vm_r.c

Actions VRAM 驱动源码

/*
********************************************************************************
*                       ACTOS
*                  ((            ))
*
*                (c) Copyright 2002-2003, Actions Co,Ld.
*                        All Right Reserved
*
* File   : *.msa
* By     : Gongee
* Version: 1> v1.00     first version     date
********************************************************************************
* $Id: vm_r.c,v 1.1.1.1 2006/01/11 08:07:22 rowena Exp $
********************************************************************************
*/
#include "vm_nanf.h"
#pragma memory=dataseg(BAD_R)
int mylen;
SD_RW sdrw;
#pragma memory=default

#pragma codeseg(BAC_R)
bool VMRead(void *pbuf, unsigned int address, unsigned int len)
{
    unsigned long temp;
    sdrw.faddr = SD_CAP + address;
    sdrw.sramaddr = (unsigned int)pbuf;       // & 0x3fff;
    if((unsigned int)pbuf < 0x4000)
    {
        sdrw.srampage = 8;
    }
    else
    {
        sdrw.srampage = input8(0x05) & 0x0f;
    }

    mylen = sdrw.faddr & 0x01ff;

    if(mylen + len <= 512)                  //在一页内就可以读完
    {
        SD_Read((int)(&sdrw), (word)len);
    }
    else                                    //在一页内无法读完的
    {
        mylen = 512 - mylen;

        SD_Read((int)(&sdrw), (word)mylen);

//为了使Vram驱动不调用C库而作修改  05-6-12 15:24
//        sdrw.faddr = sdrw.faddr + mylen;
        temp = sdrw.faddr + mylen;
        sdrw.faddr = temp;
//为了使Vram驱动不调用C库而作修改  05-6-12 15:24

        sdrw.sramaddr += mylen;

        mylen = len - mylen;

        while(mylen > 512)
        {
            SD_Read((int)(&sdrw), 512);
            mylen -= 512;
//为了使Vram驱动不调用C库而作修改  05-6-12 15:24
//            sdrw.faddr += 512;
            temp = sdrw.faddr + 512;
            sdrw.faddr = temp;
//为了使Vram驱动不调用C库而作修改  05-6-12 15:24
            sdrw.sramaddr += 512;
        }
        if(mylen)
        {
            SD_Read((int)(&sdrw), (word)mylen);
        }
     }
    return 1;
}