cpu/arm926ejs/cpu.c

   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, <garyj@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
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  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 <asm/system.h>
  35
  36 #ifdef CONFIG_USE_IRQ
  37 DECLARE_GLOBAL_DATA_PTR;
  38 #endif
  39
  40 static void cache_flush(void);
  41
  42 int cpu_init (void)
  43 {
  44         /*
  45          * setup up stacks if necessary
  46          */
  47 #ifdef CONFIG_USE_IRQ
  48         IRQ_STACK_START = _armboot_start - CONFIG_SYS_MALLOC_LEN - CONFIG_SYS_GBL_DATA_SIZE - 4;
  49         FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;
  50 #endif
  51         return 0;
  52 }
  53
  54 int cleanup_before_linux (void)
  55 {
  56         /*
  57          * this function is called just before we call linux
  58          * it prepares the processor for linux
  59          *
  60          * we turn off caches etc ...
  61          */
  62
  63         disable_interrupts ();
  64
  65
  66         /* turn off I/D-cache */
  67         icache_disable();
  68         dcache_disable();
  69         /* flush I/D-cache */
  70         cache_flush();
  71
  72         return 0;
  73 }
  74
  75 /* flush I/D-cache */
  76 static void cache_flush (void)
  77 {
  78         unsigned long i = 0;
  79
  80         asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i));
  81 }