************************************************************
3 * Copyright 2001 MontaVista Software Inc.
4 * Author: jsun@mvista.com or jsun@junsun.net
6 * arch/mips/ddb5xxx/common/prom.c
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
14 ***********************************************************************
16 #include <linux/config.h>
17 #include <linux/init.h>
19 #include <linux/sched.h>
20 #include <linux/bootmem.h>
22 #include <asm/addrspace.h>
23 #include <asm/bootinfo.h>
24 #include <asm/ddb5xxx/ddb5xxx.h>
25 #include <asm/debug.h>
27 char arcs_cmdline[CL_SIZE];
29 void ddb5477_runtime_detection(void);
31 const char *get_system_type(void)
33 switch (mips_machtype) {
34 case MACH_NEC_DDB5074: return "NEC DDB Vrc-5074";
35 case MACH_NEC_DDB5476: return "NEC DDB Vrc-5476";
36 case MACH_NEC_DDB5477: return "NEC DDB Vrc-5477";
37 case MACH_NEC_ROCKHOPPER: return "NEC Rockhopper";
38 case MACH_NEC_ROCKHOPPERII: return "NEC RockhopperII";
39 default: return "Unknown NEC board";
43 /* [jsun@junsun.net] PMON passes arguments in C main() style */
44 void __init prom_init(int argc, const char **arg)
48 /* arg[0] is "g", the rest is boot parameters */
49 arcs_cmdline[0] = '\0';
50 for (i = 1; i < argc; i++) {
51 if (strlen(arcs_cmdline) + strlen(arg[i] + 1)
52 >= sizeof(arcs_cmdline))
54 strcat(arcs_cmdline, arg[i]);
55 strcat(arcs_cmdline, " ");
58 /* by default all these boards use dhcp/nfs root fs */
59 strcat(arcs_cmdline, "ip=bootp");
61 mips_machgroup = MACH_GROUP_NEC_DDB;
63 #if defined(CONFIG_DDB5074)
64 mips_machtype = MACH_NEC_DDB5074;
65 add_memory_region(0, DDB_SDRAM_SIZE, BOOT_MEM_RAM);
66 #elif defined(CONFIG_DDB5476)
67 mips_machtype = MACH_NEC_DDB5476;
68 add_memory_region(0, DDB_SDRAM_SIZE, BOOT_MEM_RAM);
69 #elif defined(CONFIG_DDB5477)
70 ddb5477_runtime_detection();
71 add_memory_region(0, board_ram_size, BOOT_MEM_RAM);
75 void __init prom_free_prom_memory(void)
79 #if defined(CONFIG_DDB5477)
81 #define DEFAULT_LCS1_BASE 0x19000000
86 void ddb5477_runtime_detection(void)
88 volatile char *test_offset;
91 /* Determine if this is a DDB5477 board, or a BSB-VR0300
92 base board. We can tell by checking for the location of
93 the NVRAM. It lives at the beginning of LCS1 on the DDB5477,
94 and the beginning of LCS1 on the BSB-VR0300 is flash memory.
95 The first 2K of the NVRAM are reserved, so don't we'll poke
96 around just after that.
99 /* We can only use the PCI bus to distinquish between
100 the Rockhopper and RockhopperII backplanes and this must
101 wait until ddb5477_board_init() in setup.c after the 5477
102 is initialized. So, until then handle
103 both Rockhopper and RockhopperII backplanes as Rockhopper 1
106 test_offset = (char *)KSEG1ADDR(DEFAULT_LCS1_BASE + 0x800);
107 saved_test_byte = *test_offset;
109 *test_offset = TESTVAL1;
110 if (*test_offset != TESTVAL1) {
111 /* We couldn't set our test value, so it must not be NVRAM,
112 so it's a BSB_VR0300 */
113 mips_machtype = MACH_NEC_ROCKHOPPER;
115 /* We may have gotten lucky, and the TESTVAL1 was already
116 stored at the test location, so we must check a second
118 *test_offset = TESTVAL2;
119 if (*test_offset != TESTVAL2) {
120 /* OK, we couldn't set this value either, so it must
121 definately be a BSB_VR0300 */
122 mips_machtype = MACH_NEC_ROCKHOPPER;
124 /* We could change the value twice, so it must be
125 NVRAM, so it's a DDB_VRC5477 */
126 mips_machtype = MACH_NEC_DDB5477;
129 /* Restore the original byte */
130 *test_offset = saved_test_byte;
132 /* before we know a better way, we will trust PMON for getting
135 board_ram_size = 1 << (36 - (ddb_in32(DDB_SDRAM0) & 0xf));
137 db_run(printk("DDB run-time detection : %s, %d MB RAM\n",
138 mips_machtype == MACH_NEC_DDB5477 ?
139 "DDB5477" : "Rockhopper",
140 board_ram_size >> 20));
142 /* we can't handle ram size > 128 MB */
143 db_assert(board_ram_size <= (128 << 20));