Archipelago » qemu

/*

 * QEMU PPC PREP hardware System Emulator

 * 

 * Copyright (c) 2003-2004 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 "vl.h"

#include "m48t59.h"

/* XXX: move all TB related stuff in ppc_prep.c and suppress ppc.c ? */

ppc_tb_t *cpu_ppc_tb_init (CPUPPCState *env, uint32_t freq);

//#define HARD_DEBUG_PPC_IO

//#define DEBUG_PPC_IO

extern int loglevel;

extern FILE *logfile;

#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, args...)                     \

do {                                                     \

    if (loglevel > 0) {                                  \

        fprintf(logfile, "%s: " fmt, __func__ , ##args); \

    } else {                                             \

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

    }                                                    \

} while (0)

#elif defined (DEBUG_PPC_IO)

#define PPC_IO_DPRINTF(fmt, args...)                     \

do {                                                     \

    if (loglevel > 0) {                                  \

        fprintf(logfile, "%s: " fmt, __func__ , ##args); \

    }                                                    \

} while (0)

#else

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

#endif

#define BIOS_FILENAME "ppc_rom.bin"

#define KERNEL_LOAD_ADDR    0x00000000

#define KERNEL_STACK_ADDR   0x00400000

#define INITRD_LOAD_ADDR    0x00800000

int load_kernel(const char *filename, uint8_t *addr, 

                uint8_t *real_addr)

{

    int fd, size;

    int setup_sects;

    fd = open(filename, O_RDONLY);

    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 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 };

/* IO ports emulation */

#define PPC_IO_BASE 0x80000000

static void PPC_io_writeb (target_phys_addr_t addr, uint32_t value)

{

    /* Don't polute serial port output */

#if 0

    if ((addr < 0x800003F0 || addr > 0x80000400) &&

        (addr < 0x80000074 || addr > 0x80000077) &&

        (addr < 0x80000020 || addr > 0x80000021) &&

        (addr < 0x800000a0 || addr > 0x800000a1) &&

        (addr < 0x800001f0 || addr > 0x800001f7) &&

        (addr < 0x80000170 || addr > 0x80000177)) 

#endif

    {

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

    }

    cpu_outb(NULL, addr - PPC_IO_BASE, value);

}

static uint32_t PPC_io_readb (target_phys_addr_t addr)

{

    uint32_t ret = cpu_inb(NULL, addr - PPC_IO_BASE);

#if 0

    if ((addr < 0x800003F0 || addr > 0x80000400) &&

        (addr < 0x80000074 || addr > 0x80000077) &&

        (addr < 0x80000020 || addr > 0x80000021) &&

        (addr < 0x800000a0 || addr > 0x800000a1) &&

        (addr < 0x800001f0 || addr > 0x800001f7) &&

        (addr < 0x80000170 || addr > 0x80000177) &&

        (addr < 0x8000060 || addr > 0x8000064))

#endif

    {

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

    }

    return ret;

}

static void PPC_io_writew (target_phys_addr_t addr, uint32_t value)

{

    if ((addr < 0x800001f0 || addr > 0x800001f7) &&

        (addr < 0x80000170 || addr > 0x80000177)) {

        PPC_IO_DPRINTF("0x%08x => 0x%04x\n", addr - PPC_IO_BASE, value);

    }

#ifdef TARGET_WORDS_BIGENDIAN

    value = bswap16(value);

#endif

    cpu_outw(NULL, addr - PPC_IO_BASE, value);

}

static uint32_t PPC_io_readw (target_phys_addr_t addr)

{

    uint32_t ret = cpu_inw(NULL, addr - PPC_IO_BASE);

#ifdef TARGET_WORDS_BIGENDIAN

    ret = bswap16(ret);

#endif

    if ((addr < 0x800001f0 || addr > 0x800001f7) &&

        (addr < 0x80000170 || addr > 0x80000177)) {

        PPC_IO_DPRINTF("0x%08x <= 0x%04x\n", addr - PPC_IO_BASE, ret);

    }

    return ret;

}

static void PPC_io_writel (target_phys_addr_t addr, uint32_t value)

{

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

#ifdef TARGET_WORDS_BIGENDIAN

    value = bswap32(value);

#endif

    cpu_outl(NULL, addr - PPC_IO_BASE, value);

}

static uint32_t PPC_io_readl (target_phys_addr_t addr)

{

    uint32_t ret = cpu_inl(NULL, addr - PPC_IO_BASE);

#ifdef TARGET_WORDS_BIGENDIAN

    ret = bswap32(ret);

#endif

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

    return ret;

}

static CPUWriteMemoryFunc *PPC_io_write[] = {

    &PPC_io_writeb,

    &PPC_io_writew,

    &PPC_io_writel,

};

static CPUReadMemoryFunc *PPC_io_read[] = {

    &PPC_io_readb,

    &PPC_io_readw,

    &PPC_io_readl,

};

/* Read-only register (?) */

static void _PPC_ioB_write (target_phys_addr_t addr, uint32_t value)

{

    //    printf("%s: 0x%08x => 0x%08x\n", __func__, addr, value);

}

static uint32_t _PPC_ioB_read (target_phys_addr_t addr)

{

    uint32_t retval = 0;

    if (addr == 0xBFFFFFF0)

        retval = pic_intack_read(NULL);

       //   printf("%s: 0x%08x <= %d\n", __func__, addr, retval);

    return retval;

}

static CPUWriteMemoryFunc *PPC_ioB_write[] = {

    &_PPC_ioB_write,

    &_PPC_ioB_write,

    &_PPC_ioB_write,

};

static CPUReadMemoryFunc *PPC_ioB_read[] = {

    &_PPC_ioB_read,

    &_PPC_ioB_read,

    &_PPC_ioB_read,

};

#if 0

static CPUWriteMemoryFunc *PPC_io3_write[] = {

    &PPC_io3_writeb,

    &PPC_io3_writew,

    &PPC_io3_writel,

};

static CPUReadMemoryFunc *PPC_io3_read[] = {

    &PPC_io3_readb,

    &PPC_io3_readw,

    &PPC_io3_readl,

};

#endif

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

static uint8_t PREP_fake_io[2];

static uint8_t NVRAM_lock;

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

{

    PPC_IO_DPRINTF("0x%08x => 0x%08x\n", addr - PPC_IO_BASE, val);

    PREP_fake_io[addr - 0x0398] = val;

}

static uint32_t PREP_io_read (void *opaque, uint32_t addr)

{

    PPC_IO_DPRINTF("0x%08x <= 0x%08x\n", addr - PPC_IO_BASE, PREP_fake_io[addr - 0x0398]);

    return PREP_fake_io[addr - 0x0398];

}

static uint8_t syscontrol;

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

{

    PPC_IO_DPRINTF("0x%08x => 0x%08x\n", addr - PPC_IO_BASE, val);

    switch (addr) {

    case 0x0092:

        /* Special port 92 */

        /* Check soft reset asked */

        if (val & 0x80) {

            printf("Soft reset asked... Stop emulation\n");

            abort();

        }

        /* Check LE mode */

        if (val & 0x40) {

            printf("Little Endian mode isn't supported (yet ?)\n");

            abort();

        }

        break;

    case 0x0808:

        /* Hardfile light register: don't care */

        break;

    case 0x0810:

        /* Password protect 1 register */

        NVRAM_lock ^= 0x01;

        break;

    case 0x0812:

        /* Password protect 2 register */

        NVRAM_lock ^= 0x02;

        break;

    case 0x0814:

        /* L2 invalidate register: don't care */

        break;

    case 0x081C:

        /* system control register */

        syscontrol = val;

        break;

    case 0x0850:

        /* I/O map type register */

        if (val & 0x80) {

            printf("No support for non-continuous I/O map mode\n");

            abort();

        }

        break;

    default:

        break;

    }

}

static uint32_t PREP_io_800_readb (void *opaque, uint32_t addr)

{

    uint32_t retval = 0xFF;

    switch (addr) {

    case 0x0092:

        /* Special port 92 */

        retval = 0x40;

        break;

    case 0x080C:

        /* Equipment present register:

         *  no L2 cache

         *  no upgrade processor

         *  no cards in PCI slots

         *  SCSI fuse is bad

         */

        retval = 0xFC;

        break;

    case 0x0818:

        /* Keylock */

        retval = 0x00;

        break;

    case 0x081C:

        /* system control register

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

         */

        retval = syscontrol;

        break;

    case 0x0823:

        /* */

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

        break;

    case 0x0850:

        /* I/O map type register */

        retval = 0x00;

        break;

    default:

        break;

    }

    PPC_IO_DPRINTF("0x%08x <= 0x%08x\n", addr - PPC_IO_BASE, retval);

    return retval;

}

#define NVRAM_SIZE        0x2000

#define NVRAM_END         0x1FF0

#define NVRAM_OSAREA_SIZE 512

#define NVRAM_CONFSIZE    1024

static inline void NVRAM_set_byte (m48t59_t *nvram, uint32_t addr, uint8_t value)

{

    m48t59_set_addr(nvram, addr);

    m48t59_write(nvram, value);

}

static inline uint8_t NVRAM_get_byte (m48t59_t *nvram, uint32_t addr)

{

    m48t59_set_addr(nvram, addr);

    return m48t59_read(nvram);

}

static inline void NVRAM_set_word (m48t59_t *nvram, uint32_t addr, uint16_t value)

{

    m48t59_set_addr(nvram, addr);

    m48t59_write(nvram, value >> 8);

    m48t59_set_addr(nvram, addr + 1);

    m48t59_write(nvram, value & 0xFF);

}

static inline uint16_t NVRAM_get_word (m48t59_t *nvram, uint32_t addr)

{

    uint16_t tmp;

    m48t59_set_addr(nvram, addr);

    tmp = m48t59_read(nvram) << 8;

    m48t59_set_addr(nvram, addr + 1);

    tmp |= m48t59_read(nvram);

    return tmp;

}

static inline void NVRAM_set_lword (m48t59_t *nvram, uint32_t addr,

                                    uint32_t value)

{

    m48t59_set_addr(nvram, addr);

    m48t59_write(nvram, value >> 24);

    m48t59_set_addr(nvram, addr + 1);

    m48t59_write(nvram, (value >> 16) & 0xFF);

    m48t59_set_addr(nvram, addr + 2);

    m48t59_write(nvram, (value >> 8) & 0xFF);

    m48t59_set_addr(nvram, addr + 3);

    m48t59_write(nvram, value & 0xFF);

}

static inline uint32_t NVRAM_get_lword (m48t59_t *nvram, uint32_t addr)

{

    uint32_t tmp;

    m48t59_set_addr(nvram, addr);

    tmp = m48t59_read(nvram) << 24;

    m48t59_set_addr(nvram, addr + 1);

    tmp |= m48t59_read(nvram) << 16;

    m48t59_set_addr(nvram, addr + 2);

    tmp |= m48t59_read(nvram) << 8;

    m48t59_set_addr(nvram, addr + 3);

    tmp |= m48t59_read(nvram);

    return tmp;

}

static uint16_t NVRAM_crc_update (uint16_t prev, uint16_t value)

{

    uint16_t tmp;

    uint16_t pd, pd1, pd2;

    tmp = prev >> 8;

    pd = prev ^ value;

    pd1 = pd & 0x000F;

    pd2 = ((pd >> 4) & 0x000F) ^ pd1;

    tmp ^= (pd1 << 3) | (pd1 << 8);

    tmp ^= pd2 | (pd2 << 7) | (pd2 << 12);

    return tmp;

}

static void NVRAM_set_crc (m48t59_t *nvram, uint32_t addr,

                           uint32_t start, uint32_t count)

{

    uint32_t i;

    uint16_t crc = 0xFFFF;

    int odd = 0;

    if (count & 1)

        odd = 1;

    count &= ~1;

    for (i = 0; i != count; i++) {

        crc = NVRAM_crc_update(crc, NVRAM_get_word(nvram, start + i));

    }

    if (odd) {

        crc = NVRAM_crc_update(crc, NVRAM_get_byte(nvram, start + i) << 8);

    }

    NVRAM_set_word(nvram, addr, crc);

}

static void prep_NVRAM_init (void)

{

    m48t59_t *nvram;

    nvram = m48t59_init(8, 0x0074, NVRAM_SIZE);

    /* NVRAM header */

    /* 0x00: NVRAM size in kB */

    NVRAM_set_word(nvram, 0x00, NVRAM_SIZE >> 10);

    /* 0x02: NVRAM version */

    NVRAM_set_byte(nvram, 0x02, 0x01);

    /* 0x03: NVRAM revision */

    NVRAM_set_byte(nvram, 0x03, 0x01);

    /* 0x08: last OS */

    NVRAM_set_byte(nvram, 0x08, 0x00); /* Unknown */

    /* 0x09: endian */

    NVRAM_set_byte(nvram, 0x09, 'B');  /* Big-endian */

    /* 0x0A: OSArea usage */

    NVRAM_set_byte(nvram, 0x0A, 0x00); /* Empty */

    /* 0x0B: PM mode */

    NVRAM_set_byte(nvram, 0x0B, 0x00); /* Normal */

    /* Restart block description record */

    /* 0x0C: restart block version */

    NVRAM_set_word(nvram, 0x0C, 0x01);

    /* 0x0E: restart block revision */

    NVRAM_set_word(nvram, 0x0E, 0x01);

    /* 0x20: restart address */

    NVRAM_set_lword(nvram, 0x20, 0x00);

    /* 0x24: save area address */

    NVRAM_set_lword(nvram, 0x24, 0x00);

    /* 0x28: save area length */

    NVRAM_set_lword(nvram, 0x28, 0x00);

    /* 0x1C: checksum of restart block */

    NVRAM_set_crc(nvram, 0x1C, 0x0C, 32);

    /* Security section */

    /* Set all to zero */

    /* 0xC4: pointer to global environment area */

    NVRAM_set_lword(nvram, 0xC4, 0x0100);

    /* 0xC8: size of global environment area */

    NVRAM_set_lword(nvram, 0xC8,

                    NVRAM_END - NVRAM_OSAREA_SIZE - NVRAM_CONFSIZE - 0x0100);

    /* 0xD4: pointer to configuration area */

    NVRAM_set_lword(nvram, 0xD4, NVRAM_END - NVRAM_CONFSIZE);

    /* 0xD8: size of configuration area */

    NVRAM_set_lword(nvram, 0xD8, NVRAM_CONFSIZE);

    /* 0xE8: pointer to OS specific area */

    NVRAM_set_lword(nvram, 0xE8,

                    NVRAM_END - NVRAM_CONFSIZE - NVRAM_OSAREA_SIZE);

    /* 0xD8: size of OS specific area */

    NVRAM_set_lword(nvram, 0xEC, NVRAM_OSAREA_SIZE);

    /* Configuration area */

    /* RTC init */

    //    NVRAM_set_lword(nvram, 0x1FFC, 0x50);

    /* 0x04: checksum 0 => OS area   */

    NVRAM_set_crc(nvram, 0x04, 0x00,

                  NVRAM_END - NVRAM_CONFSIZE - NVRAM_OSAREA_SIZE);

    /* 0x06: checksum of config area */

    NVRAM_set_crc(nvram, 0x06, NVRAM_END - NVRAM_CONFSIZE, NVRAM_CONFSIZE);

}

int load_initrd (const char *filename, uint8_t *addr)

{

    int fd, size;

    printf("Load initrd\n");

    fd = open(filename, O_RDONLY);

    if (fd < 0)

        return -1;

    size = read(fd, addr, 16 * 1024 * 1024);

    if (size < 0)

        goto fail;

    close(fd);

    printf("Load initrd: %d\n", size);

    return size;

 fail:

    close(fd);

    printf("Load initrd failed\n");

    return -1;

}

/* Quick hack for PPC memory infos... */

static void put_long (void *addr, uint32_t l)

{

    char *pos = addr;

    pos[0] = (l >> 24) & 0xFF;

    pos[1] = (l >> 16) & 0xFF;

    pos[2] = (l >> 8) & 0xFF;

    pos[3] = l & 0xFF;

}

/* bootloader infos are in the form:

 * uint32_t TAG

 * uint32_t TAG_size (from TAG to next TAG).

 * data

 * ....

 */

#if !defined (USE_OPEN_FIRMWARE)

static void *set_bootinfo_tag (void *addr, uint32_t tag, uint32_t size,

                               void *data)

{

    char *pos = addr;

    put_long(pos, tag);

    pos += 4;

    put_long(pos, size + 8);

    pos += 4;

    memcpy(pos, data, size);

    pos += size;

    return pos;

}

#endif

typedef struct boot_dev_t {

    const unsigned char *name;

    int major;

    int minor;

} boot_dev_t;

static boot_dev_t boot_devs[] = 

{

    { "/dev/fd0", 2, 0, },

    { "/dev/fd1", 2, 1, },

    { "/dev/hda", 3, 1, },

//    { "/dev/ide/host0/bus0/target0/lun0/part1", 3, 1, },

//    { "/dev/hdc", 22, 0, },

    { "/dev/hdc", 22, 1, },

    { "/dev/ram0 init=/linuxrc", 1, 0, },

};

/* BATU:

 * BEPI  : bloc virtual address

 * BL    : area size bits (128 kB is 0, 256 1, 512 3, ...

 * Vs/Vp

 * BATL:

 * BPRN  : bloc real address align on 4MB boundary

 * WIMG  : cache access mode : not used

 * PP    : protection bits

 */

static void setup_BAT (CPUPPCState *env, int BAT,

                       uint32_t virtual, uint32_t physical,

                       uint32_t size, int Vs, int Vp, int PP)

{

    uint32_t sz_bits, tmp_sz, align, tmp;

    sz_bits = 0;

    align = 131072;

    for (tmp_sz = size / 131072; tmp_sz != 1; tmp_sz = tmp_sz >> 1) {

        sz_bits = (sz_bits << 1) + 1;

        align = align << 1;

    }

    tmp = virtual & ~(align - 1);  /* Align virtual area start */

    tmp |= sz_bits << 2;           /* Fix BAT size             */

    tmp |= Vs << 1;                /* Supervisor access        */

    tmp |= Vp;                     /* User access              */

    env->DBAT[0][BAT] = tmp;

    env->IBAT[0][BAT] = tmp;

    tmp = physical & ~(align - 1); /* Align physical area start */

    tmp |= 0;                      /* Don't care about WIMG     */

    tmp |= PP;                     /* Protection                */

    env->DBAT[1][BAT] = tmp;

    env->IBAT[1][BAT] = tmp;

    printf("Set BATU0 to 0x%08x BATL0 to 0x%08x\n",

           env->DBAT[0][BAT], env->DBAT[1][BAT]);

}

static void VGA_printf (uint8_t *s)

{

    uint16_t *arg_ptr;

    unsigned int format_width, i;

    int in_format;

    uint16_t arg, digit, nibble;

    uint8_t c;

    arg_ptr = (uint16_t *)((void *)&s);

    in_format = 0;

    format_width = 0;

    while ((c = *s) != '\0') {

        if (c == '%') {

            in_format = 1;

            format_width = 0;

        } else if (in_format) {

            if ((c >= '0') && (c <= '9')) {

                format_width = (format_width * 10) + (c - '0');

            } else if (c == 'x') {

                arg_ptr++; // increment to next arg

                arg = *arg_ptr;

                if (format_width == 0)

                    format_width = 4;

                digit = format_width - 1;

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

                    nibble = (arg >> (4 * digit)) & 0x000f;

                    if (nibble <= 9)

                        PPC_io_writeb(PPC_IO_BASE + 0x500, nibble + '0');

                    else

                        PPC_io_writeb(PPC_IO_BASE + 0x500, nibble + 'A');

                    digit--;

                }

                in_format = 0;

            }

            //else if (c == 'd') {

            //  in_format = 0;

            //  }

        } else {

            PPC_io_writeb(PPC_IO_BASE + 0x500, c);

        }

        s++;

    }

}

static void VGA_init (void)

{

    /* Basic VGA init, inspired by plex86 VGAbios */

#if 1

    /* switch to color mode and enable CPU access 480 lines */

    PPC_io_writeb(PPC_IO_BASE + 0x3C2, 0xC3);

    /* more than 64k 3C4/04 */

    PPC_io_writeb(PPC_IO_BASE + 0x3C4, 0x04);

    PPC_io_writeb(PPC_IO_BASE + 0x3C5, 0x02);

#endif

    VGA_printf("PPC VGA BIOS...\n");

}

extern CPUPPCState *global_env;

static uint32_t get_le32 (void *addr)

{

    return le32_to_cpu(*((uint32_t *)addr));

}

void PPC_init_hw (/*CPUPPCState *env,*/ uint32_t mem_size,

                  uint32_t kernel_addr, uint32_t kernel_size,

                  uint32_t stack_addr, int boot_device,

                  const unsigned char *initrd_file)

{

    CPUPPCState *env = global_env;

    uint8_t *p;

#if !defined (USE_OPEN_FIRMWARE)

    char *tmp;

    uint32_t tmpi[2];

#endif

    printf("RAM size: %u 0x%08x (%u)\n", mem_size, mem_size, mem_size >> 20);

#if defined (USE_OPEN_FIRMWARE)

    setup_memory(env, mem_size);

#endif

    /* Fake bootloader */

    {

#if 1

        uint32_t offset = get_le32(phys_ram_base + kernel_addr);

#else

        uint32_t offset = 12;

#endif

        env->nip = kernel_addr + offset;

        printf("Start address: 0x%08x\n", env->nip);

    }

    /* Set up msr according to PREP specification */

    msr_ee = 0;

    msr_fp = 1;

    msr_pr = 0; /* Start in supervisor mode */

    msr_me = 1;

    msr_fe0 = msr_fe1 = 0;

    msr_ip = 0;

    msr_ir = msr_dr = 1;

//    msr_sf = 0;

    msr_le = msr_ile = 0;

    env->gpr[1] = stack_addr; /* Let's have a stack */

    env->gpr[2] = 0;

    env->gpr[8] = kernel_addr;

    /* There is a bug in  2.4 kernels:

     * if a decrementer exception is pending when it enables msr_ee,

     * it's not ready to handle it...

     */

    p = phys_ram_base + kernel_addr;

#if !defined (USE_OPEN_FIRMWARE)

    /* Let's register the whole memory available only in supervisor mode */

    setup_BAT(env, 0, 0x00000000, 0x00000000, mem_size, 1, 0, 2);

    /* Avoid open firmware init call (to get a console)

     * This will make the kernel think we are a PREP machine...

     */

    put_long(p, 0xdeadc0de);

    /* Build a real stack room */

    p = phys_ram_base + stack_addr;

    put_long(p, stack_addr);

    p -= 32;

    env->gpr[1] -= 32;

    /* Pretend there are no residual data */

    env->gpr[3] = 0;

    if (initrd_file != NULL) {

        int size;

        env->gpr[4] = (kernel_addr + kernel_size + 4095) & ~4095;

        size = load_initrd(initrd_file,

                           phys_ram_base + env->gpr[4]);

        if (size < 0) {

            /* No initrd */

            env->gpr[4] = env->gpr[5] = 0;

        } else {

            env->gpr[5] = size;

            boot_device = 'e';

        }

        printf("Initrd loaded at 0x%08x (%d) (0x%08x 0x%08x)\n",

               env->gpr[4], env->gpr[5], kernel_addr, kernel_size);

    } else {

        env->gpr[4] = env->gpr[5] = 0;

    }

    /* We have to put bootinfos after the BSS

     * The BSS starts after the kernel end.

     */

#if 0

    p = phys_ram_base + kernel_addr +

        kernel_size + (1 << 20) - 1) & ~((1 << 20) - 1);

#else

    p = phys_ram_base + kernel_addr + 0x400000;

#endif

    if (loglevel > 0) {

        fprintf(logfile, "bootinfos: %p 0x%08x\n",

                p, (int)(p - phys_ram_base));

    } else {

        printf("bootinfos: %p 0x%08x\n",

               p, (int)(p - phys_ram_base));

    }

    /* Command line: let's put it after bootinfos */

#if 0

    sprintf(p + 0x1000, "console=ttyS0,9600 root=%02x%02x mem=%dM",

            boot_devs[boot_device - 'a'].major,

            boot_devs[boot_device - 'a'].minor,

            mem_size >> 20);

#else

    sprintf(p + 0x1000, "console=ttyS0,9600 console=tty0 root=%s mem=%dM",

            boot_devs[boot_device - 'a'].name,

            mem_size >> 20);

#endif

    env->gpr[6] = p + 0x1000 - phys_ram_base;

    env->gpr[7] = env->gpr[6] + strlen(p + 0x1000);

    if (loglevel > 0) {

        fprintf(logfile, "cmdline: %p 0x%08x [%s]\n",

                p + 0x1000, env->gpr[6], p + 0x1000);

    } else {

        printf("cmdline: %p 0x%08x [%s]\n",

               p + 0x1000, env->gpr[6], p + 0x1000);

    }

    /* BI_FIRST */

    p = set_bootinfo_tag(p, 0x1010, 0, 0);

    /* BI_CMD_LINE */

    p = set_bootinfo_tag(p, 0x1012, env->gpr[7] - env->gpr[6],

                         env->gpr[6] + phys_ram_base);

    /* BI_MEM_SIZE */

    tmp = (void *)tmpi;

    tmp[0] = (mem_size >> 24) & 0xFF;

    tmp[1] = (mem_size >> 16) & 0xFF;

    tmp[2] = (mem_size >> 8) & 0xFF;

    tmp[3] = mem_size & 0xFF;

    p = set_bootinfo_tag(p, 0x1017, 4, tmpi);

    /* BI_INITRD */

    tmp[0] = (env->gpr[4] >> 24) & 0xFF;

    tmp[1] = (env->gpr[4] >> 16) & 0xFF;

    tmp[2] = (env->gpr[4] >> 8) & 0xFF;

    tmp[3] = env->gpr[4] & 0xFF;

    tmp[4] = (env->gpr[5] >> 24) & 0xFF;

    tmp[5] = (env->gpr[5] >> 16) & 0xFF;

    tmp[6] = (env->gpr[5] >> 8) & 0xFF;

    tmp[7] = env->gpr[5] & 0xFF;

    p = set_bootinfo_tag(p, 0x1014, 8, tmpi);

    env->gpr[4] = env->gpr[5] = 0;

    /* BI_LAST */

    p = set_bootinfo_tag(p, 0x1011, 0, 0);

#else

    /* Set up MMU:

     * kernel is loaded at kernel_addr and wants to be seen at 0x01000000

     */

    setup_BAT(env, 0, 0x01000000, kernel_addr, 0x00400000, 1, 0, 2);

    {

#if 0

        uint32_t offset = get_le32(phys_ram_base + kernel_addr);

#else

        uint32_t offset = 12;

#endif

        env->nip = 0x01000000 | (kernel_addr + offset);

        printf("Start address: 0x%08x\n", env->nip);

    }

    env->gpr[1] = env->nip + (1 << 22);

    p = phys_ram_base + stack_addr;

    put_long(p - 32, stack_addr);

    env->gpr[1] -= 32;

    printf("Kernel starts at 0x%08x stack 0x%08x\n", env->nip, env->gpr[1]);

    /* We want all lower address not to be translated */

    setup_BAT(env, 1, 0x00000000, 0x00000000, 0x010000000, 1, 1, 2);

    /* We also need a BAT to access OF */

    setup_BAT(env, 2, 0xFFFE0000, mem_size - 131072, 131072, 1, 0, 1);

    /* Setup OF entry point */

    {

        char *p;

        p = (char *)phys_ram_base + mem_size - 131072;

        /* Special opcode to call OF */

        *p++ = 0x18; *p++ = 0x00; *p++ = 0x00; *p++ = 0x02;

        /* blr */

        *p++ = 0x4E; *p++ = 0x80; *p++ = 0x00; *p++ = 0x20;

    }

    env->gpr[5] = 0xFFFE0000;

    /* Register translations */

    {

        OF_transl_t translations[3] = {