2config PRINTK_TIME
   3        bool "Show timing information on printks"
   4        depends on PRINTK
   5        help
   6          Selecting this option causes timing information to be
   7          included in printk output.  This allows you to measure
   8          the interval between kernel operations, including bootup
   9          operations.  This is useful for identifying long delays
  10          in kernel startup.
  13        bool "Enable __deprecated logic"
  14        default y
  15        help
  16          Enable the __deprecated logic in the kernel build.
  17          Disable this to suppress the "warning: 'foo' is deprecated
  18          (declared at kernel/power/somefile.c:1234)" messages.
  21        bool "Enable __must_check logic"
  22        default y
  23        help
  24          Enable the __must_check logic in the kernel build.  Disable this to
  25          suppress the "warning: ignoring return value of 'foo', declared with
  26          attribute warn_unused_result" messages.
  28config FRAME_WARN
  29        int "Warn for stack frames larger than (needs gcc 4.4)"
  30        range 0 8192
  31        default 1024 if !64BIT
  32        default 2048 if 64BIT
  33        help
  34          Tell gcc to warn at build time for stack frames larger than this.
  35          Setting this too low will cause a lot of warnings.
  36          Setting it to 0 disables the warning.
  37          Requires gcc 4.4
  39config MAGIC_SYSRQ
  40        bool "Magic SysRq key"
  41        depends on !UML
  42        help
  43          If you say Y here, you will have some control over the system even
  44          if the system crashes for example during kernel debugging (e.g., you
  45          will be able to flush the buffer cache to disk, reboot the system
  46          immediately or dump some status information). This is accomplished
  47          by pressing various keys while holding SysRq (Alt+PrintScreen). It
  48          also works on a serial console (on PC hardware at least), if you
  49          send a BREAK and then within 5 seconds a command keypress. The
  50          keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
  51          unless you really know what this hack does.
  54        bool "Enable unused/obsolete exported symbols"
  55        default y if X86
  56        help
  57          Unused but exported symbols make the kernel needlessly bigger.  For
  58          that reason most of these unused exports will soon be removed.  This
  59          option is provided temporarily to provide a transition period in case
  60          some external kernel module needs one of these symbols anyway. If you
  61          encounter such a case in your module, consider if you are actually
  62          using the right API.  (rationale: since nobody in the kernel is using
  63          this in a module, there is a pretty good chance it's actually the
  64          wrong interface to use).  If you really need the symbol, please send a
  65          mail to the linux kernel mailing list mentioning the symbol and why
  66          you really need it, and what the merge plan to the mainline kernel for
  67          your module is.
  69config DEBUG_FS
  70        bool "Debug Filesystem"
  71        depends on SYSFS
  72        help
  73          debugfs is a virtual file system that kernel developers use to put
  74          debugging files into.  Enable this option to be able to read and
  75          write to these files.
  77          For detailed documentation on the debugfs API, see
  78          Documentation/DocBook/filesystems.
  80          If unsure, say N.
  82config HEADERS_CHECK
  83        bool "Run 'make headers_check' when building vmlinux"
  84        depends on !UML
  85        help
  86          This option will extract the user-visible kernel headers whenever
  87          building the kernel, and will run basic sanity checks on them to
  88          ensure that exported files do not attempt to include files which
  89          were not exported, etc.
  91          If you're making modifications to header files which are
  92          relevant for userspace, say 'Y', and check the headers
  93          exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in
  94          your build tree), to make sure they're suitable.
  97        bool "Enable full Section mismatch analysis"
  98        depends on UNDEFINED
  99        # This option is on purpose disabled for now.
 100        # It will be enabled when we are down to a resonable number
 101        # of section mismatch warnings (< 10 for an allyesconfig build)
 102        help
 103          The section mismatch analysis checks if there are illegal
 104          references from one section to another section.
 105          Linux will during link or during runtime drop some sections
 106          and any use of code/data previously in these sections will
 107          most likely result in an oops.
 108          In the code functions and variables are annotated with
 109          __init, __devinit etc. (see full list in include/linux/init.h)
 110          which results in the code/data being placed in specific sections.
 111          The section mismatch analysis is always done after a full
 112          kernel build but enabling this option will in addition
 113          do the following:
 114          - Add the option -fno-inline-functions-called-once to gcc
 115            When inlining a function annotated __init in a non-init
 116            function we would lose the section information and thus
 117            the analysis would not catch the illegal reference.
 118            This option tells gcc to inline less but will also
 119            result in a larger kernel.
 120          - Run the section mismatch analysis for each module/built-in.o
 121            When we run the section mismatch analysis on vmlinux.o we
 122            lose valueble information about where the mismatch was
 123            introduced.
 124            Running the analysis for each module/built-in.o file
 125            will tell where the mismatch happens much closer to the
 126            source. The drawback is that we will report the same
 127            mismatch at least twice.
 128          - Enable verbose reporting from modpost to help solving
 129            the section mismatches reported.
 131config DEBUG_KERNEL
 132        bool "Kernel debugging"
 133        help
 134          Say Y here if you are developing drivers or trying to debug and
 135          identify kernel problems.
 137config DEBUG_SHIRQ
 138        bool "Debug shared IRQ handlers"
 139        depends on DEBUG_KERNEL && GENERIC_HARDIRQS
 140        help
 141          Enable this to generate a spurious interrupt as soon as a shared
 142          interrupt handler is registered, and just before one is deregistered.
 143          Drivers ought to be able to handle interrupts coming in at those
 144          points; some don't and need to be caught.
 147        bool "Detect Soft Lockups"
 148        depends on DEBUG_KERNEL && !S390
 149        default y
 150        help
 151          Say Y here to enable the kernel to detect "soft lockups",
 152          which are bugs that cause the kernel to loop in kernel
 153          mode for more than 60 seconds, without giving other tasks a
 154          chance to run.
 156          When a soft-lockup is detected, the kernel will print the
 157          current stack trace (which you should report), but the
 158          system will stay locked up. This feature has negligible
 159          overhead.
 161          (Note that "hard lockups" are separate type of bugs that
 162           can be detected via the NMI-watchdog, on platforms that
 163           support it.)
 166        bool "Panic (Reboot) On Soft Lockups"
 167        depends on DETECT_SOFTLOCKUP
 168        help
 169          Say Y here to enable the kernel to panic on "soft lockups",
 170          which are bugs that cause the kernel to loop in kernel
 171          mode for more than 60 seconds, without giving other tasks a
 172          chance to run.
 174          The panic can be used in combination with panic_timeout,
 175          to cause the system to reboot automatically after a
 176          lockup has been detected. This feature is useful for
 177          high-availability systems that have uptime guarantees and
 178          where a lockup must be resolved ASAP.
 180          Say N if unsure.
 183        int
 184        depends on DETECT_SOFTLOCKUP
 185        range 0 1
 186        default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
 187        default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
 189config SCHED_DEBUG
 190        bool "Collect scheduler debugging info"
 191        depends on DEBUG_KERNEL && PROC_FS
 192        default y
 193        help
 194          If you say Y here, the /proc/sched_debug file will be provided
 195          that can help debug the scheduler. The runtime overhead of this
 196          option is minimal.
 198config SCHEDSTATS
 199        bool "Collect scheduler statistics"
 200        depends on DEBUG_KERNEL && PROC_FS
 201        help
 202          If you say Y here, additional code will be inserted into the
 203          scheduler and related routines to collect statistics about
 204          scheduler behavior and provide them in /proc/schedstat.  These
 205          stats may be useful for both tuning and debugging the scheduler
 206          If you aren't debugging the scheduler or trying to tune a specific
 207          application, you can say N to avoid the very slight overhead
 208          this adds.
 210config TIMER_STATS
 211        bool "Collect kernel timers statistics"
 212        depends on DEBUG_KERNEL && PROC_FS
 213        help
 214          If you say Y here, additional code will be inserted into the
 215          timer routines to collect statistics about kernel timers being
 216          reprogrammed. The statistics can be read from /proc/timer_stats.
 217          The statistics collection is started by writing 1 to /proc/timer_stats,
 218          writing 0 stops it. This feature is useful to collect information
 219          about timer usage patterns in kernel and userspace. This feature
 220          is lightweight if enabled in the kernel config but not activated
 221          (it defaults to deactivated on bootup and will only be activated
 222          if some application like powertop activates it explicitly).
 224config DEBUG_OBJECTS
 225        bool "Debug object operations"
 226        depends on DEBUG_KERNEL
 227        help
 228          If you say Y here, additional code will be inserted into the
 229          kernel to track the life time of various objects and validate
 230          the operations on those objects.
 233        bool "Debug objects selftest"
 234        depends on DEBUG_OBJECTS
 235        help
 236          This enables the selftest of the object debug code.
 239        bool "Debug objects in freed memory"
 240        depends on DEBUG_OBJECTS
 241        help
 242          This enables checks whether a k/v free operation frees an area
 243          which contains an object which has not been deactivated
 244          properly. This can make kmalloc/kfree-intensive workloads
 245          much slower.
 248        bool "Debug timer objects"
 249        depends on DEBUG_OBJECTS
 250        help
 251          If you say Y here, additional code will be inserted into the
 252          timer routines to track the life time of timer objects and
 253          validate the timer operations.
 255config DEBUG_SLAB
 256        bool "Debug slab memory allocations"
 257        depends on DEBUG_KERNEL && SLAB
 258        help
 259          Say Y here to have the kernel do limited verification on memory
 260          allocation as well as poisoning memory on free to catch use of freed
 261          memory. This can make kmalloc/kfree-intensive workloads much slower.
 263config DEBUG_SLAB_LEAK
 264        bool "Memory leak debugging"
 265        depends on DEBUG_SLAB
 267config SLUB_DEBUG_ON
 268        bool "SLUB debugging on by default"
 269        depends on SLUB && SLUB_DEBUG
 270        default n
 271        help
 272          Boot with debugging on by default. SLUB boots by default with
 273          the runtime debug capabilities switched off. Enabling this is
 274          equivalent to specifying the "slub_debug" parameter on boot.
 275          There is no support for more fine grained debug control like
 276          possible with slub_debug=xxx. SLUB debugging may be switched
 277          off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
 278          "slub_debug=-".
 280config SLUB_STATS
 281        default n
 282        bool "Enable SLUB performance statistics"
 283        depends on SLUB && SLUB_DEBUG && SYSFS
 284        help
 285          SLUB statistics are useful to debug SLUBs allocation behavior in
 286          order find ways to optimize the allocator. This should never be
 287          enabled for production use since keeping statistics slows down
 288          the allocator by a few percentage points. The slabinfo command
 289          supports the determination of the most active slabs to figure
 290          out which slabs are relevant to a particular load.
 291          Try running: slabinfo -DA
 293config DEBUG_PREEMPT
 294        bool "Debug preemptible kernel"
 295        depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64)
 296        default y
 297        help
 298          If you say Y here then the kernel will use a debug variant of the
 299          commonly used smp_processor_id() function and will print warnings
 300          if kernel code uses it in a preemption-unsafe way. Also, the kernel
 301          will detect preemption count underflows.
 304        bool "RT Mutex debugging, deadlock detection"
 305        depends on DEBUG_KERNEL && RT_MUTEXES
 306        help
 307         This allows rt mutex semantics violations and rt mutex related
 308         deadlocks (lockups) to be detected and reported automatically.
 310config DEBUG_PI_LIST
 311        bool
 312        default y
 313        depends on DEBUG_RT_MUTEXES
 315config RT_MUTEX_TESTER
 316        bool "Built-in scriptable tester for rt-mutexes"
 317        depends on DEBUG_KERNEL && RT_MUTEXES
 318        help
 319          This option enables a rt-mutex tester.
 322        bool "Spinlock and rw-lock debugging: basic checks"
 323        depends on DEBUG_KERNEL
 324        help
 325          Say Y here and build SMP to catch missing spinlock initialization
 326          and certain other kinds of spinlock errors commonly made.  This is
 327          best used in conjunction with the NMI watchdog so that spinlock
 328          deadlocks are also debuggable.
 330config DEBUG_MUTEXES
 331        bool "Mutex debugging: basic checks"
 332        depends on DEBUG_KERNEL
 333        help
 334         This feature allows mutex semantics violations to be detected and
 335         reported.
 338        bool "Lock debugging: detect incorrect freeing of live locks"
 340        select DEBUG_SPINLOCK
 341        select DEBUG_MUTEXES
 342        select LOCKDEP
 343        help
 344         This feature will check whether any held lock (spinlock, rwlock,
 345         mutex or rwsem) is incorrectly freed by the kernel, via any of the
 346         memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
 347         vfree(), etc.), whether a live lock is incorrectly reinitialized via
 348         spin_lock_init()/mutex_init()/etc., or whether there is any lock
 349         held during task exit.
 351config PROVE_LOCKING
 352        bool "Lock debugging: prove locking correctness"
 354        select LOCKDEP
 355        select DEBUG_SPINLOCK
 356        select DEBUG_MUTEXES
 357        select DEBUG_LOCK_ALLOC
 358        default n
 359        help
 360         This feature enables the kernel to prove that all locking
 361         that occurs in the kernel runtime is mathematically
 362         correct: that under no circumstance could an arbitrary (and
 363         not yet triggered) combination of observed locking
 364         sequences (on an arbitrary number of CPUs, running an
 365         arbitrary number of tasks and interrupt contexts) cause a
 366         deadlock.
 368         In short, this feature enables the kernel to report locking
 369         related deadlocks before they actually occur.
 371         The proof does not depend on how hard and complex a
 372         deadlock scenario would be to trigger: how many
 373         participant CPUs, tasks and irq-contexts would be needed
 374         for it to trigger. The proof also does not depend on
 375         timing: if a race and a resulting deadlock is possible
 376         theoretically (no matter how unlikely the race scenario
 377         is), it will be proven so and will immediately be
 378         reported by the kernel (once the event is observed that
 379         makes the deadlock theoretically possible).
 381         If a deadlock is impossible (i.e. the locking rules, as
 382         observed by the kernel, are mathematically correct), the
 383         kernel reports nothing.
 385         NOTE: this feature can also be enabled for rwlocks, mutexes
 386         and rwsems - in which case all dependencies between these
 387         different locking variants are observed and mapped too, and
 388         the proof of observed correctness is also maintained for an
 389         arbitrary combination of these separate locking variants.
 391         For more details, see Documentation/lockdep-design.txt.
 393config LOCKDEP
 394        bool
 396        select STACKTRACE
 397        select FRAME_POINTER if !MIPS && !PPC
 398        select KALLSYMS
 399        select KALLSYMS_ALL
 401config LOCK_STAT
 402        bool "Lock usage statistics"
 404        select LOCKDEP
 405        select DEBUG_SPINLOCK
 406        select DEBUG_MUTEXES
 407        select DEBUG_LOCK_ALLOC
 408        default n
 409        help
 410         This feature enables tracking lock contention points
 412         For more details, see Documentation/lockstat.txt
 414config DEBUG_LOCKDEP
 415        bool "Lock dependency engine debugging"
 416        depends on DEBUG_KERNEL && LOCKDEP
 417        help
 418          If you say Y here, the lock dependency engine will do
 419          additional runtime checks to debug itself, at the price
 420          of more runtime overhead.
 423        depends on DEBUG_KERNEL
 424        bool
 425        default y
 426        depends on TRACE_IRQFLAGS_SUPPORT
 427        depends on PROVE_LOCKING
 430        bool "Spinlock debugging: sleep-inside-spinlock checking"
 431        depends on DEBUG_KERNEL
 432        help
 433          If you say Y here, various routines which may sleep will become very
 434          noisy if they are called with a spinlock held.
 437        bool "Locking API boot-time self-tests"
 438        depends on DEBUG_KERNEL
 439        help
 440          Say Y here if you want the kernel to run a short self-test during
 441          bootup. The self-test checks whether common types of locking bugs
 442          are detected by debugging mechanisms or not. (if you disable
 443          lock debugging then those bugs wont be detected of course.)
 444          The following locking APIs are covered: spinlocks, rwlocks,
 445          mutexes and rwsems.
 447config STACKTRACE
 448        bool
 449        depends on STACKTRACE_SUPPORT
 451config DEBUG_KOBJECT
 452        bool "kobject debugging"
 453        depends on DEBUG_KERNEL
 454        help
 455          If you say Y here, some extra kobject debugging messages will be sent
 456          to the syslog. 
 458config DEBUG_HIGHMEM
 459        bool "Highmem debugging"
 460        depends on DEBUG_KERNEL && HIGHMEM
 461        help
 462          This options enables addition error checking for high memory systems.
 463          Disable for production systems.
 466        bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED
 467        depends on BUG
 468        depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \
 469                   FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300
 470        default !EMBEDDED
 471        help
 472          Say Y here to make BUG() panics output the file name and line number
 473          of the BUG call as well as the EIP and oops trace.  This aids
 474          debugging but costs about 70-100K of memory.
 476config DEBUG_INFO
 477        bool "Compile the kernel with debug info"
 478        depends on DEBUG_KERNEL
 479        help
 480          If you say Y here the resulting kernel image will include
 481          debugging info resulting in a larger kernel image.
 482          This adds debug symbols to the kernel and modules (gcc -g), and
 483          is needed if you intend to use kernel crashdump or binary object
 484          tools like crash, kgdb, LKCD, gdb, etc on the kernel.
 485          Say Y here only if you plan to debug the kernel.
 487          If unsure, say N.
 489config DEBUG_VM
 490        bool "Debug VM"
 491        depends on DEBUG_KERNEL
 492        help
 493          Enable this to turn on extended checks in the virtual-memory system
 494          that may impact performance.
 496          If unsure, say N.
 499        bool "Debug filesystem writers count"
 500        depends on DEBUG_KERNEL
 501        help
 502          Enable this to catch wrong use of the writers count in struct
 503          vfsmount.  This will increase the size of each file struct by
 504          32 bits.
 506          If unsure, say N.
 509        bool "Debug memory initialisation" if EMBEDDED
 510        default !EMBEDDED
 511        help
 512          Enable this for additional checks during memory initialisation.
 513          The sanity checks verify aspects of the VM such as the memory model
 514          and other information provided by the architecture. Verbose
 515          information will be printed at KERN_DEBUG loglevel depending
 516          on the mminit_loglevel= command-line option.
 518          If unsure, say Y
 520config DEBUG_LIST
 521        bool "Debug linked list manipulation"
 522        depends on DEBUG_KERNEL
 523        help
 524          Enable this to turn on extended checks in the linked-list
 525          walking routines.
 527          If unsure, say N.
 529config DEBUG_SG
 530        bool "Debug SG table operations"
 531        depends on DEBUG_KERNEL
 532        help
 533          Enable this to turn on checks on scatter-gather tables. This can
 534          help find problems with drivers that do not properly initialize
 535          their sg tables.
 537          If unsure, say N.
 539config FRAME_POINTER
 540        bool "Compile the kernel with frame pointers"
 541        depends on DEBUG_KERNEL && \
 542                (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \
 543                 AVR32 || SUPERH || BLACKFIN || MN10300)
 544        default y if DEBUG_INFO && UML
 545        help
 546          If you say Y here the resulting kernel image will be slightly larger
 547          and slower, but it might give very useful debugging information on
 548          some architectures or if you use external debuggers.
 549          If you don't debug the kernel, you can say N.
 552        bool "Delay each boot printk message by N milliseconds"
 554        help
 555          This build option allows you to read kernel boot messages
 556          by inserting a short delay after each one.  The delay is
 557          specified in milliseconds on the kernel command line,
 558          using "boot_delay=N".
 560          It is likely that you would also need to use "lpj=M" to preset
 561          the "loops per jiffie" value.
 562          See a previous boot log for the "lpj" value to use for your
 563          system, and then set "lpj=M" before setting "boot_delay=N".
 564          NOTE:  Using this option may adversely affect SMP systems.
 565          I.e., processors other than the first one may not boot up.
 566          BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
 567          what it believes to be lockup conditions.
 570        tristate "torture tests for RCU"
 571        depends on DEBUG_KERNEL
 572        default n
 573        help
 574          This option provides a kernel module that runs torture tests
 575          on the RCU infrastructure.  The kernel module may be built
 576          after the fact on the running kernel to be tested, if desired.
 578          Say Y here if you want RCU torture tests to be built into
 579          the kernel.
 580          Say M if you want the RCU torture tests to build as a module.
 581          Say N if you are unsure.
 584        bool "torture tests for RCU runnable by default"
 585        depends on RCU_TORTURE_TEST = y
 586        default n
 587        help
 588          This option provides a way to build the RCU torture tests
 589          directly into the kernel without them starting up at boot
 590          time.  You can use /proc/sys/kernel/rcutorture_runnable
 591          to manually override this setting.  This /proc file is
 592          available only when the RCU torture tests have been built
 593          into the kernel.
 595          Say Y here if you want the RCU torture tests to start during
 596          boot (you probably don't).
 597          Say N here if you want the RCU torture tests to start only
 598          after being manually enabled via /proc.
 601        bool "Kprobes sanity tests"
 602        depends on DEBUG_KERNEL
 603        depends on KPROBES
 604        default n
 605        help
 606          This option provides for testing basic kprobes functionality on
 607          boot. A sample kprobe, jprobe and kretprobe are inserted and
 608          verified for functionality.
 610          Say N if you are unsure.
 613        tristate "Self test for the backtrace code"
 614        depends on DEBUG_KERNEL
 615        default n
 616        help
 617          This option provides a kernel module that can be used to test
 618          the kernel stack backtrace code. This option is not useful
 619          for distributions or general kernels, but only for kernel
 620          developers working on architecture code.
 622          Note that if you want to also test saved backtraces, you will
 623          have to enable STACKTRACE as well.
 625          Say N if you are unsure.
 627config LKDTM
 628        tristate "Linux Kernel Dump Test Tool Module"
 629        depends on DEBUG_KERNEL
 630        depends on KPROBES
 631        depends on BLOCK
 632        default n
 633        help
 634        This module enables testing of the different dumping mechanisms by
 635        inducing system failures at predefined crash points.
 636        If you don't need it: say N
 637        Choose M here to compile this code as a module. The module will be
 638        called lkdtm.
 640        Documentation on how to use the module can be found in
 641        drivers/misc/lkdtm.c
 644        bool "Fault-injection framework"
 645        depends on DEBUG_KERNEL
 646        help
 647          Provide fault-injection framework.
 648          For more details, see Documentation/fault-injection/.
 650config FAILSLAB
 651        bool "Fault-injection capability for kmalloc"
 652        depends on FAULT_INJECTION
 653        help
 654          Provide fault-injection capability for kmalloc.
 656config FAIL_PAGE_ALLOC
 657        bool "Fault-injection capabilitiy for alloc_pages()"
 658        depends on FAULT_INJECTION
 659        help
 660          Provide fault-injection capability for alloc_pages().
 663        bool "Fault-injection capability for disk IO"
 664        depends on FAULT_INJECTION
 665        help
 666          Provide fault-injection capability for disk IO.
 669        bool "Debugfs entries for fault-injection capabilities"
 670        depends on FAULT_INJECTION && SYSFS && DEBUG_FS
 671        help
 672          Enable configuration of fault-injection capabilities via debugfs.
 675        bool "stacktrace filter for fault-injection capabilities"
 677        depends on !X86_64
 678        select STACKTRACE
 679        select FRAME_POINTER if !PPC
 680        help
 681          Provide stacktrace filter for fault-injection capabilities
 683config LATENCYTOP
 684        bool "Latency measuring infrastructure"
 685        select FRAME_POINTER if !MIPS && !PPC
 686        select KALLSYMS
 687        select KALLSYMS_ALL
 688        select STACKTRACE
 689        select SCHEDSTATS
 690        select SCHED_DEBUG
 691        depends on HAVE_LATENCYTOP_SUPPORT
 692        help
 693          Enable this option if you want to use the LatencyTOP tool
 694          to find out which userspace is blocking on what kernel operations.
 697        bool "Sysctl checks"
 698        depends on SYSCTL_SYSCALL
 699        ---help---
 700          sys_sysctl uses binary paths that have been found challenging
 701          to properly maintain and use. This enables checks that help
 702          you to keep things correct.
 704source kernel/trace/Kconfig
 706config PROVIDE_OHCI1394_DMA_INIT
 707        bool "Remote debugging over FireWire early on boot"
 708        depends on PCI && X86
 709        help
 710          If you want to debug problems which hang or crash the kernel early
 711          on boot and the crashing machine has a FireWire port, you can use
 712          this feature to remotely access the memory of the crashed machine
 713          over FireWire. This employs remote DMA as part of the OHCI1394
 714          specification which is now the standard for FireWire controllers.
 716          With remote DMA, you can monitor the printk buffer remotely using
 717          firescope and access all memory below 4GB using fireproxy from gdb.
 718          Even controlling a kernel debugger is possible using remote DMA.
 720          Usage:
 722          If ohci1394_dma=early is used as boot parameter, it will initialize
 723          all OHCI1394 controllers which are found in the PCI config space.
 725          As all changes to the FireWire bus such as enabling and disabling
 726          devices cause a bus reset and thereby disable remote DMA for all
 727          devices, be sure to have the cable plugged and FireWire enabled on
 728          the debugging host before booting the debug target for debugging.
 730          This code (~1k) is freed after boot. By then, the firewire stack
 731          in charge of the OHCI-1394 controllers should be used instead.
 733          See Documentation/debugging-via-ohci1394.txt for more information.
 736        bool "Remote debugging over FireWire with firewire-ohci"
 737        depends on FIREWIRE_OHCI
 738        help
 739          This option lets you use the FireWire bus for remote debugging
 740          with help of the firewire-ohci driver. It enables unfiltered
 741          remote DMA in firewire-ohci.
 742          See Documentation/debugging-via-ohci1394.txt for more information.
 744          If unsure, say N.
 746menuconfig BUILD_DOCSRC
 747        bool "Build targets in Documentation/ tree"
 748        depends on HEADERS_CHECK
 749        help
 750          This option attempts to build objects from the source files in the
 751          kernel Documentation/ tree.
 753          Say N if you are unsure.
 755source "samples/Kconfig"
 757source "lib/Kconfig.kgdb"