pc.c

qemu虚拟机代码

/*
 * QEMU PC System Emulator
 * 
 * Copyright (c) 2003-2004 Fabrice Bellard
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "vl.h"

/* output Bochs bios info messages */
//#define DEBUG_BIOS

#define BIOS_FILENAME "bios.bin"
#define VGABIOS_FILENAME "vgabios.bin"
#define VGABIOS_CIRRUS_FILENAME "vgabios-cirrus.bin"
#define LINUX_BOOT_FILENAME "linux_boot.bin"

#define KERNEL_LOAD_ADDR     0x00100000
#define INITRD_LOAD_ADDR     0x00600000
#define KERNEL_PARAMS_ADDR   0x00090000
#define KERNEL_CMDLINE_ADDR  0x00099000

static fdctrl_t *floppy_controller;
static RTCState *rtc_state;
static PITState *pit;
static IOAPICState *ioapic;
static USBPort *usb_root_ports[2];

static void ioport80_write(void *opaque, uint32_t addr, uint32_t data)
{
}

/* MSDOS compatibility mode FPU exception support */
/* XXX: add IGNNE support */
void cpu_set_ferr(CPUX86State *s)
{
    pic_set_irq(13, 1);
}

static void ioportF0_write(void *opaque, uint32_t addr, uint32_t data)
{
    pic_set_irq(13, 0);
}

/* TSC handling */

uint64_t cpu_get_tsc(CPUX86State *env)
{
    return qemu_get_clock(vm_clock);
}

/* IRQ handling */
int cpu_get_pic_interrupt(CPUState *env)
{
    int intno;

    intno = apic_get_interrupt(env);
    if (intno >= 0) {
        /* set irq request if a PIC irq is still pending */
        /* XXX: improve that */
        pic_update_irq(isa_pic); 
        return intno;
    }
    /* read the irq from the PIC */
    intno = pic_read_irq(isa_pic);
    return intno;
}

static void pic_irq_request(void *opaque, int level)
{
    CPUState *env = opaque;
    if (level)
        cpu_interrupt(env, CPU_INTERRUPT_HARD);
    else
        cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
}

/* PC cmos mappings */

#define REG_EQUIPMENT_BYTE          0x14
#define REG_IBM_CENTURY_BYTE        0x32
#define REG_IBM_PS2_CENTURY_BYTE    0x37


static inline int to_bcd(RTCState *s, int a)
{
    return ((a / 10) << 4) | (a % 10);
}

static int cmos_get_fd_drive_type(int fd0)
{
    int val;

    switch (fd0) {
    case 0:
        /* 1.44 Mb 3"5 drive */
        val = 4;
        break;
    case 1:
        /* 2.88 Mb 3"5 drive */
        val = 5;
        break;
    case 2:
        /* 1.2 Mb 5"5 drive */
        val = 2;
        break;
    default:
        val = 0;
        break;
    }
    return val;
}

static void cmos_init_hd(int type_ofs, int info_ofs, BlockDriverState *hd) 
{
    RTCState *s = rtc_state;
    int cylinders, heads, sectors;
    bdrv_get_geometry_hint(hd, &cylinders, &heads, &sectors);
    rtc_set_memory(s, type_ofs, 47);
    rtc_set_memory(s, info_ofs, cylinders);
    rtc_set_memory(s, info_ofs + 1, cylinders >> 8);
    rtc_set_memory(s, info_ofs + 2, heads);
    rtc_set_memory(s, info_ofs + 3, 0xff);
    rtc_set_memory(s, info_ofs + 4, 0xff);
    rtc_set_memory(s, info_ofs + 5, 0xc0 | ((heads > 8) << 3));
    rtc_set_memory(s, info_ofs + 6, cylinders);
    rtc_set_memory(s, info_ofs + 7, cylinders >> 8);
    rtc_set_memory(s, info_ofs + 8, sectors);
}

/* hd_table must contain 4 block drivers */
static void cmos_init(int ram_size, int boot_device, BlockDriverState **hd_table)
{
    RTCState *s = rtc_state;
    int val;
    int fd0, fd1, nb;
    time_t ti;
    struct tm *tm;
    int i;

    /* set the CMOS date */
    time(&ti);
    if (rtc_utc)
        tm = gmtime(&ti);
    else
        tm = localtime(&ti);
    rtc_set_date(s, tm);

    val = to_bcd(s, (tm->tm_year / 100) + 19);
    rtc_set_memory(s, REG_IBM_CENTURY_BYTE, val);
    rtc_set_memory(s, REG_IBM_PS2_CENTURY_BYTE, val);

    /* various important CMOS locations needed by PC/Bochs bios */

    /* memory size */
    val = 640; /* base memory in K */
    rtc_set_memory(s, 0x15, val);
    rtc_set_memory(s, 0x16, val >> 8);

    val = (ram_size / 1024) - 1024;
    if (val > 65535)
        val = 65535;
    rtc_set_memory(s, 0x17, val);
    rtc_set_memory(s, 0x18, val >> 8);
    rtc_set_memory(s, 0x30, val);
    rtc_set_memory(s, 0x31, val >> 8);

    if (ram_size > (16 * 1024 * 1024))
        val = (ram_size / 65536) - ((16 * 1024 * 1024) / 65536);
    else
        val = 0;
    if (val > 65535)
        val = 65535;
    rtc_set_memory(s, 0x34, val);
    rtc_set_memory(s, 0x35, val >> 8);
    
    switch(boot_device) {
    case 'a':
    case 'b':
        rtc_set_memory(s, 0x3d, 0x01); /* floppy boot */
        break;
    default:
    case 'c':
        rtc_set_memory(s, 0x3d, 0x02); /* hard drive boot */
        break;
    case 'd':
        rtc_set_memory(s, 0x3d, 0x03); /* CD-ROM boot */
        break;
    }

    /* floppy type */

    fd0 = fdctrl_get_drive_type(floppy_controller, 0);
    fd1 = fdctrl_get_drive_type(floppy_controller, 1);

    val = (cmos_get_fd_drive_type(fd0) << 4) | cmos_get_fd_drive_type(fd1);
    rtc_set_memory(s, 0x10, val);
    
    val = 0;
    nb = 0;
    if (fd0 < 3)
        nb++;
    if (fd1 < 3)
        nb++;
    switch (nb) {
    case 0:
        break;
    case 1:
        val |= 0x01; /* 1 drive, ready for boot */
        break;
    case 2:
        val |= 0x41; /* 2 drives, ready for boot */
        break;
    }
    val |= 0x02; /* FPU is there */
    val |= 0x04; /* PS/2 mouse installed */
    rtc_set_memory(s, REG_EQUIPMENT_BYTE, val);

    /* hard drives */

    rtc_set_memory(s, 0x12, (hd_table[0] ? 0xf0 : 0) | (hd_table[1] ? 0x0f : 0));
    if (hd_table[0])
        cmos_init_hd(0x19, 0x1b, hd_table[0]);
    if (hd_table[1]) 
        cmos_init_hd(0x1a, 0x24, hd_table[1]);

    val = 0;
    for (i = 0; i < 4; i++) {
        if (hd_table[i]) {
            int cylinders, heads, sectors, translation;
            /* NOTE: bdrv_get_geometry_hint() returns the physical
                geometry.  It is always such that: 1 <= sects <= 63, 1
                <= heads <= 16, 1 <= cylinders <= 16383. The BIOS
                geometry can be different if a translation is done. */
            translation = bdrv_get_translation_hint(hd_table[i]);
            if (translation == BIOS_ATA_TRANSLATION_AUTO) {
                bdrv_get_geometry_hint(hd_table[i], &cylinders, &heads, &sectors);
                if (cylinders <= 1024 && heads <= 16 && sectors <= 63) {
                    /* No translation. */
                    translation = 0;
                } else {
                    /* LBA translation. */
                    translation = 1;
                }
            } else {
                translation--;
            }
            val |= translation << (i * 2);
        }
    }
    rtc_set_memory(s, 0x39, val);

    /* Disable check of 0x55AA signature on the last two bytes of
       first sector of disk. XXX: make it the default ? */
    //    rtc_set_memory(s, 0x38, 1);
}

void ioport_set_a20(int enable)
{
    /* XXX: send to all CPUs ? */
    cpu_x86_set_a20(first_cpu, enable);
}

int ioport_get_a20(void)
{
    return ((first_cpu->a20_mask >> 20) & 1);
}

static void ioport92_write(void *opaque, uint32_t addr, uint32_t val)
{
    ioport_set_a20((val >> 1) & 1);
    /* XXX: bit 0 is fast reset */
}

static uint32_t ioport92_read(void *opaque, uint32_t addr)
{
    return ioport_get_a20() << 1;
}

/***********************************************************/
/* Bochs BIOS debug ports */

void bochs_bios_write(void *opaque, uint32_t addr, uint32_t val)
{
    static const char shutdown_str[8] = "Shutdown";
    static int shutdown_index = 0;
    
    switch(addr) {
        /* Bochs BIOS messages */
    case 0x400:
    case 0x401:
        fprintf(stderr, "BIOS panic at rombios.c, line %d\n", val);
        exit(1);
    case 0x402:
    case 0x403:
#ifdef DEBUG_BIOS
        fprintf(stderr, "%c", val);
#endif
        break;
    case 0x8900:
        /* same as Bochs power off */
        if (val == shutdown_str[shutdown_index]) {
            shutdown_index++;
            if (shutdown_index == 8) {
                shutdown_index = 0;
                qemu_system_shutdown_request();
            }
        } else {
            shutdown_index = 0;
        }
        break;

        /* LGPL'ed VGA BIOS messages */
    case 0x501:
    case 0x502:
        fprintf(stderr, "VGA BIOS panic, line %d\n", val);
        exit(1);
    case 0x500:
    case 0x503:
#ifdef DEBUG_BIOS
        fprintf(stderr, "%c", val);
#endif
        break;
    }
}

void bochs_bios_init(void)
{
    register_ioport_write(0x400, 1, 2, bochs_bios_write, NULL);
    register_ioport_write(0x401, 1, 2, bochs_bios_write, NULL);
    register_ioport_write(0x402, 1, 1, bochs_bios_write, NULL);
    register_ioport_write(0x403, 1, 1, bochs_bios_write, NULL);
    register_ioport_write(0x8900, 1, 1, bochs_bios_write, NULL);

    register_ioport_write(0x501, 1, 2, bochs_bios_write, NULL);
    register_ioport_write(0x502, 1, 2, bochs_bios_write, NULL);
    register_ioport_write(0x500, 1, 1, bochs_bios_write, NULL);
    register_ioport_write(0x503, 1, 1, bochs_bios_write, NULL);
}


int load_kernel(const char *filename, uint8_t *addr, 
                uint8_t *real_addr)
{
    int fd, size;
    int setup_sects;

    fd = open(filename, O_RDONLY | O_BINARY);
    if (fd < 0)
        return -1;

    /* load 16 bit code */
    if (read(fd, real_addr, 512) != 512)
        goto fail;
    setup_sects = real_addr[0x1F1];
    if (!setup_sects)
        setup_sects = 4;
    if (read(fd, real_addr + 512, setup_sects * 512) != 
        setup_sects * 512)
        goto fail;
    
    /* load 32 bit code */
    size = read(fd, addr, 16 * 1024 * 1024);
    if (size < 0)
        goto fail;
    close(fd);
    return size;
 fail:
    close(fd);
    return -1;
}

static void main_cpu_reset(void *opaque)
{
    CPUState *env = opaque;
    cpu_reset(env);
}

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

static void putb(uint8_t **pp, int val)
{
    uint8_t *q;
    q = *pp;
    *q++ = val;
    *pp = q;
}

static void putstr(uint8_t **pp, const char *str)
{
    uint8_t *q;
    q = *pp;
    while (*str)
        *q++ = *str++;
    *pp = q;
}

static void putle16(uint8_t **pp, int val)
{
    uint8_t *q;
    q = *pp;
    *q++ = val;
    *q++ = val >> 8;
    *pp = q;
}

static void putle32(uint8_t **pp, int val)
{
    uint8_t *q;
    q = *pp;
    *q++ = val;
    *q++ = val >> 8;
    *q++ = val >> 16;
    *q++ = val >> 24;
    *pp = q;
}

static int mpf_checksum(const uint8_t *data, int len)
{
    int sum, i;
    sum = 0;
    for(i = 0; i < len; i++)
        sum += data[i];
    return sum & 0xff;
}