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74f4304e WD |
1 | /* |
2 | * (C) Copyright 2002 | |
3 | * Sysgo Real-Time Solutions, GmbH <www.elinos.com> | |
4 | * Marius Groeger <mgroeger@sysgo.de> | |
5 | * | |
6 | * (C) Copyright 2002 | |
7 | * Gary Jennejohn, DENX Software Engineering, <gj@denx.de> | |
8 | * | |
9 | * See file CREDITS for list of people who contributed to this | |
10 | * project. | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of | |
15 | * the License, or (at your option) any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, | |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
fe7eb5d8 | 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
74f4304e WD |
20 | * GNU General Public License for more details. |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
23 | * along with this program; if not, write to the Free Software | |
24 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
25 | * MA 02111-1307 USA | |
26 | */ | |
27 | ||
28 | /* | |
29 | * CPU specific code | |
30 | */ | |
31 | ||
32 | #include <common.h> | |
33 | #include <command.h> | |
34 | #include <arm946es.h> | |
35 | ||
d87080b7 WD |
36 | #ifdef CONFIG_USE_IRQ |
37 | DECLARE_GLOBAL_DATA_PTR; | |
38 | #endif | |
39 | ||
74f4304e WD |
40 | /* read co-processor 15, register #1 (control register) */ |
41 | static unsigned long read_p15_c1 (void) | |
42 | { | |
43 | unsigned long value; | |
44 | ||
45 | __asm__ __volatile__( | |
fe7eb5d8 | 46 | "mrc p15, 0, %0, c1, c0, 0 @ read control reg\n" |
74f4304e WD |
47 | : "=r" (value) |
48 | : | |
49 | : "memory"); | |
50 | ||
51 | #ifdef MMU_DEBUG | |
52 | printf ("p15/c1 is = %08lx\n", value); | |
53 | #endif | |
54 | return value; | |
55 | } | |
56 | ||
57 | /* write to co-processor 15, register #1 (control register) */ | |
58 | static void write_p15_c1 (unsigned long value) | |
59 | { | |
60 | #ifdef MMU_DEBUG | |
61 | printf ("write %08lx to p15/c1\n", value); | |
62 | #endif | |
63 | __asm__ __volatile__( | |
fe7eb5d8 | 64 | "mcr p15, 0, %0, c1, c0, 0 @ write it back\n" |
74f4304e WD |
65 | : |
66 | : "r" (value) | |
67 | : "memory"); | |
68 | ||
69 | read_p15_c1 (); | |
70 | } | |
71 | ||
72 | static void cp_delay (void) | |
73 | { | |
74 | volatile int i; | |
75 | ||
76 | /* copro seems to need some delay between reading and writing */ | |
77 | for (i = 0; i < 100; i++); | |
78 | } | |
79 | ||
80 | /* See also ARM946E-S Technical Reference Manual */ | |
81 | #define C1_MMU (1<<0) /* mmu off/on */ | |
82 | #define C1_ALIGN (1<<1) /* alignment faults off/on */ | |
83 | #define C1_DC (1<<2) /* dcache off/on */ | |
84 | ||
85 | #define C1_BIG_ENDIAN (1<<7) /* big endian off/on */ | |
86 | #define C1_SYS_PROT (1<<8) /* system protection */ | |
87 | #define C1_ROM_PROT (1<<9) /* ROM protection */ | |
88 | #define C1_IC (1<<12) /* icache off/on */ | |
fe7eb5d8 | 89 | #define C1_HIGH_VECTORS (1<<13) /* location of vectors: low/high addresses */ |
74f4304e WD |
90 | |
91 | ||
92 | int cpu_init (void) | |
93 | { | |
94 | /* | |
95 | * setup up stacks if necessary | |
96 | */ | |
97 | #ifdef CONFIG_USE_IRQ | |
6d0f6bcf | 98 | IRQ_STACK_START = _armboot_start - CONFIG_SYS_MALLOC_LEN - CONFIG_SYS_GBL_DATA_SIZE - 4; |
74f4304e WD |
99 | FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ; |
100 | #endif | |
101 | return 0; | |
102 | } | |
103 | ||
104 | int cleanup_before_linux (void) | |
105 | { | |
106 | /* | |
107 | * this function is called just before we call linux | |
108 | * it prepares the processor for linux | |
109 | * | |
110 | * we turn off caches etc ... | |
111 | */ | |
112 | ||
113 | unsigned long i; | |
114 | ||
115 | disable_interrupts (); | |
116 | ||
fe7eb5d8 WD |
117 | /* ARM926E-S needs the protection unit enabled for the icache to have |
118 | * been enabled - left for possible later use | |
74f4304e | 119 | * should turn off the protection unit as well.... |
fe7eb5d8 | 120 | */ |
74f4304e WD |
121 | /* turn off I/D-cache */ |
122 | asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i)); | |
123 | i &= ~(C1_DC | C1_IC); | |
124 | asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i)); | |
125 | ||
126 | /* flush I/D-cache */ | |
127 | i = 0; | |
128 | asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (i)); | |
129 | asm ("mcr p15, 0, %0, c7, c6, 0": :"r" (i)); | |
130 | return (0); | |
131 | } | |
132 | ||
133 | int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) | |
134 | { | |
135 | extern void reset_cpu (ulong addr); | |
136 | ||
137 | disable_interrupts (); | |
138 | reset_cpu (0); | |
139 | /*NOTREACHED*/ | |
140 | return (0); | |
141 | } | |
142 | /* ARM926E-S needs the protection unit enabled for this to have any effect | |
143 | - left for possible later use */ | |
144 | void icache_enable (void) | |
145 | { | |
146 | ulong reg; | |
147 | ||
148 | reg = read_p15_c1 (); /* get control reg. */ | |
149 | cp_delay (); | |
150 | write_p15_c1 (reg | C1_IC); | |
151 | } | |
152 | ||
153 | void icache_disable (void) | |
154 | { | |
155 | ulong reg; | |
156 | ||
157 | reg = read_p15_c1 (); | |
158 | cp_delay (); | |
159 | write_p15_c1 (reg & ~C1_IC); | |
160 | } | |
161 | ||
162 | int icache_status (void) | |
163 | { | |
164 | return (read_p15_c1 () & C1_IC) != 0; | |
165 | } |