2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
16 config RWSEM_GENERIC_SPINLOCK
19 config RWSEM_XCHGADD_ALGORITHM
23 config GENERIC_ISA_DMA
43 # We optimistically allocate largepages from the VM, so make the limit
44 # large enough (16MB). This badly named config option is actually
46 config FORCE_MAX_ZONEORDER
54 depends on COMPAT && SYSVIPC
57 menu "Platform support"
60 prompt "Platform Type"
67 bool "pSeries / PowerMac G5"
80 depends on PPC_PSERIES
84 # VMX is pSeries only for now until somebody writes the iSeries
85 # exception vectors for it
87 bool "Support for VMX (Altivec) vector unit"
88 depends on PPC_PSERIES
92 depends on PPC_PSERIES
93 bool "Apple PowerMac G5 support"
97 depends on PPC_PSERIES
98 bool "Support for shared-processor logical partitions"
101 Enabling this option will make the kernel run more efficiently
102 on logically-partitioned pSeries systems which use shared
103 processors, that is, which share physical processors between
104 two or more partitions.
107 bool "Enable DART/IOMMU on PowerMac (allow >2G of RAM)"
109 depends on EXPERIMENTAL
112 Enabling DART makes it possible to boot a PowerMac G5 with more
113 than 2GB of memory. Note that the code is very new and untested
114 at this time, so it has to be considered experimental. Enabling
115 this might result in data loss.
123 bool "Support for early boot text console"
126 Say Y here to see progress messages from the boot firmware in text
127 mode. Requires an Open Firmware compatible video card.
130 bool "Optimize for POWER4"
133 Cause the compiler to optimize for POWER4 processors. The resulting
134 binary will not work on POWER3 or RS64 processors when compiled with
135 binutils 2.15 or later.
138 bool "Enable IOMMU virtual merging (EXPERIMENTAL)"
139 depends on EXPERIMENTAL
142 Cause IO segments sent to a device for DMA to be merged virtually
143 by the IOMMU when they happen to have been allocated contiguously.
144 This doesn't add pressure to the IOMMU allocator. However, some
145 drivers don't support getting large merged segments coming back
146 from *_map_sg(). Say Y if you know the drivers you are using are
147 properly handling this case.
150 bool "Symmetric multi-processing support"
152 This enables support for systems with more than one CPU. If you have
153 a system with only one CPU, say N. If you have a system with more
156 If you say N here, the kernel will run on single and multiprocessor
157 machines, but will use only one CPU of a multiprocessor machine. If
158 you say Y here, the kernel will run on single-processor machines.
159 On a single-processor machine, the kernel will run faster if you say
162 If you don't know what to do here, say Y.
165 bool "Distribute interrupts on all CPUs by default"
166 depends on SMP && PPC_PSERIES
168 This option gives the kernel permission to distribute IRQs across
169 multiple CPUs. Saying N here will route all IRQs to the first
173 int "Maximum number of CPUs (2-128)"
179 bool "Hardware multithreading"
180 depends on SMP && PPC_PSERIES
183 bool "Discontiguous Memory Support"
184 depends on SMP && PPC_PSERIES
188 depends on DISCONTIGMEM
191 bool "SMT (Hyperthreading) scheduler support"
195 SMT scheduler support improves the CPU scheduler's decision making
196 when dealing with POWER5 cpus at a cost of slightly increased
197 overhead in some places. If unsure say N here.
200 bool "Preemptible Kernel"
203 This option reduces the latency of the kernel when reacting to
204 real-time or interactive events by allowing a low priority process to
205 be preempted even if it is in kernel mode executing a system call.
207 Say Y here if you are building a kernel for a desktop, embedded
208 or real-time system. Say N if you are unsure.
212 depends on PPC_ISERIES
217 bool "Proc interface to RTAS"
218 depends on !PPC_ISERIES
221 tristate "Firmware flash interface"
225 tristate "Scanlog dump interface"
229 bool "LPAR Configuration Data"
231 Provide system capacity information via human readable
232 <key word>=<value> pairs through a /proc/ppc64/lparcfg interface.
242 Find out whether you have ISA slots on your motherboard. ISA is the
243 name of a bus system, i.e. the way the CPU talks to the other stuff
244 inside your box. If you have an Apple machine, say N here; if you
245 have an IBM RS/6000 or pSeries machine or a PReP machine, say Y. If
246 you have an embedded board, consult your board documentation.
261 Find out whether your system includes a PCI bus. PCI is the name of
262 a bus system, i.e. the way the CPU talks to the other stuff inside
263 your box. If you say Y here, the kernel will include drivers and
264 infrastructure code to support PCI bus devices.
270 source "fs/Kconfig.binfmt"
272 source "drivers/pci/Kconfig"
275 bool "Support for hot-pluggable CPUs"
276 depends on SMP && HOTPLUG && EXPERIMENTAL
278 Say Y here to be able to turn CPUs off and on.
280 Say N if you are unsure.
282 source "drivers/pcmcia/Kconfig"
284 source "drivers/pci/hotplug/Kconfig"
286 config PROC_DEVICETREE
287 bool "Support for Open Firmware device tree in /proc"
288 depends on !PPC_ISERIES
290 This option adds a device-tree directory under /proc which contains
291 an image of the device tree that the kernel copies from Open
292 Firmware. If unsure, say Y here.
295 bool "Default bootloader kernel arguments"
296 depends on !PPC_ISERIES
299 string "Initial kernel command string"
300 depends on CMDLINE_BOOL
301 default "console=ttyS0,9600 console=tty0 root=/dev/sda2"
303 On some platforms, there is currently no way for the boot loader to
304 pass arguments to the kernel. For these platforms, you can supply
305 some command-line options at build time by entering them here. In
306 most cases you will need to specify the root device here.
310 source "drivers/Kconfig"
314 menu "iSeries device drivers"
315 depends on PPC_ISERIES
318 tristate "iSeries Virtual Console Support"
321 tristate "iSeries Virtual I/O disk support"
323 If you are running on an iSeries system and you want to use
324 virtual disks created and managed by OS/400, say Y.
327 tristate "iSeries Virtual I/O CD support"
329 If you are running Linux on an IBM iSeries system and you want to
330 read a CD drive owned by OS/400, say Y here.
333 tristate "iSeries Virtual Tape Support"
335 If you are running Linux on an iSeries system and you want Linux
336 to read and/or write a tape drive owned by OS/400, say Y here.
342 depends on VIOCONS || VIODASD || VIOCD || VIOTAPE || VETH
345 source "arch/ppc64/oprofile/Kconfig"
347 menu "Kernel hacking"
350 bool "Kernel debugging"
352 Say Y here if you are developing drivers or trying to debug and
353 identify kernel problems.
355 config DEBUG_STACKOVERFLOW
356 bool "Check for stack overflows"
357 depends on DEBUG_KERNEL
359 config DEBUG_STACK_USAGE
360 bool "Stack utilization instrumentation"
361 depends on DEBUG_KERNEL
363 Enables the display of the minimum amount of free stack which each
364 task has ever had available in the sysrq-T and sysrq-P debug output.
366 This option will slow down process creation somewhat.
369 bool "Debug memory allocations"
370 depends on DEBUG_KERNEL
372 Say Y here to have the kernel do limited verification on memory
373 allocation as well as poisoning memory on free to catch use of freed
377 bool "Magic SysRq key"
378 depends on DEBUG_KERNEL
380 If you say Y here, you will have some control over the system even
381 if the system crashes for example during kernel debugging (e.g., you
382 will be able to flush the buffer cache to disk, reboot the system
383 immediately or dump some status information). This is accomplished
384 by pressing various keys while holding SysRq (Alt+PrintScreen). It
385 also works on a serial console (on PC hardware at least), if you
386 send a BREAK and then within 5 seconds a command keypress. The
387 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
388 unless you really know what this hack does.
391 bool "Enable debugger hooks"
392 depends on DEBUG_KERNEL
394 Include in-kernel hooks for kernel debuggers. Unless you are
395 intending to debug the kernel, say N here.
398 bool "Include xmon kernel debugger"
401 Include in-kernel hooks for the xmon kernel monitor/debugger.
402 Unless you are intending to debug the kernel, say N here.
405 bool "Enable xmon by default"
409 bool "Include PPCDBG realtime debugging"
410 depends on DEBUG_KERNEL
413 bool "Compile the kernel with debug info"
414 depends on DEBUG_KERNEL
416 If you say Y here the resulting kernel image will include
417 debugging info resulting in a larger kernel image.
418 Say Y here only if you plan to use gdb to debug the kernel.
419 If you don't debug the kernel, you can say N.
422 bool "Use separate kernel stacks when processing interrupts"
424 If you say Y here the kernel will use separate kernel stacks
425 for handling hard and soft interrupts. This can help avoid
426 overflowing the process kernel stacks.
431 bool "Inline spinlock code at each call site"
432 depends on SMP && !PPC_SPLPAR && !PPC_ISERIES
434 Say Y if you want to have the code for acquiring spinlocks
435 and rwlocks inlined at each call site. This makes the kernel
436 somewhat bigger, but can be useful when profiling the kernel.
440 source "kernel/vserver/Kconfig"
442 source "security/Kconfig"
444 source "crypto/Kconfig"