osfmk/kern/startup.c

   1 /*
   2  * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  * NOTICE: This file was modified by McAfee Research in 2004 to introduce
  58  * support for mandatory and extensible security protections.  This notice
  59  * is included in support of clause 2.2 (b) of the Apple Public License,
  60  * Version 2.0.
  61  */
  62 /*
  63  */
  64
  65 /*
  66  *      Mach kernel startup.
  67  */
  68
  69 #include <debug.h>
  70 #include <xpr_debug.h>
  71 #include <mach_kdp.h>
  72
  73 #include <mach/boolean.h>
  74 #include <mach/machine.h>
  75 #include <mach/thread_act.h>
  76 #include <mach/task_special_ports.h>
  77 #include <mach/vm_param.h>
  78 #include <ipc/ipc_init.h>
  79 #include <kern/assert.h>
  80 #include <kern/mach_param.h>
  81 #include <kern/misc_protos.h>
  82 #include <kern/clock.h>
  83 #include <kern/coalition.h>
  84 #include <kern/cpu_number.h>
  85 #include <kern/ledger.h>
  86 #include <kern/machine.h>
  87 #include <kern/processor.h>
  88 #include <kern/sched_prim.h>
  89 #include <kern/sfi.h>
  90 #include <kern/startup.h>
  91 #include <kern/task.h>
  92 #include <kern/thread.h>
  93 #include <kern/timer.h>
  94 #if CONFIG_TELEMETRY
  95 #include <kern/telemetry.h>
  96 #endif
  97 #include <kern/wait_queue.h>
  98 #include <kern/xpr.h>
  99 #include <kern/zalloc.h>
 100 #include <kern/locks.h>
 101 #include <prng/random.h>
 102 #include <console/serial_protos.h>
 103 #include <vm/vm_kern.h>
 104 #include <vm/vm_init.h>
 105 #include <vm/vm_map.h>
 106 #include <vm/vm_object.h>
 107 #include <vm/vm_page.h>
 108 #include <vm/vm_pageout.h>
 109 #include <vm/vm_shared_region.h>
 110 #include <machine/pmap.h>
 111 #include <machine/commpage.h>
 112 #include <libkern/version.h>
 113 #include <sys/codesign.h>
 114 #include <sys/kdebug.h>
 115 #include <sys/random.h>
 116
 117 #if CONFIG_ATM
 118 #include <atm/atm_internal.h>
 119 #endif
 120
 121 #if CONFIG_CSR
 122 #include <sys/csr.h>
 123 #endif
 124
 125 #if CONFIG_BANK
 126 #include <bank/bank_internal.h>
 127 #endif
 128
 129 #if ALTERNATE_DEBUGGER
 130 #include <arm64/alternate_debugger.h>
 131 #endif
 132
 133 #if MACH_KDP
 134 #include <kdp/kdp.h>
 135 #endif
 136
 137 #if CONFIG_MACF
 138 #include <security/mac_mach_internal.h>
 139 #endif
 140
 141 #if CONFIG_COUNTERS
 142 #include <pmc/pmc.h>
 143 #endif
 144
 145 #if KPC
 146 #include <kern/kpc.h>
 147 #endif
 148
 149 #if KPERF
 150 #include <kperf/kperf.h>
 151 #endif
 152
 153 #if HYPERVISOR
 154 #include <kern/hv_support.h>
 155 #endif
 156
 157
 158 #include <i386/pmCPU.h>
 159 static void             kernel_bootstrap_thread(void);
 160
 161 static void             load_context(
 162                                         thread_t        thread);
 163 #if (defined(__i386__) || defined(__x86_64__)) && NCOPY_WINDOWS > 0
 164 extern void cpu_userwindow_init(int);
 165 extern void cpu_physwindow_init(int);
 166 #endif
 167
 168 #if CONFIG_ECC_LOGGING
 169 #include <kern/ecc.h>
 170 #endif
 171
 172 #if (defined(__i386__) || defined(__x86_64__)) && CONFIG_VMX
 173 #include <i386/vmx/vmx_cpu.h>
 174 #endif
 175
 176 // libkern/OSKextLib.cpp
 177 extern void     OSKextRemoveKextBootstrap(void);
 178
 179 void scale_setup(void);
 180 extern void bsd_scale_setup(int);
 181 extern unsigned int semaphore_max;
 182 extern void stackshot_lock_init(void);
 183
 184 /*
 185  *      Running in virtual memory, on the interrupt stack.
 186  */
 187
 188 extern int serverperfmode;
 189
 190 /* size of kernel trace buffer, disabled by default */
 191 unsigned int new_nkdbufs = 0;
 192 unsigned int wake_nkdbufs = 0;
 193 unsigned int write_trace_on_panic = 0;
 194 unsigned int trace_typefilter = 0;
 195
 196 /* mach leak logging */
 197 int log_leaks = 0;
 198 int turn_on_log_leaks = 0;
 199
 200 static inline void
 201 kernel_bootstrap_log(const char *message)
 202 {
 203 //      kprintf("kernel_bootstrap: %s\n", message);
 204         kernel_debug_string(message);
 205 }
 206
 207 static inline void
 208 kernel_bootstrap_thread_log(const char *message)
 209 {
 210 //      kprintf("kernel_bootstrap_thread: %s\n", message);
 211         kernel_debug_string(message);
 212 }
 213
 214 void
 215 kernel_early_bootstrap(void)
 216 {
 217         /* serverperfmode is needed by timer setup */
 218         if (PE_parse_boot_argn("serverperfmode", &serverperfmode, sizeof (serverperfmode))) {
 219                 serverperfmode = 1;
 220         }
 221
 222         lck_mod_init();
 223
 224         /*
 225          * Initialize the timer callout world
 226          */
 227         timer_call_init();
 228
 229         /*
 230          * Configure SFI classes
 231          */
 232         sfi_early_init();
 233 }
 234
 235
 236 void
 237 kernel_bootstrap(void)
 238 {
 239         kern_return_t   result;
 240         thread_t        thread;
 241         char            namep[16];
 242
 243         printf("%s\n", version); /* log kernel version */
 244
 245         if (PE_parse_boot_argn("-l", namep, sizeof (namep))) /* leaks logging */
 246                 turn_on_log_leaks = 1;
 247
 248         PE_parse_boot_argn("trace", &new_nkdbufs, sizeof (new_nkdbufs));
 249         PE_parse_boot_argn("trace_wake", &wake_nkdbufs, sizeof (wake_nkdbufs));
 250         PE_parse_boot_argn("trace_panic", &write_trace_on_panic, sizeof(write_trace_on_panic));
 251         PE_parse_boot_argn("trace_typefilter", &trace_typefilter, sizeof(trace_typefilter));
 252
 253         scale_setup();
 254
 255         kernel_bootstrap_log("vm_mem_bootstrap");
 256         vm_mem_bootstrap();
 257
 258         kernel_bootstrap_log("cs_init");
 259         cs_init();
 260
 261         kernel_bootstrap_log("vm_mem_init");
 262         vm_mem_init();
 263
 264         machine_info.memory_size = (uint32_t)mem_size;
 265         machine_info.max_mem = max_mem;
 266         machine_info.major_version = version_major;
 267         machine_info.minor_version = version_minor;
 268
 269 #if CONFIG_TELEMETRY
 270         kernel_bootstrap_log("telemetry_init");
 271         telemetry_init();
 272 #endif
 273
 274         kernel_bootstrap_log("stackshot_lock_init");
 275         stackshot_lock_init();
 276
 277         kernel_bootstrap_log("sched_init");
 278         sched_init();
 279
 280         kernel_bootstrap_log("wait_queue_bootstrap");
 281         wait_queue_bootstrap();
 282
 283         kernel_bootstrap_log("ipc_bootstrap");
 284         ipc_bootstrap();
 285
 286 #if CONFIG_MACF
 287         mac_policy_init();
 288 #endif
 289         kernel_bootstrap_log("ipc_init");
 290         ipc_init();
 291
 292         /*
 293          * As soon as the virtual memory system is up, we record
 294          * that this CPU is using the kernel pmap.
 295          */
 296         kernel_bootstrap_log("PMAP_ACTIVATE_KERNEL");
 297         PMAP_ACTIVATE_KERNEL(master_cpu);
 298
 299         kernel_bootstrap_log("mapping_free_prime");
 300         mapping_free_prime();                                           /* Load up with temporary mapping blocks */
 301
 302         kernel_bootstrap_log("machine_init");
 303         machine_init();
 304
 305         kernel_bootstrap_log("clock_init");
 306         clock_init();
 307
 308         ledger_init();
 309
 310         /*
 311          *      Initialize the IPC, task, and thread subsystems.
 312          */
 313 #if CONFIG_COALITIONS
 314         kernel_bootstrap_log("coalition_init");
 315         coalition_init();
 316 #endif
 317
 318         kernel_bootstrap_log("task_init");
 319         task_init();
 320
 321         kernel_bootstrap_log("thread_init");
 322         thread_init();
 323
 324 #if CONFIG_ATM
 325         /* Initialize the Activity Trace Resource Manager. */
 326         kernel_bootstrap_log("atm_init");
 327         atm_init();
 328 #endif
 329
 330 #if CONFIG_CSR
 331         kernel_bootstrap_log("csr_init");
 332         csr_init();
 333 #endif
 334
 335 #if CONFIG_BANK
 336         /* Initialize the BANK Manager. */
 337         kernel_bootstrap_log("bank_init");
 338         bank_init();
 339 #endif
 340
 341         /*
 342          *      Create a kernel thread to execute the kernel bootstrap.
 343          */
 344         kernel_bootstrap_log("kernel_thread_create");
 345         result = kernel_thread_create((thread_continue_t)kernel_bootstrap_thread, NULL, MAXPRI_KERNEL, &thread);
 346
 347         if (result != KERN_SUCCESS) panic("kernel_bootstrap: result = %08X\n", result);
 348
 349         thread->state = TH_RUN;
 350         thread_deallocate(thread);
 351
 352         kernel_bootstrap_log("load_context - done");
 353         load_context(thread);
 354         /*NOTREACHED*/
 355 }
 356
 357 int kth_started = 0;
 358
 359 vm_offset_t vm_kernel_addrperm;
 360 vm_offset_t buf_kernel_addrperm;
 361
 362 /*
 363  * Now running in a thread.  Kick off other services,
 364  * invoke user bootstrap, enter pageout loop.
 365  */
 366 static void
 367 kernel_bootstrap_thread(void)
 368 {
 369         processor_t             processor = current_processor();
 370
 371 #define kernel_bootstrap_thread_kprintf(x...) /* kprintf("kernel_bootstrap_thread: " x) */
 372         kernel_bootstrap_thread_log("idle_thread_create");
 373         /*
 374          * Create the idle processor thread.
 375          */
 376         idle_thread_create(processor);
 377
 378         /*
 379          * N.B. Do not stick anything else
 380          * before this point.
 381          *
 382          * Start up the scheduler services.
 383          */
 384         kernel_bootstrap_thread_log("sched_startup");
 385         sched_startup();
 386
 387         /*
 388          * Thread lifecycle maintenance (teardown, stack allocation)
 389          */
 390         kernel_bootstrap_thread_log("thread_daemon_init");
 391         thread_daemon_init();
 392
 393         /* Create kernel map entry reserve */
 394         vm_kernel_reserved_entry_init();
 395
 396         /*
 397          * Thread callout service.
 398          */
 399         kernel_bootstrap_thread_log("thread_call_initialize");
 400         thread_call_initialize();
 401
 402         /*
 403          * Remain on current processor as
 404          * additional processors come online.
 405          */
 406         kernel_bootstrap_thread_log("thread_bind");
 407         thread_bind(processor);
 408
 409         /*
 410          * Initialize ipc thread call support.
 411          */
 412         kernel_bootstrap_thread_log("ipc_thread_call_init");
 413         ipc_thread_call_init();
 414
 415         /*
 416          * Kick off memory mapping adjustments.
 417          */
 418         kernel_bootstrap_thread_log("mapping_adjust");
 419         mapping_adjust();
 420
 421         /*
 422          *      Create the clock service.
 423          */
 424         kernel_bootstrap_thread_log("clock_service_create");
 425         clock_service_create();
 426
 427         /*
 428          *      Create the device service.
 429          */
 430         device_service_create();
 431
 432         kth_started = 1;
 433
 434 #if (defined(__i386__) || defined(__x86_64__)) && NCOPY_WINDOWS > 0
 435         /*
 436          * Create and initialize the physical copy window for processor 0
 437          * This is required before starting kicking off  IOKit.
 438          */
 439         cpu_physwindow_init(0);
 440 #endif
 441
 442
 443
 444 #if MACH_KDP
 445         kernel_bootstrap_log("kdp_init");
 446         kdp_init();
 447 #endif
 448
 449 #if ALTERNATE_DEBUGGER
 450         alternate_debugger_init();
 451 #endif
 452
 453 #if CONFIG_COUNTERS
 454         pmc_bootstrap();
 455 #endif
 456
 457 #if KPC
 458         kpc_init();
 459 #endif
 460
 461 #if CONFIG_ECC_LOGGING
 462         ecc_log_init();
 463 #endif
 464
 465 #if KPERF
 466         kperf_bootstrap();
 467 #endif
 468
 469 #if HYPERVISOR
 470         hv_support_init();
 471 #endif
 472
 473 #if CONFIG_TELEMETRY
 474         kernel_bootstrap_log("bootprofile_init");
 475         bootprofile_init();
 476 #endif
 477
 478 #if (defined(__i386__) || defined(__x86_64__)) && CONFIG_VMX
 479         vmx_init();
 480 #endif
 481
 482 #if (defined(__i386__) || defined(__x86_64__))
 483         if (turn_on_log_leaks && !new_nkdbufs)
 484                 new_nkdbufs = 200000;
 485         if (trace_typefilter)
 486                 start_kern_tracing_with_typefilter(new_nkdbufs,
 487                                                    FALSE,
 488                                                    trace_typefilter);
 489         else
 490                 start_kern_tracing(new_nkdbufs, FALSE);
 491         if (turn_on_log_leaks)
 492                 log_leaks = 1;
 493
 494 #endif
 495
 496         kernel_bootstrap_log("prng_init");
 497         prng_cpu_init(master_cpu);
 498
 499 #ifdef  IOKIT
 500         PE_init_iokit();
 501 #endif
 502
 503         assert(ml_get_interrupts_enabled() == FALSE);
 504         (void) spllo();         /* Allow interruptions */
 505
 506 #if (defined(__i386__) || defined(__x86_64__)) && NCOPY_WINDOWS > 0
 507         /*
 508          * Create and initialize the copy window for processor 0
 509          * This also allocates window space for all other processors.
 510          * However, this is dependent on the number of processors - so this call
 511          * must be after IOKit has been started because IOKit performs processor
 512          * discovery.
 513          */
 514         cpu_userwindow_init(0);
 515 #endif
 516
 517 #if (!defined(__i386__) && !defined(__x86_64__))
 518         if (turn_on_log_leaks && !new_nkdbufs)
 519                 new_nkdbufs = 200000;
 520         if (trace_typefilter)
 521                 start_kern_tracing_with_typefilter(new_nkdbufs, FALSE, trace_typefilter);
 522         else
 523                 start_kern_tracing(new_nkdbufs, FALSE);
 524         if (turn_on_log_leaks)
 525                 log_leaks = 1;
 526 #endif
 527
 528         /*
 529          *      Initialize the shared region module.
 530          */
 531         vm_shared_region_init();
 532         vm_commpage_init();
 533         vm_commpage_text_init();
 534
 535
 536 #if CONFIG_MACF
 537         kernel_bootstrap_log("mac_policy_initmach");
 538         mac_policy_initmach();
 539 #endif
 540
 541         kernel_bootstrap_log("sfi_init");
 542         sfi_init();
 543
 544         /*
 545          * Initialize the global used for permuting kernel
 546          * addresses that may be exported to userland as tokens
 547          * using VM_KERNEL_ADDRPERM(). Force the random number
 548          * to be odd to avoid mapping a non-zero
 549          * word-aligned address to zero via addition.
 550          * Note: at this stage we can use the cryptographically secure PRNG
 551          * rather than early_random().
 552          */
 553         read_random(&vm_kernel_addrperm, sizeof(vm_kernel_addrperm));
 554         vm_kernel_addrperm |= 1;
 555         read_random(&buf_kernel_addrperm, sizeof(buf_kernel_addrperm));
 556         buf_kernel_addrperm |= 1;
 557
 558         /*
 559          *      Start the user bootstrap.
 560          */
 561 #ifdef  MACH_BSD
 562         bsd_init();
 563 #endif
 564
 565     /*
 566      * Get rid of segments used to bootstrap kext loading. This removes
 567      * the KLD, PRELINK symtab, LINKEDIT, and symtab segments/load commands.
 568      */
 569         OSKextRemoveKextBootstrap();
 570
 571         serial_keyboard_init();         /* Start serial keyboard if wanted */
 572
 573         vm_page_init_local_q();
 574
 575         thread_bind(PROCESSOR_NULL);
 576
 577         /*
 578          *      Become the pageout daemon.
 579          */
 580         vm_pageout();
 581         /*NOTREACHED*/
 582 }
 583
 584 /*
 585  *      slave_main:
 586  *
 587  *      Load the first thread to start a processor.
 588  */
 589 void
 590 slave_main(void *machine_param)
 591 {
 592         processor_t             processor = current_processor();
 593         thread_t                thread;
 594
 595         /*
 596          *      Use the idle processor thread if there
 597          *      is no dedicated start up thread.
 598          */
 599         if (processor->next_thread == THREAD_NULL) {
 600                 thread = processor->idle_thread;
 601                 thread->continuation = (thread_continue_t)processor_start_thread;
 602                 thread->parameter = machine_param;
 603         }
 604         else {
 605                 thread = processor->next_thread;
 606                 processor->next_thread = THREAD_NULL;
 607         }
 608
 609         load_context(thread);
 610         /*NOTREACHED*/
 611 }
 612
 613 /*
 614  *      processor_start_thread:
 615  *
 616  *      First thread to execute on a started processor.
 617  *
 618  *      Called at splsched.
 619  */
 620 void
 621 processor_start_thread(void *machine_param)
 622 {
 623         processor_t             processor = current_processor();
 624         thread_t                self = current_thread();
 625
 626         slave_machine_init(machine_param);
 627
 628         /*
 629          *      If running the idle processor thread,
 630          *      reenter the idle loop, else terminate.
 631          */
 632         if (self == processor->idle_thread)
 633                 thread_block((thread_continue_t)idle_thread);
 634
 635         thread_terminate(self);
 636         /*NOTREACHED*/
 637 }
 638
 639 /*
 640  *      load_context:
 641  *
 642  *      Start the first thread on a processor.
 643  */
 644 static void
 645 load_context(
 646         thread_t                thread)
 647 {
 648         processor_t             processor = current_processor();
 649
 650
 651 #define load_context_kprintf(x...) /* kprintf("load_context: " x) */
 652
 653         load_context_kprintf("machine_set_current_thread\n");
 654         machine_set_current_thread(thread);
 655
 656         load_context_kprintf("processor_up\n");
 657         processor_up(processor);
 658
 659         PMAP_ACTIVATE_KERNEL(processor->cpu_id);
 660
 661         /*
 662          * Acquire a stack if none attached.  The panic
 663          * should never occur since the thread is expected
 664          * to have reserved stack.
 665          */
 666         load_context_kprintf("thread %p, stack %lx, stackptr %lx\n", thread,
 667                              thread->kernel_stack, thread->machine.kstackptr);
 668         if (!thread->kernel_stack) {
 669                 load_context_kprintf("stack_alloc_try\n");
 670                 if (!stack_alloc_try(thread))
 671                         panic("load_context");
 672         }
 673
 674         /*
 675          * The idle processor threads are not counted as
 676          * running for load calculations.
 677          */
 678         if (!(thread->state & TH_IDLE))
 679                 sched_run_incr(thread);
 680
 681         processor->active_thread = thread;
 682         processor->current_pri = thread->sched_pri;
 683         processor->current_thmode = thread->sched_mode;
 684         processor->deadline = UINT64_MAX;
 685         thread->last_processor = processor;
 686
 687         processor->last_dispatch = mach_absolute_time();
 688         timer_start(&thread->system_timer, processor->last_dispatch);
 689         PROCESSOR_DATA(processor, thread_timer) = PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
 690
 691         timer_start(&PROCESSOR_DATA(processor, system_state), processor->last_dispatch);
 692         PROCESSOR_DATA(processor, current_state) = &PROCESSOR_DATA(processor, system_state);
 693
 694         PMAP_ACTIVATE_USER(thread, processor->cpu_id);
 695
 696         load_context_kprintf("machine_load_context\n");
 697         machine_load_context(thread);
 698         /*NOTREACHED*/
 699 }
 700
 701 void
 702 scale_setup()
 703 {
 704         int scale = 0;
 705 #if defined(__LP64__)
 706         typeof(task_max) task_max_base = task_max;
 707
 708         /* Raise limits for servers with >= 16G */
 709         if ((serverperfmode != 0) && ((uint64_t)sane_size >= (uint64_t)(16 * 1024 * 1024 *1024ULL))) {
 710                 scale = (int)((uint64_t)sane_size / (uint64_t)(8 * 1024 * 1024 *1024ULL));
 711                 /* limit to 128 G */
 712                 if (scale > 16)
 713                         scale = 16;
 714                 task_max_base = 2500;
 715         } else if ((uint64_t)sane_size >= (uint64_t)(3 * 1024 * 1024 *1024ULL))
 716                 scale = 2;
 717
 718         task_max = MAX(task_max, task_max_base * scale);
 719
 720         if (scale != 0) {
 721                 task_threadmax = task_max;
 722                 thread_max = task_max * 5;
 723         }
 724
 725 #endif
 726
 727         bsd_scale_setup(scale);
 728
 729         ipc_space_max = SPACE_MAX;
 730         ipc_port_max = PORT_MAX;
 731         ipc_pset_max = SET_MAX;
 732         semaphore_max = SEMAPHORE_MAX;
 733 }
 734