arch/arm-efika/kernel/kernel_startup.c

   1 /*
   2     Copyright © 1995-2010, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: english
   7 */
   8
   9 #include <utility/tagitem.h>
  10 #include <proto/arossupport.h>
  11 #include <strings.h>
  12 #include <inttypes.h>
  13
  14 #include <kernel_base.h>
  15 #include <kernel_debug.h>
  16
  17 asm(".section .aros.init,\"ax\"\n\t"
  18     ".globl start\n\t"
  19     ".type start,%function\n"
  20         "start: ldr r12, 3f                             \n"             // Load address of top of stack pointer
  21         "               ldr sp, [r12]                   \n"             // Load temporary stack pointer
  22         "               mov r4, r0                              \n"
  23         "               bl      clear_bss                       \n"             // clear bss regions
  24         "               mov r0, r4                              \n"             // restore boot msg parameter
  25         "               ldr r12, 4f                             \n"             // load supervisor stack
  26         "               ldr sp, [r12]                   \n"
  27         "               ldr     pc, 2f                          \n"             // jump to the kernel
  28         "1:             b       1b                                      \n"             // we never return from here
  29         "2:             .word startup                   \n"
  30         "3:             .word tmp_stack_end             \n"
  31         "4:     .word ssp_stack_end             \n"
  32 );
  33
  34 /*
  35  * Temporary stack for very early init. It's used only during clearing of
  36  * .bss sections in all modules. Rest of this space is occupied by TagItem
  37  * boot message. prepared by the bootstrap.
  38  */
  39 union {
  40         uint32_t                stack[128];
  41         struct TagItem  tags[64]
  42 } temporary __attribute__((aligned(32),used,section(".data")));
  43
  44 static uint32_t ssp_stack[4096];
  45 static const uint32_t *ssp_stack_end __used = &ssp_stack[4096];
  46 static const uint32_t *tmp_stack_end __used = &temporary.stack[128];
  47
  48 struct TagItem *BootMsg;
  49
  50 static void __used clear_bss(struct TagItem *msg)
  51 {
  52         struct TagItem *tag = LibFindTagItem(KRN_KernelBss, msg);
  53
  54         if (tag)
  55         {
  56                 struct KernelBSS *bss = (struct KernelbSS *)tag->ti_Data;
  57
  58                 if (bss)
  59                 {
  60                         __clear_bss(bss);
  61                 }
  62         }
  63 }
  64
  65 void startup(struct TagItem *tags)
  66 {
  67         bug("\n[KRN] AROS for EfikaMX built on %s starting...\n", __DATE__);
  68         bug("[KRN] BootMsg @ %08x\n", tags);
  69
  70         while(1);
  71 }