arch/microblaze/kernel/head.S

   1 /*
   2  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2007-2009 PetaLogix
   4  * Copyright (C) 2006 Atmark Techno, Inc.
   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
  11 #include <linux/linkage.h>
  12 #include <asm/thread_info.h>
  13 #include <asm/page.h>
  14
  15         .text
  16 ENTRY(_start)
  17         mfs     r1, rmsr
  18         andi    r1, r1, ~2
  19         mts     rmsr, r1
  20
  21 /* save fdt to kernel location */
  22 /* r7 stores pointer to fdt blob */
  23         beqi    r7, no_fdt_arg
  24         or      r11, r0, r0 /* incremment */
  25         ori     r4, r0, TOPHYS(_fdt_start) /* save bram context */
  26         ori     r3, r0, (0x4000 - 4)
  27 _copy_fdt:
  28         lw      r12, r7, r11 /* r12 = r7 + r11 */
  29         sw      r12, r4, r11 /* addr[r4 + r11] = r12 */
  30         addik   r11, r11, 4 /* increment counting */
  31         bgtid   r3, _copy_fdt /* loop for all entries */
  32         addik   r3, r3, -4 /* descrement loop */
  33 no_fdt_arg:
  34
  35         /* Initialize small data anchors */
  36         la      r13, r0, _KERNEL_SDA_BASE_
  37         la      r2, r0, _KERNEL_SDA2_BASE_
  38
  39         /* Initialize stack pointer */
  40         la      r1, r0, init_thread_union + THREAD_SIZE - 4
  41
  42         /* Initialize r31 with current task address */
  43         la      r31, r0, init_task
  44
  45         /*
  46          * Call platform dependent initialize function.
  47          * Please see $(ARCH)/mach-$(SUBARCH)/setup.c for
  48          * the function.
  49          */
  50         la      r8, r0, machine_early_init
  51         brald   r15, r8
  52         nop
  53
  54         la      r15, r0, machine_halt
  55         braid   start_kernel
  56         nop