Archipelago » qemu

/*

 * QEMU PPC PREP hardware System Emulator

 *

 * Copyright (c) 2003-2007 Jocelyn Mayer

 *

 * 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 "hw.h"

#include "nvram.h"

#include "pc.h"

#include "fdc.h"

#include "net.h"

#include "sysemu.h"

#include "isa.h"

#include "pci.h"

#include "pci_host.h"

#include "ppc.h"

#include "boards.h"

#include "qemu-log.h"

#include "ide.h"

#include "loader.h"

#include "mc146818rtc.h"

#include "blockdev.h"

#include "arch_init.h"

#include "exec-memory.h"

//#define HARD_DEBUG_PPC_IO

//#define DEBUG_PPC_IO

/* SMP is not enabled, for now */

#define MAX_CPUS 1

#define MAX_IDE_BUS 2

#define BIOS_SIZE (1024 * 1024)

#define BIOS_FILENAME "ppc_rom.bin"

#define KERNEL_LOAD_ADDR 0x01000000

#define INITRD_LOAD_ADDR 0x01800000

#if defined (HARD_DEBUG_PPC_IO) && !defined (DEBUG_PPC_IO)

#define DEBUG_PPC_IO

#endif

#if defined (HARD_DEBUG_PPC_IO)

#define PPC_IO_DPRINTF(fmt, ...)                         \

do {                                                     \

    if (qemu_loglevel_mask(CPU_LOG_IOPORT)) {            \

        qemu_log("%s: " fmt, __func__ , ## __VA_ARGS__); \

    } else {                                             \

        printf("%s : " fmt, __func__ , ## __VA_ARGS__);  \

    }                                                    \

} while (0)

#elif defined (DEBUG_PPC_IO)

#define PPC_IO_DPRINTF(fmt, ...) \

qemu_log_mask(CPU_LOG_IOPORT, fmt, ## __VA_ARGS__)

#else

#define PPC_IO_DPRINTF(fmt, ...) do { } while (0)

#endif

/* Constants for devices init */

static const int ide_iobase[2] = { 0x1f0, 0x170 };

static const int ide_iobase2[2] = { 0x3f6, 0x376 };

static const int ide_irq[2] = { 13, 13 };

#define NE2000_NB_MAX 6

static uint32_t ne2000_io[NE2000_NB_MAX] = { 0x300, 0x320, 0x340, 0x360, 0x280, 0x380 };

static int ne2000_irq[NE2000_NB_MAX] = { 9, 10, 11, 3, 4, 5 };

/* ISA IO ports bridge */

#define PPC_IO_BASE 0x80000000

/* PowerPC control and status registers */

#if 0 // Not used

static struct {

    /* IDs */

    uint32_t veni_devi;

    uint32_t revi;

    /* Control and status */

    uint32_t gcsr;

    uint32_t xcfr;

    uint32_t ct32;

    uint32_t mcsr;

    /* General purpose registers */

    uint32_t gprg[6];

    /* Exceptions */

    uint32_t feen;

    uint32_t fest;

    uint32_t fema;

    uint32_t fecl;

    uint32_t eeen;

    uint32_t eest;

    uint32_t eecl;

    uint32_t eeint;

    uint32_t eemck0;

    uint32_t eemck1;

    /* Error diagnostic */

} XCSR;

static void PPC_XCSR_writeb (void *opaque,

                             target_phys_addr_t addr, uint32_t value)

{

    printf("%s: 0x" TARGET_FMT_plx " => 0x%08" PRIx32 "\n", __func__, addr,

           value);

}

static void PPC_XCSR_writew (void *opaque,

                             target_phys_addr_t addr, uint32_t value)

{

    printf("%s: 0x" TARGET_FMT_plx " => 0x%08" PRIx32 "\n", __func__, addr,

           value);

}

static void PPC_XCSR_writel (void *opaque,

                             target_phys_addr_t addr, uint32_t value)

{

    printf("%s: 0x" TARGET_FMT_plx " => 0x%08" PRIx32 "\n", __func__, addr,

           value);

}

static uint32_t PPC_XCSR_readb (void *opaque, target_phys_addr_t addr)

{

    uint32_t retval = 0;

    printf("%s: 0x" TARGET_FMT_plx " <= %08" PRIx32 "\n", __func__, addr,

           retval);

    return retval;

}

static uint32_t PPC_XCSR_readw (void *opaque, target_phys_addr_t addr)

{

    uint32_t retval = 0;

    printf("%s: 0x" TARGET_FMT_plx " <= %08" PRIx32 "\n", __func__, addr,

           retval);

    return retval;

}

static uint32_t PPC_XCSR_readl (void *opaque, target_phys_addr_t addr)

{

    uint32_t retval = 0;

    printf("%s: 0x" TARGET_FMT_plx " <= %08" PRIx32 "\n", __func__, addr,

           retval);

    return retval;

}

static const MemoryRegionOps PPC_XCSR_ops = {

    .old_mmio = {

        .read = { PPC_XCSR_readb, PPC_XCSR_readw, PPC_XCSR_readl, },

        .write = { PPC_XCSR_writeb, PPC_XCSR_writew, PPC_XCSR_writel, },

    },

    .endianness = DEVICE_LITTLE_ENDIAN,

};

#endif

/* Fake super-io ports for PREP platform (Intel 82378ZB) */

typedef struct sysctrl_t {

    qemu_irq reset_irq;

    M48t59State *nvram;

    uint8_t state;

    uint8_t syscontrol;

    uint8_t fake_io[2];

    int contiguous_map;

    int endian;

} sysctrl_t;

enum {

    STATE_HARDFILE = 0x01,

};

static sysctrl_t *sysctrl;

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

{

    sysctrl_t *sysctrl = opaque;

    PPC_IO_DPRINTF("0x%08" PRIx32 " => 0x%02" PRIx32 "\n", addr - PPC_IO_BASE,

                   val);

    sysctrl->fake_io[addr - 0x0398] = val;

}

static uint32_t PREP_io_read (void *opaque, uint32_t addr)

{

    sysctrl_t *sysctrl = opaque;

    PPC_IO_DPRINTF("0x%08" PRIx32 " <= 0x%02" PRIx32 "\n", addr - PPC_IO_BASE,

                   sysctrl->fake_io[addr - 0x0398]);

    return sysctrl->fake_io[addr - 0x0398];

}

static void PREP_io_800_writeb (void *opaque, uint32_t addr, uint32_t val)

{

    sysctrl_t *sysctrl = opaque;

    PPC_IO_DPRINTF("0x%08" PRIx32 " => 0x%02" PRIx32 "\n",

                   addr - PPC_IO_BASE, val);

    switch (addr) {

    case 0x0092:

        /* Special port 92 */

        /* Check soft reset asked */

        if (val & 0x01) {

            qemu_irq_raise(sysctrl->reset_irq);

        } else {

            qemu_irq_lower(sysctrl->reset_irq);

        }

        /* Check LE mode */

        if (val & 0x02) {

            sysctrl->endian = 1;

        } else {

            sysctrl->endian = 0;

        }

        break;

    case 0x0800:

        /* Motorola CPU configuration register : read-only */

        break;

    case 0x0802:

        /* Motorola base module feature register : read-only */

        break;

    case 0x0803:

        /* Motorola base module status register : read-only */

        break;

    case 0x0808:

        /* Hardfile light register */

        if (val & 1)

            sysctrl->state |= STATE_HARDFILE;

        else

            sysctrl->state &= ~STATE_HARDFILE;

        break;

    case 0x0810:

        /* Password protect 1 register */

        if (sysctrl->nvram != NULL)

            m48t59_toggle_lock(sysctrl->nvram, 1);

        break;

    case 0x0812:

        /* Password protect 2 register */

        if (sysctrl->nvram != NULL)

            m48t59_toggle_lock(sysctrl->nvram, 2);

        break;

    case 0x0814:

        /* L2 invalidate register */

        //        tlb_flush(first_cpu, 1);

        break;

    case 0x081C:

        /* system control register */

        sysctrl->syscontrol = val & 0x0F;

        break;

    case 0x0850:

        /* I/O map type register */

        sysctrl->contiguous_map = val & 0x01;

        break;

    default:

        printf("ERROR: unaffected IO port write: %04" PRIx32

               " => %02" PRIx32"\n", addr, val);

        break;

    }

}

static uint32_t PREP_io_800_readb (void *opaque, uint32_t addr)

{

    sysctrl_t *sysctrl = opaque;

    uint32_t retval = 0xFF;

    switch (addr) {

    case 0x0092:

        /* Special port 92 */

        retval = 0x00;

        break;

    case 0x0800:

        /* Motorola CPU configuration register */

        retval = 0xEF; /* MPC750 */

        break;

    case 0x0802:

        /* Motorola Base module feature register */

        retval = 0xAD; /* No ESCC, PMC slot neither ethernet */

        break;

    case 0x0803:

        /* Motorola base module status register */

        retval = 0xE0; /* Standard MPC750 */

        break;

    case 0x080C:

        /* Equipment present register:

         *  no L2 cache

         *  no upgrade processor

         *  no cards in PCI slots

         *  SCSI fuse is bad

         */

        retval = 0x3C;

        break;

    case 0x0810:

        /* Motorola base module extended feature register */

        retval = 0x39; /* No USB, CF and PCI bridge. NVRAM present */

        break;

    case 0x0814:

        /* L2 invalidate: don't care */

        break;

    case 0x0818:

        /* Keylock */

        retval = 0x00;

        break;

    case 0x081C:

        /* system control register

         * 7 - 6 / 1 - 0: L2 cache enable

         */

        retval = sysctrl->syscontrol;

        break;

    case 0x0823:

        /* */

        retval = 0x03; /* no L2 cache */

        break;

    case 0x0850:

        /* I/O map type register */

        retval = sysctrl->contiguous_map;

        break;

    default:

        printf("ERROR: unaffected IO port: %04" PRIx32 " read\n", addr);

        break;

    }

    PPC_IO_DPRINTF("0x%08" PRIx32 " <= 0x%02" PRIx32 "\n",

                   addr - PPC_IO_BASE, retval);

    return retval;

}

static inline target_phys_addr_t prep_IO_address(sysctrl_t *sysctrl,

                                                 target_phys_addr_t addr)

{

    if (sysctrl->contiguous_map == 0) {

        /* 64 KB contiguous space for IOs */

        addr &= 0xFFFF;

    } else {

        /* 8 MB non-contiguous space for IOs */

        addr = (addr & 0x1F) | ((addr & 0x007FFF000) >> 7);

    }

    return addr;

}

static void PPC_prep_io_writeb (void *opaque, target_phys_addr_t addr,

                                uint32_t value)

{

    sysctrl_t *sysctrl = opaque;

    addr = prep_IO_address(sysctrl, addr);

    cpu_outb(addr, value);

}

static uint32_t PPC_prep_io_readb (void *opaque, target_phys_addr_t addr)

{

    sysctrl_t *sysctrl = opaque;

    uint32_t ret;

    addr = prep_IO_address(sysctrl, addr);

    ret = cpu_inb(addr);

    return ret;

}

static void PPC_prep_io_writew (void *opaque, target_phys_addr_t addr,

                                uint32_t value)

{

    sysctrl_t *sysctrl = opaque;

    addr = prep_IO_address(sysctrl, addr);

    PPC_IO_DPRINTF("0x" TARGET_FMT_plx " => 0x%08" PRIx32 "\n", addr, value);

    cpu_outw(addr, value);

}

static uint32_t PPC_prep_io_readw (void *opaque, target_phys_addr_t addr)

{

    sysctrl_t *sysctrl = opaque;

    uint32_t ret;

    addr = prep_IO_address(sysctrl, addr);

    ret = cpu_inw(addr);

    PPC_IO_DPRINTF("0x" TARGET_FMT_plx " <= 0x%08" PRIx32 "\n", addr, ret);

    return ret;

}

static void PPC_prep_io_writel (void *opaque, target_phys_addr_t addr,

                                uint32_t value)

{

    sysctrl_t *sysctrl = opaque;

    addr = prep_IO_address(sysctrl, addr);

    PPC_IO_DPRINTF("0x" TARGET_FMT_plx " => 0x%08" PRIx32 "\n", addr, value);

    cpu_outl(addr, value);

}

static uint32_t PPC_prep_io_readl (void *opaque, target_phys_addr_t addr)

{

    sysctrl_t *sysctrl = opaque;

    uint32_t ret;

    addr = prep_IO_address(sysctrl, addr);

    ret = cpu_inl(addr);

    PPC_IO_DPRINTF("0x" TARGET_FMT_plx " <= 0x%08" PRIx32 "\n", addr, ret);

    return ret;

}

static const MemoryRegionOps PPC_prep_io_ops = {

    .old_mmio = {

        .read = { PPC_prep_io_readb, PPC_prep_io_readw, PPC_prep_io_readl },

        .write = { PPC_prep_io_writeb, PPC_prep_io_writew, PPC_prep_io_writel },

    },

    .endianness = DEVICE_LITTLE_ENDIAN,

};

#define NVRAM_SIZE        0x2000

static void cpu_request_exit(void *opaque, int irq, int level)

{

    CPUPPCState *env = cpu_single_env;

    if (env && level) {

        cpu_exit(env);

    }

}

static void ppc_prep_reset(void *opaque)

{

    PowerPCCPU *cpu = opaque;

    cpu_reset(CPU(cpu));

}

/* PowerPC PREP hardware initialisation */

static void ppc_prep_init (ram_addr_t ram_size,

                           const char *boot_device,

                           const char *kernel_filename,

                           const char *kernel_cmdline,

                           const char *initrd_filename,

                           const char *cpu_model)

{

    MemoryRegion *sysmem = get_system_memory();

    PowerPCCPU *cpu = NULL;

    CPUPPCState *env = NULL;

    char *filename;

    nvram_t nvram;

    M48t59State *m48t59;

    MemoryRegion *PPC_io_memory = g_new(MemoryRegion, 1);

#if 0

    MemoryRegion *xcsr = g_new(MemoryRegion, 1);

#endif

    int linux_boot, i, nb_nics1, bios_size;

    MemoryRegion *ram = g_new(MemoryRegion, 1);

    MemoryRegion *bios = g_new(MemoryRegion, 1);

    uint32_t kernel_base, initrd_base;

    long kernel_size, initrd_size;

    DeviceState *dev;

    PCIHostState *pcihost;

    PCIBus *pci_bus;

    PCIDevice *pci;

    ISABus *isa_bus;

    qemu_irq *cpu_exit_irq;

    int ppc_boot_device;

    DriveInfo *hd[MAX_IDE_BUS * MAX_IDE_DEVS];

    DriveInfo *fd[MAX_FD];

    sysctrl = g_malloc0(sizeof(sysctrl_t));

    linux_boot = (kernel_filename != NULL);

    /* init CPUs */

    if (cpu_model == NULL)

        cpu_model = "602";

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

        cpu = cpu_ppc_init(cpu_model);

        if (cpu == NULL) {

            fprintf(stderr, "Unable to find PowerPC CPU definition\n");

            exit(1);

        }

        env = &cpu->env;

        if (env->flags & POWERPC_FLAG_RTC_CLK) {

            /* POWER / PowerPC 601 RTC clock frequency is 7.8125 MHz */

            cpu_ppc_tb_init(env, 7812500UL);

        } else {

            /* Set time-base frequency to 100 Mhz */

            cpu_ppc_tb_init(env, 100UL * 1000UL * 1000UL);

        }

        qemu_register_reset(ppc_prep_reset, cpu);

    }

    /* allocate RAM */

    memory_region_init_ram(ram, "ppc_prep.ram", ram_size);

    vmstate_register_ram_global(ram);

    memory_region_add_subregion(sysmem, 0, ram);

    /* allocate and load BIOS */

    memory_region_init_ram(bios, "ppc_prep.bios", BIOS_SIZE);

    memory_region_set_readonly(bios, true);

    memory_region_add_subregion(sysmem, (uint32_t)(-BIOS_SIZE), bios);

    vmstate_register_ram_global(bios);

    if (bios_name == NULL)

        bios_name = BIOS_FILENAME;

    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);

    if (filename) {

        bios_size = get_image_size(filename);

    } else {

        bios_size = -1;

    }

    if (bios_size > 0 && bios_size <= BIOS_SIZE) {

        target_phys_addr_t bios_addr;

        bios_size = (bios_size + 0xfff) & ~0xfff;

        bios_addr = (uint32_t)(-bios_size);

        bios_size = load_image_targphys(filename, bios_addr, bios_size);

    }

    if (bios_size < 0 || bios_size > BIOS_SIZE) {

        hw_error("qemu: could not load PPC PREP bios '%s'\n", bios_name);

    }

    if (filename) {

        g_free(filename);

    }

    if (linux_boot) {

        kernel_base = KERNEL_LOAD_ADDR;

        /* now we can load the kernel */

        kernel_size = load_image_targphys(kernel_filename, kernel_base,

                                          ram_size - kernel_base);

        if (kernel_size < 0) {

            hw_error("qemu: could not load kernel '%s'\n", kernel_filename);

            exit(1);

        }

        /* load initrd */

        if (initrd_filename) {

            initrd_base = INITRD_LOAD_ADDR;

            initrd_size = load_image_targphys(initrd_filename, initrd_base,

                                              ram_size - initrd_base);

            if (initrd_size < 0) {

                hw_error("qemu: could not load initial ram disk '%s'\n",

                          initrd_filename);

            }

        } else {

            initrd_base = 0;

            initrd_size = 0;

        }

        ppc_boot_device = 'm';

    } else {

        kernel_base = 0;

        kernel_size = 0;

        initrd_base = 0;

        initrd_size = 0;

        ppc_boot_device = '\0';

        /* For now, OHW cannot boot from the network. */

        for (i = 0; boot_device[i] != '\0'; i++) {

            if (boot_device[i] >= 'a' && boot_device[i] <= 'f') {

                ppc_boot_device = boot_device[i];

                break;

            }

        }

        if (ppc_boot_device == '\0') {

            fprintf(stderr, "No valid boot device for Mac99 machine\n");

            exit(1);

        }

    }

    if (PPC_INPUT(env) != PPC_FLAGS_INPUT_6xx) {

        hw_error("Only 6xx bus is supported on PREP machine\n");

    }

    dev = qdev_create(NULL, "raven-pcihost");

    pcihost = PCI_HOST_BRIDGE(dev);

    pcihost->address_space = get_system_memory();

    object_property_add_child(qdev_get_machine(), "raven", OBJECT(dev), NULL);

    qdev_init_nofail(dev);

    pci_bus = (PCIBus *)qdev_get_child_bus(dev, "pci.0");

    if (pci_bus == NULL) {

        fprintf(stderr, "Couldn't create PCI host controller.\n");

        exit(1);

    }

    /* PCI -> ISA bridge */

    pci = pci_create_simple(pci_bus, PCI_DEVFN(1, 0), "i82378");

    cpu_exit_irq = qemu_allocate_irqs(cpu_request_exit, NULL, 1);

    qdev_connect_gpio_out(&pci->qdev, 0,

                          first_cpu->irq_inputs[PPC6xx_INPUT_INT]);

    qdev_connect_gpio_out(&pci->qdev, 1, *cpu_exit_irq);

    sysbus_connect_irq(&pcihost->busdev, 0, qdev_get_gpio_in(&pci->qdev, 9));

    sysbus_connect_irq(&pcihost->busdev, 1, qdev_get_gpio_in(&pci->qdev, 11));

    sysbus_connect_irq(&pcihost->busdev, 2, qdev_get_gpio_in(&pci->qdev, 9));

    sysbus_connect_irq(&pcihost->busdev, 3, qdev_get_gpio_in(&pci->qdev, 11));

    isa_bus = DO_UPCAST(ISABus, qbus, qdev_get_child_bus(&pci->qdev, "isa.0"));

    /* Register 8 MB of ISA IO space (needed for non-contiguous map) */

    memory_region_init_io(PPC_io_memory, &PPC_prep_io_ops, sysctrl,

                          "ppc-io", 0x00800000);

    memory_region_add_subregion(sysmem, 0x80000000, PPC_io_memory);

    /* init basic PC hardware */

    pci_vga_init(pci_bus);

    if (serial_hds[0])

        serial_isa_init(isa_bus, 0, serial_hds[0]);

    nb_nics1 = nb_nics;

    if (nb_nics1 > NE2000_NB_MAX)

        nb_nics1 = NE2000_NB_MAX;

    for(i = 0; i < nb_nics1; i++) {

        if (nd_table[i].model == NULL) {

            nd_table[i].model = g_strdup("ne2k_isa");

        }

        if (strcmp(nd_table[i].model, "ne2k_isa") == 0) {

            isa_ne2000_init(isa_bus, ne2000_io[i], ne2000_irq[i],

                            &nd_table[i]);

        } else {

            pci_nic_init_nofail(&nd_table[i], "ne2k_pci", NULL);

        }

    }

    ide_drive_get(hd, MAX_IDE_BUS);

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

        isa_ide_init(isa_bus, ide_iobase[i], ide_iobase2[i], ide_irq[i],

                     hd[2 * i],

                     hd[2 * i + 1]);

    }

    isa_create_simple(isa_bus, "i8042");

    //    SB16_init();

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

        fd[i] = drive_get(IF_FLOPPY, 0, i);

    }

    fdctrl_init_isa(isa_bus, fd);

    /* Register fake IO ports for PREP */

    sysctrl->reset_irq = first_cpu->irq_inputs[PPC6xx_INPUT_HRESET];

    register_ioport_read(0x398, 2, 1, &PREP_io_read, sysctrl);

    register_ioport_write(0x398, 2, 1, &PREP_io_write, sysctrl);

    /* System control ports */

    register_ioport_read(0x0092, 0x01, 1, &PREP_io_800_readb, sysctrl);

    register_ioport_write(0x0092, 0x01, 1, &PREP_io_800_writeb, sysctrl);

    register_ioport_read(0x0800, 0x52, 1, &PREP_io_800_readb, sysctrl);

    register_ioport_write(0x0800, 0x52, 1, &PREP_io_800_writeb, sysctrl);

    /* PowerPC control and status register group */

#if 0

    memory_region_init_io(xcsr, &PPC_XCSR_ops, NULL, "ppc-xcsr", 0x1000);

    memory_region_add_subregion(sysmem, 0xFEFF0000, xcsr);

#endif

    if (usb_enabled) {

        pci_create_simple(pci_bus, -1, "pci-ohci");

    }

    m48t59 = m48t59_init_isa(isa_bus, 0x0074, NVRAM_SIZE, 59);

    if (m48t59 == NULL)

        return;

    sysctrl->nvram = m48t59;

    /* Initialise NVRAM */

    nvram.opaque = m48t59;

    nvram.read_fn = &m48t59_read;

    nvram.write_fn = &m48t59_write;

    PPC_NVRAM_set_params(&nvram, NVRAM_SIZE, "PREP", ram_size, ppc_boot_device,

                         kernel_base, kernel_size,

                         kernel_cmdline,

                         initrd_base, initrd_size,

                         /* XXX: need an option to load a NVRAM image */

                         0,

                         graphic_width, graphic_height, graphic_depth);

    /* Special port to get debug messages from Open-Firmware */

    register_ioport_write(0x0F00, 4, 1, &PPC_debug_write, NULL);

    /* Initialize audio subsystem */

    audio_init(isa_bus, pci_bus);

}

static QEMUMachine prep_machine = {

    .name = "prep",

    .desc = "PowerPC PREP platform",

    .init = ppc_prep_init,

    .max_cpus = MAX_CPUS,

};

static void prep_machine_init(void)

{

    qemu_register_machine(&prep_machine);

}

machine_init(prep_machine_init);