arch/xtensa/boot/boot-elf/bootstrap.S

   1 /*
   2  * arch/xtensa/boot/boot-elf/bootstrap.S
   3  *
   4  * Low-level exception handling
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  *
  10  * Copyright (C) 2004 - 2013 by Tensilica Inc.
  11  *
  12  * Chris Zankel <chris@zankel.net>
  13  * Marc Gauthier <marc@tensilica.com>
  14  * Piet Delaney <piet@tensilica.com>
  15  */
  16
  17 #include <asm/bootparam.h>
  18 #include <asm/processor.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/page.h>
  21 #include <asm/cacheasm.h>
  22 #include <asm/initialize_mmu.h>
  23 #include <asm/vectors.h>
  24 #include <linux/linkage.h>
  25
  26         .section        .ResetVector.text, "ax"
  27         .global         _ResetVector
  28         .global         reset
  29
  30 _ResetVector:
  31         _j _SetupMMU
  32
  33         .begin  no-absolute-literals
  34         .literal_position
  35
  36         .align 4
  37 RomInitAddr:
  38         .word   LOAD_MEMORY_ADDRESS
  39 RomBootParam:
  40         .word _bootparam
  41 _bootparam:
  42         .short  BP_TAG_FIRST
  43         .short  4
  44         .long   BP_VERSION
  45         .short  BP_TAG_LAST
  46         .short  0
  47         .long   0
  48
  49         .align  4
  50 _SetupMMU:
  51         movi    a0, 0
  52         wsr     a0, windowbase
  53         rsync
  54         movi    a0, 1
  55         wsr     a0, windowstart
  56         rsync
  57         movi    a0, 0x1F
  58         wsr     a0, ps
  59         rsync
  60
  61         Offset = _SetupMMU - _ResetVector
  62
  63 #ifndef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
  64         initialize_mmu
  65 #endif
  66
  67         .end    no-absolute-literals
  68
  69         rsil    a0, XCHAL_DEBUGLEVEL-1
  70         rsync
  71 reset:
  72         l32r    a0, RomInitAddr
  73         l32r    a2, RomBootParam
  74         movi    a3, 0
  75         movi    a4, 0
  76         jx      a0
  77
  78 #ifdef CONFIG_MMU
  79         .align 4
  80
  81         .section        .ResetVector.remapped_text, "x"
  82         .global         _RemappedResetVector
  83
  84         /* Do org before literals */
  85         .org 0
  86
  87 _RemappedResetVector:
  88         .begin  no-absolute-literals
  89         .literal_position
  90
  91         _j      _RemappedSetupMMU
  92
  93         /* Position Remapped code at the same location as the original code */
  94         . = _RemappedResetVector + Offset
  95
  96 _RemappedSetupMMU:
  97 #ifndef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
  98         initialize_mmu
  99 #endif
 100
 101         .end    no-absolute-literals
 102 #endif