src/BeOS/main_beos.cpp

/*
 *  main_beos.cpp - Startup code for BeOS
 *
 *  Basilisk II (C) 1997-2000 Christian Bauer
 *
 *  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) 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, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <AppKit.h>
#include <InterfaceKit.h>
#include <KernelKit.h>
#include <StorageKit.h>

#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#include "sysdeps.h"
#include "cpu_emulation.h"
#include "xpram.h"
#include "timer.h"
#include "video.h"
#include "rom_patches.h"
#include "prefs.h"
#include "prefs_editor.h"
#include "sys.h"
#include "user_strings.h"
#include "version.h"
#include "main.h"

#include "sheep_driver.h"

#define DEBUG 0
#include "debug.h"


// Constants
const char APP_SIGNATURE[] = "application/x-vnd.cebix-BasiliskII";
const char ROM_FILE_NAME[] = "ROM";
const char RAM_AREA_NAME[] = "Macintosh RAM";
const char ROM_AREA_NAME[] = "Macintosh ROM";
const uint32 MSG_START = 'strt';                        // Emulator start message
const uint32 ROM_AREA_SIZE = 0x500000;          // Enough to hold PowerMac ROM (for powerrom_cpu)

// Prototypes
#if __POWERPC__
static void sigsegv_handler(vregs *r);
#endif


// Application object
class BasiliskII : public BApplication {
public:
        BasiliskII() : BApplication(APP_SIGNATURE)
        {
                // Find application directory and cwd to it
                app_info the_info;
                GetAppInfo(&the_info);
                BEntry the_file(&the_info.ref);
                BEntry the_dir;
                the_file.GetParent(&the_dir);
                BPath the_path;
                the_dir.GetPath(&the_path);
                chdir(the_path.Path());

                // Initialize other variables
                rom_area = ram_area = -1;
                xpram_thread = tick_thread = -1;
                xpram_thread_active = true;
                tick_thread_active = true;
                AllowQuitting = true;
        }
        virtual void ReadyToRun(void);
        virtual void MessageReceived(BMessage *msg);
        void StartEmulator(void);
        virtual bool QuitRequested(void);
        virtual void Quit(void);

        thread_id xpram_thread;         // XPRAM watchdog
        thread_id tick_thread;          // 60Hz thread

        volatile bool xpram_thread_active;      // Flag for quitting the XPRAM thread
        volatile bool tick_thread_active;       // Flag for quitting the 60Hz thread

        bool AllowQuitting;                     // Flag: Alt-Q quitting allowed

private:
        static status_t emul_func(void *arg);
        static status_t tick_func(void *arg);
        static status_t xpram_func(void *arg);
        static void sigsegv_invoc(int sig, void *arg, vregs *r);

        void init_rom(void);
        void load_rom(void);

        area_id rom_area;               // ROM area ID
        area_id ram_area;               // RAM area ID

        struct sigaction sigsegv_action;        // Data access exception signal (of emulator thread)

        // Exceptions
        class area_error {};
        class file_open_error {};
        class file_read_error {};
        class rom_size_error {};
};

static BasiliskII *the_app;


// CPU and FPU type, addressing mode
int CPUType;
bool CPUIs68060;
int FPUType;
bool TwentyFourBitAddressing;


// Global variables for PowerROM CPU
thread_id emul_thread = -1;                     // Emulator thread

#if __POWERPC__
int sheep_fd = -1;                                      // fd of sheep driver
#endif


/*
 *  Create application object and start it
 */

int main(int argc, char **argv)
{       
        the_app = new BasiliskII();
        the_app->Run();
        delete the_app;
        return 0;
}


/*
 *  Run application
 */

void BasiliskII::ReadyToRun(void)
{
        // Initialize variables
        RAMBaseHost = NULL;
        ROMBaseHost = NULL;
        srand(real_time_clock());
        tzset();

        // Print some info
        printf(GetString(STR_ABOUT_TEXT1), VERSION_MAJOR, VERSION_MINOR);
        printf(" %s\n", GetString(STR_ABOUT_TEXT2));

        // Delete old areas
        area_id old_ram_area = find_area(RAM_AREA_NAME);
        if (old_ram_area > 0)
                delete_area(old_ram_area);
        area_id old_rom_area = find_area(ROM_AREA_NAME);
        if (old_rom_area > 0)
                delete_area(old_rom_area);

        // Read preferences
        PrefsInit(0, NULL);

        // Init system routines
        SysInit();

        // Show preferences editor (or start emulator directly)
        if (!PrefsFindBool("nogui"))
                PrefsEditor();
        else
                PostMessage(MSG_START);
}


/*
 *  Message received
 */

void BasiliskII::MessageReceived(BMessage *msg)
{
        switch (msg->what) {
                case MSG_START:
                        StartEmulator();
                        break;
                default:
                        BApplication::MessageReceived(msg);
        }
}


/*
 *  Start emulator
 */

void BasiliskII::StartEmulator(void)
{
        char str[256];

#if REAL_ADDRESSING
        // Open sheep driver and remap low memory
        sheep_fd = open("/dev/sheep", 0);
        if (sheep_fd < 0) {
                sprintf(str, GetString(STR_NO_SHEEP_DRIVER_ERR), strerror(sheep_fd), sheep_fd);
                ErrorAlert(str);
                PostMessage(B_QUIT_REQUESTED);
                return;
        }
        status_t res = ioctl(sheep_fd, SHEEP_UP);
        if (res < 0) {
                sprintf(str, GetString(STR_SHEEP_UP_ERR), strerror(res), res);
                ErrorAlert(str);
                PostMessage(B_QUIT_REQUESTED);
                return;
        }
#endif

        // Create area for Mac RAM
        RAMSize = PrefsFindInt32("ramsize") & 0xfff00000;       // Round down to 1MB boundary
        if (RAMSize < 1024*1024) {
                WarningAlert(GetString(STR_SMALL_RAM_WARN));
                RAMSize = 1024*1024;
        }

        RAMBaseHost = (uint8 *)0x10000000;
        ram_area = create_area(RAM_AREA_NAME, (void **)&RAMBaseHost, B_BASE_ADDRESS, RAMSize, B_NO_LOCK, B_READ_AREA | B_WRITE_AREA);
        if (ram_area < 0) {
                ErrorAlert(GetString(STR_NO_RAM_AREA_ERR));
                PostMessage(B_QUIT_REQUESTED);
                return;
        }
        D(bug("RAM area %ld at %p\n", ram_area, RAMBaseHost));

        // Create area and load Mac ROM
        try {
                init_rom();
        } catch (area_error) {
                ErrorAlert(GetString(STR_NO_ROM_AREA_ERR));
                PostMessage(B_QUIT_REQUESTED);
                return;
        } catch (file_open_error) {
                ErrorAlert(GetString(STR_NO_ROM_FILE_ERR));
                PostMessage(B_QUIT_REQUESTED);
                return;
        } catch (file_read_error) {
                ErrorAlert(GetString(STR_ROM_FILE_READ_ERR));
                PostMessage(B_QUIT_REQUESTED);
                return;
        } catch (rom_size_error) {
                ErrorAlert(GetString(STR_ROM_SIZE_ERR));
                PostMessage(B_QUIT_REQUESTED);
                return;
        }

        // Initialize everything
        if (!InitAll()) {
                PostMessage(B_QUIT_REQUESTED);
                return;
        }

        // Write protect ROM
        set_area_protection(rom_area, B_READ_AREA);

        // Disallow quitting with Alt-Q from now on
        AllowQuitting = false;

        // Start XPRAM watchdog thread
        xpram_thread = spawn_thread(xpram_func, "XPRAM Watchdog", B_LOW_PRIORITY, this);
        resume_thread(xpram_thread);

        // Start 60Hz interrupt
        tick_thread = spawn_thread(tick_func, "60Hz", B_REAL_TIME_PRIORITY, this);
        resume_thread(tick_thread);

        // Start emulator thread
        emul_thread = spawn_thread(emul_func, "MacOS", B_NORMAL_PRIORITY, this);
        resume_thread(emul_thread);
}


/*
 *  Quit emulator
 */

void QuitEmulator(void)
{
        the_app->AllowQuitting = true;
        be_app->PostMessage(B_QUIT_REQUESTED);
        exit_thread(0);
}

bool BasiliskII::QuitRequested(void)
{
        if (AllowQuitting)
                return BApplication::QuitRequested();
        else
                return false;
}

void BasiliskII::Quit(void)
{
        status_t l;

        // Stop 60Hz interrupt
        if (tick_thread > 0) {
                tick_thread_active = false;
                wait_for_thread(tick_thread, &l);
        }

        // Wait for emulator thread to finish
        if (emul_thread > 0)
                wait_for_thread(emul_thread, &l);

        // Exit 680x0 emulation
        Exit680x0();

        // Stop XPRAM watchdog thread
        if (xpram_thread > 0) {
                xpram_thread_active = false;
                suspend_thread(xpram_thread);   // Wake thread up from snooze()
                snooze(1000);
                resume_thread(xpram_thread);
                wait_for_thread(xpram_thread, &l);
        }

        // Deinitialize everything
        ExitAll();

        // Delete ROM area
        if (rom_area >= 0)
                delete_area(rom_area);

        // Delete RAM area
        if (ram_area >= 0)
                delete_area(ram_area);

#if REAL_ADDRESSING
        // Unmap low memory and close memory mess driver
        if (sheep_fd >= 0) {
                ioctl(sheep_fd, SHEEP_DOWN);
                close(sheep_fd);
        }
#endif

        // Exit system routines
        SysExit();

        // Exit preferences
        PrefsExit();

        BApplication::Quit();
}


/*
 *  Create area for ROM (sets rom_area) and load ROM file
 *
 *  area_error     : Cannot create area
 *  file_open_error: Cannot open ROM file
 *  file_read_error: Cannot read ROM file
 */

void BasiliskII::init_rom(void)
{
        // Create area for ROM
        ROMBaseHost = (uint8 *)0x40800000;
        rom_area = create_area(ROM_AREA_NAME, (void **)&ROMBaseHost, B_BASE_ADDRESS, ROM_AREA_SIZE, B_NO_LOCK, B_READ_AREA | B_WRITE_AREA);
        if (rom_area < 0)
                throw area_error();
        D(bug("ROM area %ld at %p\n", rom_area, ROMBaseHost));

        // Load ROM
        load_rom();
}


/*
 *  Load ROM file
 *
 *  file_open_error: Cannot open ROM file
 *  file_read_error: Cannot read ROM file
 */

void BasiliskII::load_rom(void)
{
        // Get rom file path from preferences
        const char *rom_path = PrefsFindString("rom");

        // Try to open ROM file
        BFile file(rom_path ? rom_path : ROM_FILE_NAME, B_READ_ONLY);
        if (file.InitCheck() != B_NO_ERROR)
                throw file_open_error();

        printf(GetString(STR_READING_ROM_FILE));

        // Is the ROM size correct?
        off_t rom_size = 0;
        file.GetSize(&rom_size);
        if (rom_size != 64*1024 && rom_size != 128*1024 && rom_size != 256*1024 && rom_size != 512*1024 && rom_size != 1024*1024)
                throw rom_size_error();

        uint8 *rom = new uint8[rom_size];       // Reading directly into the area doesn't work
        ssize_t actual = file.Read((void *)rom, rom_size);
        if (actual == rom_size)
                memcpy(ROMBaseHost, rom, rom_size);
        delete[] rom;
        if (actual != rom_size)
                throw file_read_error();
        ROMSize = rom_size;
}


/*
 *  Emulator thread function
 */

status_t BasiliskII::emul_func(void *arg)
{
        BasiliskII *obj = (BasiliskII *)arg;

#if __POWERPC__
        // Install data access signal handler
        sigemptyset(&obj->sigsegv_action.sa_mask);
        obj->sigsegv_action.sa_handler = (__signal_func_ptr)(obj->sigsegv_invoc);
        obj->sigsegv_action.sa_flags = 0;
        obj->sigsegv_action.sa_userdata = arg;
        sigaction(SIGSEGV, &obj->sigsegv_action, NULL);
#endif

        // Exceptions will send signals
        disable_debugger(true);

        // Start 68k and jump to ROM boot routine
        Start680x0();

        // Quit program
        obj->AllowQuitting = true;
        be_app->PostMessage(B_QUIT_REQUESTED);
        return 0;
}


/*
 *  Code was patched, flush caches if neccessary (i.e. when using a real 680x0
 *  or a dynamically recompiling emulator)
 */

void FlushCodeCache(void *start, uint32 size)
{
}


/*
 *  Interrupt flags (must be handled atomically!)
 */

uint32 InterruptFlags = 0;

void SetInterruptFlag(uint32 flag)
{
        atomic_or((int32 *)&InterruptFlags, flag);
}

void ClearInterruptFlag(uint32 flag)
{
        atomic_and((int32 *)&InterruptFlags, ~flag);
}


/*
 *  60Hz thread (really 60.15Hz)
 */

status_t BasiliskII::tick_func(void *arg)
{
        BasiliskII *obj = (BasiliskII *)arg;
        int tick_counter = 0;
        bigtime_t current = system_time();

        while (obj->tick_thread_active) {

                // Wait
                current += 16625;
                snooze_until(current, B_SYSTEM_TIMEBASE);

                // Pseudo Mac 1Hz interrupt, update local time
                if (++tick_counter > 60) {
                        tick_counter = 0;
                        WriteMacInt32(0x20c, TimerDateTime());
                        SetInterruptFlag(INTFLAG_1HZ);
                        TriggerInterrupt();
                }

                // Trigger 60Hz interrupt
                SetInterruptFlag(INTFLAG_60HZ);
                TriggerInterrupt();
        }
        return 0;
}


/*
 *  XPRAM watchdog thread (saves XPRAM every minute)
 */

status_t BasiliskII::xpram_func(void *arg)
{
        uint8 last_xpram[256];
        memcpy(last_xpram, XPRAM, 256);

        while (((BasiliskII *)arg)->xpram_thread_active) {
                snooze(60*1000000);
                if (memcmp(last_xpram, XPRAM, 256)) {
                        memcpy(last_xpram, XPRAM, 256);
                        SaveXPRAM();
                }
        }
        return 0;
}


/*
 *  Display error alert
 */

void ErrorAlert(const char *text)
{
        if (PrefsFindBool("nogui")) {
                printf(GetString(STR_SHELL_ERROR_PREFIX), text);
                return;
        }
        VideoQuitFullScreen();
        char str[256];
        sprintf(str, GetString(STR_GUI_ERROR_PREFIX), text);
        BAlert *alert = new BAlert(GetString(STR_ERROR_ALERT_TITLE), str, GetString(STR_QUIT_BUTTON), NULL, NULL, B_WIDTH_AS_USUAL, B_STOP_ALERT);
        alert->Go();
}


/*
 *  Display warning alert
 */

void WarningAlert(const char *text)
{
        if (PrefsFindBool("nogui")) {
                printf(GetString(STR_SHELL_WARNING_PREFIX), text);
                return;
        }
        char str[256];
        sprintf(str, GetString(STR_GUI_WARNING_PREFIX), text);
        BAlert *alert = new BAlert(GetString(STR_WARNING_ALERT_TITLE), str, GetString(STR_OK_BUTTON), NULL, NULL, B_WIDTH_AS_USUAL, B_INFO_ALERT);
        alert->Go();
}


/*
 *  Display choice alert
 */

bool ChoiceAlert(const char *text, const char *pos, const char *neg)
{
        char str[256];
        sprintf(str, GetString(STR_GUI_WARNING_PREFIX), text);
        BAlert *alert = new BAlert(GetString(STR_WARNING_ALERT_TITLE), str, pos, neg, NULL, B_WIDTH_AS_USUAL, B_INFO_ALERT);
        return alert->Go() == 0;
}


/*
 *  SEGV handler
 */

#if __POWERPC__
static uint32 segv_r[32];

asm void BasiliskII::sigsegv_invoc(register int sig, register void *arg, register vregs *r)
{
        mflr    r0
        stw             r0,8(r1)
        stwu    r1,-56(r1)

        lwz             r3,segv_r(r2)
        stmw    r13,13*4(r3)

        mr              r3,r5
        bl              sigsegv_handler

        lwz             r3,segv_r(r2)
        lmw             r13,13*4(r3)

        lwz             r0,56+8(r1)
        mtlr    r0
        addi    r1,r1,56
        blr
}

static void sigsegv_handler(vregs *r)
{
        // Fetch volatile registers
        segv_r[0] = r->r0;
        segv_r[1] = r->r1;
        segv_r[2] = r->r2;
        segv_r[3] = r->r3;
        segv_r[4] = r->r4;
        segv_r[5] = r->r5;
        segv_r[6] = r->r6;
        segv_r[7] = r->r7;
        segv_r[8] = r->r8;
        segv_r[9] = r->r9;
        segv_r[10] = r->r10;
        segv_r[11] = r->r11;
        segv_r[12] = r->r12;

        // Get opcode and divide into fields
        uint32 opcode = *(uint32 *)r->pc;
        uint32 primop = opcode >> 26;
        uint32 exop = (opcode >> 1) & 0x3ff;
        uint32 ra = (opcode >> 16) & 0x1f;
        uint32 rb = (opcode >> 11) & 0x1f;
        uint32 rd = (opcode >> 21) & 0x1f;
        uint32 imm = opcode & 0xffff;

        // Analyze opcode
        enum {
                TYPE_UNKNOWN,
                TYPE_LOAD,
                TYPE_STORE
        } transfer_type = TYPE_UNKNOWN;
        enum {
                SIZE_UNKNOWN,
                SIZE_BYTE,
                SIZE_HALFWORD,
                SIZE_WORD
        } transfer_size = SIZE_UNKNOWN;
        enum {
                MODE_UNKNOWN,
                MODE_NORM,
                MODE_U,
                MODE_X,
                MODE_UX
        } addr_mode = MODE_UNKNOWN;
        switch (primop) {
                case 31:
                        switch (exop) {
                                case 23:        // lwzx
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
                                case 55:        // lwzux
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
                                case 87:        // lbzx
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
                                case 119:       // lbzux
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
                                case 151:       // stwx
                                        transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
                                case 183:       // stwux
                                        transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
                                case 215:       // stbx
                                        transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
                                case 247:       // stbux
                                        transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
                                case 279:       // lhzx
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_X; break;
                                case 311:       // lhzux
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_UX; break;
                                case 343:       // lhax
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_X; break;
                                case 375:       // lhaux
                                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_UX; break;
                                case 407:       // sthx
                                        transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_X; break;
                                case 439:       // sthux
                                        transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_UX; break;
                        }
                        break;

                case 32:        // lwz
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
                case 33:        // lwzu
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
                case 34:        // lbz
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
                case 35:        // lbzu
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
                case 36:        // stw
                        transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
                case 37:        // stwu
                        transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
                case 38:        // stb
                        transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
                case 39:        // stbu
                        transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
                case 40:        // lhz
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_NORM; break;
                case 41:        // lhzu
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_U; break;
                case 42:        // lha
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_NORM; break;
                case 43:        // lhau
                        transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_U; break;
                case 44:        // sth
                        transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_NORM; break;
                case 45:        // sthu
                        transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_U; break;
        }

        // Calculate effective address
        uint32 addr = 0;
        switch (addr_mode) {
                case MODE_X:
                case MODE_UX:
                        if (ra == 0)
                                addr = segv_r[rb];
                        else
                                addr = segv_r[ra] + segv_r[rb];
                        break;
                case MODE_NORM:
                case MODE_U:
                        if (ra == 0)
                                addr = (int32)(int16)imm;
                        else
                                addr = segv_r[ra] + (int32)(int16)imm;
                        break;
        }

        // Ignore ROM writes
        if (transfer_type == TYPE_STORE && addr >= (uint32)ROMBaseHost && addr < (uint32)ROMBaseHost + ROMSize) {
//              D(bug("WARNING: %s write access to ROM at %p, 68k pc %p\n", transfer_size == SIZE_BYTE ? "Byte" : transfer_size == SIZE_HALFWORD ? "Halfword" : "Word", addr, r->pc));
                if (addr_mode == MODE_U || addr_mode == MODE_UX)
                        segv_r[ra] = addr;
                r->pc += 4;
                goto rti;
        }

        // For all other errors, jump into debugger
        char str[256];
        sprintf(str, "SIGSEGV\n"
                "   pc %08lx     lr %08lx    ctr %08lx    msr %08lx\n"
                "  xer %08lx     cr %08lx  fpscr %08lx\n"
                "   r0 %08lx     r1 %08lx     r2 %08lx     r3 %08lx\n"
                "   r4 %08lx     r5 %08lx     r6 %08lx     r7 %08lx\n"
                "   r8 %08lx     r9 %08lx    r10 %08lx    r11 %08lx\n"
                "  r12 %08lx    r13 %08lx    r14 %08lx    r15 %08lx\n"
                "  r16 %08lx    r17 %08lx    r18 %08lx    r19 %08lx\n"
                "  r20 %08lx    r21 %08lx    r22 %08lx    r23 %08lx\n"
                "  r24 %08lx    r25 %08lx    r26 %08lx    r27 %08lx\n"
                "  r28 %08lx    r29 %08lx    r30 %08lx    r31 %08lx\n",
                r->pc, r->lr, r->ctr, r->msr,
                r->xer, r->cr, r->fpscr,
                r->r0, r->r1, r->r2, r->r3,
                r->r4, r->r5, r->r6, r->r7,
                r->r8, r->r9, r->r10, r->r11,
                r->r12, segv_r[13], segv_r[14], segv_r[15],
                segv_r[16], segv_r[17], segv_r[18], segv_r[19],
                segv_r[20], segv_r[21], segv_r[22], segv_r[23],
                segv_r[24], segv_r[25], segv_r[26], segv_r[27],
                segv_r[28], segv_r[29], segv_r[30], segv_r[31]);
        disable_debugger(false);
        debugger(str);
        QuitEmulator();
        return;

rti:
        // Restore volatile registers
        r->r0 = segv_r[0];
        r->r1 = segv_r[1];
        r->r2 = segv_r[2];
        r->r3 = segv_r[3];
        r->r4 = segv_r[4];
        r->r5 = segv_r[5];
        r->r6 = segv_r[6];
        r->r7 = segv_r[7];
        r->r8 = segv_r[8];
        r->r9 = segv_r[9];
        r->r10 = segv_r[10];
        r->r11 = segv_r[11];
        r->r12 = segv_r[12];
}
#endif
Revision:	1.6
Committed:	2001-01-04T19:50:22Z (23 years, 10 months ago) by cebix
Branch:	MAIN
Changes since 1.5:	+1 -1 lines
Log Message:	- removed the INT16 prefs item type; use INT32 instead - AmigaOS/Unix: it's now possible to specify preferences items on the command line - Unix: command line options now take "--"-prefix, e.g. "--rominfo"
#	Content
1	/*
2	* main_beos.cpp - Startup code for BeOS
3	*
4	* Basilisk II (C) 1997-2000 Christian Bauer
5	*
6	* This program is free software; you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation; either version 2 of the License, or
9	* (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19	*/
20
21	#include <AppKit.h>
22	#include <InterfaceKit.h>
23	#include <KernelKit.h>
24	#include <StorageKit.h>
25
26	#include <unistd.h>
27	#include <fcntl.h>
28	#include <signal.h>
29	#include <stdio.h>
30	#include <stdlib.h>
31	#include <time.h>
32
33	#include "sysdeps.h"
34	#include "cpu_emulation.h"
35	#include "xpram.h"
36	#include "timer.h"
37	#include "video.h"
38	#include "rom_patches.h"
39	#include "prefs.h"
40	#include "prefs_editor.h"
41	#include "sys.h"
42	#include "user_strings.h"
43	#include "version.h"
44	#include "main.h"
45
46	#include "sheep_driver.h"
47
48	#define DEBUG 0
49	#include "debug.h"
50
51
52	// Constants
53	const char APP_SIGNATURE[] = "application/x-vnd.cebix-BasiliskII";
54	const char ROM_FILE_NAME[] = "ROM";
55	const char RAM_AREA_NAME[] = "Macintosh RAM";
56	const char ROM_AREA_NAME[] = "Macintosh ROM";
57	const uint32 MSG_START = 'strt'; // Emulator start message
58	const uint32 ROM_AREA_SIZE = 0x500000; // Enough to hold PowerMac ROM (for powerrom_cpu)
59
60	// Prototypes
61	#if __POWERPC__
62	static void sigsegv_handler(vregs *r);
63	#endif
64
65
66	// Application object
67	class BasiliskII : public BApplication {
68	public:
69	BasiliskII() : BApplication(APP_SIGNATURE)
70	{
71	// Find application directory and cwd to it
72	app_info the_info;
73	GetAppInfo(&the_info);
74	BEntry the_file(&the_info.ref);
75	BEntry the_dir;
76	the_file.GetParent(&the_dir);
77	BPath the_path;
78	the_dir.GetPath(&the_path);
79	chdir(the_path.Path());
80
81	// Initialize other variables
82	rom_area = ram_area = -1;
83	xpram_thread = tick_thread = -1;
84	xpram_thread_active = true;
85	tick_thread_active = true;
86	AllowQuitting = true;
87	}
88	virtual void ReadyToRun(void);
89	virtual void MessageReceived(BMessage *msg);
90	void StartEmulator(void);
91	virtual bool QuitRequested(void);
92	virtual void Quit(void);
93
94	thread_id xpram_thread; // XPRAM watchdog
95	thread_id tick_thread; // 60Hz thread
96
97	volatile bool xpram_thread_active; // Flag for quitting the XPRAM thread
98	volatile bool tick_thread_active; // Flag for quitting the 60Hz thread
99
100	bool AllowQuitting; // Flag: Alt-Q quitting allowed
101
102	private:
103	static status_t emul_func(void *arg);
104	static status_t tick_func(void *arg);
105	static status_t xpram_func(void *arg);
106	static void sigsegv_invoc(int sig, void arg, vregs r);
107
108	void init_rom(void);
109	void load_rom(void);
110
111	area_id rom_area; // ROM area ID
112	area_id ram_area; // RAM area ID
113
114	struct sigaction sigsegv_action; // Data access exception signal (of emulator thread)
115
116	// Exceptions
117	class area_error {};
118	class file_open_error {};
119	class file_read_error {};
120	class rom_size_error {};
121	};
122
123	static BasiliskII *the_app;
124
125
126	// CPU and FPU type, addressing mode
127	int CPUType;
128	bool CPUIs68060;
129	int FPUType;
130	bool TwentyFourBitAddressing;
131
132
133	// Global variables for PowerROM CPU
134	thread_id emul_thread = -1; // Emulator thread
135
136	#if __POWERPC__
137	int sheep_fd = -1; // fd of sheep driver
138	#endif
139
140
141	/*
142	* Create application object and start it
143	*/
144
145	int main(int argc, char **argv)
146	{
147	the_app = new BasiliskII();
148	the_app->Run();
149	delete the_app;
150	return 0;
151	}
152
153
154	/*
155	* Run application
156	*/
157
158	void BasiliskII::ReadyToRun(void)
159	{
160	// Initialize variables
161	RAMBaseHost = NULL;
162	ROMBaseHost = NULL;
163	srand(real_time_clock());
164	tzset();
165
166	// Print some info
167	printf(GetString(STR_ABOUT_TEXT1), VERSION_MAJOR, VERSION_MINOR);
168	printf(" %s\n", GetString(STR_ABOUT_TEXT2));
169
170	// Delete old areas
171	area_id old_ram_area = find_area(RAM_AREA_NAME);
172	if (old_ram_area > 0)
173	delete_area(old_ram_area);
174	area_id old_rom_area = find_area(ROM_AREA_NAME);
175	if (old_rom_area > 0)
176	delete_area(old_rom_area);
177
178	// Read preferences
179	PrefsInit(0, NULL);
180
181	// Init system routines
182	SysInit();
183
184	// Show preferences editor (or start emulator directly)
185	if (!PrefsFindBool("nogui"))
186	PrefsEditor();
187	else
188	PostMessage(MSG_START);
189	}
190
191
192	/*
193	* Message received
194	*/
195
196	void BasiliskII::MessageReceived(BMessage *msg)
197	{
198	switch (msg->what) {
199	case MSG_START:
200	StartEmulator();
201	break;
202	default:
203	BApplication::MessageReceived(msg);
204	}
205	}
206
207
208	/*
209	* Start emulator
210	*/
211
212	void BasiliskII::StartEmulator(void)
213	{
214	char str[256];
215
216	#if REAL_ADDRESSING
217	// Open sheep driver and remap low memory
218	sheep_fd = open("/dev/sheep", 0);
219	if (sheep_fd < 0) {
220	sprintf(str, GetString(STR_NO_SHEEP_DRIVER_ERR), strerror(sheep_fd), sheep_fd);
221	ErrorAlert(str);
222	PostMessage(B_QUIT_REQUESTED);
223	return;
224	}
225	status_t res = ioctl(sheep_fd, SHEEP_UP);
226	if (res < 0) {
227	sprintf(str, GetString(STR_SHEEP_UP_ERR), strerror(res), res);
228	ErrorAlert(str);
229	PostMessage(B_QUIT_REQUESTED);
230	return;
231	}
232	#endif
233
234	// Create area for Mac RAM
235	RAMSize = PrefsFindInt32("ramsize") & 0xfff00000; // Round down to 1MB boundary
236	if (RAMSize < 1024*1024) {
237	WarningAlert(GetString(STR_SMALL_RAM_WARN));
238	RAMSize = 1024*1024;
239	}
240
241	RAMBaseHost = (uint8 *)0x10000000;
242	ram_area = create_area(RAM_AREA_NAME, (void **)&RAMBaseHost, B_BASE_ADDRESS, RAMSize, B_NO_LOCK, B_READ_AREA \| B_WRITE_AREA);
243	if (ram_area < 0) {
244	ErrorAlert(GetString(STR_NO_RAM_AREA_ERR));
245	PostMessage(B_QUIT_REQUESTED);
246	return;
247	}
248	D(bug("RAM area %ld at %p\n", ram_area, RAMBaseHost));
249
250	// Create area and load Mac ROM
251	try {
252	init_rom();
253	} catch (area_error) {
254	ErrorAlert(GetString(STR_NO_ROM_AREA_ERR));
255	PostMessage(B_QUIT_REQUESTED);
256	return;
257	} catch (file_open_error) {
258	ErrorAlert(GetString(STR_NO_ROM_FILE_ERR));
259	PostMessage(B_QUIT_REQUESTED);
260	return;
261	} catch (file_read_error) {
262	ErrorAlert(GetString(STR_ROM_FILE_READ_ERR));
263	PostMessage(B_QUIT_REQUESTED);
264	return;
265	} catch (rom_size_error) {
266	ErrorAlert(GetString(STR_ROM_SIZE_ERR));
267	PostMessage(B_QUIT_REQUESTED);
268	return;
269	}
270
271	// Initialize everything
272	if (!InitAll()) {
273	PostMessage(B_QUIT_REQUESTED);
274	return;
275	}
276
277	// Write protect ROM
278	set_area_protection(rom_area, B_READ_AREA);
279
280	// Disallow quitting with Alt-Q from now on
281	AllowQuitting = false;
282
283	// Start XPRAM watchdog thread
284	xpram_thread = spawn_thread(xpram_func, "XPRAM Watchdog", B_LOW_PRIORITY, this);
285	resume_thread(xpram_thread);
286
287	// Start 60Hz interrupt
288	tick_thread = spawn_thread(tick_func, "60Hz", B_REAL_TIME_PRIORITY, this);
289	resume_thread(tick_thread);
290
291	// Start emulator thread
292	emul_thread = spawn_thread(emul_func, "MacOS", B_NORMAL_PRIORITY, this);
293	resume_thread(emul_thread);
294	}
295
296
297	/*
298	* Quit emulator
299	*/
300
301	void QuitEmulator(void)
302	{
303	the_app->AllowQuitting = true;
304	be_app->PostMessage(B_QUIT_REQUESTED);
305	exit_thread(0);
306	}
307
308	bool BasiliskII::QuitRequested(void)
309	{
310	if (AllowQuitting)
311	return BApplication::QuitRequested();
312	else
313	return false;
314	}
315
316	void BasiliskII::Quit(void)
317	{
318	status_t l;
319
320	// Stop 60Hz interrupt
321	if (tick_thread > 0) {
322	tick_thread_active = false;
323	wait_for_thread(tick_thread, &l);
324	}
325
326	// Wait for emulator thread to finish
327	if (emul_thread > 0)
328	wait_for_thread(emul_thread, &l);
329
330	// Exit 680x0 emulation
331	Exit680x0();
332
333	// Stop XPRAM watchdog thread
334	if (xpram_thread > 0) {
335	xpram_thread_active = false;
336	suspend_thread(xpram_thread); // Wake thread up from snooze()
337	snooze(1000);
338	resume_thread(xpram_thread);
339	wait_for_thread(xpram_thread, &l);
340	}
341
342	// Deinitialize everything
343	ExitAll();
344
345	// Delete ROM area
346	if (rom_area >= 0)
347	delete_area(rom_area);
348
349	// Delete RAM area
350	if (ram_area >= 0)
351	delete_area(ram_area);
352
353	#if REAL_ADDRESSING
354	// Unmap low memory and close memory mess driver
355	if (sheep_fd >= 0) {
356	ioctl(sheep_fd, SHEEP_DOWN);
357	close(sheep_fd);
358	}
359	#endif
360
361	// Exit system routines
362	SysExit();
363
364	// Exit preferences
365	PrefsExit();
366
367	BApplication::Quit();
368	}
369
370
371	/*
372	* Create area for ROM (sets rom_area) and load ROM file
373	*
374	* area_error : Cannot create area
375	* file_open_error: Cannot open ROM file
376	* file_read_error: Cannot read ROM file
377	*/
378
379	void BasiliskII::init_rom(void)
380	{
381	// Create area for ROM
382	ROMBaseHost = (uint8 *)0x40800000;
383	rom_area = create_area(ROM_AREA_NAME, (void **)&ROMBaseHost, B_BASE_ADDRESS, ROM_AREA_SIZE, B_NO_LOCK, B_READ_AREA \| B_WRITE_AREA);
384	if (rom_area < 0)
385	throw area_error();
386	D(bug("ROM area %ld at %p\n", rom_area, ROMBaseHost));
387
388	// Load ROM
389	load_rom();
390	}
391
392
393	/*
394	* Load ROM file
395	*
396	* file_open_error: Cannot open ROM file
397	* file_read_error: Cannot read ROM file
398	*/
399
400	void BasiliskII::load_rom(void)
401	{
402	// Get rom file path from preferences
403	const char *rom_path = PrefsFindString("rom");
404
405	// Try to open ROM file
406	BFile file(rom_path ? rom_path : ROM_FILE_NAME, B_READ_ONLY);
407	if (file.InitCheck() != B_NO_ERROR)
408	throw file_open_error();
409
410	printf(GetString(STR_READING_ROM_FILE));
411
412	// Is the ROM size correct?
413	off_t rom_size = 0;
414	file.GetSize(&rom_size);
415	if (rom_size != 641024 && rom_size != 1281024 && rom_size != 2561024 && rom_size != 5121024 && rom_size != 1024*1024)
416	throw rom_size_error();
417
418	uint8 *rom = new uint8[rom_size]; // Reading directly into the area doesn't work
419	ssize_t actual = file.Read((void *)rom, rom_size);
420	if (actual == rom_size)
421	memcpy(ROMBaseHost, rom, rom_size);
422	delete[] rom;
423	if (actual != rom_size)
424	throw file_read_error();
425	ROMSize = rom_size;
426	}
427
428
429	/*
430	* Emulator thread function
431	*/
432
433	status_t BasiliskII::emul_func(void *arg)
434	{
435	BasiliskII obj = (BasiliskII )arg;
436
437	#if __POWERPC__
438	// Install data access signal handler
439	sigemptyset(&obj->sigsegv_action.sa_mask);
440	obj->sigsegv_action.sa_handler = (__signal_func_ptr)(obj->sigsegv_invoc);
441	obj->sigsegv_action.sa_flags = 0;
442	obj->sigsegv_action.sa_userdata = arg;
443	sigaction(SIGSEGV, &obj->sigsegv_action, NULL);
444	#endif
445
446	// Exceptions will send signals
447	disable_debugger(true);
448
449	// Start 68k and jump to ROM boot routine
450	Start680x0();
451
452	// Quit program
453	obj->AllowQuitting = true;
454	be_app->PostMessage(B_QUIT_REQUESTED);
455	return 0;
456	}
457
458
459	/*
460	* Code was patched, flush caches if neccessary (i.e. when using a real 680x0
461	* or a dynamically recompiling emulator)
462	*/
463
464	void FlushCodeCache(void *start, uint32 size)
465	{
466	}
467
468
469	/*
470	* Interrupt flags (must be handled atomically!)
471	*/
472
473	uint32 InterruptFlags = 0;
474
475	void SetInterruptFlag(uint32 flag)
476	{
477	atomic_or((int32 *)&InterruptFlags, flag);
478	}
479
480	void ClearInterruptFlag(uint32 flag)
481	{
482	atomic_and((int32 *)&InterruptFlags, ~flag);
483	}
484
485
486	/*
487	* 60Hz thread (really 60.15Hz)
488	*/
489
490	status_t BasiliskII::tick_func(void *arg)
491	{
492	BasiliskII obj = (BasiliskII )arg;
493	int tick_counter = 0;
494	bigtime_t current = system_time();
495
496	while (obj->tick_thread_active) {
497
498	// Wait
499	current += 16625;
500	snooze_until(current, B_SYSTEM_TIMEBASE);
501
502	// Pseudo Mac 1Hz interrupt, update local time
503	if (++tick_counter > 60) {
504	tick_counter = 0;
505	WriteMacInt32(0x20c, TimerDateTime());
506	SetInterruptFlag(INTFLAG_1HZ);
507	TriggerInterrupt();
508	}
509
510	// Trigger 60Hz interrupt
511	SetInterruptFlag(INTFLAG_60HZ);
512	TriggerInterrupt();
513	}
514	return 0;
515	}
516
517
518	/*
519	* XPRAM watchdog thread (saves XPRAM every minute)
520	*/
521
522	status_t BasiliskII::xpram_func(void *arg)
523	{
524	uint8 last_xpram[256];
525	memcpy(last_xpram, XPRAM, 256);
526
527	while (((BasiliskII *)arg)->xpram_thread_active) {
528	snooze(60*1000000);
529	if (memcmp(last_xpram, XPRAM, 256)) {
530	memcpy(last_xpram, XPRAM, 256);
531	SaveXPRAM();
532	}
533	}
534	return 0;
535	}
536
537
538	/*
539	* Display error alert
540	*/
541
542	void ErrorAlert(const char *text)
543	{
544	if (PrefsFindBool("nogui")) {
545	printf(GetString(STR_SHELL_ERROR_PREFIX), text);
546	return;
547	}
548	VideoQuitFullScreen();
549	char str[256];
550	sprintf(str, GetString(STR_GUI_ERROR_PREFIX), text);
551	BAlert *alert = new BAlert(GetString(STR_ERROR_ALERT_TITLE), str, GetString(STR_QUIT_BUTTON), NULL, NULL, B_WIDTH_AS_USUAL, B_STOP_ALERT);
552	alert->Go();
553	}
554
555
556	/*
557	* Display warning alert
558	*/
559
560	void WarningAlert(const char *text)
561	{
562	if (PrefsFindBool("nogui")) {
563	printf(GetString(STR_SHELL_WARNING_PREFIX), text);
564	return;
565	}
566	char str[256];
567	sprintf(str, GetString(STR_GUI_WARNING_PREFIX), text);
568	BAlert *alert = new BAlert(GetString(STR_WARNING_ALERT_TITLE), str, GetString(STR_OK_BUTTON), NULL, NULL, B_WIDTH_AS_USUAL, B_INFO_ALERT);
569	alert->Go();
570	}
571
572
573	/*
574	* Display choice alert
575	*/
576
577	bool ChoiceAlert(const char text, const char pos, const char *neg)
578	{
579	char str[256];
580	sprintf(str, GetString(STR_GUI_WARNING_PREFIX), text);
581	BAlert *alert = new BAlert(GetString(STR_WARNING_ALERT_TITLE), str, pos, neg, NULL, B_WIDTH_AS_USUAL, B_INFO_ALERT);
582	return alert->Go() == 0;
583	}
584
585
586	/*
587	* SEGV handler
588	*/
589
590	#if __POWERPC__
591	static uint32 segv_r[32];
592
593	asm void BasiliskII::sigsegv_invoc(register int sig, register void arg, register vregs r)
594	{
595	mflr r0
596	stw r0,8(r1)
597	stwu r1,-56(r1)
598
599	lwz r3,segv_r(r2)
600	stmw r13,13*4(r3)
601
602	mr r3,r5
603	bl sigsegv_handler
604
605	lwz r3,segv_r(r2)
606	lmw r13,13*4(r3)
607
608	lwz r0,56+8(r1)
609	mtlr r0
610	addi r1,r1,56
611	blr
612	}
613
614	static void sigsegv_handler(vregs *r)
615	{
616	// Fetch volatile registers
617	segv_r[0] = r->r0;
618	segv_r[1] = r->r1;
619	segv_r[2] = r->r2;
620	segv_r[3] = r->r3;
621	segv_r[4] = r->r4;
622	segv_r[5] = r->r5;
623	segv_r[6] = r->r6;
624	segv_r[7] = r->r7;
625	segv_r[8] = r->r8;
626	segv_r[9] = r->r9;
627	segv_r[10] = r->r10;
628	segv_r[11] = r->r11;
629	segv_r[12] = r->r12;
630
631	// Get opcode and divide into fields
632	uint32 opcode = (uint32 )r->pc;
633	uint32 primop = opcode >> 26;
634	uint32 exop = (opcode >> 1) & 0x3ff;
635	uint32 ra = (opcode >> 16) & 0x1f;
636	uint32 rb = (opcode >> 11) & 0x1f;
637	uint32 rd = (opcode >> 21) & 0x1f;
638	uint32 imm = opcode & 0xffff;
639
640	// Analyze opcode
641	enum {
642	TYPE_UNKNOWN,
643	TYPE_LOAD,
644	TYPE_STORE
645	} transfer_type = TYPE_UNKNOWN;
646	enum {
647	SIZE_UNKNOWN,
648	SIZE_BYTE,
649	SIZE_HALFWORD,
650	SIZE_WORD
651	} transfer_size = SIZE_UNKNOWN;
652	enum {
653	MODE_UNKNOWN,
654	MODE_NORM,
655	MODE_U,
656	MODE_X,
657	MODE_UX
658	} addr_mode = MODE_UNKNOWN;
659	switch (primop) {
660	case 31:
661	switch (exop) {
662	case 23: // lwzx
663	transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
664	case 55: // lwzux
665	transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
666	case 87: // lbzx
667	transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
668	case 119: // lbzux
669	transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
670	case 151: // stwx
671	transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
672	case 183: // stwux
673	transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
674	case 215: // stbx
675	transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
676	case 247: // stbux
677	transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
678	case 279: // lhzx
679	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_X; break;
680	case 311: // lhzux
681	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_UX; break;
682	case 343: // lhax
683	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_X; break;
684	case 375: // lhaux
685	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_UX; break;
686	case 407: // sthx
687	transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_X; break;
688	case 439: // sthux
689	transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_UX; break;
690	}
691	break;
692
693	case 32: // lwz
694	transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
695	case 33: // lwzu
696	transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
697	case 34: // lbz
698	transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
699	case 35: // lbzu
700	transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
701	case 36: // stw
702	transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
703	case 37: // stwu
704	transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
705	case 38: // stb
706	transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
707	case 39: // stbu
708	transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
709	case 40: // lhz
710	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_NORM; break;
711	case 41: // lhzu
712	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_U; break;
713	case 42: // lha
714	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_NORM; break;
715	case 43: // lhau
716	transfer_type = TYPE_LOAD; transfer_size = SIZE_HALFWORD; addr_mode = MODE_U; break;
717	case 44: // sth
718	transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_NORM; break;
719	case 45: // sthu
720	transfer_type = TYPE_STORE; transfer_size = SIZE_HALFWORD; addr_mode = MODE_U; break;
721	}
722
723	// Calculate effective address
724	uint32 addr = 0;
725	switch (addr_mode) {
726	case MODE_X:
727	case MODE_UX:
728	if (ra == 0)
729	addr = segv_r[rb];
730	else
731	addr = segv_r[ra] + segv_r[rb];
732	break;
733	case MODE_NORM:
734	case MODE_U:
735	if (ra == 0)
736	addr = (int32)(int16)imm;
737	else
738	addr = segv_r[ra] + (int32)(int16)imm;
739	break;
740	}
741
742	// Ignore ROM writes
743	if (transfer_type == TYPE_STORE && addr >= (uint32)ROMBaseHost && addr < (uint32)ROMBaseHost + ROMSize) {
744	// D(bug("WARNING: %s write access to ROM at %p, 68k pc %p\n", transfer_size == SIZE_BYTE ? "Byte" : transfer_size == SIZE_HALFWORD ? "Halfword" : "Word", addr, r->pc));
745	if (addr_mode == MODE_U \|\| addr_mode == MODE_UX)
746	segv_r[ra] = addr;
747	r->pc += 4;
748	goto rti;
749	}
750
751	// For all other errors, jump into debugger
752	char str[256];
753	sprintf(str, "SIGSEGV\n"
754	" pc %08lx lr %08lx ctr %08lx msr %08lx\n"
755	" xer %08lx cr %08lx fpscr %08lx\n"
756	" r0 %08lx r1 %08lx r2 %08lx r3 %08lx\n"
757	" r4 %08lx r5 %08lx r6 %08lx r7 %08lx\n"
758	" r8 %08lx r9 %08lx r10 %08lx r11 %08lx\n"
759	" r12 %08lx r13 %08lx r14 %08lx r15 %08lx\n"
760	" r16 %08lx r17 %08lx r18 %08lx r19 %08lx\n"
761	" r20 %08lx r21 %08lx r22 %08lx r23 %08lx\n"
762	" r24 %08lx r25 %08lx r26 %08lx r27 %08lx\n"
763	" r28 %08lx r29 %08lx r30 %08lx r31 %08lx\n",
764	r->pc, r->lr, r->ctr, r->msr,
765	r->xer, r->cr, r->fpscr,
766	r->r0, r->r1, r->r2, r->r3,
767	r->r4, r->r5, r->r6, r->r7,
768	r->r8, r->r9, r->r10, r->r11,
769	r->r12, segv_r[13], segv_r[14], segv_r[15],
770	segv_r[16], segv_r[17], segv_r[18], segv_r[19],
771	segv_r[20], segv_r[21], segv_r[22], segv_r[23],
772	segv_r[24], segv_r[25], segv_r[26], segv_r[27],
773	segv_r[28], segv_r[29], segv_r[30], segv_r[31]);
774	disable_debugger(false);
775	debugger(str);
776	QuitEmulator();
777	return;
778
779	rti:
780	// Restore volatile registers
781	r->r0 = segv_r[0];
782	r->r1 = segv_r[1];
783	r->r2 = segv_r[2];
784	r->r3 = segv_r[3];
785	r->r4 = segv_r[4];
786	r->r5 = segv_r[5];
787	r->r6 = segv_r[6];
788	r->r7 = segv_r[7];
789	r->r8 = segv_r[8];
790	r->r9 = segv_r[9];
791	r->r10 = segv_r[10];
792	r->r11 = segv_r[11];
793	r->r12 = segv_r[12];
794	}
795	#endif