ether2000.c

著名操作系统Plan 9的第三版的部分核心源代码。现在很难找到了。Plan 9是bell实验室开发的Unix后继者。

#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "../port/error.h"
#include "../port/netif.h"

#include "etherif.h"
#include "ether8390.h"

/*
 * Driver written for the 'Notebook Computer Ethernet LAN Adapter',
 * a plug-in to the bus-slot on the rear of the Gateway NOMAD 425DXL
 * laptop. The manual says NE2000 compatible.
 * The interface appears to be pretty well described in the National
 * Semiconductor Local Area Network Databook (1992) as one of the
 * AT evaluation cards.
 *
 * The NE2000 is really just a DP8390[12] plus a data port
 * and a reset port.
 */
enum {
	Data		= 0x10,		/* offset from I/O base of data port */
	Reset		= 0x1F,		/* offset from I/O base of reset port */
};

static int
reset(Ether* ether)
{
	ushort buf[16];
	ulong port;
	Dp8390 *ctlr;
	int i;
	uchar ea[Eaddrlen];

	/*
	 * Set up the software configuration.
	 * Use defaults for port, irq, mem and size
	 * if not specified.
	 */
	if(ether->port == 0)
		ether->port = 0x300;
	if(ether->irq == 0)
		ether->irq = 2;
	if(ether->mem == 0)
		ether->mem = 0x4000;
	if(ether->size == 0)
		ether->size = 16*1024;
	port = ether->port;

	if(ioalloc(ether->port, 0x20, 0, "ne2000") < 0)
		return -1;

	ether->ctlr = malloc(sizeof(Dp8390));
	ctlr = ether->ctlr;
	ctlr->width = 2;
	ctlr->ram = 0;

	ctlr->port = port;
	ctlr->data = port+Data;

	ctlr->tstart = HOWMANY(ether->mem, Dp8390BufSz);
	ctlr->pstart = ctlr->tstart + HOWMANY(sizeof(Etherpkt), Dp8390BufSz);
	ctlr->pstop = ctlr->tstart + HOWMANY(ether->size, Dp8390BufSz);

	ctlr->dummyrr = 1;
	for(i = 0; i < ether->nopt; i++){
		if(strcmp(ether->opt[i], "nodummyrr"))
			continue;
		ctlr->dummyrr = 0;
		break;
	}

	/*
	 * Reset the board. This is done by doing a read
	 * followed by a write to the Reset address.
	 */
	buf[0] = inb(port+Reset);
	delay(2);
	outb(port+Reset, buf[0]);
	delay(2);
	
	/*
	 * Init the (possible) chip, then use the (possible)
	 * chip to read the (possible) PROM for ethernet address
	 * and a marker byte.
	 * Could just look at the DP8390 command register after
	 * initialisation has been tried, but that wouldn't be
	 * enough, there are other ethernet boards which could
	 * match.
	 */
	dp8390reset(ether);
	memset(buf, 0, sizeof(buf));
	dp8390read(ctlr, buf, 0, sizeof(buf));
	if((buf[0x0E] & 0xFF) != 0x57 || (buf[0x0F] & 0xFF) != 0x57){
		iofree(ether->port);
		free(ether->ctlr);
		return -1;
	}

	/*
	 * Stupid machine. Shorts were asked for,
	 * shorts were delivered, although the PROM is a byte array.
	 * Set the ethernet address.
	 */
	memset(ea, 0, Eaddrlen);
	if(memcmp(ea, ether->ea, Eaddrlen) == 0){
		for(i = 0; i < sizeof(ether->ea); i++)
			ether->ea[i] = buf[i];
	}
	dp8390setea(ether);

	return 0;
}

void
ether2000link(void)
{
	addethercard("NE2000", reset);
}