arch/arc/lib/start.S

   1 /*
   2  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <asm-offsets.h>
   8 #include <config.h>
   9 #include <linux/linkage.h>
  10 #include <asm/arcregs.h>
  11
  12 ENTRY(_start)
  13         /* Setup interrupt vector base that matches "__text_start" */
  14         sr      __ivt_start, [ARC_AUX_INTR_VEC_BASE]
  15
  16         /* Setup stack- and frame-pointers */
  17         mov     %sp, CONFIG_SYS_INIT_SP_ADDR
  18         mov     %fp, %sp
  19
  20         /* Unconditionally disable caches */
  21         bl      flush_dcache_all
  22         bl      dcache_disable
  23         bl      icache_disable
  24
  25         /* Zero the one and only argument of "board_init_f" */
  26         mov_s   %r0, 0
  27         j       board_init_f
  28 ENDPROC(_start)
  29
  30 /*
  31  * void board_init_f_r_trampoline(stack-pointer address)
  32  *
  33  * This "function" does not return, instead it continues in RAM
  34  * after relocating the monitor code.
  35  *
  36  * r0 = new stack-pointer
  37  */
  38 ENTRY(board_init_f_r_trampoline)
  39         /* Set up the stack- and frame-pointers */
  40         mov     %sp, %r0
  41         mov     %fp, %sp
  42
  43         /* Update position of intterupt vector table */
  44         lr      %r0, [ARC_AUX_INTR_VEC_BASE]
  45         ld      %r1, [%r25, GD_RELOC_OFF]
  46         add     %r0, %r0, %r1
  47         sr      %r0, [ARC_AUX_INTR_VEC_BASE]
  48
  49         /* Re-enter U-Boot by calling board_init_f_r */
  50         j       board_init_f_r
  51 ENDPROC(board_init_f_r_trampoline)