/* sysMotVpdALib.s - Motorola PPMC750 VPD assembly routines *//* Copyright 1984-1999 Wind River Systems, Inc. *//* Copyright 1999 Motorola, Inc. All Rights Reserved */    .data	.globl	copyright_wind_river	.long	copyright_wind_river/*modification history--------------------01a,31aug00,dmw  Written (from version 0b of mcpn765/sysMotVpdALib.s).*//*DESCRIPTIONThis module contains VPD routines written in assemblylanguage.*/#define _ASMLANGUAGE#include "vxWorks.h"#include "sysLib.h"#include "config.h"#include "regs.h"	#include "asm.h"#include "harrier.h"    /* defines */#define HARRIER_U0BO 6  /* bit 6 of UCTL */    /* convert bit numbering from 0=LSB to 31=LSB (standard to PPC) */#define BAUDOUT      (31-HARRIER_U0BO)	/* globals */	FUNC_EXPORT(sysTimeEdges)        FUNC_EXPORT(sysMotGetDec)		_WRS_TEXT_SEG_START	/******************************************************************************** sysTimeEdges - Time HARRIER_UCTL_U0BO Signal Edges** This function monitors the HARRIER_UCTL_U0BO signal in the system status * register and reports the number of time-base ticks required for the caller-* specified number of HARRIER_UCTL_U0BO edges to occur. It is used to * calculate the processor's bus speed.** From a C programmers point of view, the routine is defined as follows:* SYNOPSIS* \ss*       UINT32 sysTimeEdges (UINT32 edges);* \se* INPUTS:* r3    = number of edges to time** OUTPUTS* r3    = number of elapsed time base low register ticks**/FUNC_BEGIN(sysTimeEdges)        mtctr   r3              /* move number of edges to counter */        lis     r6,HIADJ(HARRIER_UART_CONTROL_REG)	/* address of UART reg */        addi    r6,r6,LO(HARRIER_UART_CONTROL_REG)        lbz     r5,0(r6)        /* read initial state of HARRIER_UCTL_U0BO */        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)/******************************************************************************** sysMotGetDec - read from the Decrementer register SPR22.** This routine will read the contents the decrementer (SPR22)** From a C point of view, the routine is defined as follows:* SYNOPSIS:* \ss*    UINT sysMotGetDec()* \se* RETURNS: value of SPR22 (in r3)*/FUNC_BEGIN(sysMotGetDec)    mfspr r3,22    bclr 20,0FUNC_END(sysMotGetDec)