xref: /openbmc/u-boot/arch/arm/cpu/armv7/cpu.c (revision 939e5bf9)
1 /*
2  * (C) Copyright 2008 Texas Insturments
3  *
4  * (C) Copyright 2002
5  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
6  * Marius Groeger <mgroeger@sysgo.de>
7  *
8  * (C) Copyright 2002
9  * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
10  *
11  * See file CREDITS for list of people who contributed to this
12  * project.
13  *
14  * This program is free software; you can redistribute it and/or
15  * modify it under the terms of the GNU General Public License as
16  * published by the Free Software Foundation; either version 2 of
17  * the License, or (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24  * You should have received a copy of the GNU General Public License
25  * along with this program; if not, write to the Free Software
26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27  * MA 02111-1307 USA
28  */
29 
30 /*
31  * CPU specific code
32  */
33 
34 #include <common.h>
35 #include <command.h>
36 #include <asm/system.h>
37 #include <asm/cache.h>
38 #include <asm/armv7.h>
39 
40 int cleanup_before_linux(void)
41 {
42 	/*
43 	 * this function is called just before we call linux
44 	 * it prepares the processor for linux
45 	 *
46 	 * we turn off caches etc ...
47 	 */
48 	disable_interrupts();
49 
50 	/*
51 	 * Turn off I-cache and invalidate it
52 	 */
53 	icache_disable();
54 	invalidate_icache_all();
55 
56 	/*
57 	 * turn off D-cache
58 	 * dcache_disable() in turn flushes the d-cache and disables MMU
59 	 */
60 	dcache_disable();
61 
62 	/*
63 	 * After D-cache is flushed and before it is disabled there may
64 	 * be some new valid entries brought into the cache. We are sure
65 	 * that these lines are not dirty and will not affect our execution.
66 	 * (because unwinding the call-stack and setting a bit in CP15 SCTRL
67 	 * is all we did during this. We have not pushed anything on to the
68 	 * stack. Neither have we affected any static data)
69 	 * So just invalidate the entire d-cache again to avoid coherency
70 	 * problems for kernel
71 	 */
72 	invalidate_dcache_all();
73 
74 	return 0;
75 }
76