src/Windows/main_windows.cpp

/*
 *  main_windows.cpp - Emulation core, Windows implementation
 *
 *  SheepShaver (C) 1997-2005 Christian Bauer and Marc Hellwig
 *
 *  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 <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <SDL.h>

#include "sysdeps.h"
#include "main.h"
#include "version.h"
#include "prefs.h"
#include "prefs_editor.h"
#include "cpu_emulation.h"
#include "emul_op.h"
#include "xlowmem.h"
#include "xpram.h"
#include "timer.h"
#include "adb.h"
#include "video.h"
#include "sys.h"
#include "macos_util.h"
#include "rom_patches.h"
#include "user_strings.h"
#include "vm_alloc.h"
#include "sigsegv.h"
#include "util_windows.h"

#define DEBUG 0
#include "debug.h"

#ifdef ENABLE_MON
#include "mon.h"
#endif


// Constants
const char ROM_FILE_NAME[] = "ROM";
const char ROM_FILE_NAME2[] = "Mac OS ROM";

const uintptr RAM_BASE = 0x10000000;            // Base address of RAM
const uint32 SIG_STACK_SIZE = 0x10000;          // Size of signal stack


// Global variables (exported)
uint32 RAMBase;                 // Base address of Mac RAM
uint32 RAMSize;                 // Size of Mac RAM
uint32 KernelDataAddr;  // Address of Kernel Data
uint32 BootGlobsAddr;   // Address of BootGlobs structure at top of Mac RAM
uint32 DRCacheAddr;             // Address of DR Cache
uint32 PVR;                             // Theoretical PVR
int64 CPUClockSpeed;    // Processor clock speed (Hz)
int64 BusClockSpeed;    // Bus clock speed (Hz)
int64 TimebaseSpeed;    // Timebase clock speed (Hz)
uint8 *RAMBaseHost;             // Base address of Mac RAM (host address space)
uint8 *ROMBaseHost;             // Base address of Mac ROM (host address space)


// Global variables
static bool lm_area_mapped = false;                     // Flag: Low Memory area mmap()ped
static int kernel_area = -1;                            // SHM ID of Kernel Data area
static bool rom_area_mapped = false;            // Flag: Mac ROM mmap()ped
static bool ram_area_mapped = false;            // Flag: Mac RAM mmap()ped
static bool dr_cache_area_mapped = false;       // Flag: Mac DR Cache mmap()ped
static bool dr_emulator_area_mapped = false;// Flag: Mac DR Emulator mmap()ped
static KernelData *kernel_data;                         // Pointer to Kernel Data
static EmulatorData *emulator_data;

static uint8 last_xpram[XPRAM_SIZE];            // Buffer for monitoring XPRAM changes
static bool nvram_thread_active = false;        // Flag: NVRAM watchdog installed
static volatile bool nvram_thread_cancel;       // Flag: Cancel NVRAM thread
static HANDLE nvram_thread = NULL;                      // NVRAM watchdog
static bool tick_thread_active = false;         // Flag: MacOS thread installed
static volatile bool tick_thread_cancel;        // Flag: Cancel 60Hz thread
static HANDLE tick_thread = NULL;                       // 60Hz thread
static HANDLE emul_thread = NULL;                       // MacOS thread
static uintptr sig_stack = 0;                           // Stack for PowerPC interrupt routine

uint32  SheepMem::page_size;                            // Size of a native page
uintptr SheepMem::zero_page = 0;                        // Address of ro page filled in with zeros
uintptr SheepMem::base = 0x60000000;            // Address of SheepShaver data
uintptr SheepMem::proc;                                         // Bottom address of SheepShave procedures
uintptr SheepMem::data;                                         // Top of SheepShaver data (stack like storage)


// Prototypes
static bool kernel_data_init(void);
static void kernel_data_exit(void);
static void Quit(void);
static DWORD WINAPI nvram_func(void *arg);
static DWORD WINAPI tick_func(void *arg);

static void jump_to_rom(uint32 entry);
extern void emul_ppc(uint32 start);
extern void init_emul_ppc(void);
extern void exit_emul_ppc(void);
sigsegv_return_t sigsegv_handler(sigsegv_address_t, sigsegv_address_t);


/*
 *  Return signal stack base
 */

uintptr SignalStackBase(void)
{
        return sig_stack + SIG_STACK_SIZE;
}


/*
 *  Memory management helpers
 */

static inline int vm_mac_acquire(uint32 addr, uint32 size)
{
        return vm_acquire_fixed(Mac2HostAddr(addr), size);
}

static inline int vm_mac_release(uint32 addr, uint32 size)
{
        return vm_release(Mac2HostAddr(addr), size);
}


/*
 *  Main program
 */

static void usage(const char *prg_name)
{
        printf("Usage: %s [OPTION...]\n", prg_name);
        printf("\nUnix options:\n");
        printf("  --display STRING\n    X display to use\n");
        PrefsPrintUsage();
        exit(0);
}

int main(int argc, char **argv)
{
        char str[256];
        int16 i16;
        HANDLE rom_fh;
        const char *rom_path;
        uint32 rom_size;
        DWORD actual;
        uint8 *rom_tmp;

        // Initialize variables
        RAMBase = 0;
        tzset();

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

        // Read preferences
        PrefsInit(argc, argv);

        // Parse command line arguments
        for (int i=1; i<argc; i++) {
                if (strcmp(argv[i], "--help") == 0) {
                        usage(argv[0]);
                } else if (argv[i][0] == '-') {
                        fprintf(stderr, "Unrecognized option '%s'\n", argv[i]);
                        usage(argv[0]);
                }
        }

        // Initialize SDL system
        int sdl_flags = 0;
#ifdef USE_SDL_VIDEO
        sdl_flags |= SDL_INIT_VIDEO;
#endif
#ifdef USE_SDL_AUDIO
        sdl_flags |= SDL_INIT_AUDIO;
#endif
        assert(sdl_flags != 0);
        if (SDL_Init(sdl_flags) == -1) {
                char str[256];
                sprintf(str, "Could not initialize SDL: %s.\n", SDL_GetError());
                ErrorAlert(str);
                goto quit;
        }
        atexit(SDL_Quit);

#ifdef ENABLE_MON
        // Initialize mon
        mon_init();
#endif

        // Install SIGSEGV handler for CPU emulator
        if (!sigsegv_install_handler(sigsegv_handler)) {
                sprintf(str, GetString(STR_SIGSEGV_INSTALL_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }

        // Initialize VM system
        vm_init();

        // Get system info
        PVR = 0x00040000;                       // Default: 604
        CPUClockSpeed = 100000000;      // Default: 100MHz
        BusClockSpeed = 100000000;      // Default: 100MHz
        TimebaseSpeed =  25000000;      // Default:  25MHz
        PVR = 0x000c0000;                       // Default: 7400 (with AltiVec)
        D(bug("PVR: %08x (assumed)\n", PVR));

        // Init system routines
        SysInit();

        // Show preferences editor
        if (!PrefsFindBool("nogui"))
                if (!PrefsEditor())
                        goto quit;

        // Create Low Memory area (0x0000..0x3000)
        if (vm_mac_acquire(0, 0x3000) < 0) {
                sprintf(str, GetString(STR_LOW_MEM_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
        lm_area_mapped = true;

        // Create areas for Kernel Data
        if (!kernel_data_init())
                goto quit;
        kernel_data = (KernelData *)Mac2HostAddr(KERNEL_DATA_BASE);
        emulator_data = &kernel_data->ed;
        KernelDataAddr = KERNEL_DATA_BASE;
        D(bug("Kernel Data at %p (%08x)\n", kernel_data, KERNEL_DATA_BASE));
        D(bug("Emulator Data at %p (%08x)\n", emulator_data, KERNEL_DATA_BASE + offsetof(KernelData, ed)));

        // Create area for DR Cache
        if (vm_mac_acquire(DR_EMULATOR_BASE, DR_EMULATOR_SIZE) < 0) {
                sprintf(str, GetString(STR_DR_EMULATOR_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
        dr_emulator_area_mapped = true;
        if (vm_mac_acquire(DR_CACHE_BASE, DR_CACHE_SIZE) < 0) {
                sprintf(str, GetString(STR_DR_CACHE_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
        dr_cache_area_mapped = true;
        DRCacheAddr = (uint32)Mac2HostAddr(DR_CACHE_BASE);
        D(bug("DR Cache at %p (%08x)\n", DRCacheAddr, DR_CACHE_BASE));

        // Create area for SheepShaver data
        if (!SheepMem::Init()) {
                sprintf(str, GetString(STR_SHEEP_MEM_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }

        // Create area for Mac ROM
        if (vm_mac_acquire(ROM_BASE, ROM_AREA_SIZE) < 0) {
                sprintf(str, GetString(STR_ROM_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
        ROMBaseHost = Mac2HostAddr(ROM_BASE);
        rom_area_mapped = true;
        D(bug("ROM area at %p (%08x)\n", ROMBaseHost, ROM_BASE));

        // Create area for Mac RAM
        RAMSize = PrefsFindInt32("ramsize");
        if (RAMSize < 8*1024*1024) {
                WarningAlert(GetString(STR_SMALL_RAM_WARN));
                RAMSize = 8*1024*1024;
        }

        if (vm_mac_acquire(RAM_BASE, RAMSize) < 0) {
                sprintf(str, GetString(STR_RAM_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
        RAMBaseHost = Mac2HostAddr(RAM_BASE);
        RAMBase = RAM_BASE;
        ram_area_mapped = true;
        D(bug("RAM area at %p (%08x)\n", RAMBaseHost, RAMBase));

        if (RAMBase > ROM_BASE) {
                ErrorAlert(GetString(STR_RAM_HIGHER_THAN_ROM_ERR));
                goto quit;
        }

        // Load Mac ROM
        rom_path = PrefsFindString("rom");
        rom_fh = CreateFile(rom_path ? rom_path : ROM_FILE_NAME,
                                                GENERIC_READ, 0, NULL, OPEN_EXISTING,
                                                FILE_ATTRIBUTE_NORMAL, NULL);

        if (rom_fh == INVALID_HANDLE_VALUE) {
                rom_fh = CreateFile(rom_path ? rom_path : ROM_FILE_NAME2,
                                                        GENERIC_READ, 0, NULL, OPEN_EXISTING,
                                                        FILE_ATTRIBUTE_NORMAL, NULL);

                if (rom_fh == INVALID_HANDLE_VALUE) {
                        ErrorAlert(GetString(STR_NO_ROM_FILE_ERR));
                        goto quit;
                }
        }
        printf(GetString(STR_READING_ROM_FILE));
        rom_size = GetFileSize(rom_fh, NULL);
        rom_tmp = new uint8[ROM_SIZE];
        ReadFile(rom_fh, (void *)rom_tmp, ROM_SIZE, &actual, NULL);
        CloseHandle(rom_fh);
        
        // Decode Mac ROM
        if (!DecodeROM(rom_tmp, actual)) {
                if (rom_size != 4*1024*1024) {
                        ErrorAlert(GetString(STR_ROM_SIZE_ERR));
                        goto quit;
                } else {
                        ErrorAlert(GetString(STR_ROM_FILE_READ_ERR));
                        goto quit;
                }
        }
        delete[] rom_tmp;

        // Initialize everything
        if (!InitAll())
                goto quit;
        D(bug("Initialization complete\n"));

        // Write protect ROM
        vm_protect(ROMBaseHost, ROM_AREA_SIZE, VM_PAGE_READ);

        // Start 60Hz thread
        tick_thread_cancel = false;
        tick_thread_active = ((tick_thread = create_thread(tick_func)) != NULL);
        SetThreadPriority(tick_thread, THREAD_PRIORITY_ABOVE_NORMAL);
        D(bug("Tick thread installed (%ld)\n", tick_thread));

        // Start NVRAM watchdog thread
        memcpy(last_xpram, XPRAM, XPRAM_SIZE);
        nvram_thread_cancel = false;
        nvram_thread_active = ((nvram_thread = create_thread(nvram_func, NULL)) != NULL);
        SetThreadPriority(nvram_thread, THREAD_PRIORITY_BELOW_NORMAL);
        D(bug("NVRAM thread installed (%ld)\n", nvram_thread));

        // Get my thread ID and jump to ROM boot routine
        emul_thread = GetCurrentThread();
        D(bug("Jumping to ROM\n"));
        jump_to_rom(ROM_BASE + 0x310000);
        D(bug("Returned from ROM\n"));

quit:
        Quit();
        return 0;
}


/*
 *  Cleanup and quit
 */

static void Quit(void)
{
        // Exit PowerPC emulation
        exit_emul_ppc();

        // Stop 60Hz thread
        if (tick_thread_active) {
                tick_thread_cancel = true;
                wait_thread(tick_thread);
        }

        // Stop NVRAM watchdog thread
        if (nvram_thread_active) {
                nvram_thread_cancel = true;
                wait_thread(nvram_thread);
        }

        // Deinitialize everything
        ExitAll();

        // Delete SheepShaver globals
        SheepMem::Exit();

        // Delete RAM area
        if (ram_area_mapped)
                vm_mac_release(RAM_BASE, RAMSize);

        // Delete ROM area
        if (rom_area_mapped)
                vm_mac_release(ROM_BASE, ROM_AREA_SIZE);

        // Delete DR cache areas
        if (dr_emulator_area_mapped)
                vm_mac_release(DR_EMULATOR_BASE, DR_EMULATOR_SIZE);
        if (dr_cache_area_mapped)
                vm_mac_release(DR_CACHE_BASE, DR_CACHE_SIZE);

        // Delete Kernel Data area
        kernel_data_exit();

        // Delete Low Memory area
        if (lm_area_mapped)
                vm_mac_release(0, 0x3000);

        // Exit system routines
        SysExit();

        // Exit preferences
        PrefsExit();

#ifdef ENABLE_MON
        // Exit mon
        mon_exit();
#endif

        exit(0);
}


/*
 *  Initialize Kernel Data segments
 */

static HANDLE kernel_handle;                            // Shared memory handle for Kernel Data
static DWORD allocation_granule;                        // Minimum size of allocateable are (64K)
static DWORD kernel_area_size;                          // Size of Kernel Data area

static bool kernel_data_init(void)
{
        char str[256];
        SYSTEM_INFO si;
        GetSystemInfo(&si);
        allocation_granule = si.dwAllocationGranularity;
        kernel_area_size = (KERNEL_AREA_SIZE + allocation_granule - 1) & -allocation_granule;

        char rcs[10];
        LPVOID kernel_addr;
        kernel_handle = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, kernel_area_size, NULL);
        if (kernel_handle == NULL) {
                sprintf(rcs, "%d", GetLastError());
                sprintf(str, GetString(STR_KD_SHMGET_ERR), rcs);
                ErrorAlert(str);
                return false;
        }
        kernel_addr = (LPVOID)Mac2HostAddr(KERNEL_DATA_BASE & -allocation_granule);
        if (MapViewOfFileEx(kernel_handle, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, kernel_area_size, kernel_addr) != kernel_addr) {
                sprintf(rcs, "%d", GetLastError());
                sprintf(str, GetString(STR_KD_SHMAT_ERR), rcs);
                ErrorAlert(str);
                return false;
        }
        kernel_addr = (LPVOID)Mac2HostAddr(KERNEL_DATA2_BASE & -allocation_granule);
        if (MapViewOfFileEx(kernel_handle, FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, kernel_area_size, kernel_addr) != kernel_addr) {
                sprintf(rcs, "%d", GetLastError());
                sprintf(str, GetString(STR_KD2_SHMAT_ERR), rcs);
                ErrorAlert(str);
                return false;
        }
        return true;
}


/*
 *  Deallocate Kernel Data segments
 */

static void kernel_data_exit(void)
{
        if (kernel_handle) {
                UnmapViewOfFile(Mac2HostAddr(KERNEL_DATA_BASE & -allocation_granule));
                UnmapViewOfFile(Mac2HostAddr(KERNEL_DATA2_BASE & -allocation_granule));
                CloseHandle(kernel_handle);
        }
}


/*
 *  Jump into Mac ROM, start 680x0 emulator
 */

void jump_to_rom(uint32 entry)
{
        init_emul_ppc();
        emul_ppc(entry);
}


/*
 *  Quit emulator (cause return from jump_to_rom)
 */

void QuitEmulator(void)
{
        Quit();
}


/*
 *  Pause/resume emulator
 */

void PauseEmulator(void)
{
        SuspendThread(emul_thread);
}

void ResumeEmulator(void)
{
        ResumeThread(emul_thread);
}


/*
 *  Dump 68k registers
 */

void Dump68kRegs(M68kRegisters *r)
{
        // Display 68k registers
        for (int i=0; i<8; i++) {
                printf("d%d: %08x", i, r->d[i]);
                if (i == 3 || i == 7)
                        printf("\n");
                else
                        printf(", ");
        }
        for (int i=0; i<8; i++) {
                printf("a%d: %08x", i, r->a[i]);
                if (i == 3 || i == 7)
                        printf("\n");
                else
                        printf(", ");
        }
}


/*
 *  Make code executable
 */

void MakeExecutable(int dummy, uint32 start, uint32 length)
{
        if ((start >= ROM_BASE) && (start < (ROM_BASE + ROM_SIZE)))
                return;
        FlushCodeCache(start, start + length);
}


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

static void nvram_watchdog(void)
{
        if (memcmp(last_xpram, XPRAM, XPRAM_SIZE)) {
                memcpy(last_xpram, XPRAM, XPRAM_SIZE);
                SaveXPRAM();
        }
}

static DWORD nvram_func(void *arg)
{
        while (!nvram_thread_cancel) {
                for (int i=0; i<60 && !nvram_thread_cancel; i++)
                        Delay_usec(999999);             // Only wait 1 second so we quit promptly when nvram_thread_cancel becomes true
                nvram_watchdog();
        }
        return 0;
}


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

static DWORD tick_func(void *arg)
{
        int tick_counter = 0;
        uint64 start = GetTicks_usec();
        int64 ticks = 0;
        uint64 next = GetTicks_usec();

        while (!tick_thread_cancel) {

                // Wait
                next += 16625;
                int64 delay = next - GetTicks_usec();
                if (delay > 0)
                        Delay_usec(delay);
                else if (delay < -16625)
                        next = GetTicks_usec();
                ticks++;

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

                // Trigger 60Hz interrupt
                if (ReadMacInt32(XLM_IRQ_NEST) == 0) {
                        SetInterruptFlag(INTFLAG_VIA);
                        TriggerInterrupt();
                }
        }

        uint64 end = GetTicks_usec();
        D(bug("%Ld ticks in %Ld usec = %f ticks/sec\n", ticks, end - start, ticks * 1000000.0 / (end - start)));
        return 0;
}


/*
 *  Mutexes
 */

struct B2_mutex {
        mutex_t m;
};

B2_mutex *B2_create_mutex(void)
{
        return new B2_mutex;
}

void B2_lock_mutex(B2_mutex *mutex)
{
        mutex->m.lock();
}

void B2_unlock_mutex(B2_mutex *mutex)
{
        mutex->m.unlock();
}

void B2_delete_mutex(B2_mutex *mutex)
{
        delete mutex;
}


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

volatile uint32 InterruptFlags = 0;
static mutex_t intflags_mutex;

void SetInterruptFlag(uint32 flag)
{
        intflags_mutex.lock();
        InterruptFlags |= flag;
        intflags_mutex.unlock();
}

void ClearInterruptFlag(uint32 flag)
{
        intflags_mutex.lock();
        InterruptFlags &= ~flag;
        intflags_mutex.unlock();
}


/*
 *  Disable interrupts
 */

void DisableInterrupt(void)
{
        WriteMacInt32(XLM_IRQ_NEST, int32(ReadMacInt32(XLM_IRQ_NEST)) + 1);
}


/*
 *  Enable interrupts
 */

void EnableInterrupt(void)
{
        WriteMacInt32(XLM_IRQ_NEST, int32(ReadMacInt32(XLM_IRQ_NEST)) - 1);
}


/*
 *  Helpers to share 32-bit addressable data with MacOS
 */

bool SheepMem::Init(void)
{
        // Size of a native page
        page_size = vm_get_page_size();

        // Allocate SheepShaver globals
        proc = base;
        if (vm_mac_acquire(base, size) < 0)
                return false;

        // Allocate page with all bits set to 0, right in the middle
        // This is also used to catch undesired overlaps between proc and data areas
        zero_page = proc + (size / 2);
        Mac_memset(zero_page, 0, page_size);
        if (vm_protect(Mac2HostAddr(zero_page), page_size, VM_PAGE_READ) < 0)
                return false;

        // Allocate alternate stack for PowerPC interrupt routine
        sig_stack = base + size;
        if (vm_mac_acquire(sig_stack, SIG_STACK_SIZE) < 0)
                return false;

        data = base + size;
        return true;
}

void SheepMem::Exit(void)
{
        if (data) {
                // Delete SheepShaver globals
                vm_mac_release(base, size);

                // Delete alternate stack for PowerPC interrupt routine
                vm_mac_release(sig_stack, SIG_STACK_SIZE);
        }
}


/*
 *  Get the main window handle
 */

#ifdef USE_SDL_VIDEO
#include <SDL_syswm.h>
static HWND GetMainWindowHandle(void)
{
        SDL_SysWMinfo wmInfo;
        wmInfo.version.major = SDL_MAJOR_VERSION;
        wmInfo.version.minor = SDL_MINOR_VERSION;
        wmInfo.version.patch = SDL_PATCHLEVEL;
        return SDL_GetWMInfo(&wmInfo) ? wmInfo.window : NULL;
}
#endif


/*
 *  Display alert
 */

static void display_alert(int title_id, const char *text, int flags)
{
        HWND hMainWnd = GetMainWindowHandle();
        MessageBox(hMainWnd, text, GetString(title_id), MB_OK | flags);
}


/*
 *  Display error alert
 */

void ErrorAlert(const char *text)
{
        if (PrefsFindBool("nogui"))
                return;

        VideoQuitFullScreen();
        display_alert(STR_ERROR_ALERT_TITLE, text, MB_ICONSTOP);
}


/*
 *  Display warning alert
 */

void WarningAlert(const char *text)
{
        if (PrefsFindBool("nogui"))
                return;

        display_alert(STR_WARNING_ALERT_TITLE, text, MB_ICONINFORMATION);
}


/*
 *  Display choice alert
 */

bool ChoiceAlert(const char *text, const char *pos, const char *neg)
{
        printf(GetString(STR_SHELL_WARNING_PREFIX), text);
        return false;   //!!
}
Revision:	1.7
Committed:	2005-01-30T21:48:20Z (19 years, 4 months ago) by gbeauche
Branch:	MAIN
Changes since 1.6:	+1 -1 lines
Log Message:	Happy New Year 2005!
#	Content
1	/*
2	* main_windows.cpp - Emulation core, Windows implementation
3	*
4	* SheepShaver (C) 1997-2005 Christian Bauer and Marc Hellwig
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 <errno.h>
22	#include <stdio.h>
23	#include <stdlib.h>
24	#include <string.h>
25
26	#include <SDL.h>
27
28	#include "sysdeps.h"
29	#include "main.h"
30	#include "version.h"
31	#include "prefs.h"
32	#include "prefs_editor.h"
33	#include "cpu_emulation.h"
34	#include "emul_op.h"
35	#include "xlowmem.h"
36	#include "xpram.h"
37	#include "timer.h"
38	#include "adb.h"
39	#include "video.h"
40	#include "sys.h"
41	#include "macos_util.h"
42	#include "rom_patches.h"
43	#include "user_strings.h"
44	#include "vm_alloc.h"
45	#include "sigsegv.h"
46	#include "util_windows.h"
47
48	#define DEBUG 0
49	#include "debug.h"
50
51	#ifdef ENABLE_MON
52	#include "mon.h"
53	#endif
54
55
56	// Constants
57	const char ROM_FILE_NAME[] = "ROM";
58	const char ROM_FILE_NAME2[] = "Mac OS ROM";
59
60	const uintptr RAM_BASE = 0x10000000; // Base address of RAM
61	const uint32 SIG_STACK_SIZE = 0x10000; // Size of signal stack
62
63
64	// Global variables (exported)
65	uint32 RAMBase; // Base address of Mac RAM
66	uint32 RAMSize; // Size of Mac RAM
67	uint32 KernelDataAddr; // Address of Kernel Data
68	uint32 BootGlobsAddr; // Address of BootGlobs structure at top of Mac RAM
69	uint32 DRCacheAddr; // Address of DR Cache
70	uint32 PVR; // Theoretical PVR
71	int64 CPUClockSpeed; // Processor clock speed (Hz)
72	int64 BusClockSpeed; // Bus clock speed (Hz)
73	int64 TimebaseSpeed; // Timebase clock speed (Hz)
74	uint8 *RAMBaseHost; // Base address of Mac RAM (host address space)
75	uint8 *ROMBaseHost; // Base address of Mac ROM (host address space)
76
77
78	// Global variables
79	static bool lm_area_mapped = false; // Flag: Low Memory area mmap()ped
80	static int kernel_area = -1; // SHM ID of Kernel Data area
81	static bool rom_area_mapped = false; // Flag: Mac ROM mmap()ped
82	static bool ram_area_mapped = false; // Flag: Mac RAM mmap()ped
83	static bool dr_cache_area_mapped = false; // Flag: Mac DR Cache mmap()ped
84	static bool dr_emulator_area_mapped = false;// Flag: Mac DR Emulator mmap()ped
85	static KernelData *kernel_data; // Pointer to Kernel Data
86	static EmulatorData *emulator_data;
87
88	static uint8 last_xpram[XPRAM_SIZE]; // Buffer for monitoring XPRAM changes
89	static bool nvram_thread_active = false; // Flag: NVRAM watchdog installed
90	static volatile bool nvram_thread_cancel; // Flag: Cancel NVRAM thread
91	static HANDLE nvram_thread = NULL; // NVRAM watchdog
92	static bool tick_thread_active = false; // Flag: MacOS thread installed
93	static volatile bool tick_thread_cancel; // Flag: Cancel 60Hz thread
94	static HANDLE tick_thread = NULL; // 60Hz thread
95	static HANDLE emul_thread = NULL; // MacOS thread
96	static uintptr sig_stack = 0; // Stack for PowerPC interrupt routine
97
98	uint32 SheepMem::page_size; // Size of a native page
99	uintptr SheepMem::zero_page = 0; // Address of ro page filled in with zeros
100	uintptr SheepMem::base = 0x60000000; // Address of SheepShaver data
101	uintptr SheepMem::proc; // Bottom address of SheepShave procedures
102	uintptr SheepMem::data; // Top of SheepShaver data (stack like storage)
103
104
105	// Prototypes
106	static bool kernel_data_init(void);
107	static void kernel_data_exit(void);
108	static void Quit(void);
109	static DWORD WINAPI nvram_func(void *arg);
110	static DWORD WINAPI tick_func(void *arg);
111
112	static void jump_to_rom(uint32 entry);
113	extern void emul_ppc(uint32 start);
114	extern void init_emul_ppc(void);
115	extern void exit_emul_ppc(void);
116	sigsegv_return_t sigsegv_handler(sigsegv_address_t, sigsegv_address_t);
117
118
119	/*
120	* Return signal stack base
121	*/
122
123	uintptr SignalStackBase(void)
124	{
125	return sig_stack + SIG_STACK_SIZE;
126	}
127
128
129	/*
130	* Memory management helpers
131	*/
132
133	static inline int vm_mac_acquire(uint32 addr, uint32 size)
134	{
135	return vm_acquire_fixed(Mac2HostAddr(addr), size);
136	}
137
138	static inline int vm_mac_release(uint32 addr, uint32 size)
139	{
140	return vm_release(Mac2HostAddr(addr), size);
141	}
142
143
144	/*
145	* Main program
146	*/
147
148	static void usage(const char *prg_name)
149	{
150	printf("Usage: %s [OPTION...]\n", prg_name);
151	printf("\nUnix options:\n");
152	printf(" --display STRING\n X display to use\n");
153	PrefsPrintUsage();
154	exit(0);
155	}
156
157	int main(int argc, char **argv)
158	{
159	char str[256];
160	int16 i16;
161	HANDLE rom_fh;
162	const char *rom_path;
163	uint32 rom_size;
164	DWORD actual;
165	uint8 *rom_tmp;
166
167	// Initialize variables
168	RAMBase = 0;
169	tzset();
170
171	// Print some info
172	printf(GetString(STR_ABOUT_TEXT1), VERSION_MAJOR, VERSION_MINOR);
173	printf(" %s\n", GetString(STR_ABOUT_TEXT2));
174
175	// Read preferences
176	PrefsInit(argc, argv);
177
178	// Parse command line arguments
179	for (int i=1; i<argc; i++) {
180	if (strcmp(argv[i], "--help") == 0) {
181	usage(argv[0]);
182	} else if (argv[i][0] == '-') {
183	fprintf(stderr, "Unrecognized option '%s'\n", argv[i]);
184	usage(argv[0]);
185	}
186	}
187
188	// Initialize SDL system
189	int sdl_flags = 0;
190	#ifdef USE_SDL_VIDEO
191	sdl_flags \|= SDL_INIT_VIDEO;
192	#endif
193	#ifdef USE_SDL_AUDIO
194	sdl_flags \|= SDL_INIT_AUDIO;
195	#endif
196	assert(sdl_flags != 0);
197	if (SDL_Init(sdl_flags) == -1) {
198	char str[256];
199	sprintf(str, "Could not initialize SDL: %s.\n", SDL_GetError());
200	ErrorAlert(str);
201	goto quit;
202	}
203	atexit(SDL_Quit);
204
205	#ifdef ENABLE_MON
206	// Initialize mon
207	mon_init();
208	#endif
209
210	// Install SIGSEGV handler for CPU emulator
211	if (!sigsegv_install_handler(sigsegv_handler)) {
212	sprintf(str, GetString(STR_SIGSEGV_INSTALL_ERR), strerror(errno));
213	ErrorAlert(str);
214	goto quit;
215	}
216
217	// Initialize VM system
218	vm_init();
219
220	// Get system info
221	PVR = 0x00040000; // Default: 604
222	CPUClockSpeed = 100000000; // Default: 100MHz
223	BusClockSpeed = 100000000; // Default: 100MHz
224	TimebaseSpeed = 25000000; // Default: 25MHz
225	PVR = 0x000c0000; // Default: 7400 (with AltiVec)
226	D(bug("PVR: %08x (assumed)\n", PVR));
227
228	// Init system routines
229	SysInit();
230
231	// Show preferences editor
232	if (!PrefsFindBool("nogui"))
233	if (!PrefsEditor())
234	goto quit;
235
236	// Create Low Memory area (0x0000..0x3000)
237	if (vm_mac_acquire(0, 0x3000) < 0) {
238	sprintf(str, GetString(STR_LOW_MEM_MMAP_ERR), strerror(errno));
239	ErrorAlert(str);
240	goto quit;
241	}
242	lm_area_mapped = true;
243
244	// Create areas for Kernel Data
245	if (!kernel_data_init())
246	goto quit;
247	kernel_data = (KernelData *)Mac2HostAddr(KERNEL_DATA_BASE);
248	emulator_data = &kernel_data->ed;
249	KernelDataAddr = KERNEL_DATA_BASE;
250	D(bug("Kernel Data at %p (%08x)\n", kernel_data, KERNEL_DATA_BASE));
251	D(bug("Emulator Data at %p (%08x)\n", emulator_data, KERNEL_DATA_BASE + offsetof(KernelData, ed)));
252
253	// Create area for DR Cache
254	if (vm_mac_acquire(DR_EMULATOR_BASE, DR_EMULATOR_SIZE) < 0) {
255	sprintf(str, GetString(STR_DR_EMULATOR_MMAP_ERR), strerror(errno));
256	ErrorAlert(str);
257	goto quit;
258	}
259	dr_emulator_area_mapped = true;
260	if (vm_mac_acquire(DR_CACHE_BASE, DR_CACHE_SIZE) < 0) {
261	sprintf(str, GetString(STR_DR_CACHE_MMAP_ERR), strerror(errno));
262	ErrorAlert(str);
263	goto quit;
264	}
265	dr_cache_area_mapped = true;
266	DRCacheAddr = (uint32)Mac2HostAddr(DR_CACHE_BASE);
267	D(bug("DR Cache at %p (%08x)\n", DRCacheAddr, DR_CACHE_BASE));
268
269	// Create area for SheepShaver data
270	if (!SheepMem::Init()) {
271	sprintf(str, GetString(STR_SHEEP_MEM_MMAP_ERR), strerror(errno));
272	ErrorAlert(str);
273	goto quit;
274	}
275
276	// Create area for Mac ROM
277	if (vm_mac_acquire(ROM_BASE, ROM_AREA_SIZE) < 0) {
278	sprintf(str, GetString(STR_ROM_MMAP_ERR), strerror(errno));
279	ErrorAlert(str);
280	goto quit;
281	}
282	ROMBaseHost = Mac2HostAddr(ROM_BASE);
283	rom_area_mapped = true;
284	D(bug("ROM area at %p (%08x)\n", ROMBaseHost, ROM_BASE));
285
286	// Create area for Mac RAM
287	RAMSize = PrefsFindInt32("ramsize");
288	if (RAMSize < 810241024) {
289	WarningAlert(GetString(STR_SMALL_RAM_WARN));
290	RAMSize = 810241024;
291	}
292
293	if (vm_mac_acquire(RAM_BASE, RAMSize) < 0) {
294	sprintf(str, GetString(STR_RAM_MMAP_ERR), strerror(errno));
295	ErrorAlert(str);
296	goto quit;
297	}
298	RAMBaseHost = Mac2HostAddr(RAM_BASE);
299	RAMBase = RAM_BASE;
300	ram_area_mapped = true;
301	D(bug("RAM area at %p (%08x)\n", RAMBaseHost, RAMBase));
302
303	if (RAMBase > ROM_BASE) {
304	ErrorAlert(GetString(STR_RAM_HIGHER_THAN_ROM_ERR));
305	goto quit;
306	}
307
308	// Load Mac ROM
309	rom_path = PrefsFindString("rom");
310	rom_fh = CreateFile(rom_path ? rom_path : ROM_FILE_NAME,
311	GENERIC_READ, 0, NULL, OPEN_EXISTING,
312	FILE_ATTRIBUTE_NORMAL, NULL);
313
314	if (rom_fh == INVALID_HANDLE_VALUE) {
315	rom_fh = CreateFile(rom_path ? rom_path : ROM_FILE_NAME2,
316	GENERIC_READ, 0, NULL, OPEN_EXISTING,
317	FILE_ATTRIBUTE_NORMAL, NULL);
318
319	if (rom_fh == INVALID_HANDLE_VALUE) {
320	ErrorAlert(GetString(STR_NO_ROM_FILE_ERR));
321	goto quit;
322	}
323	}
324	printf(GetString(STR_READING_ROM_FILE));
325	rom_size = GetFileSize(rom_fh, NULL);
326	rom_tmp = new uint8[ROM_SIZE];
327	ReadFile(rom_fh, (void *)rom_tmp, ROM_SIZE, &actual, NULL);
328	CloseHandle(rom_fh);
329
330	// Decode Mac ROM
331	if (!DecodeROM(rom_tmp, actual)) {
332	if (rom_size != 410241024) {
333	ErrorAlert(GetString(STR_ROM_SIZE_ERR));
334	goto quit;
335	} else {
336	ErrorAlert(GetString(STR_ROM_FILE_READ_ERR));
337	goto quit;
338	}
339	}
340	delete[] rom_tmp;
341
342	// Initialize everything
343	if (!InitAll())
344	goto quit;
345	D(bug("Initialization complete\n"));
346
347	// Write protect ROM
348	vm_protect(ROMBaseHost, ROM_AREA_SIZE, VM_PAGE_READ);
349
350	// Start 60Hz thread
351	tick_thread_cancel = false;
352	tick_thread_active = ((tick_thread = create_thread(tick_func)) != NULL);
353	SetThreadPriority(tick_thread, THREAD_PRIORITY_ABOVE_NORMAL);
354	D(bug("Tick thread installed (%ld)\n", tick_thread));
355
356	// Start NVRAM watchdog thread
357	memcpy(last_xpram, XPRAM, XPRAM_SIZE);
358	nvram_thread_cancel = false;
359	nvram_thread_active = ((nvram_thread = create_thread(nvram_func, NULL)) != NULL);
360	SetThreadPriority(nvram_thread, THREAD_PRIORITY_BELOW_NORMAL);
361	D(bug("NVRAM thread installed (%ld)\n", nvram_thread));
362
363	// Get my thread ID and jump to ROM boot routine
364	emul_thread = GetCurrentThread();
365	D(bug("Jumping to ROM\n"));
366	jump_to_rom(ROM_BASE + 0x310000);
367	D(bug("Returned from ROM\n"));
368
369	quit:
370	Quit();
371	return 0;
372	}
373
374
375	/*
376	* Cleanup and quit
377	*/
378
379	static void Quit(void)
380	{
381	// Exit PowerPC emulation
382	exit_emul_ppc();
383
384	// Stop 60Hz thread
385	if (tick_thread_active) {
386	tick_thread_cancel = true;
387	wait_thread(tick_thread);
388	}
389
390	// Stop NVRAM watchdog thread
391	if (nvram_thread_active) {
392	nvram_thread_cancel = true;
393	wait_thread(nvram_thread);
394	}
395
396	// Deinitialize everything
397	ExitAll();
398
399	// Delete SheepShaver globals
400	SheepMem::Exit();
401
402	// Delete RAM area
403	if (ram_area_mapped)
404	vm_mac_release(RAM_BASE, RAMSize);
405
406	// Delete ROM area
407	if (rom_area_mapped)
408	vm_mac_release(ROM_BASE, ROM_AREA_SIZE);
409
410	// Delete DR cache areas
411	if (dr_emulator_area_mapped)
412	vm_mac_release(DR_EMULATOR_BASE, DR_EMULATOR_SIZE);
413	if (dr_cache_area_mapped)
414	vm_mac_release(DR_CACHE_BASE, DR_CACHE_SIZE);
415
416	// Delete Kernel Data area
417	kernel_data_exit();
418
419	// Delete Low Memory area
420	if (lm_area_mapped)
421	vm_mac_release(0, 0x3000);
422
423	// Exit system routines
424	SysExit();
425
426	// Exit preferences
427	PrefsExit();
428
429	#ifdef ENABLE_MON
430	// Exit mon
431	mon_exit();
432	#endif
433
434	exit(0);
435	}
436
437
438	/*
439	* Initialize Kernel Data segments
440	*/
441
442	static HANDLE kernel_handle; // Shared memory handle for Kernel Data
443	static DWORD allocation_granule; // Minimum size of allocateable are (64K)
444	static DWORD kernel_area_size; // Size of Kernel Data area
445
446	static bool kernel_data_init(void)
447	{
448	char str[256];
449	SYSTEM_INFO si;
450	GetSystemInfo(&si);
451	allocation_granule = si.dwAllocationGranularity;
452	kernel_area_size = (KERNEL_AREA_SIZE + allocation_granule - 1) & -allocation_granule;
453
454	char rcs[10];
455	LPVOID kernel_addr;
456	kernel_handle = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, kernel_area_size, NULL);
457	if (kernel_handle == NULL) {
458	sprintf(rcs, "%d", GetLastError());
459	sprintf(str, GetString(STR_KD_SHMGET_ERR), rcs);
460	ErrorAlert(str);
461	return false;
462	}
463	kernel_addr = (LPVOID)Mac2HostAddr(KERNEL_DATA_BASE & -allocation_granule);
464	if (MapViewOfFileEx(kernel_handle, FILE_MAP_READ \| FILE_MAP_WRITE, 0, 0, kernel_area_size, kernel_addr) != kernel_addr) {
465	sprintf(rcs, "%d", GetLastError());
466	sprintf(str, GetString(STR_KD_SHMAT_ERR), rcs);
467	ErrorAlert(str);
468	return false;
469	}
470	kernel_addr = (LPVOID)Mac2HostAddr(KERNEL_DATA2_BASE & -allocation_granule);
471	if (MapViewOfFileEx(kernel_handle, FILE_MAP_READ \| FILE_MAP_WRITE, 0, 0, kernel_area_size, kernel_addr) != kernel_addr) {
472	sprintf(rcs, "%d", GetLastError());
473	sprintf(str, GetString(STR_KD2_SHMAT_ERR), rcs);
474	ErrorAlert(str);
475	return false;
476	}
477	return true;
478	}
479
480
481	/*
482	* Deallocate Kernel Data segments
483	*/
484
485	static void kernel_data_exit(void)
486	{
487	if (kernel_handle) {
488	UnmapViewOfFile(Mac2HostAddr(KERNEL_DATA_BASE & -allocation_granule));
489	UnmapViewOfFile(Mac2HostAddr(KERNEL_DATA2_BASE & -allocation_granule));
490	CloseHandle(kernel_handle);
491	}
492	}
493
494
495	/*
496	* Jump into Mac ROM, start 680x0 emulator
497	*/
498
499	void jump_to_rom(uint32 entry)
500	{
501	init_emul_ppc();
502	emul_ppc(entry);
503	}
504
505
506	/*
507	* Quit emulator (cause return from jump_to_rom)
508	*/
509
510	void QuitEmulator(void)
511	{
512	Quit();
513	}
514
515
516	/*
517	* Pause/resume emulator
518	*/
519
520	void PauseEmulator(void)
521	{
522	SuspendThread(emul_thread);
523	}
524
525	void ResumeEmulator(void)
526	{
527	ResumeThread(emul_thread);
528	}
529
530
531	/*
532	* Dump 68k registers
533	*/
534
535	void Dump68kRegs(M68kRegisters *r)
536	{
537	// Display 68k registers
538	for (int i=0; i<8; i++) {
539	printf("d%d: %08x", i, r->d[i]);
540	if (i == 3 \|\| i == 7)
541	printf("\n");
542	else
543	printf(", ");
544	}
545	for (int i=0; i<8; i++) {
546	printf("a%d: %08x", i, r->a[i]);
547	if (i == 3 \|\| i == 7)
548	printf("\n");
549	else
550	printf(", ");
551	}
552	}
553
554
555	/*
556	* Make code executable
557	*/
558
559	void MakeExecutable(int dummy, uint32 start, uint32 length)
560	{
561	if ((start >= ROM_BASE) && (start < (ROM_BASE + ROM_SIZE)))
562	return;
563	FlushCodeCache(start, start + length);
564	}
565
566
567	/*
568	* NVRAM watchdog thread (saves NVRAM every minute)
569	*/
570
571	static void nvram_watchdog(void)
572	{
573	if (memcmp(last_xpram, XPRAM, XPRAM_SIZE)) {
574	memcpy(last_xpram, XPRAM, XPRAM_SIZE);
575	SaveXPRAM();
576	}
577	}
578
579	static DWORD nvram_func(void *arg)
580	{
581	while (!nvram_thread_cancel) {
582	for (int i=0; i<60 && !nvram_thread_cancel; i++)
583	Delay_usec(999999); // Only wait 1 second so we quit promptly when nvram_thread_cancel becomes true
584	nvram_watchdog();
585	}
586	return 0;
587	}
588
589
590	/*
591	* 60Hz thread (really 60.15Hz)
592	*/
593
594	static DWORD tick_func(void *arg)
595	{
596	int tick_counter = 0;
597	uint64 start = GetTicks_usec();
598	int64 ticks = 0;
599	uint64 next = GetTicks_usec();
600
601	while (!tick_thread_cancel) {
602
603	// Wait
604	next += 16625;
605	int64 delay = next - GetTicks_usec();
606	if (delay > 0)
607	Delay_usec(delay);
608	else if (delay < -16625)
609	next = GetTicks_usec();
610	ticks++;
611
612	// Pseudo Mac 1Hz interrupt, update local time
613	if (++tick_counter > 60) {
614	tick_counter = 0;
615	WriteMacInt32(0x20c, TimerDateTime());
616	}
617
618	// Trigger 60Hz interrupt
619	if (ReadMacInt32(XLM_IRQ_NEST) == 0) {
620	SetInterruptFlag(INTFLAG_VIA);
621	TriggerInterrupt();
622	}
623	}
624
625	uint64 end = GetTicks_usec();
626	D(bug("%Ld ticks in %Ld usec = %f ticks/sec\n", ticks, end - start, ticks * 1000000.0 / (end - start)));
627	return 0;
628	}
629
630
631	/*
632	* Mutexes
633	*/
634
635	struct B2_mutex {
636	mutex_t m;
637	};
638
639	B2_mutex *B2_create_mutex(void)
640	{
641	return new B2_mutex;
642	}
643
644	void B2_lock_mutex(B2_mutex *mutex)
645	{
646	mutex->m.lock();
647	}
648
649	void B2_unlock_mutex(B2_mutex *mutex)
650	{
651	mutex->m.unlock();
652	}
653
654	void B2_delete_mutex(B2_mutex *mutex)
655	{
656	delete mutex;
657	}
658
659
660	/*
661	* Interrupt flags (must be handled atomically!)
662	*/
663
664	volatile uint32 InterruptFlags = 0;
665	static mutex_t intflags_mutex;
666
667	void SetInterruptFlag(uint32 flag)
668	{
669	intflags_mutex.lock();
670	InterruptFlags \|= flag;
671	intflags_mutex.unlock();
672	}
673
674	void ClearInterruptFlag(uint32 flag)
675	{
676	intflags_mutex.lock();
677	InterruptFlags &= ~flag;
678	intflags_mutex.unlock();
679	}
680
681
682	/*
683	* Disable interrupts
684	*/
685
686	void DisableInterrupt(void)
687	{
688	WriteMacInt32(XLM_IRQ_NEST, int32(ReadMacInt32(XLM_IRQ_NEST)) + 1);
689	}
690
691
692	/*
693	* Enable interrupts
694	*/
695
696	void EnableInterrupt(void)
697	{
698	WriteMacInt32(XLM_IRQ_NEST, int32(ReadMacInt32(XLM_IRQ_NEST)) - 1);
699	}
700
701
702	/*
703	* Helpers to share 32-bit addressable data with MacOS
704	*/
705
706	bool SheepMem::Init(void)
707	{
708	// Size of a native page
709	page_size = vm_get_page_size();
710
711	// Allocate SheepShaver globals
712	proc = base;
713	if (vm_mac_acquire(base, size) < 0)
714	return false;
715
716	// Allocate page with all bits set to 0, right in the middle
717	// This is also used to catch undesired overlaps between proc and data areas
718	zero_page = proc + (size / 2);
719	Mac_memset(zero_page, 0, page_size);
720	if (vm_protect(Mac2HostAddr(zero_page), page_size, VM_PAGE_READ) < 0)
721	return false;
722
723	// Allocate alternate stack for PowerPC interrupt routine
724	sig_stack = base + size;
725	if (vm_mac_acquire(sig_stack, SIG_STACK_SIZE) < 0)
726	return false;
727
728	data = base + size;
729	return true;
730	}
731
732	void SheepMem::Exit(void)
733	{
734	if (data) {
735	// Delete SheepShaver globals
736	vm_mac_release(base, size);
737
738	// Delete alternate stack for PowerPC interrupt routine
739	vm_mac_release(sig_stack, SIG_STACK_SIZE);
740	}
741	}
742
743
744	/*
745	* Get the main window handle
746	*/
747
748	#ifdef USE_SDL_VIDEO
749	#include <SDL_syswm.h>
750	static HWND GetMainWindowHandle(void)
751	{
752	SDL_SysWMinfo wmInfo;
753	wmInfo.version.major = SDL_MAJOR_VERSION;
754	wmInfo.version.minor = SDL_MINOR_VERSION;
755	wmInfo.version.patch = SDL_PATCHLEVEL;
756	return SDL_GetWMInfo(&wmInfo) ? wmInfo.window : NULL;
757	}
758	#endif
759
760
761	/*
762	* Display alert
763	*/
764
765	static void display_alert(int title_id, const char *text, int flags)
766	{
767	HWND hMainWnd = GetMainWindowHandle();
768	MessageBox(hMainWnd, text, GetString(title_id), MB_OK \| flags);
769	}
770
771
772	/*
773	* Display error alert
774	*/
775
776	void ErrorAlert(const char *text)
777	{
778	if (PrefsFindBool("nogui"))
779	return;
780
781	VideoQuitFullScreen();
782	display_alert(STR_ERROR_ALERT_TITLE, text, MB_ICONSTOP);
783	}
784
785
786	/*
787	* Display warning alert
788	*/
789
790	void WarningAlert(const char *text)
791	{
792	if (PrefsFindBool("nogui"))
793	return;
794
795	display_alert(STR_WARNING_ALERT_TITLE, text, MB_ICONINFORMATION);
796	}
797
798
799	/*
800	* Display choice alert
801	*/
802
803	bool ChoiceAlert(const char text, const char pos, const char *neg)
804	{
805	printf(GetString(STR_SHELL_WARNING_PREFIX), text);
806	return false; //!!
807	}