Archipelago » qemu

/*

 * QEMU i8255x (PRO100) emulation

 *

 * Copyright (C) 2006-2011 Stefan Weil

 *

 * Portions of the code are copies from grub / etherboot eepro100.c

 * and linux e100.c.

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 2 of the License, or

 * (at your option) version 3 or any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 *

 * Tested features (i82559):

 *      PXE boot (i386 guest, i386 / mips / mipsel / ppc host) ok

 *      Linux networking (i386) ok

 *

 * Untested:

 *      Windows networking

 *

 * References:

 *

 * Intel 8255x 10/100 Mbps Ethernet Controller Family

 * Open Source Software Developer Manual

 *

 * TODO:

 *      * PHY emulation should be separated from nic emulation.

 *        Most nic emulations could share the same phy code.

 *      * i82550 is untested. It is programmed like the i82559.

 *      * i82562 is untested. It is programmed like the i82559.

 *      * Power management (i82558 and later) is not implemented.

 *      * Wake-on-LAN is not implemented.

 */

#include <stddef.h>             /* offsetof */

#include "hw.h"

#include "pci.h"

#include "net.h"

#include "eeprom93xx.h"

#include "sysemu.h"

#include "dma.h"

/* QEMU sends frames smaller than 60 bytes to ethernet nics.

 * Such frames are rejected by real nics and their emulations.

 * To avoid this behaviour, other nic emulations pad received

 * frames. The following definition enables this padding for

 * eepro100, too. We keep the define around in case it might

 * become useful the future if the core networking is ever

 * changed to pad short packets itself. */

#define CONFIG_PAD_RECEIVED_FRAMES

#define KiB 1024

/* Debug EEPRO100 card. */

#if 0

# define DEBUG_EEPRO100

#endif

#ifdef DEBUG_EEPRO100

#define logout(fmt, ...) fprintf(stderr, "EE100\t%-24s" fmt, __func__, ## __VA_ARGS__)

#else

#define logout(fmt, ...) ((void)0)

#endif

/* Set flags to 0 to disable debug output. */

#define INT     1       /* interrupt related actions */

#define MDI     1       /* mdi related actions */

#define OTHER   1

#define RXTX    1

#define EEPROM  1       /* eeprom related actions */

#define TRACE(flag, command) ((flag) ? (command) : (void)0)

#define missing(text) fprintf(stderr, "eepro100: feature is missing in this emulation: " text "\n")

#define MAX_ETH_FRAME_SIZE 1514

/* This driver supports several different devices which are declared here. */

#define i82550          0x82550

#define i82551          0x82551

#define i82557A         0x82557a

#define i82557B         0x82557b

#define i82557C         0x82557c

#define i82558A         0x82558a

#define i82558B         0x82558b

#define i82559A         0x82559a

#define i82559B         0x82559b

#define i82559C         0x82559c

#define i82559ER        0x82559e

#define i82562          0x82562

#define i82801          0x82801

/* Use 64 word EEPROM. TODO: could be a runtime option. */

#define EEPROM_SIZE     64

#define PCI_MEM_SIZE            (4 * KiB)

#define PCI_IO_SIZE             64

#define PCI_FLASH_SIZE          (128 * KiB)

#define BIT(n) (1 << (n))

#define BITS(n, m) (((0xffffffffU << (31 - n)) >> (31 - n + m)) << m)

/* The SCB accepts the following controls for the Tx and Rx units: */

#define  CU_NOP         0x0000  /* No operation. */

#define  CU_START       0x0010  /* CU start. */

#define  CU_RESUME      0x0020  /* CU resume. */

#define  CU_STATSADDR   0x0040  /* Load dump counters address. */

#define  CU_SHOWSTATS   0x0050  /* Dump statistical counters. */

#define  CU_CMD_BASE    0x0060  /* Load CU base address. */

#define  CU_DUMPSTATS   0x0070  /* Dump and reset statistical counters. */

#define  CU_SRESUME     0x00a0  /* CU static resume. */

#define  RU_NOP         0x0000

#define  RX_START       0x0001

#define  RX_RESUME      0x0002

#define  RU_ABORT       0x0004

#define  RX_ADDR_LOAD   0x0006

#define  RX_RESUMENR    0x0007

#define INT_MASK        0x0100

#define DRVR_INT        0x0200  /* Driver generated interrupt. */

typedef struct {

    PCIDeviceInfo pci;

    uint32_t device;

    uint8_t stats_size;

    bool has_extended_tcb_support;

    bool power_management;

} E100PCIDeviceInfo;

/* Offsets to the various registers.

   All accesses need not be longword aligned. */

typedef enum {

    SCBStatus = 0,              /* Status Word. */

    SCBAck = 1,

    SCBCmd = 2,                 /* Rx/Command Unit command and status. */

    SCBIntmask = 3,

    SCBPointer = 4,             /* General purpose pointer. */

    SCBPort = 8,                /* Misc. commands and operands.  */

    SCBflash = 12,              /* Flash memory control. */

    SCBeeprom = 14,             /* EEPROM control. */

    SCBCtrlMDI = 16,            /* MDI interface control. */

    SCBEarlyRx = 20,            /* Early receive byte count. */

    SCBFlow = 24,               /* Flow Control. */

    SCBpmdr = 27,               /* Power Management Driver. */

    SCBgctrl = 28,              /* General Control. */

    SCBgstat = 29,              /* General Status. */

} E100RegisterOffset;

/* A speedo3 transmit buffer descriptor with two buffers... */

typedef struct {

    uint16_t status;

    uint16_t command;

    uint32_t link;              /* void * */

    uint32_t tbd_array_addr;    /* transmit buffer descriptor array address. */

    uint16_t tcb_bytes;         /* transmit command block byte count (in lower 14 bits */

    uint8_t tx_threshold;       /* transmit threshold */

    uint8_t tbd_count;          /* TBD number */

#if 0

    /* This constitutes two "TBD" entries: hdr and data */

    uint32_t tx_buf_addr0;  /* void *, header of frame to be transmitted.  */

    int32_t  tx_buf_size0;  /* Length of Tx hdr. */

    uint32_t tx_buf_addr1;  /* void *, data to be transmitted.  */

    int32_t  tx_buf_size1;  /* Length of Tx data. */

#endif

} eepro100_tx_t;

/* Receive frame descriptor. */

typedef struct {

    int16_t status;

    uint16_t command;

    uint32_t link;              /* struct RxFD * */

    uint32_t rx_buf_addr;       /* void * */

    uint16_t count;

    uint16_t size;

    /* Ethernet frame data follows. */

} eepro100_rx_t;

typedef enum {

    COMMAND_EL = BIT(15),

    COMMAND_S = BIT(14),

    COMMAND_I = BIT(13),

    COMMAND_NC = BIT(4),

    COMMAND_SF = BIT(3),

    COMMAND_CMD = BITS(2, 0),

} scb_command_bit;

typedef enum {

    STATUS_C = BIT(15),

    STATUS_OK = BIT(13),

} scb_status_bit;

typedef struct {

    uint32_t tx_good_frames, tx_max_collisions, tx_late_collisions,

             tx_underruns, tx_lost_crs, tx_deferred, tx_single_collisions,

             tx_multiple_collisions, tx_total_collisions;

    uint32_t rx_good_frames, rx_crc_errors, rx_alignment_errors,

             rx_resource_errors, rx_overrun_errors, rx_cdt_errors,

             rx_short_frame_errors;

    uint32_t fc_xmt_pause, fc_rcv_pause, fc_rcv_unsupported;

    uint16_t xmt_tco_frames, rcv_tco_frames;

    /* TODO: i82559 has six reserved statistics but a total of 24 dwords. */

    uint32_t reserved[4];

} eepro100_stats_t;

typedef enum {

    cu_idle = 0,

    cu_suspended = 1,

    cu_active = 2,

    cu_lpq_active = 2,

    cu_hqp_active = 3

} cu_state_t;

typedef enum {

    ru_idle = 0,

    ru_suspended = 1,

    ru_no_resources = 2,

    ru_ready = 4

} ru_state_t;

typedef struct {

    PCIDevice dev;

    /* Hash register (multicast mask array, multiple individual addresses). */

    uint8_t mult[8];

    MemoryRegion mmio_bar;

    MemoryRegion io_bar;

    MemoryRegion flash_bar;

    NICState *nic;

    NICConf conf;

    uint8_t scb_stat;           /* SCB stat/ack byte */

    uint8_t int_stat;           /* PCI interrupt status */

    /* region must not be saved by nic_save. */

    uint16_t mdimem[32];

    eeprom_t *eeprom;

    uint32_t device;            /* device variant */

    /* (cu_base + cu_offset) address the next command block in the command block list. */

    uint32_t cu_base;           /* CU base address */

    uint32_t cu_offset;         /* CU address offset */

    /* (ru_base + ru_offset) address the RFD in the Receive Frame Area. */

    uint32_t ru_base;           /* RU base address */

    uint32_t ru_offset;         /* RU address offset */

    uint32_t statsaddr;         /* pointer to eepro100_stats_t */

    /* Temporary status information (no need to save these values),

     * used while processing CU commands. */

    eepro100_tx_t tx;           /* transmit buffer descriptor */

    uint32_t cb_address;        /* = cu_base + cu_offset */

    /* Statistical counters. Also used for wake-up packet (i82559). */

    eepro100_stats_t statistics;

    /* Data in mem is always in the byte order of the controller (le).

     * It must be dword aligned to allow direct access to 32 bit values. */

    uint8_t mem[PCI_MEM_SIZE] __attribute__((aligned(8)));;

    /* Configuration bytes. */

    uint8_t configuration[22];

    /* vmstate for each particular nic */

    VMStateDescription *vmstate;

    /* Quasi static device properties (no need to save them). */

    uint16_t stats_size;

    bool has_extended_tcb_support;

} EEPRO100State;

/* Word indices in EEPROM. */

typedef enum {

    EEPROM_CNFG_MDIX  = 0x03,

    EEPROM_ID         = 0x05,

    EEPROM_PHY_ID     = 0x06,

    EEPROM_VENDOR_ID  = 0x0c,

    EEPROM_CONFIG_ASF = 0x0d,

    EEPROM_DEVICE_ID  = 0x23,

    EEPROM_SMBUS_ADDR = 0x90,

} EEPROMOffset;

/* Bit values for EEPROM ID word. */

typedef enum {

    EEPROM_ID_MDM = BIT(0),     /* Modem */

    EEPROM_ID_STB = BIT(1),     /* Standby Enable */

    EEPROM_ID_WMR = BIT(2),     /* ??? */

    EEPROM_ID_WOL = BIT(5),     /* Wake on LAN */

    EEPROM_ID_DPD = BIT(6),     /* Deep Power Down */

    EEPROM_ID_ALT = BIT(7),     /* */

    /* BITS(10, 8) device revision */

    EEPROM_ID_BD = BIT(11),     /* boot disable */

    EEPROM_ID_ID = BIT(13),     /* id bit */

    /* BITS(15, 14) signature */

    EEPROM_ID_VALID = BIT(14),  /* signature for valid eeprom */

} eeprom_id_bit;

/* Default values for MDI (PHY) registers */

static const uint16_t eepro100_mdi_default[] = {

    /* MDI Registers 0 - 6, 7 */

    0x3000, 0x780d, 0x02a8, 0x0154, 0x05e1, 0x0000, 0x0000, 0x0000,

    /* MDI Registers 8 - 15 */

    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,

    /* MDI Registers 16 - 31 */

    0x0003, 0x0000, 0x0001, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,

    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,

};

/* Readonly mask for MDI (PHY) registers */

static const uint16_t eepro100_mdi_mask[] = {

    0x0000, 0xffff, 0xffff, 0xffff, 0xc01f, 0xffff, 0xffff, 0x0000,

    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,

    0x0fff, 0x0000, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff,

    0xffff, 0xffff, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,

};

#define POLYNOMIAL 0x04c11db6

/* From FreeBSD */

/* XXX: optimize */

static unsigned compute_mcast_idx(const uint8_t * ep)

{

    uint32_t crc;

    int carry, i, j;

    uint8_t b;

    crc = 0xffffffff;

    for (i = 0; i < 6; i++) {

        b = *ep++;

        for (j = 0; j < 8; j++) {

            carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);

            crc <<= 1;

            b >>= 1;

            if (carry) {

                crc = ((crc ^ POLYNOMIAL) | carry);

            }

        }

    }

    return (crc & BITS(7, 2)) >> 2;

}

/* Read a 16 bit control/status (CSR) register. */

static uint16_t e100_read_reg2(EEPRO100State *s, E100RegisterOffset addr)

{

    assert(!((uintptr_t)&s->mem[addr] & 1));

    return le16_to_cpup((uint16_t *)&s->mem[addr]);

}

/* Read a 32 bit control/status (CSR) register. */

static uint32_t e100_read_reg4(EEPRO100State *s, E100RegisterOffset addr)

{

    assert(!((uintptr_t)&s->mem[addr] & 3));

    return le32_to_cpup((uint32_t *)&s->mem[addr]);

}

/* Write a 16 bit control/status (CSR) register. */

static void e100_write_reg2(EEPRO100State *s, E100RegisterOffset addr,

                            uint16_t val)

{

    assert(!((uintptr_t)&s->mem[addr] & 1));

    cpu_to_le16w((uint16_t *)&s->mem[addr], val);

}

/* Read a 32 bit control/status (CSR) register. */

static void e100_write_reg4(EEPRO100State *s, E100RegisterOffset addr,

                            uint32_t val)

{

    assert(!((uintptr_t)&s->mem[addr] & 3));

    cpu_to_le32w((uint32_t *)&s->mem[addr], val);

}

#if defined(DEBUG_EEPRO100)

static const char *nic_dump(const uint8_t * buf, unsigned size)

{

    static char dump[3 * 16 + 1];

    char *p = &dump[0];

    if (size > 16) {

        size = 16;

    }

    while (size-- > 0) {

        p += sprintf(p, " %02x", *buf++);

    }

    return dump;

}

#endif                          /* DEBUG_EEPRO100 */

enum scb_stat_ack {

    stat_ack_not_ours = 0x00,

    stat_ack_sw_gen = 0x04,

    stat_ack_rnr = 0x10,

    stat_ack_cu_idle = 0x20,

    stat_ack_frame_rx = 0x40,

    stat_ack_cu_cmd_done = 0x80,

    stat_ack_not_present = 0xFF,

    stat_ack_rx = (stat_ack_sw_gen | stat_ack_rnr | stat_ack_frame_rx),

    stat_ack_tx = (stat_ack_cu_idle | stat_ack_cu_cmd_done),

};

static void disable_interrupt(EEPRO100State * s)

{

    if (s->int_stat) {

        TRACE(INT, logout("interrupt disabled\n"));

        qemu_irq_lower(s->dev.irq[0]);

        s->int_stat = 0;

    }

}

static void enable_interrupt(EEPRO100State * s)

{

    if (!s->int_stat) {

        TRACE(INT, logout("interrupt enabled\n"));

        qemu_irq_raise(s->dev.irq[0]);

        s->int_stat = 1;

    }

}

static void eepro100_acknowledge(EEPRO100State * s)

{

    s->scb_stat &= ~s->mem[SCBAck];

    s->mem[SCBAck] = s->scb_stat;

    if (s->scb_stat == 0) {

        disable_interrupt(s);

    }

}

static void eepro100_interrupt(EEPRO100State * s, uint8_t status)

{

    uint8_t mask = ~s->mem[SCBIntmask];

    s->mem[SCBAck] |= status;

    status = s->scb_stat = s->mem[SCBAck];

    status &= (mask | 0x0f);

#if 0

    status &= (~s->mem[SCBIntmask] | 0x0xf);

#endif

    if (status && (mask & 0x01)) {

        /* SCB mask and SCB Bit M do not disable interrupt. */

        enable_interrupt(s);

    } else if (s->int_stat) {

        disable_interrupt(s);

    }

}

static void eepro100_cx_interrupt(EEPRO100State * s)

{

    /* CU completed action command. */

    /* Transmit not ok (82557 only, not in emulation). */

    eepro100_interrupt(s, 0x80);

}

static void eepro100_cna_interrupt(EEPRO100State * s)

{

    /* CU left the active state. */

    eepro100_interrupt(s, 0x20);

}

static void eepro100_fr_interrupt(EEPRO100State * s)

{

    /* RU received a complete frame. */

    eepro100_interrupt(s, 0x40);

}

static void eepro100_rnr_interrupt(EEPRO100State * s)

{

    /* RU is not ready. */

    eepro100_interrupt(s, 0x10);

}

static void eepro100_mdi_interrupt(EEPRO100State * s)

{

    /* MDI completed read or write cycle. */

    eepro100_interrupt(s, 0x08);

}

static void eepro100_swi_interrupt(EEPRO100State * s)

{

    /* Software has requested an interrupt. */

    eepro100_interrupt(s, 0x04);

}

#if 0

static void eepro100_fcp_interrupt(EEPRO100State * s)

{

    /* Flow control pause interrupt (82558 and later). */

    eepro100_interrupt(s, 0x01);

}

#endif

static void e100_pci_reset(EEPRO100State * s, E100PCIDeviceInfo *e100_device)

{

    uint32_t device = s->device;

    uint8_t *pci_conf = s->dev.config;

    TRACE(OTHER, logout("%p\n", s));

    /* PCI Status */

    pci_set_word(pci_conf + PCI_STATUS, PCI_STATUS_DEVSEL_MEDIUM |

                                        PCI_STATUS_FAST_BACK);

    /* PCI Latency Timer */

    pci_set_byte(pci_conf + PCI_LATENCY_TIMER, 0x20);   /* latency timer = 32 clocks */

    /* Capability Pointer is set by PCI framework. */

    /* Interrupt Line */

    /* Interrupt Pin */

    pci_set_byte(pci_conf + PCI_INTERRUPT_PIN, 1);      /* interrupt pin A */

    /* Minimum Grant */

    pci_set_byte(pci_conf + PCI_MIN_GNT, 0x08);

    /* Maximum Latency */

    pci_set_byte(pci_conf + PCI_MAX_LAT, 0x18);

    s->stats_size = e100_device->stats_size;

    s->has_extended_tcb_support = e100_device->has_extended_tcb_support;

    switch (device) {

    case i82550:

    case i82551:

    case i82557A:

    case i82557B:

    case i82557C:

    case i82558A:

    case i82558B:

    case i82559A:

    case i82559B:

    case i82559ER:

    case i82562:

    case i82801:

    case i82559C:

        break;

    default:

        logout("Device %X is undefined!\n", device);

    }

    /* Standard TxCB. */

    s->configuration[6] |= BIT(4);

    /* Standard statistical counters. */

    s->configuration[6] |= BIT(5);

    if (s->stats_size == 80) {

        /* TODO: check TCO Statistical Counters bit. Documentation not clear. */

        if (s->configuration[6] & BIT(2)) {

            /* TCO statistical counters. */

            assert(s->configuration[6] & BIT(5));

        } else {

            if (s->configuration[6] & BIT(5)) {

                /* No extended statistical counters, i82557 compatible. */

                s->stats_size = 64;

            } else {

                /* i82558 compatible. */

                s->stats_size = 76;

            }

        }

    } else {

        if (s->configuration[6] & BIT(5)) {

            /* No extended statistical counters. */

            s->stats_size = 64;

        }

    }

    assert(s->stats_size > 0 && s->stats_size <= sizeof(s->statistics));

    if (e100_device->power_management) {

        /* Power Management Capabilities */

        int cfg_offset = 0xdc;

        int r = pci_add_capability(&s->dev, PCI_CAP_ID_PM,

                                   cfg_offset, PCI_PM_SIZEOF);

        assert(r >= 0);

        pci_set_word(pci_conf + cfg_offset + PCI_PM_PMC, 0x7e21);

#if 0 /* TODO: replace dummy code for power management emulation. */

        /* TODO: Power Management Control / Status. */

        pci_set_word(pci_conf + cfg_offset + PCI_PM_CTRL, 0x0000);

        /* TODO: Ethernet Power Consumption Registers (i82559 and later). */

        pci_set_byte(pci_conf + cfg_offset + PCI_PM_PPB_EXTENSIONS, 0x0000);

#endif

    }

#if EEPROM_SIZE > 0

    if (device == i82557C || device == i82558B || device == i82559C) {

        /*

        TODO: get vendor id from EEPROM for i82557C or later.

        TODO: get device id from EEPROM for i82557C or later.

        TODO: status bit 4 can be disabled by EEPROM for i82558, i82559.

        TODO: header type is determined by EEPROM for i82559.

        TODO: get subsystem id from EEPROM for i82557C or later.

        TODO: get subsystem vendor id from EEPROM for i82557C or later.

        TODO: exp. rom baddr depends on a bit in EEPROM for i82558 or later.

        TODO: capability pointer depends on EEPROM for i82558.

        */

        logout("Get device id and revision from EEPROM!!!\n");

    }

#endif /* EEPROM_SIZE > 0 */

}

static void nic_selective_reset(EEPRO100State * s)

{

    size_t i;

    uint16_t *eeprom_contents = eeprom93xx_data(s->eeprom);

#if 0

    eeprom93xx_reset(s->eeprom);

#endif

    memcpy(eeprom_contents, s->conf.macaddr.a, 6);

    eeprom_contents[EEPROM_ID] = EEPROM_ID_VALID;

    if (s->device == i82557B || s->device == i82557C)

        eeprom_contents[5] = 0x0100;

    eeprom_contents[EEPROM_PHY_ID] = 1;

    uint16_t sum = 0;

    for (i = 0; i < EEPROM_SIZE - 1; i++) {

        sum += eeprom_contents[i];

    }

    eeprom_contents[EEPROM_SIZE - 1] = 0xbaba - sum;

    TRACE(EEPROM, logout("checksum=0x%04x\n", eeprom_contents[EEPROM_SIZE - 1]));

    memset(s->mem, 0, sizeof(s->mem));

    e100_write_reg4(s, SCBCtrlMDI, BIT(21));

    assert(sizeof(s->mdimem) == sizeof(eepro100_mdi_default));

    memcpy(&s->mdimem[0], &eepro100_mdi_default[0], sizeof(s->mdimem));

}

static void nic_reset(void *opaque)

{

    EEPRO100State *s = opaque;

    TRACE(OTHER, logout("%p\n", s));

    /* TODO: Clearing of hash register for selective reset, too? */

    memset(&s->mult[0], 0, sizeof(s->mult));

    nic_selective_reset(s);

}

#if defined(DEBUG_EEPRO100)

static const char * const e100_reg[PCI_IO_SIZE / 4] = {

    "Command/Status",

    "General Pointer",

    "Port",

    "EEPROM/Flash Control",

    "MDI Control",

    "Receive DMA Byte Count",

    "Flow Control",

    "General Status/Control"

};

static char *regname(uint32_t addr)

{

    static char buf[32];

    if (addr < PCI_IO_SIZE) {

        const char *r = e100_reg[addr / 4];

        if (r != 0) {

            snprintf(buf, sizeof(buf), "%s+%u", r, addr % 4);

        } else {

            snprintf(buf, sizeof(buf), "0x%02x", addr);

        }

    } else {

        snprintf(buf, sizeof(buf), "??? 0x%08x", addr);

    }

    return buf;

}

#endif                          /* DEBUG_EEPRO100 */

/*****************************************************************************

 *

 * Command emulation.

 *

 ****************************************************************************/

#if 0

static uint16_t eepro100_read_command(EEPRO100State * s)

{

    uint16_t val = 0xffff;

    TRACE(OTHER, logout("val=0x%04x\n", val));

    return val;

}

#endif

/* Commands that can be put in a command list entry. */

enum commands {

    CmdNOp = 0,

    CmdIASetup = 1,

    CmdConfigure = 2,

    CmdMulticastList = 3,

    CmdTx = 4,

    CmdTDR = 5,                 /* load microcode */

    CmdDump = 6,

    CmdDiagnose = 7,

    /* And some extra flags: */

    CmdSuspend = 0x4000,        /* Suspend after completion. */

    CmdIntr = 0x2000,           /* Interrupt after completion. */

    CmdTxFlex = 0x0008,         /* Use "Flexible mode" for CmdTx command. */

};

static cu_state_t get_cu_state(EEPRO100State * s)

{

    return ((s->mem[SCBStatus] & BITS(7, 6)) >> 6);

}

static void set_cu_state(EEPRO100State * s, cu_state_t state)

{

    s->mem[SCBStatus] = (s->mem[SCBStatus] & ~BITS(7, 6)) + (state << 6);

}

static ru_state_t get_ru_state(EEPRO100State * s)

{

    return ((s->mem[SCBStatus] & BITS(5, 2)) >> 2);

}

static void set_ru_state(EEPRO100State * s, ru_state_t state)

{

    s->mem[SCBStatus] = (s->mem[SCBStatus] & ~BITS(5, 2)) + (state << 2);

}

static void dump_statistics(EEPRO100State * s)

{

    /* Dump statistical data. Most data is never changed by the emulation

     * and always 0, so we first just copy the whole block and then those

     * values which really matter.

     * Number of data should check configuration!!!

     */

    pci_dma_write(&s->dev, s->statsaddr,

                  (uint8_t *) &s->statistics, s->stats_size);

    stl_le_pci_dma(&s->dev, s->statsaddr + 0,

                   s->statistics.tx_good_frames);

    stl_le_pci_dma(&s->dev, s->statsaddr + 36,

                   s->statistics.rx_good_frames);

    stl_le_pci_dma(&s->dev, s->statsaddr + 48,

                   s->statistics.rx_resource_errors);

    stl_le_pci_dma(&s->dev, s->statsaddr + 60,

                   s->statistics.rx_short_frame_errors);

#if 0

    stw_le_pci_dma(&s->dev, s->statsaddr + 76, s->statistics.xmt_tco_frames);

    stw_le_pci_dma(&s->dev, s->statsaddr + 78, s->statistics.rcv_tco_frames);

    missing("CU dump statistical counters");

#endif

}

static void read_cb(EEPRO100State *s)

{

    pci_dma_read(&s->dev, s->cb_address, (uint8_t *) &s->tx, sizeof(s->tx));

    s->tx.status = le16_to_cpu(s->tx.status);

    s->tx.command = le16_to_cpu(s->tx.command);

    s->tx.link = le32_to_cpu(s->tx.link);

    s->tx.tbd_array_addr = le32_to_cpu(s->tx.tbd_array_addr);

    s->tx.tcb_bytes = le16_to_cpu(s->tx.tcb_bytes);

}

static void tx_command(EEPRO100State *s)

{

    uint32_t tbd_array = le32_to_cpu(s->tx.tbd_array_addr);

    uint16_t tcb_bytes = (le16_to_cpu(s->tx.tcb_bytes) & 0x3fff);

    /* Sends larger than MAX_ETH_FRAME_SIZE are allowed, up to 2600 bytes. */

    uint8_t buf[2600];

    uint16_t size = 0;

    uint32_t tbd_address = s->cb_address + 0x10;

    TRACE(RXTX, logout

        ("transmit, TBD array address 0x%08x, TCB byte count 0x%04x, TBD count %u\n",

         tbd_array, tcb_bytes, s->tx.tbd_count));

    if (tcb_bytes > 2600) {

        logout("TCB byte count too large, using 2600\n");

        tcb_bytes = 2600;

    }

    if (!((tcb_bytes > 0) || (tbd_array != 0xffffffff))) {

        logout

            ("illegal values of TBD array address and TCB byte count!\n");

    }

    assert(tcb_bytes <= sizeof(buf));

    while (size < tcb_bytes) {

        uint32_t tx_buffer_address = ldl_le_pci_dma(&s->dev, tbd_address);

        uint16_t tx_buffer_size = lduw_le_pci_dma(&s->dev, tbd_address + 4);

#if 0

        uint16_t tx_buffer_el = lduw_le_pci_dma(&s->dev, tbd_address + 6);

#endif

        tbd_address += 8;

        TRACE(RXTX, logout

            ("TBD (simplified mode): buffer address 0x%08x, size 0x%04x\n",

             tx_buffer_address, tx_buffer_size));

        tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);

        pci_dma_read(&s->dev, tx_buffer_address, &buf[size], tx_buffer_size);

        size += tx_buffer_size;

    }

    if (tbd_array == 0xffffffff) {

        /* Simplified mode. Was already handled by code above. */

    } else {

        /* Flexible mode. */

        uint8_t tbd_count = 0;

        if (s->has_extended_tcb_support && !(s->configuration[6] & BIT(4))) {

            /* Extended Flexible TCB. */

            for (; tbd_count < 2; tbd_count++) {

                uint32_t tx_buffer_address = ldl_le_pci_dma(&s->dev,

                                                            tbd_address);

                uint16_t tx_buffer_size = lduw_le_pci_dma(&s->dev,

                                                          tbd_address + 4);

                uint16_t tx_buffer_el = lduw_le_pci_dma(&s->dev,

                                                        tbd_address + 6);

                tbd_address += 8;

                TRACE(RXTX, logout

                    ("TBD (extended flexible mode): buffer address 0x%08x, size 0x%04x\n",

                     tx_buffer_address, tx_buffer_size));

                tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);

                pci_dma_read(&s->dev, tx_buffer_address,

                             &buf[size], tx_buffer_size);

                size += tx_buffer_size;

                if (tx_buffer_el & 1) {

                    break;

                }

            }

        }

        tbd_address = tbd_array;

        for (; tbd_count < s->tx.tbd_count; tbd_count++) {

            uint32_t tx_buffer_address = ldl_le_pci_dma(&s->dev, tbd_address);

            uint16_t tx_buffer_size = lduw_le_pci_dma(&s->dev, tbd_address + 4);

            uint16_t tx_buffer_el = lduw_le_pci_dma(&s->dev, tbd_address + 6);

            tbd_address += 8;

            TRACE(RXTX, logout

                ("TBD (flexible mode): buffer address 0x%08x, size 0x%04x\n",

                 tx_buffer_address, tx_buffer_size));

            tx_buffer_size = MIN(tx_buffer_size, sizeof(buf) - size);

            pci_dma_read(&s->dev, tx_buffer_address,

                         &buf[size], tx_buffer_size);

            size += tx_buffer_size;

            if (tx_buffer_el & 1) {

                break;

            }

        }

    }

    TRACE(RXTX, logout("%p sending frame, len=%d,%s\n", s, size, nic_dump(buf, size)));

    qemu_send_packet(&s->nic->nc, buf, size);

    s->statistics.tx_good_frames++;

    /* Transmit with bad status would raise an CX/TNO interrupt.

     * (82557 only). Emulation never has bad status. */

#if 0

    eepro100_cx_interrupt(s);

#endif

}

static void set_multicast_list(EEPRO100State *s)

{

    uint16_t multicast_count = s->tx.tbd_array_addr & BITS(13, 0);

    uint16_t i;

    memset(&s->mult[0], 0, sizeof(s->mult));

    TRACE(OTHER, logout("multicast list, multicast count = %u\n", multicast_count));

    for (i = 0; i < multicast_count; i += 6) {

        uint8_t multicast_addr[6];

        pci_dma_read(&s->dev, s->cb_address + 10 + i, multicast_addr, 6);

        TRACE(OTHER, logout("multicast entry %s\n", nic_dump(multicast_addr, 6)));

        unsigned mcast_idx = compute_mcast_idx(multicast_addr);

        assert(mcast_idx < 64);

        s->mult[mcast_idx >> 3] |= (1 << (mcast_idx & 7));

    }

}

static void action_command(EEPRO100State *s)

{

    for (;;) {

        bool bit_el;

        bool bit_s;

        bool bit_i;

        bool bit_nc;

        uint16_t ok_status = STATUS_OK;

        s->cb_address = s->cu_base + s->cu_offset;

        read_cb(s);

        bit_el = ((s->tx.command & COMMAND_EL) != 0);

        bit_s = ((s->tx.command & COMMAND_S) != 0);

        bit_i = ((s->tx.command & COMMAND_I) != 0);

        bit_nc = ((s->tx.command & COMMAND_NC) != 0);

#if 0

        bool bit_sf = ((s->tx.command & COMMAND_SF) != 0);

#endif

        s->cu_offset = s->tx.link;

        TRACE(OTHER,

              logout("val=(cu start), status=0x%04x, command=0x%04x, link=0x%08x\n",