www.pudn.com > tcpip5151.rar > Eth.c
//-----------------------------------------------------------------------------
// Net ETH.C
//
// This module is the Ethernet layer
//-----------------------------------------------------------------------------
#include
#include
#include
#include
#include
#include "net.h"
#include "serial.h"
#include "arp.h"
#include "ip.h"
#include "eth.h"
#define reg00 XBYTE[0xc000] //reg00- 10为isa网卡接口的寄存器地址300-310；
#define reg01 XBYTE[0xc100]
#define reg02 XBYTE[0xc200]
#define reg03 XBYTE[0xc300]
#define reg04 XBYTE[0xc400]
#define reg05 XBYTE[0xc500]
#define reg06 XBYTE[0xc600]
#define reg07 XBYTE[0xc700]
#define reg08 XBYTE[0xc800]
#define reg09 XBYTE[0xc900]
#define reg0a XBYTE[0xca00]
#define reg0b XBYTE[0xcb00]
#define reg0c XBYTE[0xcc00]
#define reg0d XBYTE[0xcd00]
#define reg0e XBYTE[0xce00]
#define reg0f XBYTE[0xcf00]
#define reg10 XBYTE[0xd000]
bit txd_buffer_select=0; //选择网卡的发送缓冲区
extern UCHAR idata debug;
extern UCHAR xdata arpbuf[];
extern UCHAR code my_hwaddr[];
void Delay1ms(unsigned char T);
extern UCHAR idata rcve_buf_allocated;
extern UINT volatile event_word;
sbit RST8019=P3^2;
//------------------------------------------------------------------------
// Initialize the Cirrus Logic 8019 chip
//------------------------------------------------------------------------
void page(unsigned char pagenumber)
{
unsigned char data temp;
temp=reg00;
temp=temp&0x3B ;
pagenumber=pagenumber <<6;
temp=temp | pagenumber;
reg00=temp;
}
void Rtl8019AS_Reset() //复位网卡
{
RST8019=1;
Delay1ms(200);
Delay1ms(200);
Delay1ms(200);
RST8019=0;
Delay1ms(100);
}
void ReadRtl8019NodeID(void)//读出网卡的物理地址存到my_ethernet_address.bytes[6]里
{
unsigned char data i;
page(0);
reg09=0; //读取网卡的ram的地址为0x0000
reg08=0;
reg0b=0;
reg0a=12; //读取12个字节
reg00=0x0a; //读ram
for (i=0;i<6;i++)
{
// my_hwaddr[i]=reg10;
// my_hwaddr[i]=reg10;
}
}
void WriteRtl8019NodeID()
{
page(1);
reg01=my_hwaddr[0];
reg02=my_hwaddr[1];
reg03=my_hwaddr[2];
reg04=my_hwaddr[3];
reg05=my_hwaddr[4];
reg06=my_hwaddr[5];
page(0);
}
void init_8019(void)
{
Rtl8019AS_Reset(); //复位8019
// R8019_CHIP_SELECT;
reg00=0x21; //使芯片处于停止模式,这时进行寄存器设置 停止模式下,将不会发送和接收数据包
Delay1ms(10); //延时10毫秒,确保芯片进入停止模式
page(0);
reg0a=0x00; reg0b=0x00;
reg0c= 0xe0; //monitor mode (no packet receive)
reg0d= 0xe2; //loop back mode 使芯片处于mon和loopback模式,跟外部网络断开
reg01=0x4c; reg02=0x80; reg03=0x4c; reg04=0x40;
reg07=0xff; //清除所有中断标志位
reg0f=0x00; //disable all interrupt
reg0e=0xc8; //byte dma 8位dma方式
page(1);
reg07=0x4d; reg08=0x00; reg09=0x00; reg0a=0x00; reg0b=0x00;
reg0c=0x00; reg0d=0x00; reg0e=0x00; reg0f=0x00;
reg00=0x22; //这时让芯片开始工作
ReadRtl8019NodeID(); //读出网卡的物理地址48位
WriteRtl8019NodeID(); //将网卡地址写入到mar寄存器
page(0);
reg0c=0xcc; //将网卡设置成正常的模式,跟外部网络连接
reg0d=0xe0;
reg00=0x22; //这时让芯片开始工作
reg07=0xff; //清除所有中断标志位
}
//------------------------------------------------------------------------
// This functions checks 8019 status then sends an ethernet
// frame to it by calling an assembler function.
//------------------------------------------------------------------------
void send_frame(UCHAR xdata * outbuf, UINT len)/*发送一个数据包的命令,长度最小为60字节,最大1514字节*/
{
UCHAR i;
UINT ii;
page(0);
if(len<60)len=60;
txd_buffer_select=!txd_buffer_select;
if (txd_buffer_select)
reg09=0x40 ; //txdwrite highaddress
else
reg09=0x46 ; //txdwrite highaddress
reg08=0x00; //read page address low
reg0b=len>>8; //read count high
reg0a=len&0xff; //read count low;
reg00=0x12; //write dma, page0
for (ii=0;ii>8; //high byte counter
reg05=len&0xff; //low byte counter
reg07=0xff;
reg00=0x3e; //to sendpacket;
free(outbuf);
printf("ETH:send frame.\n");
}
//------------------------------------------------------------------------
// This functions checks the 8019 receive event status
// word to see if an ethernet frame has arrived. If so,
// set EVENT_ETH_ARRIVED bit in global event_word
//------------------------------------------------------------------------
void query_8019(void)
{
char bnry,curr;
page(0);
bnry=reg03; //bnry page have read 读页指针
page(1);
curr=reg07; //curr writepoint 8019写页指针
page(0);
if ((curr==0)) return;
bnry=bnry++;
if (bnry>0x7f) bnry=0x4c;
if (bnry!=curr) //此时表示有新的数据包在缓冲区里
{
EA = 0;
event_word |= EVENT_ETH_ARRIVED;
EA = 1;
}
reg0b=0x00; reg0a=0x00; reg00=0x22;//complete dma page 0
}
//------------------------------------------------------------------------
// This function gets an incoming Ethernet frame from the 8019.
// There may be more than 1 waiting but just allocate memory for
// one and read one in. Use the 8019 to queue incoming packets.
//------------------------------------------------------------------------
UCHAR xdata * rcve_frame(void)//如果收到一个有效的数据包,返回收到的数据,否则返回NULL
{
UCHAR bnry,curr,next_page;
UINT len, ii;
UCHAR temp;
UCHAR xdata * buf;
page(0);
bnry=reg03; //bnry page have read 读页指针
page(1);
curr=reg07; //curr writepoint 8019写页指针
page(0);
if ((curr==0)) return NULL; //读的过程出错
next_page=bnry;
bnry=bnry++;
if (bnry>0x7f) bnry=0x4c;
if (bnry!=curr) //此时表示有新的数据包在缓冲区里
{
//读取一包的前4个字节:4字节的8019头部
page(0);
reg09=bnry; //read page address high
reg08=0x00; //read page address low
reg0b=0x00; //read count high
reg0a=4; //read count low;
reg00=0x0a; //read dma
temp = reg10; temp = reg10;
next_page = temp-1; //next page start-1
len = reg10; temp = reg10;
len += temp<<8;
reg0b=0x00; reg0a=0x00; reg00=0x22;//complete dma page 0
// Allocate enough memory to hold the incoming frame
buf = (UCHAR xdata *)malloc(len);
if (buf == NULL)
{
// out of RAM
// Tell 8019 to skip the frame
page(1);
curr=reg07; //page1
page(0); //切换回page0
bnry = curr -1;
if (bnry < 0x4c) bnry =0x7f;
reg03=bnry; //write to bnry
reg07=0xff; //清除中断状态可以不用
return NULL;
}
// This flag keeps track of allocated rcve memory
rcve_buf_allocated = TRUE;
// Call the assembler function to get the incoming frame
reg09=bnry; //read page address high
reg08=4; //read page address low
reg0b=len>>8; //read count high
reg0a=len&0xff; //read count low;
reg00=0x0a; //read dma
for(ii=0;iidest_hwaddr, hwaddr, 6);
memcpy(eth->source_hwaddr, my_hwaddr, 6);
eth->frame_type = ptype;
// We just added 14 bytes to length
send_frame(outbuf, len + 14);
}
//------------------------------------------------------------------------
// This is the handler for incoming Ethernet frames
// This is designed to handle standard Ethernet (RFC 893) frames
// See "TCP/IP Illustrated, Volume 1" Sect 2.2
//------------------------------------------------------------------------
void eth_rcve(UCHAR xdata * inbuf)
{
ETH_HEADER xdata * eth;
eth = (ETH_HEADER xdata *)inbuf;
// Reject frames in IEEE 802 format where Eth type field
// is used for length. Todo: Make it handle this format
if (eth->frame_type < 1520)
{
if (debug) printf("ETH: IEEE 802 pkt rejected\n");
return;
}
// Figure out what type of frame it is from Eth header
// Call appropriate handler and supply address of buffer
switch (eth->frame_type)
{
case ARP_PACKET:
arp_rcve(inbuf);
break;
case IP_PACKET:
ip_rcve(inbuf);
break;
default:
if (debug) printf("Error: Unknown pkt rcvd\n");
break;
}
}