cpu/arm925t/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 <arm925t.h>
  35 #include <asm/system.h>
  36
  37 #ifdef CONFIG_USE_IRQ
  38 DECLARE_GLOBAL_DATA_PTR;
  39 #endif
  40
  41 static void cache_flush(void);
  42
  43 int cpu_init (void)
  44 {
  45         /*
  46          * setup up stacks if necessary
  47          */
  48 #ifdef CONFIG_USE_IRQ
  49         IRQ_STACK_START = _armboot_start - CONFIG_SYS_MALLOC_LEN - CONFIG_SYS_GBL_DATA_SIZE - 4;
  50         FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;
  51 #endif
  52         return 0;
  53 }
  54
  55 int cleanup_before_linux (void)
  56 {
  57         /*
  58          * this function is called just before we call linux
  59          * it prepares the processor for linux
  60          *
  61          * we turn off caches etc ...
  62          */
  63
  64         disable_interrupts ();
  65
  66
  67         /* turn off I/D-cache */
  68         icache_disable();
  69         dcache_disable();
  70         /* flush I/D-cache */
  71         cache_flush();
  72
  73         return 0;
  74 }
  75
  76 /* flush I/D-cache */
  77 static void cache_flush (void)
  78 {
  79         unsigned long i = 0;
  80
  81         asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i));
  82 }