Archipelago » qemu

/*

 * ACPI implementation

 *

 * Copyright (c) 2006 Fabrice Bellard

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License version 2 as published by the Free Software Foundation.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

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

 * License along with this library; if not, see <http://www.gnu.org/licenses/>

 */

#include "hw.h"

#include "pc.h"

#include "pci.h"

#include "qemu-timer.h"

#include "sysemu.h"

#include "i2c.h"

#include "smbus.h"

#include "kvm.h"

//#define DEBUG

/* i82731AB (PIIX4) compatible power management function */

#define PM_FREQ 3579545

#define ACPI_DBG_IO_ADDR  0xb044

typedef struct PIIX4PMState {

    PCIDevice dev;

    uint16_t pmsts;

    uint16_t pmen;

    uint16_t pmcntrl;

    uint8_t apmc;

    uint8_t apms;

    QEMUTimer *tmr_timer;

    int64_t tmr_overflow_time;

    i2c_bus *smbus;

    uint8_t smb_stat;

    uint8_t smb_ctl;

    uint8_t smb_cmd;

    uint8_t smb_addr;

    uint8_t smb_data0;

    uint8_t smb_data1;

    uint8_t smb_data[32];

    uint8_t smb_index;

    qemu_irq irq;

} PIIX4PMState;

#define RSM_STS (1 << 15)

#define PWRBTN_STS (1 << 8)

#define RTC_EN (1 << 10)

#define PWRBTN_EN (1 << 8)

#define GBL_EN (1 << 5)

#define TMROF_EN (1 << 0)

#define SCI_EN (1 << 0)

#define SUS_EN (1 << 13)

#define ACPI_ENABLE 0xf1

#define ACPI_DISABLE 0xf0

#define SMBHSTSTS 0x00

#define SMBHSTCNT 0x02

#define SMBHSTCMD 0x03

#define SMBHSTADD 0x04

#define SMBHSTDAT0 0x05

#define SMBHSTDAT1 0x06

#define SMBBLKDAT 0x07

static PIIX4PMState *pm_state;

static uint32_t get_pmtmr(PIIX4PMState *s)

{

    uint32_t d;

    d = muldiv64(qemu_get_clock(vm_clock), PM_FREQ, ticks_per_sec);

    return d & 0xffffff;

}

static int get_pmsts(PIIX4PMState *s)

{

    int64_t d;

    int pmsts;

    pmsts = s->pmsts;

    d = muldiv64(qemu_get_clock(vm_clock), PM_FREQ, ticks_per_sec);

    if (d >= s->tmr_overflow_time)

        s->pmsts |= TMROF_EN;

    return s->pmsts;

}

static void pm_update_sci(PIIX4PMState *s)

{

    int sci_level, pmsts;

    int64_t expire_time;

    pmsts = get_pmsts(s);

    sci_level = (((pmsts & s->pmen) &

                  (RTC_EN | PWRBTN_EN | GBL_EN | TMROF_EN)) != 0);

    qemu_set_irq(s->irq, sci_level);

    /* schedule a timer interruption if needed */

    if ((s->pmen & TMROF_EN) && !(pmsts & TMROF_EN)) {

        expire_time = muldiv64(s->tmr_overflow_time, ticks_per_sec, PM_FREQ);

        qemu_mod_timer(s->tmr_timer, expire_time);

    } else {

        qemu_del_timer(s->tmr_timer);

    }

}

static void pm_tmr_timer(void *opaque)

{

    PIIX4PMState *s = opaque;

    pm_update_sci(s);

}

static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val)

{

    PIIX4PMState *s = opaque;

    addr &= 0x3f;

    switch(addr) {

    case 0x00:

        {

            int64_t d;

            int pmsts;

            pmsts = get_pmsts(s);

            if (pmsts & val & TMROF_EN) {

                /* if TMRSTS is reset, then compute the new overflow time */

                d = muldiv64(qemu_get_clock(vm_clock), PM_FREQ, ticks_per_sec);

                s->tmr_overflow_time = (d + 0x800000LL) & ~0x7fffffLL;

            }

            s->pmsts &= ~val;

            pm_update_sci(s);

        }

        break;

    case 0x02:

        s->pmen = val;

        pm_update_sci(s);

        break;

    case 0x04:

        {

            int sus_typ;

            s->pmcntrl = val & ~(SUS_EN);

            if (val & SUS_EN) {

                /* change suspend type */

                sus_typ = (val >> 10) & 7;

                switch(sus_typ) {

                case 0: /* soft power off */

                    qemu_system_shutdown_request();

                    break;

                case 1:

                    /* RSM_STS should be set on resume. Pretend that resume

                       was caused by power button */

                    s->pmsts |= (RSM_STS | PWRBTN_STS);

                    qemu_system_reset_request();

#if defined(TARGET_I386)

                    cmos_set_s3_resume();

#endif

                default:

                    break;

                }

            }

        }

        break;

    default:

        break;

    }

#ifdef DEBUG

    printf("PM writew port=0x%04x val=0x%04x\n", addr, val);

#endif

}

static uint32_t pm_ioport_readw(void *opaque, uint32_t addr)

{

    PIIX4PMState *s = opaque;

    uint32_t val;

    addr &= 0x3f;

    switch(addr) {

    case 0x00:

        val = get_pmsts(s);

        break;

    case 0x02:

        val = s->pmen;

        break;

    case 0x04:

        val = s->pmcntrl;

        break;

    default:

        val = 0;

        break;

    }

#ifdef DEBUG

    printf("PM readw port=0x%04x val=0x%04x\n", addr, val);

#endif

    return val;

}

static void pm_ioport_writel(void *opaque, uint32_t addr, uint32_t val)

{

    //    PIIX4PMState *s = opaque;

    addr &= 0x3f;

#ifdef DEBUG

    printf("PM writel port=0x%04x val=0x%08x\n", addr, val);

#endif

}

static uint32_t pm_ioport_readl(void *opaque, uint32_t addr)

{

    PIIX4PMState *s = opaque;

    uint32_t val;

    addr &= 0x3f;

    switch(addr) {

    case 0x08:

        val = get_pmtmr(s);

        break;

    default:

        val = 0;

        break;

    }

#ifdef DEBUG

    printf("PM readl port=0x%04x val=0x%08x\n", addr, val);

#endif

    return val;

}

static void pm_smi_writeb(void *opaque, uint32_t addr, uint32_t val)

{

    PIIX4PMState *s = opaque;

    addr &= 1;

#ifdef DEBUG

    printf("pm_smi_writeb addr=0x%x val=0x%02x\n", addr, val);

#endif

    if (addr == 0) {

        s->apmc = val;

        /* ACPI specs 3.0, 4.7.2.5 */

        if (val == ACPI_ENABLE) {

            s->pmcntrl |= SCI_EN;

        } else if (val == ACPI_DISABLE) {

            s->pmcntrl &= ~SCI_EN;

        }

        if (s->dev.config[0x5b] & (1 << 1)) {

            cpu_interrupt(first_cpu, CPU_INTERRUPT_SMI);

        }

    } else {

        s->apms = val;

    }

}

static uint32_t pm_smi_readb(void *opaque, uint32_t addr)

{

    PIIX4PMState *s = opaque;

    uint32_t val;

    addr &= 1;

    if (addr == 0) {

        val = s->apmc;

    } else {

        val = s->apms;

    }

#ifdef DEBUG

    printf("pm_smi_readb addr=0x%x val=0x%02x\n", addr, val);

#endif

    return val;

}

static void acpi_dbg_writel(void *opaque, uint32_t addr, uint32_t val)

{

#if defined(DEBUG)

    printf("ACPI: DBG: 0x%08x\n", val);

#endif

}

static void smb_transaction(PIIX4PMState *s)

{

    uint8_t prot = (s->smb_ctl >> 2) & 0x07;

    uint8_t read = s->smb_addr & 0x01;

    uint8_t cmd = s->smb_cmd;

    uint8_t addr = s->smb_addr >> 1;

    i2c_bus *bus = s->smbus;

#ifdef DEBUG

    printf("SMBus trans addr=0x%02x prot=0x%02x\n", addr, prot);

#endif

    switch(prot) {

    case 0x0:

        smbus_quick_command(bus, addr, read);

        break;

    case 0x1:

        if (read) {

            s->smb_data0 = smbus_receive_byte(bus, addr);

        } else {

            smbus_send_byte(bus, addr, cmd);

        }

        break;

    case 0x2:

        if (read) {

            s->smb_data0 = smbus_read_byte(bus, addr, cmd);

        } else {

            smbus_write_byte(bus, addr, cmd, s->smb_data0);

        }

        break;

    case 0x3:

        if (read) {

            uint16_t val;

            val = smbus_read_word(bus, addr, cmd);

            s->smb_data0 = val;

            s->smb_data1 = val >> 8;

        } else {

            smbus_write_word(bus, addr, cmd, (s->smb_data1 << 8) | s->smb_data0);

        }

        break;

    case 0x5:

        if (read) {

            s->smb_data0 = smbus_read_block(bus, addr, cmd, s->smb_data);

        } else {

            smbus_write_block(bus, addr, cmd, s->smb_data, s->smb_data0);

        }

        break;

    default:

        goto error;

    }

    return;

  error:

    s->smb_stat |= 0x04;

}

static void smb_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)

{

    PIIX4PMState *s = opaque;

    addr &= 0x3f;

#ifdef DEBUG

    printf("SMB writeb port=0x%04x val=0x%02x\n", addr, val);

#endif

    switch(addr) {

    case SMBHSTSTS:

        s->smb_stat = 0;

        s->smb_index = 0;

        break;

    case SMBHSTCNT:

        s->smb_ctl = val;

        if (val & 0x40)

            smb_transaction(s);

        break;

    case SMBHSTCMD:

        s->smb_cmd = val;

        break;

    case SMBHSTADD:

        s->smb_addr = val;

        break;

    case SMBHSTDAT0:

        s->smb_data0 = val;

        break;

    case SMBHSTDAT1:

        s->smb_data1 = val;

        break;

    case SMBBLKDAT:

        s->smb_data[s->smb_index++] = val;

        if (s->smb_index > 31)

            s->smb_index = 0;

        break;

    default:

        break;

    }

}

static uint32_t smb_ioport_readb(void *opaque, uint32_t addr)

{

    PIIX4PMState *s = opaque;

    uint32_t val;

    addr &= 0x3f;

    switch(addr) {

    case SMBHSTSTS:

        val = s->smb_stat;

        break;

    case SMBHSTCNT:

        s->smb_index = 0;

        val = s->smb_ctl & 0x1f;

        break;

    case SMBHSTCMD:

        val = s->smb_cmd;

        break;

    case SMBHSTADD:

        val = s->smb_addr;

        break;

    case SMBHSTDAT0:

        val = s->smb_data0;

        break;

    case SMBHSTDAT1:

        val = s->smb_data1;

        break;

    case SMBBLKDAT:

        val = s->smb_data[s->smb_index++];

        if (s->smb_index > 31)

            s->smb_index = 0;

        break;

    default:

        val = 0;

        break;

    }

#ifdef DEBUG

    printf("SMB readb port=0x%04x val=0x%02x\n", addr, val);

#endif

    return val;

}

static void pm_io_space_update(PIIX4PMState *s)

{

    uint32_t pm_io_base;

    if (s->dev.config[0x80] & 1) {

        pm_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x40));

        pm_io_base &= 0xffc0;

        /* XXX: need to improve memory and ioport allocation */

#if defined(DEBUG)

        printf("PM: mapping to 0x%x\n", pm_io_base);

#endif

        register_ioport_write(pm_io_base, 64, 2, pm_ioport_writew, s);

        register_ioport_read(pm_io_base, 64, 2, pm_ioport_readw, s);

        register_ioport_write(pm_io_base, 64, 4, pm_ioport_writel, s);

        register_ioport_read(pm_io_base, 64, 4, pm_ioport_readl, s);

    }

}

static void pm_write_config(PCIDevice *d,

                            uint32_t address, uint32_t val, int len)

{

    pci_default_write_config(d, address, val, len);

    if (address == 0x80)

        pm_io_space_update((PIIX4PMState *)d);

}

static int vmstate_acpi_after_load(void *opaque)

{

    PIIX4PMState *s = opaque;

    pm_io_space_update(s);

    return 0;

}

static const VMStateDescription vmstate_acpi = {

    .name = "piix4_pm",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .run_after_load = vmstate_acpi_after_load,

    .fields      = (VMStateField []) {

        VMSTATE_PCI_DEVICE(dev, PIIX4PMState),

        VMSTATE_UINT16(pmsts, PIIX4PMState),

        VMSTATE_UINT16(pmen, PIIX4PMState),

        VMSTATE_UINT16(pmcntrl, PIIX4PMState),

        VMSTATE_UINT8(apmc, PIIX4PMState),

        VMSTATE_UINT8(apms, PIIX4PMState),

        VMSTATE_TIMER(tmr_timer, PIIX4PMState),

        VMSTATE_INT64(tmr_overflow_time, PIIX4PMState),

        VMSTATE_END_OF_LIST()

    }

};

static void piix4_reset(void *opaque)

{

    PIIX4PMState *s = opaque;

    uint8_t *pci_conf = s->dev.config;

    pci_conf[0x58] = 0;

    pci_conf[0x59] = 0;

    pci_conf[0x5a] = 0;

    pci_conf[0x5b] = 0;

    if (kvm_enabled()) {

        /* Mark SMM as already inited (until KVM supports SMM). */

        pci_conf[0x5B] = 0x02;

    }

}

static void piix4_powerdown(void *opaque, int irq, int power_failing)

{

#if defined(TARGET_I386)

    PIIX4PMState *s = opaque;

    if (!s) {

        qemu_system_shutdown_request();

    } else if (s->pmen & PWRBTN_EN) {

        s->pmsts |= PWRBTN_EN;

        pm_update_sci(s);

    }

#endif

}

i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,

                       qemu_irq sci_irq)

{

    PIIX4PMState *s;

    uint8_t *pci_conf;

    s = (PIIX4PMState *)pci_register_device(bus,

                                         "PM", sizeof(PIIX4PMState),

                                         devfn, NULL, pm_write_config);

    pm_state = s;

    pci_conf = s->dev.config;

    pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_INTEL);

    pci_config_set_device_id(pci_conf, PCI_DEVICE_ID_INTEL_82371AB_3);

    pci_conf[0x06] = 0x80;

    pci_conf[0x07] = 0x02;

    pci_conf[0x08] = 0x03; // revision number

    pci_conf[0x09] = 0x00;

    pci_config_set_class(pci_conf, PCI_CLASS_BRIDGE_OTHER);

    pci_conf[PCI_HEADER_TYPE] = PCI_HEADER_TYPE_NORMAL; // header_type

    pci_conf[0x3d] = 0x01; // interrupt pin 1

    pci_conf[0x40] = 0x01; /* PM io base read only bit */

    register_ioport_write(0xb2, 2, 1, pm_smi_writeb, s);

    register_ioport_read(0xb2, 2, 1, pm_smi_readb, s);

    register_ioport_write(ACPI_DBG_IO_ADDR, 4, 4, acpi_dbg_writel, s);

    if (kvm_enabled()) {

        /* Mark SMM as already inited to prevent SMM from running.  KVM does not

         * support SMM mode. */

        pci_conf[0x5B] = 0x02;

    }

    /* XXX: which specification is used ? The i82731AB has different

       mappings */

    pci_conf[0x5f] = (parallel_hds[0] != NULL ? 0x80 : 0) | 0x10;

    pci_conf[0x63] = 0x60;

    pci_conf[0x67] = (serial_hds[0] != NULL ? 0x08 : 0) |

        (serial_hds[1] != NULL ? 0x90 : 0);

    pci_conf[0x90] = smb_io_base | 1;

    pci_conf[0x91] = smb_io_base >> 8;

    pci_conf[0xd2] = 0x09;

    register_ioport_write(smb_io_base, 64, 1, smb_ioport_writeb, s);

    register_ioport_read(smb_io_base, 64, 1, smb_ioport_readb, s);

    s->tmr_timer = qemu_new_timer(vm_clock, pm_tmr_timer, s);

    qemu_system_powerdown = *qemu_allocate_irqs(piix4_powerdown, s, 1);

    vmstate_register(0, &vmstate_acpi, s);

    s->smbus = i2c_init_bus(NULL, "i2c");

    s->irq = sci_irq;

    qemu_register_reset(piix4_reset, s);

    return s->smbus;

}

#define GPE_BASE 0xafe0

#define PCI_BASE 0xae00

#define PCI_EJ_BASE 0xae08

struct gpe_regs {

    uint16_t sts; /* status */

    uint16_t en;  /* enabled */

};

struct pci_status {

    uint32_t up;

    uint32_t down;

};

static struct gpe_regs gpe;

static struct pci_status pci0_status;

static uint32_t gpe_read_val(uint16_t val, uint32_t addr)

{

    if (addr & 1)

        return (val >> 8) & 0xff;

    return val & 0xff;

}

static uint32_t gpe_readb(void *opaque, uint32_t addr)

{

    uint32_t val = 0;

    struct gpe_regs *g = opaque;

    switch (addr) {

        case GPE_BASE:

        case GPE_BASE + 1:

            val = gpe_read_val(g->sts, addr);

            break;

        case GPE_BASE + 2:

        case GPE_BASE + 3:

            val = gpe_read_val(g->en, addr);

            break;

        default:

            break;

    }

#if defined(DEBUG)

    printf("gpe read %x == %x\n", addr, val);

#endif

    return val;

}

static void gpe_write_val(uint16_t *cur, int addr, uint32_t val)

{

    if (addr & 1)

        *cur = (*cur & 0xff) | (val << 8);

    else

        *cur = (*cur & 0xff00) | (val & 0xff);

}

static void gpe_reset_val(uint16_t *cur, int addr, uint32_t val)

{

    uint16_t x1, x0 = val & 0xff;

    int shift = (addr & 1) ? 8 : 0;

    x1 = (*cur >> shift) & 0xff;

    x1 = x1 & ~x0;

    *cur = (*cur & (0xff << (8 - shift))) | (x1 << shift);

}

static void gpe_writeb(void *opaque, uint32_t addr, uint32_t val)

{

    struct gpe_regs *g = opaque;

    switch (addr) {

        case GPE_BASE:

        case GPE_BASE + 1:

            gpe_reset_val(&g->sts, addr, val);

            break;

        case GPE_BASE + 2:

        case GPE_BASE + 3:

            gpe_write_val(&g->en, addr, val);

            break;

        default:

            break;

   }

#if defined(DEBUG)

    printf("gpe write %x <== %d\n", addr, val);

#endif

}

static uint32_t pcihotplug_read(void *opaque, uint32_t addr)

{

    uint32_t val = 0;

    struct pci_status *g = opaque;

    switch (addr) {

        case PCI_BASE:

            val = g->up;

            break;

        case PCI_BASE + 4:

            val = g->down;

            break;

        default:

            break;

    }

#if defined(DEBUG)

    printf("pcihotplug read %x == %x\n", addr, val);

#endif

    return val;

}

static void pcihotplug_write(void *opaque, uint32_t addr, uint32_t val)

{

    struct pci_status *g = opaque;

    switch (addr) {

        case PCI_BASE:

            g->up = val;

            break;

        case PCI_BASE + 4:

            g->down = val;

            break;

   }

#if defined(DEBUG)

    printf("pcihotplug write %x <== %d\n", addr, val);

#endif

}

static uint32_t pciej_read(void *opaque, uint32_t addr)

{

#if defined(DEBUG)

    printf("pciej read %x\n", addr);

#endif

    return 0;

}

static void pciej_write(void *opaque, uint32_t addr, uint32_t val)

{

#if defined (TARGET_I386)

    int slot = ffs(val) - 1;

    pci_device_hot_remove_success(0, slot);

#endif

#if defined(DEBUG)

    printf("pciej write %x <== %d\n", addr, val);

#endif

}

static void piix4_device_hot_add(int bus, int slot, int state);

void piix4_acpi_system_hot_add_init(void)

{

    register_ioport_write(GPE_BASE, 4, 1, gpe_writeb, &gpe);

    register_ioport_read(GPE_BASE, 4, 1,  gpe_readb, &gpe);

    register_ioport_write(PCI_BASE, 8, 4, pcihotplug_write, &pci0_status);

    register_ioport_read(PCI_BASE, 8, 4,  pcihotplug_read, &pci0_status);

    register_ioport_write(PCI_EJ_BASE, 4, 4, pciej_write, NULL);

    register_ioport_read(PCI_EJ_BASE, 4, 4,  pciej_read, NULL);

    qemu_system_device_hot_add_register(piix4_device_hot_add);

}

static void enable_device(struct pci_status *p, struct gpe_regs *g, int slot)

{

    g->sts |= 2;

    p->up |= (1 << slot);

}

static void disable_device(struct pci_status *p, struct gpe_regs *g, int slot)

{

    g->sts |= 2;

    p->down |= (1 << slot);

}

static void piix4_device_hot_add(int bus, int slot, int state)

{

    pci0_status.up = 0;

    pci0_status.down = 0;

    if (state)

        enable_device(&pci0_status, &gpe, slot);

    else

        disable_device(&pci0_status, &gpe, slot);

    if (gpe.en & 2) {

        qemu_set_irq(pm_state->irq, 1);

        qemu_set_irq(pm_state->irq, 0);

    }

}

static qemu_system_device_hot_add_t device_hot_add_callback;

void qemu_system_device_hot_add_register(qemu_system_device_hot_add_t callback)

{

    device_hot_add_callback = callback;

}

void qemu_system_device_hot_add(int pcibus, int slot, int state)

{

    if (device_hot_add_callback)

        device_hot_add_callback(pcibus, slot, state);

}

struct acpi_table_header

{

    char signature [4];    /* ACPI signature (4 ASCII characters) */

    uint32_t length;          /* Length of table, in bytes, including header */

    uint8_t revision;         /* ACPI Specification minor version # */

    uint8_t checksum;         /* To make sum of entire table == 0 */

    char oem_id [6];       /* OEM identification */

    char oem_table_id [8]; /* OEM table identification */

    uint32_t oem_revision;    /* OEM revision number */

    char asl_compiler_id [4]; /* ASL compiler vendor ID */

    uint32_t asl_compiler_revision; /* ASL compiler revision number */

} __attribute__((packed));

char *acpi_tables;

size_t acpi_tables_len;

static int acpi_checksum(const uint8_t *data, int len)

{

    int sum, i;

    sum = 0;

    for(i = 0; i < len; i++)

        sum += data[i];

    return (-sum) & 0xff;

}

int acpi_table_add(const char *t)

{

    static const char *dfl_id = "QEMUQEMU";

    char buf[1024], *p, *f;

    struct acpi_table_header acpi_hdr;

    unsigned long val;

    size_t off;

    memset(&acpi_hdr, 0, sizeof(acpi_hdr));

    if (get_param_value(buf, sizeof(buf), "sig", t)) {

        strncpy(acpi_hdr.signature, buf, 4);

    } else {

        strncpy(acpi_hdr.signature, dfl_id, 4);

    }

    if (get_param_value(buf, sizeof(buf), "rev", t)) {

        val = strtoul(buf, &p, 10);

        if (val > 255 || *p != '\0')

            goto out;

    } else {

        val = 1;

    }

    acpi_hdr.revision = (int8_t)val;

    if (get_param_value(buf, sizeof(buf), "oem_id", t)) {

        strncpy(acpi_hdr.oem_id, buf, 6);

    } else {

        strncpy(acpi_hdr.oem_id, dfl_id, 6);

    }

    if (get_param_value(buf, sizeof(buf), "oem_table_id", t)) {

        strncpy(acpi_hdr.oem_table_id, buf, 8);

    } else {

        strncpy(acpi_hdr.oem_table_id, dfl_id, 8);

    }

    if (get_param_value(buf, sizeof(buf), "oem_rev", t)) {

        val = strtol(buf, &p, 10);

        if(*p != '\0')

            goto out;

    } else {

        val = 1;

    }

    acpi_hdr.oem_revision = cpu_to_le32(val);

    if (get_param_value(buf, sizeof(buf), "asl_compiler_id", t)) {

        strncpy(acpi_hdr.asl_compiler_id, buf, 4);

    } else {

        strncpy(acpi_hdr.asl_compiler_id, dfl_id, 4);

    }

    if (get_param_value(buf, sizeof(buf), "asl_compiler_rev", t)) {

        val = strtol(buf, &p, 10);

        if(*p != '\0')

            goto out;

    } else {

        val = 1;

    }

    acpi_hdr.asl_compiler_revision = cpu_to_le32(val);

    if (!get_param_value(buf, sizeof(buf), "data", t)) {

         buf[0] = '\0';

    }

    acpi_hdr.length = sizeof(acpi_hdr);

    f = buf;

    while (buf[0]) {

        struct stat s;

        char *n = strchr(f, ':');

        if (n)

            *n = '\0';

        if(stat(f, &s) < 0) {

            fprintf(stderr, "Can't stat file '%s': %s\n", f, strerror(errno));

            goto out;

        }

        acpi_hdr.length += s.st_size;

        if (!n)

            break;

        *n = ':';

        f = n + 1;

    }

    if (!acpi_tables) {

        acpi_tables_len = sizeof(uint16_t);

        acpi_tables = qemu_mallocz(acpi_tables_len);

    }

    p = acpi_tables + acpi_tables_len;

    acpi_tables_len += sizeof(uint16_t) + acpi_hdr.length;

    acpi_tables = qemu_realloc(acpi_tables, acpi_tables_len);

    acpi_hdr.length = cpu_to_le32(acpi_hdr.length);

    *(uint16_t*)p = acpi_hdr.length;

    p += sizeof(uint16_t);

    memcpy(p, &acpi_hdr, sizeof(acpi_hdr));

    off = sizeof(acpi_hdr);

    f = buf;

    while (buf[0]) {

        struct stat s;

        int fd;

        char *n = strchr(f, ':');

        if (n)

            *n = '\0';

        fd = open(f, O_RDONLY);

        if(fd < 0)

            goto out;

        if(fstat(fd, &s) < 0) {

            close(fd);

            goto out;

        }

        do {

            int r;

            r = read(fd, p + off, s.st_size);

            if (r > 0) {

                off += r;

                s.st_size -= r;

            } else if ((r < 0 && errno != EINTR) || r == 0) {

                close(fd);

                goto out;

            }

        } while(s.st_size);

        close(fd);

        if (!n)

            break;

        f = n + 1;

    }

    ((struct acpi_table_header*)p)->checksum = acpi_checksum((uint8_t*)p, off);

    /* increase number of tables */

    (*(uint16_t*)acpi_tables) =

            cpu_to_le32(le32_to_cpu(*(uint16_t*)acpi_tables) + 1);

    return 0;

out:

    if (acpi_tables) {

        free(acpi_tables);

        acpi_tables = NULL;

    }

    return -1;

}