asmstartup.s

来自「使用广泛的日本著名的开源嵌入式实时操作系统T-Kernel的源码」· S 代码 · 共 56 行

/*
 *----------------------------------------------------------------------
 *    T-Kernel
 *
 *    Copyright (C) 2004-2006 by Ken Sakamura. All rights reserved.
 *    T-Kernel is distributed under the T-License.
 *----------------------------------------------------------------------
 *
 *    Version:   1.02.02
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2006/8/9.
 *
 *----------------------------------------------------------------------
 */

/*
 *	@(#)asmstartup.S (crttk)
 *
 *	Driver/manager startup 
 */

#include <machine.h>
#include <tk/asm.h>

	.text
	.balign	4
	.globl	Csym(_C_startup)
	.type	Csym(_C_startup), %function
Csym(_C_startup):
        bltz    $a0, l_noinit		// Initialization sequence is performed only when ac >= 0

        la      $t0, __data_org		// When data area does not need to be moved,
        la      $t1, __data_start	// OS loads
        beq     $t0, $t1, l_noinit

        la      $t2, _edata             // initialize data area
        bleu    $t2, $t1, nocopy_data
  copy_data:
        lw      $t4, 0($t0)
        daddu   $t0, $t0, 4
        sw      $t4, 0($t1)
        daddu   $t1, $t1, 4
        bne     $t1, $t2, copy_data
  nocopy_data:

        la      $t0, __bss_start	// clear bss area
        la      $t1, _end
        bleu    $t1, $t0, nobss
  clrbss:
        sw      $zero, 0($t0)
        daddu   $t0, $t0, 4
        bne     $t0, $t1, clrbss
  nobss:

  l_noinit:
        j       Csym(_P_startup)