rtl8139.c

i386的bootloader源码grub

#define EE_SHIFT_CLK    0x04    /* EEPROM shift clock. */
#define EE_CS           0x08    /* EEPROM chip select. */
#define EE_DATA_WRITE   0x02    /* EEPROM chip data in. */
#define EE_WRITE_0      0x00
#define EE_WRITE_1      0x02
#define EE_DATA_READ    0x01    /* EEPROM chip data out. */
#define EE_ENB          (0x80 | EE_CS)

/*
	Delay between EEPROM clock transitions.
	No extra delay is needed with 33Mhz PCI, but 66Mhz may change this.
*/

#define eeprom_delay()  inl(ee_addr)

/* The EEPROM commands include the alway-set leading bit. */
#define EE_WRITE_CMD    (5 << 6)
#define EE_READ_CMD     (6 << 6)
#define EE_ERASE_CMD    (7 << 6)

static int read_eeprom(int location)
{
	int i;
	unsigned int retval = 0;
	long ee_addr = ioaddr + Cfg9346;
	int read_cmd = location | EE_READ_CMD;

	outb(EE_ENB & ~EE_CS, ee_addr);
	outb(EE_ENB, ee_addr);

	/* Shift the read command bits out. */
	for (i = 10; i >= 0; i--) {
		int dataval = (read_cmd & (1 << i)) ? EE_DATA_WRITE : 0;
		outb(EE_ENB | dataval, ee_addr);
		eeprom_delay();
		outb(EE_ENB | dataval | EE_SHIFT_CLK, ee_addr);
		eeprom_delay();
	}
	outb(EE_ENB, ee_addr);
	eeprom_delay();

	for (i = 16; i > 0; i--) {
		outb(EE_ENB | EE_SHIFT_CLK, ee_addr);
		eeprom_delay();
		retval = (retval << 1) | ((inb(ee_addr) & EE_DATA_READ) ? 1 : 0);
		outb(EE_ENB, ee_addr);
		eeprom_delay();
	}

	/* Terminate the EEPROM access. */
	outb(~EE_CS, ee_addr);
	return retval;
}

static void rtl_reset(struct nic* nic)
{
	int i;

	outb(CmdReset, ioaddr + ChipCmd);

	cur_rx = 0;
	cur_tx = 0;

	/* Give the chip 10ms to finish the reset. */
	load_timer2(10*TICKS_PER_MS);
	while ((inb(ioaddr + ChipCmd) & CmdReset) != 0 && timer2_running())
		/* wait */;

	for (i = 0; i < ETH_ALEN; i++)
		outb(nic->node_addr[i], ioaddr + MAC0 + i);

	/* Must enable Tx/Rx before setting transfer thresholds! */
	outb(CmdRxEnb | CmdTxEnb, ioaddr + ChipCmd);
	outl((RX_FIFO_THRESH<<13) | (RX_BUF_LEN_IDX<<11) | (RX_DMA_BURST<<8),
		ioaddr + RxConfig);		/* accept no frames yet!  */
	outl((TX_DMA_BURST<<8)|0x03000000, ioaddr + TxConfig);

	/* The Linux driver changes Config1 here to use a different LED pattern
	 * for half duplex or full/autodetect duplex (for full/autodetect, the
	 * outputs are TX/RX, Link10/100, FULL, while for half duplex it uses
	 * TX/RX, Link100, Link10).  This is messy, because it doesn't match
	 * the inscription on the mounting bracket.  It should not be changed
	 * from the configuration EEPROM default, because the card manufacturer
	 * should have set that to match the card.  */

#ifdef	DEBUG_RX
	printf("rx ring address is %X\n",(unsigned long)rx_ring);
#endif
	outl((unsigned long)rx_ring, ioaddr + RxBuf);

	/* Start the chip's Tx and Rx process. */
	outl(0, ioaddr + RxMissed);
	/* set_rx_mode */
	outb(AcceptBroadcast|AcceptMyPhys, ioaddr + RxConfig);
	/* If we add multicast support, the MAR0 register would have to be
	 * initialized to 0xffffffffffffffff (two 32 bit accesses).  Etherboot
	 * only needs broadcast (for ARP/RARP/BOOTP/DHCP) and unicast.  */
	outb(CmdRxEnb | CmdTxEnb, ioaddr + ChipCmd);

	/* Disable all known interrupts by setting the interrupt mask. */
	outw(0, ioaddr + IntrMask);
}

static void rtl_transmit(struct nic *nic, const char *destaddr,
	unsigned int type, unsigned int len, const char *data)
{
	unsigned int status, to, nstype;
	unsigned long txstatus;

	memcpy(tx_buffer, destaddr, ETH_ALEN);
	memcpy(tx_buffer + ETH_ALEN, nic->node_addr, ETH_ALEN);
	nstype = htons(type);
	memcpy(tx_buffer + 2 * ETH_ALEN, (char*)&nstype, 2);
	memcpy(tx_buffer + ETH_HLEN, data, len);

	len += ETH_HLEN;
#ifdef	DEBUG_TX
	printf("sending %d bytes ethtype %hX\n", len, type);
#endif

	/* Note: RTL8139 doesn't auto-pad, send minimum payload (another 4
	 * bytes are sent automatically for the FCS, totalling to 64 bytes). */
	while (len < ETH_ZLEN) {
		tx_buffer[len++] = '\0';
	}

	outl((unsigned long)tx_buffer, ioaddr + TxAddr0 + cur_tx*4);
	outl(((TX_FIFO_THRESH<<11) & 0x003f0000) | len,
		ioaddr + TxStatus0 + cur_tx*4);

	to = currticks() + RTL_TIMEOUT;

	do {
		status = inw(ioaddr + IntrStatus);
		/* Only acknlowledge interrupt sources we can properly handle
		 * here - the RxOverflow/RxFIFOOver MUST be handled in the
		 * rtl_poll() function.  */
		outw(status & (TxOK | TxErr | PCIErr), ioaddr + IntrStatus);
		if ((status & (TxOK | TxErr | PCIErr)) != 0) break;
	} while (currticks() < to);

	txstatus = inl(ioaddr+ TxStatus0 + cur_tx*4);

	if (status & TxOK) {
		cur_tx = (cur_tx + 1) % NUM_TX_DESC;
#ifdef	DEBUG_TX
		printf("tx done (%d ticks), status %hX txstatus %X\n",
			to-currticks(), status, txstatus);
#endif
	} else {
#ifdef	DEBUG_TX
		printf("tx timeout/error (%d ticks), status %hX txstatus %X\n",
			currticks()-to, status, txstatus);
#endif
		rtl_reset(nic);
	}
}

static int rtl_poll(struct nic *nic)
{
	unsigned int status;
	unsigned int ring_offs;
	unsigned int rx_size, rx_status;

	if (inb(ioaddr + ChipCmd) & RxBufEmpty) {
		return 0;
	}

	status = inw(ioaddr + IntrStatus);
	/* See below for the rest of the interrupt acknowledges.  */
	outw(status & ~(RxFIFOOver | RxOverflow | RxOK), ioaddr + IntrStatus);

#ifdef	DEBUG_RX
	printf("rtl_poll: int %hX ", status);
#endif

	ring_offs = cur_rx % RX_BUF_LEN;
	rx_status = *(unsigned int*)(rx_ring + ring_offs);
	rx_size = rx_status >> 16;
	rx_status &= 0xffff;

	if ((rx_status & (RxBadSymbol|RxRunt|RxTooLong|RxCRCErr|RxBadAlign)) ||
	    (rx_size < ETH_ZLEN) || (rx_size > ETH_FRAME_LEN + 4)) {
		printf("rx error %hX\n", rx_status);
		rtl_reset(nic);	/* this clears all interrupts still pending */
		return 0;
	}

	/* Received a good packet */
	nic->packetlen = rx_size - 4;	/* no one cares about the FCS */
	if (ring_offs+4+rx_size-4 > RX_BUF_LEN) {
		int semi_count = RX_BUF_LEN - ring_offs - 4;

		memcpy(nic->packet, rx_ring + ring_offs + 4, semi_count);
		memcpy(nic->packet+semi_count, rx_ring, rx_size-4-semi_count);
#ifdef	DEBUG_RX
		printf("rx packet %d+%d bytes", semi_count,rx_size-4-semi_count);
#endif
	} else {
		memcpy(nic->packet, rx_ring + ring_offs + 4, nic->packetlen);
#ifdef	DEBUG_RX
		printf("rx packet %d bytes", rx_size-4);
#endif
	}
#ifdef	DEBUG_RX
	printf(" at %X type %hhX%hhX rxstatus %hX\n",
		(unsigned long)(rx_ring+ring_offs+4),
		nic->packet[12], nic->packet[13], rx_status);
#endif
	cur_rx = (cur_rx + rx_size + 4 + 3) & ~3;
	outw(cur_rx - 16, ioaddr + RxBufPtr);
	/* See RTL8139 Programming Guide V0.1 for the official handling of
	 * Rx overflow situations.  The document itself contains basically no
	 * usable information, except for a few exception handling rules.  */
	outw(status & (RxFIFOOver | RxOverflow | RxOK), ioaddr + IntrStatus);
	return 1;
}

static void rtl_disable(struct nic *nic)
{
	/* reset the chip */
	outb(CmdReset, ioaddr + ChipCmd);

	/* 10 ms timeout */
	load_timer2(10*TICKS_PER_MS);
	while ((inb(ioaddr + ChipCmd) & CmdReset) != 0 && timer2_running())
		/* wait */;
}