src/Unix/main_unix.cpp

/*
 *  main_unix.cpp - Emulation core, Unix implementation
 *
 *  SheepShaver (C) 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
 */

/*
 *  NOTES:
 *
 *  See main_beos.cpp for a description of the three operating modes.
 *
 *  In addition to that, we have to handle the fact that the MacOS ABI
 *  is slightly different from the SysV ABI used by Linux:
 *    - Stack frames are different (e.g. LR is stored in 8(r1) under
 *      MacOS, but in 4(r1) under Linux)
 *    - There is a pointer to Thread Local Storage (TLS) under Linux with
 *      recent enough glibc. This is r2 in 32-bit mode and r13 in
 *      64-bit mode (PowerOpen/AIX ABI)
 *    - r13 is used as a small data pointer under Linux (but appearently
 *      it is not used this way? To be sure, we specify -msdata=none
 *      in the Makefile)
 *    - There are no TVECTs under Linux; function pointers point
 *      directly to the function code
 *  The Execute*() functions have to account for this. Additionally, we
 *  cannot simply call MacOS functions by getting their TVECT and jumping
 *  to it. Such calls are done via the call_macos*() functions in
 *  asm_linux.S that create a MacOS stack frame, load the TOC pointer
 *  and put the arguments into the right registers.
 *
 *  As on the BeOS, we have to specify an alternate signal stack because
 *  interrupts (and, under Linux, Low Memory accesses) may occur when r1
 *  is pointing to the Kernel Data or to Low Memory. There is one
 *  problem, however, due to the alternate signal stack being global to
 *  all signal handlers. Consider the following scenario:
 *    - The main thread is executing some native PPC MacOS code in
 *      MODE_NATIVE, running on the MacOS stack (somewhere in the Mac RAM).
 *    - A SIGUSR2 interrupt occurs. The kernel switches to the signal
 *      stack and starts executing the SIGUSR2 signal handler.
 *    - The signal handler sees the MODE_NATIVE and calls ppc_interrupt()
 *      to handle a native interrupt.
 *    - ppc_interrupt() sets r1 to point to the Kernel Data and jumps to
 *      the nanokernel.
 *    - The nanokernel accesses a Low Memory global (most likely one of
 *      the XLMs), a SIGSEGV occurs.
 *    - The kernel sees that r1 does not point to the signal stack and
 *      switches to the signal stack again, thus overwriting the data that
 *      the SIGUSR2 handler put there.
 *  The same problem arises when calling ExecutePPC() inside the MODE_EMUL_OP
 *  interrupt handler.
 *
 *  The solution is to set the signal stack to a second, "extra" stack
 *  inside the SIGUSR2 handler before entering the Nanokernel or calling
 *  ExecutePPC (or any function that might cause a mode switch). The signal
 *  stack is restored before exiting the SIGUSR2 handler.
 *
 *  Note that POSIX standard says you can't modify the alternate
 *  signal stack while the process is executing on it. There is a
 *  hackaround though: we install a trampoline SIGUSR2 handler that
 *  sets up an alternate stack itself and calls the real handler.
 *  Then, when we call sigaltstack() there, we no longer get an EPERM,
 *  i.e. it now works.
 *
 *  TODO:
 *    check if SIGSEGV handler works for all registers (including FP!)
 */

#include <unistd.h>
#include <fcntl.h>
#include <time.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <sys/mman.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/stat.h>
#include <signal.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 "sigregs.h"
#include "rpc.h"

#define DEBUG 0
#include "debug.h"


#ifdef HAVE_DIRENT_H
#include <dirent.h>
#endif

#ifdef USE_SDL
#include <SDL.h>
#endif

#ifndef USE_SDL_VIDEO
#include <X11/Xlib.h>
#endif

#ifdef ENABLE_GTK
#include <gtk/gtk.h>
#endif

#ifdef ENABLE_XF86_DGA
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/extensions/Xxf86dga.h>
#endif

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


// Enable emulation of unaligned lmw/stmw?
#define EMULATE_UNALIGNED_LOADSTORE_MULTIPLE 1

// Enable Execute68k() safety checks?
#define SAFE_EXEC_68K 0

// Interrupts in EMUL_OP mode?
#define INTERRUPTS_IN_EMUL_OP_MODE 1

// Interrupts in native mode?
#define INTERRUPTS_IN_NATIVE_MODE 1


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

#if !REAL_ADDRESSING
// FIXME: needs to be >= 0x04000000
const uintptr RAM_BASE = 0x10000000;            // Base address of RAM
#endif
const uintptr ROM_BASE = 0x40800000;            // Base address of ROM
#if REAL_ADDRESSING
const uint32 ROM_ALIGNMENT = 0x100000;          // ROM must be aligned to a 1MB boundary
#endif
const uint32 SIG_STACK_SIZE = 0x10000;          // Size of signal stack


// Global variables (exported)
#if !EMULATED_PPC
void *TOC = NULL;               // Pointer to Thread Local Storage (r2)
void *R13 = NULL;               // Pointer to .sdata section (r13 under Linux)
#endif
uint32 RAMBase;                 // Base address of Mac RAM
uint32 RAMSize;                 // Size of Mac RAM
uint32 ROMBase;                 // Base address of Mac ROM
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
#ifndef USE_SDL_VIDEO
char *x_display_name = NULL;                            // X11 display name
Display *x_display = NULL;                                      // X11 display handle
#ifdef X11_LOCK_TYPE
X11_LOCK_TYPE x_display_lock = X11_LOCK_INIT; // X11 display lock
#endif
#endif

static int zero_fd = 0;                                         // FD of /dev/zero
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 pthread_t nvram_thread;                          // NVRAM watchdog
static bool tick_thread_active = false;         // Flag: MacOS thread installed
static volatile bool tick_thread_cancel;        // Flag: Cancel 60Hz thread
static pthread_t tick_thread;                           // 60Hz thread
static pthread_t emul_thread;                           // MacOS thread

static bool ready_for_signals = false;          // Handler installed, signals can be sent
static int64 num_segv = 0;                                      // Number of handled SEGV signals

static struct sigaction sigusr2_action;         // Interrupt signal (of emulator thread)
#if EMULATED_PPC
static uintptr sig_stack = 0;                           // Stack for PowerPC interrupt routine
#else
static struct sigaction sigsegv_action;         // Data access exception signal (of emulator thread)
static struct sigaction sigill_action;          // Illegal instruction signal (of emulator thread)
static stack_t sig_stack;                                       // Stack for signal handlers
static stack_t extra_stack;                                     // Stack for SIGSEGV inside interrupt handler
static bool emul_thread_fatal = false;          // Flag: MacOS thread crashed, tick thread shall dump debug output
static sigregs sigsegv_regs;                            // Register dump when crashed
static const char *crash_reason = NULL;         // Reason of the crash (SIGSEGV, SIGBUS, SIGILL)
#endif

static rpc_connection_t *gui_connection = NULL; // RPC connection to the GUI
static const char *gui_connection_path = NULL;  // GUI connection identifier

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 void *emul_func(void *arg);
static void *nvram_func(void *arg);
static void *tick_func(void *arg);
#if EMULATED_PPC
extern void emul_ppc(uint32 start);
extern void init_emul_ppc(void);
extern void exit_emul_ppc(void);
sigsegv_return_t sigsegv_handler(sigsegv_info_t *sip);
#else
extern "C" void sigusr2_handler_init(int sig, siginfo_t *sip, void *scp);
extern "C" void sigusr2_handler(int sig, siginfo_t *sip, void *scp);
static void sigsegv_handler(int sig, siginfo_t *sip, void *scp);
static void sigill_handler(int sig, siginfo_t *sip, void *scp);
#endif


// From asm_linux.S
#if !EMULATED_PPC
extern "C" void *get_sp(void);
extern "C" void *get_r2(void);
extern "C" void set_r2(void *);
extern "C" void *get_r13(void);
extern "C" void set_r13(void *);
extern "C" void flush_icache_range(uint32 start, uint32 end);
extern "C" void jump_to_rom(uint32 entry, uint32 context);
extern "C" void quit_emulator(void);
extern "C" void execute_68k(uint32 pc, M68kRegisters *r);
extern "C" void ppc_interrupt(uint32 entry, uint32 kernel_data);
extern "C" int atomic_add(int *var, int v);
extern "C" int atomic_and(int *var, int v);
extern "C" int atomic_or(int *var, int v);
extern void paranoia_check(void);
#endif


#if EMULATED_PPC
/*
 *  Return signal stack base
 */

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


/*
 *  Atomic operations
 */

#if HAVE_SPINLOCKS
static spinlock_t atomic_ops_lock = SPIN_LOCK_UNLOCKED;
#else
#define spin_lock(LOCK)
#define spin_unlock(LOCK)
#endif

int atomic_add(int *var, int v)
{
        spin_lock(&atomic_ops_lock);
        int ret = *var;
        *var += v;
        spin_unlock(&atomic_ops_lock);
        return ret;
}

int atomic_and(int *var, int v)
{
        spin_lock(&atomic_ops_lock);
        int ret = *var;
        *var &= v;
        spin_unlock(&atomic_ops_lock);
        return ret;
}

int atomic_or(int *var, int v)
{
        spin_lock(&atomic_ops_lock);
        int ret = *var;
        *var |= v;
        spin_unlock(&atomic_ops_lock);
        return ret;
}
#endif


/*
 *  Memory management helpers
 */

static inline uint8 *vm_mac_acquire(uint32 size)
{
        return (uint8 *)vm_acquire(size);
}

static inline int vm_mac_acquire_fixed(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);
}

static bool valid_vmdir(const char *path)
{
        const int suffix_len = sizeof(".sheepvm") - 1;
        int len = strlen(path);
        if (len && path[len - 1] == '/') // to support both ".sheepvm" and ".sheepvm/"
                len--;
        if (len > suffix_len && !strncmp(path + len - suffix_len, ".sheepvm", suffix_len)) {
                struct stat d;
                if (!stat(path, &d) && S_ISDIR(d.st_mode)) {
                        return true;
                }
        }
        return false;
}

static void get_system_info(void)
{
#if !EMULATED_PPC
        FILE *proc_file;
#endif

        PVR = 0x00040000;                       // Default: 604
        CPUClockSpeed = 100000000;      // Default: 100MHz
        BusClockSpeed = 100000000;      // Default: 100MHz
        TimebaseSpeed =  25000000;      // Default:  25MHz

#if EMULATED_PPC
        PVR = 0x000c0000;                       // Default: 7400 (with AltiVec)
#elif defined(__APPLE__) && defined(__MACH__)
        proc_file = popen("ioreg -c IOPlatformDevice", "r");
        if (proc_file) {
                char line[256];
                bool powerpc_node = false;
                while (fgets(line, sizeof(line) - 1, proc_file)) {
                        // Read line
                        int len = strlen(line);
                        if (len == 0)
                                continue;
                        line[len - 1] = 0;

                        // Parse line
                        if (strstr(line, "o PowerPC,"))
                                powerpc_node = true;
                        else if (powerpc_node) {
                                uint32 value;
                                char head[256];
                                if (sscanf(line, "%[ |]\"cpu-version\" = <%x>", head, &value) == 2)
                                        PVR = value;
                                else if (sscanf(line, "%[ |]\"clock-frequency\" = <%x>", head, &value) == 2)
                                        CPUClockSpeed = value;
                                else if (sscanf(line, "%[ |]\"bus-frequency\" = <%x>", head, &value) == 2)
                                        BusClockSpeed = value;
                                else if (sscanf(line, "%[ |]\"timebase-frequency\" = <%x>", head, &value) == 2)
                                        TimebaseSpeed = value;
                                else if (strchr(line, '}'))
                                        powerpc_node = false;
                        }
                }
                fclose(proc_file);
        } else {
                char str[256];
                sprintf(str, GetString(STR_PROC_CPUINFO_WARN), strerror(errno));
                WarningAlert(str);
        }
#else
        proc_file = fopen("/proc/cpuinfo", "r");
        if (proc_file) {
                // CPU specs from Linux kernel
                // TODO: make it more generic with features (e.g. AltiVec) and
                // cache information and friends for NameRegistry
                static const struct {
                        uint32 pvr_mask;
                        uint32 pvr_value;
                        const char *cpu_name;
                }
                cpu_specs[] = {
                        { 0xffff0000, 0x00010000, "601" },
                        { 0xffff0000, 0x00030000, "603" },
                        { 0xffff0000, 0x00060000, "603e" },
                        { 0xffff0000, 0x00070000, "603ev" },
                        { 0xffff0000, 0x00040000, "604" },
                        { 0xfffff000, 0x00090000, "604e" },
                        { 0xffff0000, 0x00090000, "604r" },
                        { 0xffff0000, 0x000a0000, "604ev" },
                        { 0xffffffff, 0x00084202, "740/750" },
                        { 0xfffff000, 0x00083000, "745/755" },
                        { 0xfffffff0, 0x00080100, "750CX" },
                        { 0xfffffff0, 0x00082200, "750CX" },
                        { 0xfffffff0, 0x00082210, "750CXe" },
                        { 0xffffff00, 0x70000100, "750FX" },
                        { 0xffffffff, 0x70000200, "750FX" },
                        { 0xffff0000, 0x70000000, "750FX" },
                        { 0xffff0000, 0x70020000, "750GX" },
                        { 0xffff0000, 0x00080000, "740/750" },
                        { 0xffffffff, 0x000c1101, "7400 (1.1)" },
                        { 0xffff0000, 0x000c0000, "7400" },
                        { 0xffff0000, 0x800c0000, "7410" },
                        { 0xffffffff, 0x80000200, "7450" },
                        { 0xffffffff, 0x80000201, "7450" },
                        { 0xffff0000, 0x80000000, "7450" },
                        { 0xffffff00, 0x80010100, "7455" },
                        { 0xffffffff, 0x80010200, "7455" },
                        { 0xffff0000, 0x80010000, "7455" },
                        { 0xffff0000, 0x80020000, "7457" },
                        { 0xffff0000, 0x80030000, "7447A" },
                        { 0xffff0000, 0x80040000, "7448" },
                        { 0x7fff0000, 0x00810000, "82xx" },
                        { 0x7fff0000, 0x00820000, "8280" },
                        { 0xffff0000, 0x00400000, "Power3 (630)" },
                        { 0xffff0000, 0x00410000, "Power3 (630+)" },
                        { 0xffff0000, 0x00360000, "I-star" },
                        { 0xffff0000, 0x00370000, "S-star" },
                        { 0xffff0000, 0x00350000, "Power4" },
                        { 0xffff0000, 0x00390000, "PPC970" },
                        { 0xffff0000, 0x003c0000, "PPC970FX" },
                        { 0xffff0000, 0x00440000, "PPC970MP" },
                        { 0xffff0000, 0x003a0000, "POWER5 (gr)" },
                        { 0xffff0000, 0x003b0000, "POWER5+ (gs)" },
                        { 0xffff0000, 0x003e0000, "POWER6" },
                        { 0xffff0000, 0x00700000, "Cell Broadband Engine" },
                        { 0x7fff0000, 0x00900000, "PA6T" },
                        { 0, 0, 0 }
                };

                char line[256];
                while(fgets(line, 255, proc_file)) {
                        // Read line
                        int len = strlen(line);
                        if (len == 0)
                                continue;
                        line[len-1] = 0;

                        // Parse line
                        int i;
                        float f;
                        char value[256];
                        if (sscanf(line, "cpu : %[^,]", value) == 1) {
                                // Search by name
                                const char *cpu_name = NULL;
                                for (int i = 0; cpu_specs[i].pvr_mask != 0; i++) {
                                        if (strcmp(cpu_specs[i].cpu_name, value) == 0) {
                                                cpu_name = cpu_specs[i].cpu_name;
                                                PVR = cpu_specs[i].pvr_value;
                                                break;
                                        }
                                }
                                if (cpu_name == NULL)
                                        printf("WARNING: Unknown CPU type '%s', assuming 604\n", value);
                                else
                                        printf("Found a PowerPC %s processor\n", cpu_name);
                        }
                        if (sscanf(line, "clock : %fMHz", &f) == 1)
                                CPUClockSpeed = BusClockSpeed = ((int64)f) * 1000000;
                        else if (sscanf(line, "clock : %dMHz", &i) == 1)
                                CPUClockSpeed = BusClockSpeed = i * 1000000;
                }
                fclose(proc_file);
        } else {
                char str[256];
                sprintf(str, GetString(STR_PROC_CPUINFO_WARN), strerror(errno));
                WarningAlert(str);
        }

        // Get actual bus frequency
        proc_file = fopen("/proc/device-tree/clock-frequency", "r");
        if (proc_file) {
                union { uint8 b[4]; uint32 l; } value;
                if (fread(value.b, sizeof(value), 1, proc_file) == 1)
                        BusClockSpeed = value.l;
                fclose(proc_file);
        }

        // Get actual timebase frequency
        TimebaseSpeed = BusClockSpeed / 4;
        DIR *cpus_dir;
        if ((cpus_dir = opendir("/proc/device-tree/cpus")) != NULL) {
                struct dirent *cpu_entry;
                while ((cpu_entry = readdir(cpus_dir)) != NULL) {
                        if (strstr(cpu_entry->d_name, "PowerPC,") == cpu_entry->d_name) {
                                char timebase_freq_node[256];
                                sprintf(timebase_freq_node, "/proc/device-tree/cpus/%s/timebase-frequency", cpu_entry->d_name);
                                proc_file = fopen(timebase_freq_node, "r");
                                if (proc_file) {
                                        union { uint8 b[4]; uint32 l; } value;
                                        if (fread(value.b, sizeof(value), 1, proc_file) == 1)
                                                TimebaseSpeed = value.l;
                                        fclose(proc_file);
                                }
                        }
                }
                closedir(cpus_dir);
        }
#endif

        // Remap any newer G4/G5 processor to plain G4 for compatibility
        switch (PVR >> 16) {
        case 0x8000:                            // 7450
        case 0x8001:                            // 7455
        case 0x8002:                            // 7457
        case 0x8003:                            // 7447A
        case 0x8004:                            // 7448
        case 0x0039:                            //  970
        case 0x003c:                            //  970FX
        case 0x0044:                            //  970MP
                PVR = 0x000c0000;               // 7400
                break;
        }
        D(bug("PVR: %08x (assumed)\n", PVR));
}

static bool load_mac_rom(void)
{
        uint32 rom_size, actual;
        uint8 *rom_tmp;
        const char *rom_path = PrefsFindString("rom");
        int rom_fd = open(rom_path && *rom_path ? rom_path : ROM_FILE_NAME, O_RDONLY);
        if (rom_fd < 0) {
                rom_fd = open(ROM_FILE_NAME2, O_RDONLY);
                if (rom_fd < 0) {
                        ErrorAlert(GetString(STR_NO_ROM_FILE_ERR));
                        return false;
                }
        }
        printf("%s", GetString(STR_READING_ROM_FILE));
        rom_size = lseek(rom_fd, 0, SEEK_END);
        lseek(rom_fd, 0, SEEK_SET);
        rom_tmp = new uint8[ROM_SIZE];
        actual = read(rom_fd, (void *)rom_tmp, ROM_SIZE);
        close(rom_fd);
        
        // Decode Mac ROM
        if (!DecodeROM(rom_tmp, actual)) {
                if (rom_size != 4*1024*1024) {
                        ErrorAlert(GetString(STR_ROM_SIZE_ERR));
                        return false;
                } else {
                        ErrorAlert(GetString(STR_ROM_FILE_READ_ERR));
                        return false;
                }
        }
        delete[] rom_tmp;
        return true;
}

static bool install_signal_handlers(void)
{
        char str[256];
#if !EMULATED_PPC
        // Create and install stacks for signal handlers
        sig_stack.ss_sp = malloc(SIG_STACK_SIZE);
        D(bug("Signal stack at %p\n", sig_stack.ss_sp));
        if (sig_stack.ss_sp == NULL) {
                ErrorAlert(GetString(STR_NOT_ENOUGH_MEMORY_ERR));
                return false;
        }
        sig_stack.ss_flags = 0;
        sig_stack.ss_size = SIG_STACK_SIZE;
        if (sigaltstack(&sig_stack, NULL) < 0) {
                sprintf(str, GetString(STR_SIGALTSTACK_ERR), strerror(errno));
                ErrorAlert(str);
                return false;
        }
        extra_stack.ss_sp = malloc(SIG_STACK_SIZE);
        D(bug("Extra stack at %p\n", extra_stack.ss_sp));
        if (extra_stack.ss_sp == NULL) {
                ErrorAlert(GetString(STR_NOT_ENOUGH_MEMORY_ERR));
                return false;
        }
        extra_stack.ss_flags = 0;
        extra_stack.ss_size = SIG_STACK_SIZE;

        // Install SIGSEGV and SIGBUS handlers
        sigemptyset(&sigsegv_action.sa_mask);   // Block interrupts during SEGV handling
        sigaddset(&sigsegv_action.sa_mask, SIGUSR2);
        sigsegv_action.sa_sigaction = sigsegv_handler;
        sigsegv_action.sa_flags = SA_ONSTACK | SA_SIGINFO;
#ifdef HAVE_SIGNAL_SA_RESTORER
        sigsegv_action.sa_restorer = NULL;
#endif
        if (sigaction(SIGSEGV, &sigsegv_action, NULL) < 0) {
                sprintf(str, GetString(STR_SIG_INSTALL_ERR), "SIGSEGV", strerror(errno));
                ErrorAlert(str);
                return false;
        }
        if (sigaction(SIGBUS, &sigsegv_action, NULL) < 0) {
                sprintf(str, GetString(STR_SIG_INSTALL_ERR), "SIGBUS", strerror(errno));
                ErrorAlert(str);
                return false;
        }
#else
        // Install SIGSEGV handler for CPU emulator
        if (!sigsegv_install_handler(sigsegv_handler)) {
                sprintf(str, GetString(STR_SIG_INSTALL_ERR), "SIGSEGV", strerror(errno));
                ErrorAlert(str);
                return false;
        }
#endif
        return true;
}

#ifdef USE_SDL
static bool init_sdl()
{
        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);

#ifdef USE_SDL_VIDEO
        // Don't let SDL block the screensaver
        setenv("SDL_VIDEO_ALLOW_SCREENSAVER", "1", TRUE);

        // Make SDL pass through command-clicks and option-clicks unaltered
        setenv("SDL_HAS3BUTTONMOUSE", "1", TRUE);
#endif

        if (SDL_Init(sdl_flags) == -1) {
                char str[256];
                sprintf(str, "Could not initialize SDL: %s.\n", SDL_GetError());
                ErrorAlert(str);
                return false;
        }
        atexit(SDL_Quit);

        // Don't let SDL catch SIGINT and SIGTERM signals
        signal(SIGINT, SIG_DFL);
        signal(SIGTERM, SIG_DFL);
        return true;
}
#endif

int main(int argc, char **argv)
{
        char str[256];
        bool memory_mapped_from_zero, ram_rom_areas_contiguous;
        const char *vmdir = NULL;

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

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

#if !EMULATED_PPC
#ifdef SYSTEM_CLOBBERS_R2
        // Get TOC pointer
        TOC = get_r2();
#endif
#ifdef SYSTEM_CLOBBERS_R13
        // Get r13 register
        R13 = get_r13();
#endif
#endif

        // Parse command line arguments
        for (int i=1; i<argc; i++) {
                if (strcmp(argv[i], "--help") == 0) {
                        usage(argv[0]);
#ifndef USE_SDL_VIDEO
                } else if (strcmp(argv[i], "--display") == 0) {
                        i++;
                        if (i < argc)
                                x_display_name = strdup(argv[i]);
#endif
                } else if (strcmp(argv[i], "--gui-connection") == 0) {
                        argv[i++] = NULL;
                        if (i < argc) {
                                gui_connection_path = argv[i];
                                argv[i] = NULL;
                        }
                } else if (valid_vmdir(argv[i])) {
                        vmdir = argv[i];
                        argv[i] = NULL;
                        printf("Using %s as vmdir.\n", vmdir);
                        if (chdir(vmdir)) {
                                printf("Failed to chdir to %s. Good bye.", vmdir);
                                exit(1);
                        }
                        break;
                }
        }

        // Remove processed arguments
        for (int i=1; i<argc; i++) {
                int k;
                for (k=i; k<argc; k++)
                        if (argv[k] != NULL)
                                break;
                if (k > i) {
                        k -= i;
                        for (int j=i+k; j<argc; j++)
                                argv[j-k] = argv[j];
                        argc -= k;
                }
        }

        // Connect to the external GUI
        if (gui_connection_path) {
                if ((gui_connection = rpc_init_client(gui_connection_path)) == NULL) {
                        fprintf(stderr, "Failed to initialize RPC client connection to the GUI\n");
                        return 1;
                }
        }

#ifdef ENABLE_GTK
        if (!gui_connection) {
                // Init GTK
                gtk_set_locale();
                gtk_init(&argc, &argv);
        }
#endif

        // Read preferences
        PrefsInit(vmdir, argc, argv);

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

#ifdef USE_SDL
        // Initialize SDL system
        if (!init_sdl())
                goto quit;
#endif

#ifndef USE_SDL_VIDEO
        // Open display
        x_display = XOpenDisplay(x_display_name);
        if (x_display == NULL) {
                char str[256];
                sprintf(str, GetString(STR_NO_XSERVER_ERR), XDisplayName(x_display_name));
                ErrorAlert(str);
                goto quit;
        }

#if defined(ENABLE_XF86_DGA) && !defined(ENABLE_MON)
        // Fork out, so we can return from fullscreen mode when things get ugly
        XF86DGAForkApp(DefaultScreen(x_display));
#endif
#endif

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

  // Install signal handlers
        if (!install_signal_handlers())
                goto quit;

        // Initialize VM system
        vm_init();

        // Get system info
        get_system_info();

        // Init system routines
        SysInit();

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

#if !EMULATED_PPC
        // Check some things
        paranoia_check();
#endif

        // Open /dev/zero
        zero_fd = open("/dev/zero", O_RDWR);
        if (zero_fd < 0) {
                sprintf(str, GetString(STR_NO_DEV_ZERO_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }

        // 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_fixed(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_fixed(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;
#if !EMULATED_PPC
        if (vm_protect((char *)DR_CACHE_BASE, DR_CACHE_SIZE, VM_PAGE_READ | VM_PAGE_WRITE | VM_PAGE_EXECUTE) < 0) {
                sprintf(str, GetString(STR_DR_CACHE_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
#endif
        DRCacheAddr = DR_CACHE_BASE;
        D(bug("DR Cache at %p\n", DRCacheAddr));

        // 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 RAM
        RAMSize = PrefsFindInt32("ramsize");
        if (RAMSize < 8*1024*1024) {
                WarningAlert(GetString(STR_SMALL_RAM_WARN));
                RAMSize = 8*1024*1024;
        }
        memory_mapped_from_zero = false;
        ram_rom_areas_contiguous = false;
#if REAL_ADDRESSING && HAVE_LINKER_SCRIPT
        if (vm_mac_acquire_fixed(0, RAMSize) == 0) {
                D(bug("Could allocate RAM from 0x0000\n"));
                RAMBase = 0;
                RAMBaseHost = Mac2HostAddr(RAMBase);
                memory_mapped_from_zero = true;
        }
#endif
        if (!memory_mapped_from_zero) {
#ifndef PAGEZERO_HACK
                // Create Low Memory area (0x0000..0x3000)
                if (vm_mac_acquire_fixed(0, 0x3000) < 0) {
                        sprintf(str, GetString(STR_LOW_MEM_MMAP_ERR), strerror(errno));
                        ErrorAlert(str);
                        goto quit;
                }
                lm_area_mapped = true;
#endif
#if REAL_ADDRESSING
                // Allocate RAM at any address. Since ROM must be higher than RAM, allocate the RAM
                // and ROM areas contiguously, plus a little extra to allow for ROM address alignment.
                RAMBaseHost = vm_mac_acquire(RAMSize + ROM_AREA_SIZE + ROM_ALIGNMENT);
                if (RAMBaseHost == VM_MAP_FAILED) {
                        sprintf(str, GetString(STR_RAM_ROM_MMAP_ERR), strerror(errno));
                        ErrorAlert(str);
                        goto quit;
                }
                RAMBase = Host2MacAddr(RAMBaseHost);
                ROMBase = (RAMBase + RAMSize + ROM_ALIGNMENT -1) & -ROM_ALIGNMENT;
                ROMBaseHost = Mac2HostAddr(ROMBase);
                ram_rom_areas_contiguous = true;
#else
                if (vm_mac_acquire_fixed(RAM_BASE, RAMSize) < 0) {
                        sprintf(str, GetString(STR_RAM_MMAP_ERR), strerror(errno));
                        ErrorAlert(str);
                        goto quit;
                }
                RAMBase = RAM_BASE;
                RAMBaseHost = Mac2HostAddr(RAMBase);
#endif
        }
#if !EMULATED_PPC
        if (vm_protect(RAMBaseHost, RAMSize, VM_PAGE_READ | VM_PAGE_WRITE | VM_PAGE_EXECUTE) < 0) {
                sprintf(str, GetString(STR_RAM_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
#endif
        ram_area_mapped = true;
        D(bug("RAM area at %p (%08x)\n", RAMBaseHost, RAMBase));

        if (RAMBase > KernelDataAddr) {
                ErrorAlert(GetString(STR_RAM_AREA_TOO_HIGH_ERR));
                goto quit;
        }
        
        // Create area for Mac ROM
        if (!ram_rom_areas_contiguous) {
                if (vm_mac_acquire_fixed(ROM_BASE, ROM_AREA_SIZE) < 0) {
                        sprintf(str, GetString(STR_ROM_MMAP_ERR), strerror(errno));
                        ErrorAlert(str);
                        goto quit;
                }
                ROMBase = ROM_BASE;
                ROMBaseHost = Mac2HostAddr(ROMBase);
        }
#if !EMULATED_PPC
        if (vm_protect(ROMBaseHost, ROM_AREA_SIZE, VM_PAGE_READ | VM_PAGE_WRITE | VM_PAGE_EXECUTE) < 0) {
                sprintf(str, GetString(STR_ROM_MMAP_ERR), strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
#endif
        rom_area_mapped = true;
        D(bug("ROM area at %p (%08x)\n", ROMBaseHost, ROMBase));

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

        // Load Mac ROM
        if (!load_mac_rom())
                goto quit;

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

        // Clear caches (as we loaded and patched code) and write protect ROM
#if !EMULATED_PPC
        flush_icache_range(ROMBase, ROMBase + ROM_AREA_SIZE);
#endif
        vm_protect(ROMBaseHost, ROM_AREA_SIZE, VM_PAGE_READ | VM_PAGE_EXECUTE);

        // Start 60Hz thread
        tick_thread_cancel = false;
        tick_thread_active = (pthread_create(&tick_thread, NULL, tick_func, NULL) == 0);
        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 = (pthread_create(&nvram_thread, NULL, nvram_func, NULL) == 0);
        D(bug("NVRAM thread installed (%ld)\n", nvram_thread));

#if !EMULATED_PPC
        // Install SIGILL handler
        sigemptyset(&sigill_action.sa_mask);    // Block interrupts during ILL handling
        sigaddset(&sigill_action.sa_mask, SIGUSR2);
        sigill_action.sa_sigaction = sigill_handler;
        sigill_action.sa_flags = SA_ONSTACK | SA_SIGINFO;
#ifdef HAVE_SIGNAL_SA_RESTORER
        sigill_action.sa_restorer = NULL;
#endif
        if (sigaction(SIGILL, &sigill_action, NULL) < 0) {
                sprintf(str, GetString(STR_SIG_INSTALL_ERR), "SIGILL", strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
#endif

#if !EMULATED_PPC
        // Install interrupt signal handler
        sigemptyset(&sigusr2_action.sa_mask);
        sigusr2_action.sa_sigaction = sigusr2_handler_init;
        sigusr2_action.sa_flags = SA_ONSTACK | SA_RESTART | SA_SIGINFO;
#ifdef HAVE_SIGNAL_SA_RESTORER
        sigusr2_action.sa_restorer = NULL;
#endif
        if (sigaction(SIGUSR2, &sigusr2_action, NULL) < 0) {
                sprintf(str, GetString(STR_SIG_INSTALL_ERR), "SIGUSR2", strerror(errno));
                ErrorAlert(str);
                goto quit;
        }
#endif

        // Get my thread ID and execute MacOS thread function
        emul_thread = pthread_self();
        D(bug("MacOS thread is %ld\n", emul_thread));
        emul_func(NULL);

quit:
        Quit();
        return 0;
}


/*
 *  Cleanup and quit
 */

static void Quit(void)
{
#if EMULATED_PPC
        // Exit PowerPC emulation
        exit_emul_ppc();
#endif

        // Stop 60Hz thread
        if (tick_thread_active) {
                tick_thread_cancel = true;
                pthread_cancel(tick_thread);
                pthread_join(tick_thread, NULL);
        }

        // Stop NVRAM watchdog thread
        if (nvram_thread_active) {
                nvram_thread_cancel = true;
                pthread_cancel(nvram_thread);
                pthread_join(nvram_thread, NULL);
        }

#if !EMULATED_PPC
        // Uninstall SIGSEGV and SIGBUS handlers
        sigemptyset(&sigsegv_action.sa_mask);
        sigsegv_action.sa_handler = SIG_DFL;
        sigsegv_action.sa_flags = 0;
        sigaction(SIGSEGV, &sigsegv_action, NULL);
        sigaction(SIGBUS, &sigsegv_action, NULL);

        // Uninstall SIGILL handler
        sigemptyset(&sigill_action.sa_mask);
        sigill_action.sa_handler = SIG_DFL;
        sigill_action.sa_flags = 0;
        sigaction(SIGILL, &sigill_action, NULL);

        // Delete stacks for signal handlers
        if (sig_stack.ss_sp)
                free(sig_stack.ss_sp);
        if (extra_stack.ss_sp)
                free(extra_stack.ss_sp);
#endif

        // Deinitialize everything
        ExitAll();

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

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

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

        // Close /dev/zero
        if (zero_fd > 0)
                close(zero_fd);

        // Exit system routines
        SysExit();

        // Exit preferences
        PrefsExit();

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

        // Close X11 server connection
#ifndef USE_SDL_VIDEO
        if (x_display)
                XCloseDisplay(x_display);
#endif

        // Notify GUI we are about to leave
        if (gui_connection) {
                if (rpc_method_invoke(gui_connection, RPC_METHOD_EXIT, RPC_TYPE_INVALID) == RPC_ERROR_NO_ERROR)
                        rpc_method_wait_for_reply(gui_connection, RPC_TYPE_INVALID);
        }

        exit(0);
}


/*
 *  Initialize Kernel Data segments
 */

static bool kernel_data_init(void)
{
        char str[256];
        void *kernel_addr1 = NULL;
        void *kernel_addr2 = NULL;
        uint32 kernel_area_size = (KERNEL_AREA_SIZE + SHMLBA - 1) & -SHMLBA;

        kernel_area = shmget(IPC_PRIVATE, kernel_area_size, 0600);
        if (kernel_area == -1) {
                sprintf(str, GetString(STR_KD_SHMGET_ERR), strerror(errno));
                goto fail_shmget;
        }
        kernel_addr1 = Mac2HostAddr(KERNEL_DATA_BASE & -SHMLBA);
        if (shmat(kernel_area, kernel_addr1, 0) != kernel_addr1) {
                sprintf(str, GetString(STR_KD_SHMAT_ERR), strerror(errno));
                goto fail_shmat1;
        }
        kernel_addr2 = Mac2HostAddr(KERNEL_DATA2_BASE & -SHMLBA);
        if (shmat(kernel_area, kernel_addr2, 0) != kernel_addr2) {
                sprintf(str, GetString(STR_KD2_SHMAT_ERR), strerror(errno));
                goto fail_shmat2;
        }
        atexit(kernel_data_exit);
        return true;

fail_shmat2:
        shmdt(kernel_addr1);
fail_shmat1:
        shmctl(kernel_area, IPC_RMID, NULL);
fail_shmget:
        ErrorAlert(str);
        return false;
}


/*
 *  Deallocate Kernel Data segments
 */

static void kernel_data_exit(void)
{
        if (kernel_area >= 0) {
                shmdt(Mac2HostAddr(KERNEL_DATA_BASE & -SHMLBA));
                shmdt(Mac2HostAddr(KERNEL_DATA2_BASE & -SHMLBA));
                shmctl(kernel_area, IPC_RMID, NULL);
                kernel_area = NULL;
        }
}


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

#if EMULATED_PPC
void jump_to_rom(uint32 entry)
{
        init_emul_ppc();
        emul_ppc(entry);
}
#endif


/*
 *  Emulator thread function
 */

static void *emul_func(void *arg)
{
        // We're now ready to receive signals
        ready_for_signals = true;

        // Decrease priority, so more time-critical things like audio will work better
        nice(1);

        // Jump to ROM boot routine
        D(bug("Jumping to ROM\n"));
#if EMULATED_PPC
        jump_to_rom(ROMBase + 0x310000);
#else
        jump_to_rom(ROMBase + 0x310000, (uint32)emulator_data);
#endif
        D(bug("Returned from ROM\n"));

        // We're no longer ready to receive signals
        ready_for_signals = false;
        return NULL;
}


#if !EMULATED_PPC
/*
 *  Execute 68k subroutine (must be ended with RTS)
 *  This must only be called by the emul_thread when in EMUL_OP mode
 *  r->a[7] is unused, the routine runs on the caller's stack
 */

void Execute68k(uint32 pc, M68kRegisters *r)
{
#if SAFE_EXEC_68K
        if (ReadMacInt32(XLM_RUN_MODE) != MODE_EMUL_OP)
                printf("FATAL: Execute68k() not called from EMUL_OP mode\n");
        if (!pthread_equal(pthread_self(), emul_thread))
                printf("FATAL: Execute68k() not called from emul_thread\n");
#endif
        execute_68k(pc, r);
}


/*
 *  Execute 68k A-Trap from EMUL_OP routine
 *  r->a[7] is unused, the routine runs on the caller's stack
 */

void Execute68kTrap(uint16 trap, M68kRegisters *r)
{
        uint16 proc[2] = {trap, M68K_RTS};
        Execute68k((uint32)proc, r);
}
#endif


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

void QuitEmulator(void)
{
#if EMULATED_PPC
        Quit();
#else
        quit_emulator();
#endif
}


/*
 *  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 >= ROMBase) && (start < (ROMBase + ROM_SIZE)))
                return;
#if EMULATED_PPC
        FlushCodeCache(start, start + length);
#else
        flush_icache_range(start, start + length);
#endif
}


/*
 *  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 void *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 NULL;
}


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

static void *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++;

#if !EMULATED_PPC
                // Did we crash?
                if (emul_thread_fatal) {

                        // Yes, dump registers
                        sigregs *r = &sigsegv_regs;
                        char str[256];
                        if (crash_reason == NULL)
                                crash_reason = "SIGSEGV!";
                        sprintf(str, "%s\n"
                                "   pc %08lx     lr %08lx    ctr %08lx    msr %08lx\n"
                                "  xer %08lx     cr %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",
                                crash_reason,
                                r->nip, r->link, r->ctr, r->msr,
                                r->xer, r->ccr,
                                r->gpr[0], r->gpr[1], r->gpr[2], r->gpr[3],
                                r->gpr[4], r->gpr[5], r->gpr[6], r->gpr[7],
                                r->gpr[8], r->gpr[9], r->gpr[10], r->gpr[11],
                                r->gpr[12], r->gpr[13], r->gpr[14], r->gpr[15],
                                r->gpr[16], r->gpr[17], r->gpr[18], r->gpr[19],
                                r->gpr[20], r->gpr[21], r->gpr[22], r->gpr[23],
                                r->gpr[24], r->gpr[25], r->gpr[26], r->gpr[27],
                                r->gpr[28], r->gpr[29], r->gpr[30], r->gpr[31]);
                        printf(str);
                        VideoQuitFullScreen();

                        {
                                static int (*backtrace_fn)(void**, int);
                                static char** (*backtrace_symbols_fn)(void* const*, int);
                                backtrace_fn = dlsym(RTLD_DEFAULT, "backtrace");
                                backtrace_symbols_fn = dlsym(RTLD_DEFAULT, "backtrace_symbols");
        void *frame_ptrs[64];
        int count = backtrace_fn(frame_ptrs, 64);
        char **fnames = backtrace_symbols_fn(frame_ptrs, count);
        int i;
        for (i = 0; i < count; i++)
                printf("%s", fnames[i]);
        free(fnames);
                        }

#ifdef ENABLE_MON
                        // Start up mon in real-mode
                        printf("Welcome to the sheep factory.\n");
                        char *arg[4] = {"mon", "-m", "-r", NULL};
                        mon(3, arg);
#endif
                        return NULL;
                }
#endif

                // 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("%lld ticks in %lld usec = %f ticks/sec\n", ticks, end - start, ticks * 1000000.0 / (end - start)));
        return NULL;
}


/*
 *  Pthread configuration
 */

void Set_pthread_attr(pthread_attr_t *attr, int priority)
{
#ifdef HAVE_PTHREADS
        pthread_attr_init(attr);
#if defined(_POSIX_THREAD_PRIORITY_SCHEDULING)
        // Some of these only work for superuser
        if (geteuid() == 0) {
                pthread_attr_setinheritsched(attr, PTHREAD_EXPLICIT_SCHED);
                pthread_attr_setschedpolicy(attr, SCHED_FIFO);
                struct sched_param fifo_param;
                fifo_param.sched_priority = ((sched_get_priority_min(SCHED_FIFO) + 
                                              sched_get_priority_max(SCHED_FIFO)) / 2 +
                                             priority);
                pthread_attr_setschedparam(attr, &fifo_param);
        }
        if (pthread_attr_setscope(attr, PTHREAD_SCOPE_SYSTEM) != 0) {
#ifdef PTHREAD_SCOPE_BOUND_NP
            // If system scope is not available (eg. we're not running
            // with CAP_SCHED_MGT capability on an SGI box), try bound
            // scope.  It exposes pthread scheduling to the kernel,
            // without setting realtime priority.
            pthread_attr_setscope(attr, PTHREAD_SCOPE_BOUND_NP);
#endif
        }
#endif
#endif
}


/*
 *  Mutexes
 */

#ifdef HAVE_PTHREADS

struct B2_mutex {
        B2_mutex() { 
            pthread_mutexattr_t attr;
            pthread_mutexattr_init(&attr);
            // Initialize the mutex for priority inheritance --
            // required for accurate timing.
#if defined(HAVE_PTHREAD_MUTEXATTR_SETPROTOCOL) && !defined(__CYGWIN__)
            pthread_mutexattr_setprotocol(&attr, PTHREAD_PRIO_INHERIT);
#endif
#if defined(HAVE_PTHREAD_MUTEXATTR_SETTYPE) && defined(PTHREAD_MUTEX_NORMAL)
            pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);
#endif
#ifdef HAVE_PTHREAD_MUTEXATTR_SETPSHARED
            pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE);
#endif
            pthread_mutex_init(&m, &attr);
            pthread_mutexattr_destroy(&attr);
        }
        ~B2_mutex() { 
            pthread_mutex_trylock(&m); // Make sure it's locked before
            pthread_mutex_unlock(&m);  // unlocking it.
            pthread_mutex_destroy(&m);
        }
        pthread_mutex_t m;
};

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

void B2_lock_mutex(B2_mutex *mutex)
{
        pthread_mutex_lock(&mutex->m);
}

void B2_unlock_mutex(B2_mutex *mutex)
{
        pthread_mutex_unlock(&mutex->m);
}

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

#else

struct B2_mutex {
        int dummy;
};

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

void B2_lock_mutex(B2_mutex *mutex)
{
}

void B2_unlock_mutex(B2_mutex *mutex)
{
}

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

#endif


/*
 *  Trigger signal USR2 from another thread
 */

#if !EMULATED_PPC
void TriggerInterrupt(void)
{
        if (ready_for_signals) {
                idle_resume();
                pthread_kill(emul_thread, SIGUSR2);
        }
}
#endif


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

volatile uint32 InterruptFlags = 0;

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

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


/*
 *  Disable interrupts
 */

void DisableInterrupt(void)
{
#if EMULATED_PPC
        WriteMacInt32(XLM_IRQ_NEST, int32(ReadMacInt32(XLM_IRQ_NEST)) + 1);
#else
        atomic_add((int *)XLM_IRQ_NEST, 1);
#endif
}


/*
 *  Enable interrupts
 */

void EnableInterrupt(void)
{
#if EMULATED_PPC
        WriteMacInt32(XLM_IRQ_NEST, int32(ReadMacInt32(XLM_IRQ_NEST)) - 1);
#else
        atomic_add((int *)XLM_IRQ_NEST, -1);
#endif
}


/*
 *  USR2 handler
 */

#if !EMULATED_PPC
void sigusr2_handler(int sig, siginfo_t *sip, void *scp)
{
        machine_regs *r = MACHINE_REGISTERS(scp);

#ifdef SYSTEM_CLOBBERS_R2
        // Restore pointer to Thread Local Storage
        set_r2(TOC);
#endif
#ifdef SYSTEM_CLOBBERS_R13
        // Restore pointer to .sdata section
        set_r13(R13);
#endif

#ifdef USE_SDL_VIDEO
        // We must fill in the events queue in the same thread that did call SDL_SetVideoMode()
        SDL_PumpEvents();
#endif

        // Do nothing if interrupts are disabled
        if (*(int32 *)XLM_IRQ_NEST > 0)
                return;

        // Disable MacOS stack sniffer
        WriteMacInt32(0x110, 0);

        // Interrupt action depends on current run mode
        switch (ReadMacInt32(XLM_RUN_MODE)) {
                case MODE_68K:
                        // 68k emulator active, trigger 68k interrupt level 1
                        WriteMacInt16(ntohl(kernel_data->v[0x67c >> 2]), 1);
                        r->cr() |= ntohl(kernel_data->v[0x674 >> 2]);
                        break;

#if INTERRUPTS_IN_NATIVE_MODE
                case MODE_NATIVE:
                        // 68k emulator inactive, in nanokernel?
                        if (r->gpr(1) != KernelDataAddr) {

                                // Set extra stack for SIGSEGV handler
                                sigaltstack(&extra_stack, NULL);
                                
                                // Prepare for 68k interrupt level 1
                                WriteMacInt16(ntohl(kernel_data->v[0x67c >> 2]), 1);
                                WriteMacInt32(ntohl(kernel_data->v[0x658 >> 2]) + 0xdc, ReadMacInt32(ntohl(kernel_data->v[0x658 >> 2]) + 0xdc) | ntohl(kernel_data->v[0x674 >> 2]));

                                // Execute nanokernel interrupt routine (this will activate the 68k emulator)
                                DisableInterrupt();
                                if (ROMType == ROMTYPE_NEWWORLD)
                                        ppc_interrupt(ROMBase + 0x312b1c, KernelDataAddr);
                                else
                                        ppc_interrupt(ROMBase + 0x312a3c, KernelDataAddr);

                                // Reset normal stack
                                sigaltstack(&sig_stack, NULL);
                        }
                        break;
#endif

#if INTERRUPTS_IN_EMUL_OP_MODE
                case MODE_EMUL_OP:
                        // 68k emulator active, within EMUL_OP routine, execute 68k interrupt routine directly when interrupt level is 0
                        if ((ReadMacInt32(XLM_68K_R25) & 7) == 0) {

                                // Set extra stack for SIGSEGV handler
                                sigaltstack(&extra_stack, NULL);
#if 1
                                // Execute full 68k interrupt routine
                                M68kRegisters r;
                                uint32 old_r25 = ReadMacInt32(XLM_68K_R25);     // Save interrupt level
                                WriteMacInt32(XLM_68K_R25, 0x21);                       // Execute with interrupt level 1
                                static const uint16 proc[] = {
                                        0x3f3c, 0x0000,         // move.w       #$0000,-(sp)    (fake format word)
                                        0x487a, 0x000a,         // pea          @1(pc)                  (return address)
                                        0x40e7,                         // move         sr,-(sp)                (saved SR)
                                        0x2078, 0x0064,         // move.l       $64,a0
                                        0x4ed0,                         // jmp          (a0)
                                        M68K_RTS                        // @1
                                };
                                Execute68k((uint32)proc, &r);
                                WriteMacInt32(XLM_68K_R25, old_r25);            // Restore interrupt level
#else
                                // Only update cursor
                                if (HasMacStarted()) {
                                        if (InterruptFlags & INTFLAG_VIA) {
                                                ClearInterruptFlag(INTFLAG_VIA);
                                                ADBInterrupt();
                                                ExecuteNative(NATIVE_VIDEO_VBL);
                                        }
                                }
#endif
                                // Reset normal stack
                                sigaltstack(&sig_stack, NULL);
                        }
                        break;
#endif
        }
}
#endif


/*
 *  SIGSEGV handler
 */

#if !EMULATED_PPC
static void sigsegv_handler(int sig, siginfo_t *sip, void *scp)
{
        machine_regs *r = MACHINE_REGISTERS(scp);

        // Get effective address
        uint32 addr = r->dar();
        
#ifdef SYSTEM_CLOBBERS_R2
        // Restore pointer to Thread Local Storage
        set_r2(TOC);
#endif
#ifdef SYSTEM_CLOBBERS_R13
        // Restore pointer to .sdata section
        set_r13(R13);
#endif

#if ENABLE_VOSF
        // Handle screen fault
#if SIGSEGV_CHECK_VERSION(1,0,0)
        sigsegv_info_t si;
        si.addr = (sigsegv_address_t)addr;
        si.pc = (sigsegv_address_t)r->pc();
#endif
        extern bool Screen_fault_handler(sigsegv_info_t *sip);
        if (Screen_fault_handler(&si))
                return;
#endif

        num_segv++;

        // Fault in Mac ROM or RAM or DR Cache?
        bool mac_fault = (r->pc() >= ROMBase) && (r->pc() < (ROMBase + ROM_AREA_SIZE)) || (r->pc() >= RAMBase) && (r->pc() < (RAMBase + RAMSize)) || (r->pc() >= DR_CACHE_BASE && r->pc() < (DR_CACHE_BASE + DR_CACHE_SIZE));
        if (mac_fault) {

                // "VM settings" during MacOS 8 installation
                if (r->pc() == ROMBase + 0x488160 && r->gpr(20) == 0xf8000000) {
                        r->pc() += 4;
                        r->gpr(8) = 0;
                        return;
        
                // MacOS 8.5 installation
                } else if (r->pc() == ROMBase + 0x488140 && r->gpr(16) == 0xf8000000) {
                        r->pc() += 4;
                        r->gpr(8) = 0;
                        return;
        
                // MacOS 8 serial drivers on startup
                } else if (r->pc() == ROMBase + 0x48e080 && (r->gpr(8) == 0xf3012002 || r->gpr(8) == 0xf3012000)) {
                        r->pc() += 4;
                        r->gpr(8) = 0;
                        return;
        
                // MacOS 8.1 serial drivers on startup
                } else if (r->pc() == ROMBase + 0x48c5e0 && (r->gpr(20) == 0xf3012002 || r->gpr(20) == 0xf3012000)) {
                        r->pc() += 4;
                        return;
                } else if (r->pc() == ROMBase + 0x4a10a0 && (r->gpr(20) == 0xf3012002 || r->gpr(20) == 0xf3012000)) {
                        r->pc() += 4;
                        return;
        
                // MacOS 8.6 serial drivers on startup (with DR Cache and OldWorld ROM)
                } else if ((r->pc() - DR_CACHE_BASE) < DR_CACHE_SIZE && (r->gpr(16) == 0xf3012002 || r->gpr(16) == 0xf3012000)) {
                        r->pc() += 4;
                        return;
                } else if ((r->pc() - DR_CACHE_BASE) < DR_CACHE_SIZE && (r->gpr(20) == 0xf3012002 || r->gpr(20) == 0xf3012000)) {
                        r->pc() += 4;
                        return;
                }

                // 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;
                int32 imm = (int16)(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;
#if EMULATE_UNALIGNED_LOADSTORE_MULTIPLE
                        case 46:        // lmw
                                if ((addr % 4) != 0) {
                                        uint32 ea = addr;
                                        D(bug("WARNING: unaligned lmw to EA=%08x from IP=%08x\n", ea, r->pc()));
                                        for (int i = rd; i <= 31; i++) {
                                                r->gpr(i) = ReadMacInt32(ea);
                                                ea += 4;
                                        }
                                        r->pc() += 4;
                                        goto rti;
                                }
                                break;
                        case 47:        // stmw
                                if ((addr % 4) != 0) {
                                        uint32 ea = addr;
                                        D(bug("WARNING: unaligned stmw to EA=%08x from IP=%08x\n", ea, r->pc()));
                                        for (int i = rd; i <= 31; i++) {
                                                WriteMacInt32(ea, r->gpr(i));
                                                ea += 4;
                                        }
                                        r->pc() += 4;
                                        goto rti;
                                }
                                break;
#endif
                }
        
                // Ignore ROM writes (including to the zero page, which is read-only)
                if (transfer_type == TYPE_STORE &&
                        ((addr >= ROMBase && addr < ROMBase + ROM_SIZE) ||
                         (addr >= SheepMem::ZeroPage() && addr < SheepMem::ZeroPage() + SheepMem::PageSize()))) {
//                      D(bug("WARNING: %s write access to ROM at %08lx, pc %08lx\n", transfer_size == SIZE_BYTE ? "Byte" : transfer_size == SIZE_HALFWORD ? "Halfword" : "Word", addr, r->pc()));
                        if (addr_mode == MODE_U || addr_mode == MODE_UX)
                                r->gpr(ra) = addr;
                        r->pc() += 4;
                        goto rti;
                }

                // Ignore illegal memory accesses?
                if (PrefsFindBool("ignoresegv")) {
                        if (addr_mode == MODE_U || addr_mode == MODE_UX)
                                r->gpr(ra) = addr;
                        if (transfer_type == TYPE_LOAD)
                                r->gpr(rd) = 0;
                        r->pc() += 4;
                        goto rti;
                }

                // In GUI mode, show error alert
                if (!PrefsFindBool("nogui")) {
                        char str[256];
                        if (transfer_type == TYPE_LOAD || transfer_type == TYPE_STORE)
                                sprintf(str, GetString(STR_MEM_ACCESS_ERR), transfer_size == SIZE_BYTE ? "byte" : transfer_size == SIZE_HALFWORD ? "halfword" : "word", transfer_type == TYPE_LOAD ? GetString(STR_MEM_ACCESS_READ) : GetString(STR_MEM_ACCESS_WRITE), addr, r->pc(), r->gpr(24), r->gpr(1));
                        else
                                sprintf(str, GetString(STR_UNKNOWN_SEGV_ERR), r->pc(), r->gpr(24), r->gpr(1), opcode);
                        ErrorAlert(str);
                        QuitEmulator();
                        return;
                }
        }

        // For all other errors, jump into debugger (sort of...)
        crash_reason = (sig == SIGBUS) ? "SIGBUS" : "SIGSEGV";
        if (!ready_for_signals) {
                printf("%s\n");
                printf(" sigcontext %p, machine_regs %p\n", scp, r);
                printf(
                        "   pc %08lx     lr %08lx    ctr %08lx    msr %08lx\n"
                        "  xer %08lx     cr %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",
                        crash_reason,
                        r->pc(), r->lr(), r->ctr(), r->msr(),
                        r->xer(), r->cr(),
                        r->gpr(0), r->gpr(1), r->gpr(2), r->gpr(3),
                        r->gpr(4), r->gpr(5), r->gpr(6), r->gpr(7),
                        r->gpr(8), r->gpr(9), r->gpr(10), r->gpr(11),
                        r->gpr(12), r->gpr(13), r->gpr(14), r->gpr(15),
                        r->gpr(16), r->gpr(17), r->gpr(18), r->gpr(19),
                        r->gpr(20), r->gpr(21), r->gpr(22), r->gpr(23),
                        r->gpr(24), r->gpr(25), r->gpr(26), r->gpr(27),
                        r->gpr(28), r->gpr(29), r->gpr(30), r->gpr(31));
                exit(1);
                QuitEmulator();
                return;
        } else {
                // We crashed. Save registers, tell tick thread and loop forever
                build_sigregs(&sigsegv_regs, r);
                emul_thread_fatal = true;
                for (;;) ;
        }
rti:;
}


/*
 *  SIGILL handler
 */

static void sigill_handler(int sig, siginfo_t *sip, void *scp)
{
        machine_regs *r = MACHINE_REGISTERS(scp);
        char str[256];

#ifdef SYSTEM_CLOBBERS_R2
        // Restore pointer to Thread Local Storage
        set_r2(TOC);
#endif
#ifdef SYSTEM_CLOBBERS_R13
        // Restore pointer to .sdata section
        set_r13(R13);
#endif

        // Fault in Mac ROM or RAM?
        bool mac_fault = (r->pc() >= ROMBase) && (r->pc() < (ROMBase + ROM_AREA_SIZE)) || (r->pc() >= RAMBase) && (r->pc() < (RAMBase + RAMSize));
        if (mac_fault) {

                // 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;
                int32 imm = (int16)(opcode & 0xffff);

                switch (primop) {
                        case 9:         // POWER instructions
                        case 22:
power_inst:             sprintf(str, GetString(STR_POWER_INSTRUCTION_ERR), r->pc(), r->gpr(1), opcode);
                                ErrorAlert(str);
                                QuitEmulator();
                                return;

                        case 31:
                                switch (exop) {
                                        case 83:        // mfmsr
                                                r->gpr(rd) = 0xf072;
                                                r->pc() += 4;
                                                goto rti;

                                        case 210:       // mtsr
                                        case 242:       // mtsrin
                                        case 306:       // tlbie
                                                r->pc() += 4;
                                                goto rti;

                                        case 339: {     // mfspr
                                                int spr = ra | (rb << 5);
                                                switch (spr) {
                                                        case 0:         // MQ
                                                        case 22:        // DEC
                                                        case 952:       // MMCR0
                                                        case 953:       // PMC1
                                                        case 954:       // PMC2
                                                        case 955:       // SIA
                                                        case 956:       // MMCR1
                                                        case 957:       // PMC3
                                                        case 958:       // PMC4
                                                        case 959:       // SDA
                                                                r->pc() += 4;
                                                                goto rti;
                                                        case 25:        // SDR1
                                                                r->gpr(rd) = 0xdead001f;
                                                                r->pc() += 4;
                                                                goto rti;
                                                        case 287:       // PVR
                                                                r->gpr(rd) = PVR;
                                                                r->pc() += 4;
                                                                goto rti;
                                                }
                                                break;
                                        }

                                        case 467: {     // mtspr
                                                int spr = ra | (rb << 5);
                                                switch (spr) {
                                                        case 0:         // MQ
                                                        case 22:        // DEC
                                                        case 275:       // SPRG3
                                                        case 528:       // IBAT0U
                                                        case 529:       // IBAT0L
                                                        case 530:       // IBAT1U
                                                        case 531:       // IBAT1L
                                                        case 532:       // IBAT2U
                                                        case 533:       // IBAT2L
                                                        case 534:       // IBAT3U
                                                        case 535:       // IBAT3L
                                                        case 536:       // DBAT0U
                                                        case 537:       // DBAT0L
                                                        case 538:       // DBAT1U
                                                        case 539:       // DBAT1L
                                                        case 540:       // DBAT2U
                                                        case 541:       // DBAT2L
                                                        case 542:       // DBAT3U
                                                        case 543:       // DBAT3L
                                                        case 952:       // MMCR0
                                                        case 953:       // PMC1
                                                        case 954:       // PMC2
                                                        case 955:       // SIA
                                                        case 956:       // MMCR1
                                                        case 957:       // PMC3
                                                        case 958:       // PMC4
                                                        case 959:       // SDA
                                                                r->pc() += 4;
                                                                goto rti;
                                                }
                                                break;
                                        }

                                        case 29: case 107: case 152: case 153:  // POWER instructions
                                        case 184: case 216: case 217: case 248:
                                        case 264: case 277: case 331: case 360:
                                        case 363: case 488: case 531: case 537:
                                        case 541: case 664: case 665: case 696:
                                        case 728: case 729: case 760: case 920:
                                        case 921: case 952:
                                                goto power_inst;
                                }
                }

                // In GUI mode, show error alert
                if (!PrefsFindBool("nogui")) {
                        sprintf(str, GetString(STR_UNKNOWN_SEGV_ERR), r->pc(), r->gpr(24), r->gpr(1), opcode);
                        ErrorAlert(str);
                        QuitEmulator();
                        return;
                }
        }

        // For all other errors, jump into debugger (sort of...)
        crash_reason = "SIGILL";
        if (!ready_for_signals) {
                printf("%s\n");
                printf(" sigcontext %p, machine_regs %p\n", scp, r);
                printf(
                        "   pc %08lx     lr %08lx    ctr %08lx    msr %08lx\n"
                        "  xer %08lx     cr %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",
                        crash_reason,
                        r->pc(), r->lr(), r->ctr(), r->msr(),
                        r->xer(), r->cr(),
                        r->gpr(0), r->gpr(1), r->gpr(2), r->gpr(3),
                        r->gpr(4), r->gpr(5), r->gpr(6), r->gpr(7),
                        r->gpr(8), r->gpr(9), r->gpr(10), r->gpr(11),
                        r->gpr(12), r->gpr(13), r->gpr(14), r->gpr(15),
                        r->gpr(16), r->gpr(17), r->gpr(18), r->gpr(19),
                        r->gpr(20), r->gpr(21), r->gpr(22), r->gpr(23),
                        r->gpr(24), r->gpr(25), r->gpr(26), r->gpr(27),
                        r->gpr(28), r->gpr(29), r->gpr(30), r->gpr(31));
                exit(1);
                QuitEmulator();
                return;
        } else {
                // We crashed. Save registers, tell tick thread and loop forever
                build_sigregs(&sigsegv_regs, r);
                emul_thread_fatal = true;
                for (;;) ;
        }
rti:;
}
#endif


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

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

        // Allocate SheepShaver globals
        proc = base;
        if (vm_mac_acquire_fixed(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;

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

        data = base + size;
        return true;
}

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

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


/*
 *  Display alert
 */

#ifdef ENABLE_GTK
static void dl_destroyed(void)
{
        gtk_main_quit();
}

static void dl_quit(GtkWidget *dialog)
{
        gtk_widget_destroy(dialog);
}

void display_alert(int title_id, int prefix_id, int button_id, const char *text)
{
        char str[256];
        sprintf(str, GetString(prefix_id), text);

        GtkWidget *dialog = gtk_dialog_new();
        gtk_window_set_title(GTK_WINDOW(dialog), GetString(title_id));
        gtk_container_border_width(GTK_CONTAINER(dialog), 5);
        gtk_widget_set_uposition(GTK_WIDGET(dialog), 100, 150);
        gtk_signal_connect(GTK_OBJECT(dialog), "destroy", GTK_SIGNAL_FUNC(dl_destroyed), NULL);

        GtkWidget *label = gtk_label_new(str);
        gtk_widget_show(label);
        gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), label, TRUE, TRUE, 0);

        GtkWidget *button = gtk_button_new_with_label(GetString(button_id));
        gtk_widget_show(button);
        gtk_signal_connect_object(GTK_OBJECT(button), "clicked", GTK_SIGNAL_FUNC(dl_quit), GTK_OBJECT(dialog));
        gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->action_area), button, FALSE, FALSE, 0);
        GTK_WIDGET_SET_FLAGS(button, GTK_CAN_DEFAULT);
        gtk_widget_grab_default(button);
        gtk_widget_show(dialog);

        gtk_main();
}
#endif


/*
 *  Display error alert
 */

void ErrorAlert(const char *text)
{
        if (gui_connection) {
                if (rpc_method_invoke(gui_connection, RPC_METHOD_ERROR_ALERT, RPC_TYPE_STRING, text, RPC_TYPE_INVALID) == RPC_ERROR_NO_ERROR &&
                        rpc_method_wait_for_reply(gui_connection, RPC_TYPE_INVALID) == RPC_ERROR_NO_ERROR)
                        return;
        }
#if defined(ENABLE_GTK) && !defined(USE_SDL_VIDEO)
        if (PrefsFindBool("nogui") || x_display == NULL) {
                printf(GetString(STR_SHELL_ERROR_PREFIX), text);
                return;
        }
        VideoQuitFullScreen();
        display_alert(STR_ERROR_ALERT_TITLE, STR_GUI_ERROR_PREFIX, STR_QUIT_BUTTON, text);
#else
        printf(GetString(STR_SHELL_ERROR_PREFIX), text);
#endif
}


/*
 *  Display warning alert
 */

void WarningAlert(const char *text)
{
        if (gui_connection) {
                if (rpc_method_invoke(gui_connection, RPC_METHOD_WARNING_ALERT, RPC_TYPE_STRING, text, RPC_TYPE_INVALID) == RPC_ERROR_NO_ERROR &&
                        rpc_method_wait_for_reply(gui_connection, RPC_TYPE_INVALID) == RPC_ERROR_NO_ERROR)
                        return;
        }
#if defined(ENABLE_GTK) && !defined(USE_SDL_VIDEO)
        if (PrefsFindBool("nogui") || x_display == NULL) {
                printf(GetString(STR_SHELL_WARNING_PREFIX), text);
                return;
        }
        display_alert(STR_WARNING_ALERT_TITLE, STR_GUI_WARNING_PREFIX, STR_OK_BUTTON, text);
#else
        printf(GetString(STR_SHELL_WARNING_PREFIX), text);
#endif
}


/*
 *  Display choice alert
 */

bool ChoiceAlert(const char *text, const char *pos, const char *neg)
{
        printf(GetString(STR_SHELL_WARNING_PREFIX), text);
        return false;   //!!
}
Revision:	1.101
Committed:	2012-01-01T19:11:31Z (12 years, 10 months ago) by asvitkine
Branch:	MAIN
Changes since 1.100:	+19 -13 lines
Log Message:	better cleanup of shared memory on failure