1 # SPDX-License-Identifier: GPL-2.0
2 # Put here option for CPU selection and depending optimization
4 prompt "Processor family"
6 default GENERIC_CPU if X86_64
8 This is the processor type of your CPU. This information is
9 used for optimizing purposes. In order to compile a kernel
10 that can run on all supported x86 CPU types (albeit not
11 optimally fast), you can specify "486" here.
13 Note that the 386 is no longer supported, this includes
14 AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI 486DLC/DLC2,
15 UMC 486SX-S and the NexGen Nx586.
17 The kernel will not necessarily run on earlier architectures than
18 the one you have chosen, e.g. a Pentium optimized kernel will run on
19 a PPro, but not necessarily on a i486.
21 Here are the settings recommended for greatest speed:
22 - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or
23 SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S.
24 - "586" for generic Pentium CPUs lacking the TSC
25 (time stamp counter) register.
26 - "Pentium-Classic" for the Intel Pentium.
27 - "Pentium-MMX" for the Intel Pentium MMX.
28 - "Pentium-Pro" for the Intel Pentium Pro.
29 - "Pentium-II" for the Intel Pentium II or pre-Coppermine Celeron.
30 - "Pentium-III" for the Intel Pentium III or Coppermine Celeron.
31 - "Pentium-4" for the Intel Pentium 4 or P4-based Celeron.
32 - "K6" for the AMD K6, K6-II and K6-III (aka K6-3D).
33 - "Athlon" for the AMD K7 family (Athlon/Duron/Thunderbird).
34 - "Opteron/Athlon64/Hammer/K8" for all K8 and newer AMD CPUs.
35 - "Crusoe" for the Transmeta Crusoe series.
36 - "Efficeon" for the Transmeta Efficeon series.
37 - "Winchip-C6" for original IDT Winchip.
38 - "Winchip-2" for IDT Winchips with 3dNow! capabilities.
39 - "AMD Elan" for the 32-bit AMD Elan embedded CPU.
40 - "GeodeGX1" for Geode GX1 (Cyrix MediaGX).
41 - "Geode GX/LX" For AMD Geode GX and LX processors.
42 - "CyrixIII/VIA C3" for VIA Cyrix III or VIA C3.
43 - "VIA C3-2" for VIA C3-2 "Nehemiah" (model 9 and above).
44 - "VIA C7" for VIA C7.
45 - "Intel P4" for the Pentium 4/Netburst microarchitecture.
46 - "Core 2/newer Xeon" for all core2 and newer Intel CPUs.
47 - "Intel Atom" for the Atom-microarchitecture CPUs.
48 - "Generic-x86-64" for a kernel which runs on any x86-64 CPU.
50 See each option's help text for additional details. If you don't know
51 what to do, choose "486".
57 Select this for an 486-class CPU such as AMD/Cyrix/IBM/Intel
58 486DX/DX2/DX4 or SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S.
61 bool "586/K5/5x86/6x86/6x86MX"
64 Select this for an 586 or 686 series processor such as the AMD K5,
65 the Cyrix 5x86, 6x86 and 6x86MX. This choice does not
66 assume the RDTSC (Read Time Stamp Counter) instruction.
69 bool "Pentium-Classic"
72 Select this for a Pentium Classic processor with the RDTSC (Read
73 Time Stamp Counter) instruction for benchmarking.
79 Select this for a Pentium with the MMX graphics/multimedia
80 extended instructions.
86 Select this for Intel Pentium Pro chips. This enables the use of
87 Pentium Pro extended instructions, and disables the init-time guard
88 against the f00f bug found in earlier Pentiums.
91 bool "Pentium-II/Celeron(pre-Coppermine)"
94 Select this for Intel chips based on the Pentium-II and
95 pre-Coppermine Celeron core. This option enables an unaligned
96 copy optimization, compiles the kernel with optimization flags
97 tailored for the chip, and applies any applicable Pentium Pro
101 bool "Pentium-III/Celeron(Coppermine)/Pentium-III Xeon"
104 Select this for Intel chips based on the Pentium-III and
105 Celeron-Coppermine core. This option enables use of some
106 extended prefetch instructions in addition to the Pentium II
113 Select this for Intel Pentium M (not Pentium-4 M)
117 bool "Pentium-4/Celeron(P4-based)/Pentium-4 M/older Xeon"
120 Select this for Intel Pentium 4 chips. This includes the
121 Pentium 4, Pentium D, P4-based Celeron and Xeon, and
122 Pentium-4 M (not Pentium M) chips. This option enables compile
123 flags optimized for the chip, uses the correct cache line size, and
124 applies any applicable optimizations.
126 CPUIDs: F[0-6][1-A] (in /proc/cpuinfo show = cpu family : 15 )
129 Pentiums (Pentium 4, Pentium D, Celeron, Celeron D) corename:
134 -Extreme Edition (Gallatin)
140 Xeons (Intel Xeon, Xeon MP, Xeon LV, Xeon MV) corename:
153 bool "K6/K6-II/K6-III"
156 Select this for an AMD K6-family processor. Enables use of
157 some extended instructions, and passes appropriate optimization
161 bool "Athlon/Duron/K7"
164 Select this for an AMD Athlon K7-family processor. Enables use of
165 some extended instructions, and passes appropriate optimization
169 bool "Opteron/Athlon64/Hammer/K8"
171 Select this for an AMD Opteron or Athlon64 Hammer-family processor.
172 Enables use of some extended instructions, and passes appropriate
173 optimization flags to GCC.
179 Select this for a Transmeta Crusoe processor. Treats the processor
180 like a 586 with TSC, and sets some GCC optimization flags (like a
181 Pentium Pro with no alignment requirements).
187 Select this for a Transmeta Efficeon processor.
193 Select this for an IDT Winchip C6 chip. Linux and GCC
194 treat this chip as a 586TSC with some extended instructions
195 and alignment requirements.
198 bool "Winchip-2/Winchip-2A/Winchip-3"
201 Select this for an IDT Winchip-2, 2A or 3. Linux and GCC
202 treat this chip as a 586TSC with some extended instructions
203 and alignment requirements. Also enable out of order memory
204 stores for this CPU, which can increase performance of some
211 Select this for an AMD Elan processor.
213 Do not use this option for K6/Athlon/Opteron processors!
219 Select this for a Geode GX1 (Cyrix MediaGX) chip.
225 Select this for AMD Geode GX and LX processors.
228 bool "CyrixIII/VIA-C3"
231 Select this for a Cyrix III or C3 chip. Presently Linux and GCC
232 treat this chip as a generic 586. Whilst the CPU is 686 class,
233 it lacks the cmov extension which gcc assumes is present when
235 Note that Nehemiah (Model 9) and above will not boot with this
236 kernel due to them lacking the 3DNow! instructions used in earlier
237 incarnations of the CPU.
240 bool "VIA C3-2 (Nehemiah)"
243 Select this for a VIA C3 "Nehemiah". Selecting this enables usage
244 of SSE and tells gcc to treat the CPU as a 686.
245 Note, this kernel will not boot on older (pre model 9) C3s.
251 Select this for a VIA C7. Selecting this uses the correct cache
252 shift and tells gcc to treat the CPU as a 686.
255 bool "Intel P4 / older Netburst based Xeon"
258 Optimize for Intel Pentium 4, Pentium D and older Nocona/Dempsey
259 Xeon CPUs with Intel 64bit which is compatible with x86-64.
260 Note that the latest Xeons (Xeon 51xx and 53xx) are not based on the
261 Netburst core and shouldn't use this option. You can distinguish them
262 using the cpu family field
263 in /proc/cpuinfo. Family 15 is an older Xeon, Family 6 a newer one.
266 bool "Core 2/newer Xeon"
269 Select this for Intel Core 2 and newer Core 2 Xeons (Xeon 51xx and
270 53xx) CPUs. You can distinguish newer from older Xeons by the CPU
271 family in /proc/cpuinfo. Newer ones have 6 and older ones 15
278 Select this for the Intel Atom platform. Intel Atom CPUs have an
279 in-order pipelining architecture and thus can benefit from
280 accordingly optimized code. Use a recent GCC with specific Atom
281 support in order to fully benefit from selecting this option.
284 bool "Generic-x86-64"
288 Run equally well on all x86-64 CPUs.
293 bool "Generic x86 support"
296 Instead of just including optimizations for the selected
297 x86 variant (e.g. PII, Crusoe or Athlon), include some more
298 generic optimizations as well. This will make the kernel
299 perform better on x86 CPUs other than that selected.
301 This is really intended for distributors who need more
302 generic optimizations.
305 # Define implied options from the CPU selection here
306 config X86_INTERNODE_CACHE_SHIFT
308 default "12" if X86_VSMP
309 default X86_L1_CACHE_SHIFT
311 config X86_L1_CACHE_SHIFT
313 default "7" if MPENTIUM4 || MPSC
314 default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MATOM || MVIAC7 || X86_GENERIC || GENERIC_CPU
315 default "4" if MELAN || M486 || MGEODEGX1
316 default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX
318 config X86_PPRO_FENCE
319 bool "PentiumPro memory ordering errata workaround"
320 depends on M686 || M586MMX || M586TSC || M586 || M486 || MGEODEGX1
322 Old PentiumPro multiprocessor systems had errata that could cause
323 memory operations to violate the x86 ordering standard in rare cases.
324 Enabling this option will attempt to work around some (but not all)
325 occurrences of this problem, at the cost of much heavier spinlock and
326 memory barrier operations.
328 If unsure, say n here. Even distro kernels should think twice before
329 enabling this: there are few systems, and an unlikely bug.
333 depends on M586MMX || M586TSC || M586 || M486
339 config X86_ALIGNMENT_16
341 depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 || MGEODEGX1
343 config X86_INTEL_USERCOPY
345 depends on MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7 || MEFFICEON || MCORE2
347 config X86_USE_PPRO_CHECKSUM
349 depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2 || MVIAC7 || MEFFICEON || MGEODE_LX || MCORE2 || MATOM
353 depends on (MCYRIXIII || MK7 || MGEODE_LX) && !UML
356 # P6_NOPs are a relatively minor optimization that require a family >=
357 # 6 processor, except that it is broken on certain VIA chips.
358 # Furthermore, AMD chips prefer a totally different sequence of NOPs
359 # (which work on all CPUs). In addition, it looks like Virtual PC
360 # does not understand them.
362 # As a result, disallow these if we're not compiling for X86_64 (these
363 # NOPs do work on all x86-64 capable chips); the list of processors in
364 # the right-hand clause are the cores that benefit from this optimization.
369 depends on (MCORE2 || MPENTIUM4 || MPSC)
373 depends on (MWINCHIP3D || MCRUSOE || MEFFICEON || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2 || MVIAC7 || MGEODEGX1 || MGEODE_LX || MCORE2 || MATOM) || X86_64
377 depends on X86_PAE || X86_64 || MCORE2 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MATOM
379 # this should be set for all -march=.. options where the compiler
383 depends on (MK8 || MK7 || MCORE2 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || MVIAC3_2 || MVIAC7 || MCRUSOE || MEFFICEON || X86_64 || MATOM || MGEODE_LX)
385 config X86_MINIMUM_CPU_FAMILY
387 default "64" if X86_64
388 default "6" if X86_32 && X86_P6_NOP
389 default "5" if X86_32 && X86_CMPXCHG64
392 config X86_DEBUGCTLMSR
394 depends on !(MK6 || MWINCHIPC6 || MWINCHIP3D || MCYRIXIII || M586MMX || M586TSC || M586 || M486) && !UML
396 menuconfig PROCESSOR_SELECT
397 bool "Supported processor vendors" if EXPERT
399 This lets you choose what x86 vendor support code your kernel
404 bool "Support Intel processors" if PROCESSOR_SELECT
406 This enables detection, tunings and quirks for Intel processors
408 You need this enabled if you want your kernel to run on an
409 Intel CPU. Disabling this option on other types of CPUs
410 makes the kernel a tiny bit smaller. Disabling it on an Intel
411 CPU might render the kernel unbootable.
415 config CPU_SUP_CYRIX_32
417 bool "Support Cyrix processors" if PROCESSOR_SELECT
418 depends on M486 || M586 || M586TSC || M586MMX || (EXPERT && !64BIT)
420 This enables detection, tunings and quirks for Cyrix processors
422 You need this enabled if you want your kernel to run on a
423 Cyrix CPU. Disabling this option on other types of CPUs
424 makes the kernel a tiny bit smaller. Disabling it on a Cyrix
425 CPU might render the kernel unbootable.
431 bool "Support AMD processors" if PROCESSOR_SELECT
433 This enables detection, tunings and quirks for AMD processors
435 You need this enabled if you want your kernel to run on an
436 AMD CPU. Disabling this option on other types of CPUs
437 makes the kernel a tiny bit smaller. Disabling it on an AMD
438 CPU might render the kernel unbootable.
442 config CPU_SUP_CENTAUR
444 bool "Support Centaur processors" if PROCESSOR_SELECT
446 This enables detection, tunings and quirks for Centaur processors
448 You need this enabled if you want your kernel to run on a
449 Centaur CPU. Disabling this option on other types of CPUs
450 makes the kernel a tiny bit smaller. Disabling it on a Centaur
451 CPU might render the kernel unbootable.
455 config CPU_SUP_TRANSMETA_32
457 bool "Support Transmeta processors" if PROCESSOR_SELECT
460 This enables detection, tunings and quirks for Transmeta processors
462 You need this enabled if you want your kernel to run on a
463 Transmeta CPU. Disabling this option on other types of CPUs
464 makes the kernel a tiny bit smaller. Disabling it on a Transmeta
465 CPU might render the kernel unbootable.
469 config CPU_SUP_UMC_32
471 bool "Support UMC processors" if PROCESSOR_SELECT
472 depends on M486 || (EXPERT && !64BIT)
474 This enables detection, tunings and quirks for UMC processors
476 You need this enabled if you want your kernel to run on a
477 UMC CPU. Disabling this option on other types of CPUs
478 makes the kernel a tiny bit smaller. Disabling it on a UMC
479 CPU might render the kernel unbootable.