unixalib.s

VxWorks BSP框架源代码包含头文件和驱动

/* unixALib.s - network assembly language routines */

/* Copyright 1984-2000 Wind River Systems, Inc. */
	.data
	.globl	_copyright_wind_river
	.long	_copyright_wind_river

/*
modification history
--------------------
01b,28jul00,ish  3Soft changes for ColdFire
01a,17mar00,dra  Created from T1.0.1 ColdFire and T2 m68k ports.
*/

/* optimized version available for 68020, 68040 and 68060 */

#if (defined(PORTABLE) || (CPU!=MC68020) && (CPU!=MC68040) && \
     (CPU!=MC68060) && (CPU!=MC68LC040))
    
#define unixALib_PORTABLE
#endif

#ifndef unixALib_PORTABLE
#define _ASMLANGUAGE

	/* internals */

	.globl	_cksum
	.globl  __insque
	.globl  __remque

	.text
	.even

/**************************************************************************
*
* cksum - compute check sum
*
* return 16bit one's complement sum of 'sum' and the 16bit one's
* complement sum of the string 'string' of byte length 'len'.
* Complicated by 'len' or 'sumlen' not being even.
*
* RETURNS  int
*
* int cksum (sum, string, len, sumlen);
*/
_cksum:
	movl    d2,sp@-
	movl    d3,sp@-
	movl    sp@(12),d0   	/* sum */
	movl    sp@(16),a0	/* addr */
	movl    sp@(20),d1	/* len */
	btst	#0,sp@(24+3)	/* previously summed len */
	jeq	ckEvenSum
	clrl	d2		/* odd number of bytes summed previously */
	andb    #0xf,cc		/* Clear X (extended carry flag) */
	movb	a0@+,d2		/* add the first byte into our sum */
	addxl	d2,d0		/* before others */
	subl	#1,d1
ckEvenSum:
	movl    d1,d2
	movl    d1,d3
	andl    #0x3,d3		/* count % 4 */
	lsrl    #6,d1		/* count/64 = # loop traversals */
	andl    #0x3c,d2	/* Then find fractions of a chunk */
	negl    d2
	andb    #0xf,cc		/* Clear X (extended carry flag) */
/* The jump instruction contained in the following conditional
 * compilation executes a relative jump to one of the instructions
 * between the labels ckInLoop and ckStartLoop based on the number
 * of instructions between the labels.  Since the .word hardcodes
 * this difference for non-SUN hosts, any change to the number or
 * nature of instructions between the labels must be reflected
 * in a recalculation of the binary values defined by the .word.
 */
#if	defined(AS_WORKS_WELL)
	jmp     pc@(ckStartLoop-.-2:b,d2)   /* Jump into loop */
#else
	.word   0x4efb,0x2842		    /* Jump into loop */
#endif	/* AS_WORKS_WELL */
ckInLoop:				   /* Begin inner loop... */
	movl    a0@+,d2		/*  Fetch 32-bit word */
	addxl   d2,d0		/*    Add word + previous carry */
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
	movl    a0@+,d2
	addxl   d2,d0
ckStartLoop:
	dbra    d1,ckInLoop	/* dbra doesn't affect X */
	btst    #1,d3		/* another word to add? */
	jne     ckNextWord
	btst    #0,d3		/* another byte to add? */
	jne     ckNextByte
	jra     ckGetout
ckNextWord:
	movw    a0@+,d2
	addxw   d2,d0
	btst    #0,d3		/* another byte to add? */
	jeq     ckGetout
ckNextByte:
	movw    a0@+,d2
	andw    #0xff00,d2
	addxw   d2,d0
ckGetout:
	movl    d0,d1		/* Fold 32 bit sum to 16 bits */
	swap    d1		/* swap doesn't affect X */
	addxw   d1,d0
	jcc     ckNoCarry
	addw    #1,d0
ckNoCarry:
	andl    #0xffff,d0
	movl    sp@+,d3
	movl    sp@+,d2
	rts

/****************************************************************************
*
* insque - insert a node into a linked list
*
*/
__insque:
	movel	sp@(4),a0		/* new */
	movel	sp@(8),a1		/* pred */
	movel	a1@,d0			/* succ */
	movel	d0,a0@
	movel	a1,a0@(4)
	movel	a0,a1@
	movel	d0,a1
	movel	a0,a1@(4)
	rts

/****************************************************************************
*
* remque - delete a node from a linked list
*
*/
__remque:
	movel	d0,d1
	movel	sp@(4),a0
	movel	a0@,a1
	movel	a0@(4),d0
	movel	d0,a1@(4)
	exg	d0,a0
	movel	a1,a0@
	rts
#endif	/* !unixALib_PORTABLE */