eth.c

cf8020+cp2200(网络)的驱动实现

//-----------------------------------------------------------------------------
// Copyright (c) 2002 Jim Brady
// Do not use commercially without author's permission
// Last revised August 2002
// Net ETH.C
//
// This module is the Ethernet layer
//-----------------------------------------------------------------------------

#include <stdlib.h>
#include "net.h"
#include "serial.h"
#include "arp.h"
#include "ip.h"
#include "eth.h"
#include "utils.h"
#include "CP220x_ETH.h"                // Include CP220x Ethernet Routines

//bit txd_buffer_select=0;   		//选择网卡的发送缓冲区  
extern UCHAR  debug;
extern UCHAR  arpbuf[];
extern UCHAR  my_hwaddr[]; 

void Delay1ms(unsigned char T);

extern UCHAR rcve_buf_allocated;
extern uint volatile event_word;



#define Rtl8019ResetLow 	P5 &= ~(0x4); 	// P52 
#define Rtl8019ResetHigh 	P5 |= 0x4; 		// P52

//------------------------------------------------------------------------
// Initialize the Cirrus Logic 8019 chip
//------------------------------------------------------------------------

void ReadRtl8019NodeID(void)//读出网卡的物理地址存到my_ethernet_address.bytes[6]里  
{
	unsigned char  i;
	for (i=0;i<6;i++)
	{ 
		//    	my_hwaddr[i]=reg10;
		//    	my_hwaddr[i]=reg10;
   	}
}


//------------------------------------------------------------------------
// This functions checks 8019 status then sends an ethernet
// frame to it by calling an assembler function. 
//------------------------------------------------------------------------

void send_frame(UCHAR * 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*/
{
	CP220x_SendD(outbuf, len);
//	s3c44b0_eth_send(outbuf, len);
//	printf("send packet\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)
{   

}

//------------------------------------------------------------------------
// 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 * rcve_frame()//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 * buf;
//	if (buf_head!= buf_tail)

	return NULL;
} 


void eth_send(UCHAR  * outbuf, UCHAR * hwaddr, uint ptype, uint len)
{
	ETH_HEADER  * eth;
	
	eth = (ETH_HEADER *)outbuf;
	
	// Add 14 byte Ethernet header]
    //Ethernet V2标准:14 = 目的MAC地址6 byte + 源MAC地址6 byte + 类型(2) = 14, 不包括LLC层
    //现不支持: 802.3标准. MAC数据报文最小长度46 - 1500字节。小于46, 填充0;
	
	memcpy((char*)eth->dest_hwaddr, hwaddr, 6);       //目的MAC地址6 byte
	memcpy((char*)eth->source_hwaddr, my_hwaddr, 6);  //源MAC地址6 byte
    eth->frame_type = ptype;                    //类型2 byte. 比如0x0800, 表示上层使用IP数据包.  =0x8137, 表示为Novell IPX发过来。  
#ifdef __LITTLEENDIAN__
	eth->frame_type = ntohs(eth->frame_type);
#endif
	
	// 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(uint Length, UCHAR* inbuf)
{
	ETH_HEADER * eth;
	
	eth = (ETH_HEADER *)inbuf;

#ifdef __LITTLEENDIAN__
	eth->frame_type = ntohs(eth->frame_type);	
#endif
	
	// 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)
	{
		return;      
	}
	//printf("frame_type %x", eth->frame_type);
	// 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:
#ifdef __LITTLEENDIAN__
		   eth->frame_type = ntohs(eth->frame_type);		   
#endif
		   ip_rcve(inbuf);
		   break;
		   
	   default:

		   break;
	}
}