/* sysMotVpdALib.s - Motorola PPC VPD assembly routines *//* Copyright 1984-2002 Wind River Systems, Inc. *//* Copyright 1999-2002 Motorola, Inc. All Rights Reserved */        .data	.globl	copyright_wind_river	.long	copyright_wind_river/*modification history--------------------01f,18mar02,mil  Merged from T2.1 to T2.2, updated directives.01e,22oct01,cak  Modified as per Wind River code review.01d,18jul01,cak  Changed LOPEC_SYS_STAT_REG1 to BOARD_SYS_STAT_REG1.01c,12jan01,djs  changed sysTimeEdges() to just use the time base register01b,04jan01,scb  make sysTimeEdges() immune to static baud out line01a,08dec00,rhv  created from 01a,10jun99,rhv*//*DESCRIPTIONThis module contains VPD routines written in assembly language.*/#define _ASMLANGUAGE#include "vxWorks.h"#include "sysLib.h"#include "config.h"#include "regs.h"	#include "asm.h"/* defines *//* convert bit numbering from 0=LSB to 31=LSB (standard to PPC) */#define	BAUDOUT	(31-0)#define DEC_CNT_DELAY_U	0x0010#define DEC_CNT_DELAY_L 0x0000	/* globals */	FUNC_EXPORT(sysTimeEdges)	_WRS_TEXT_SEG_START/***************************************************************************** sysTimeEdges - Time BAUDOUT Signal Edges** SYNOPSIS* \ss* UINT32 sysTimeEdges*     (*     UINT32 edges      /@ number of edges to time @/*     )* \se** INCLUDE FILES: mcpn765.h** RETURNS: number of elapsed time base low register ticks** This function monitors the BAUDOUT signal in the system status register and* reports the number of time-base ticks required for the caller-specified* number of BUADOUT edges to occur. It is used to calculate the processor's* bus speed.**/FUNC_BEGIN(sysTimeEdges)        mtctr   r3              /* move number of edges to counter */        lis     r6,HIADJ(BOARD_SYS_STAT_REG1)	/* address of status reg */        addi    r6,r6,LO(BOARD_SYS_STAT_REG1)        /* Test BAUDOUT actually wiggling, return 0 if no BAUDOUT wiggle */	lis	r7,DEC_CNT_DELAY_U	/* decrementer elapsed time max */	addi	r7,r7,DEC_CNT_DELAY_L        mftb    r8              /* snapshot time base low */	isync        lbz     r5,0(r6)        /* read and isolate initial state of BAUDOUT */        rlwinm  r5,r5,0,BAUDOUT,BAUDOUTloop0:	lbz	r4,0(r6)        rlwinm  r4,r4,0,BAUDOUT,BAUDOUT        cmplw   r4,r5        bne     itwiggles	/* No wiggle yet, see if timeout has expired */	mftb	r4	subf	r4,r8,r4	/* get elapsed time base counts */	cmpl	0,0,r7,r4	/* have we hit the timeout value yet ? */	bc	12,1,loop0	/* branch if we have not */	/* We have exahusted timeout with no BAUDOUT change */	xor	r3,r3,r3	/* zero indicates error */        blr                     /* return */	/* BAUDOUT wiggles, now we can count transitions. */itwiggles:        lbz     r5,0(r6)        /* read and isolate initial state of BAUDOUT */        rlwinm  r5,r5,0,BAUDOUT,BAUDOUTloop1:        lbz     r4,0(r6)        /* find an edge */        rlwinm  r4,r4,0,BAUDOUT,BAUDOUT        cmplw   r4,r5        beq     loop1        mftb    r3              /* found edge, snapshot time base low */loop2:        mr      r5,r4           /* save new reference state */loop3:        lbz     r4,0(r6)        /* find an edge */        rlwinm  r4,r4,0,BAUDOUT,BAUDOUT        cmplw   r4,r5        beq     loop3        bdnz    loop2           /* found edge, fall through if last one */        mftb    r4              /* snapshot time base low */        subf    r3,r3,r4        /* calculate elapsed time */        blr                     /* return */FUNC_END(sysTimeEdges)