1 comment "Processor Type"
4 prompt "CPU family support"
5 default M68KCLASSIC if MMU
6 default COLDFIRE if !MMU
8 The Freescale (was Motorola) M68K family of processors implements
9 the full 68000 processor instruction set.
10 The Freescale ColdFire family of processors is a modern derivitive
11 of the 68000 processor family. They are mainly targeted at embedded
12 applications, and are all System-On-Chip (SOC) devices, as opposed
13 to stand alone CPUs. They implement a subset of the original 68000
14 processor instruction set.
15 If you anticipate running this kernel on a computer with a classic
16 MC68xxx processor, select M68KCLASSIC.
17 If you anticipate running this kernel on a computer with a ColdFire
18 processor, select COLDFIRE.
21 bool "Classic M68K CPU family support"
24 bool "Coldfire CPU family support"
26 select ARCH_REQUIRE_GPIOLIB
27 select CPU_HAS_NO_BITFIELDS
28 select CPU_HAS_NO_MULDIV64
37 select CPU_HAS_NO_BITFIELDS
38 select CPU_HAS_NO_MULDIV64
41 The Freescale (was Motorola) 68000 CPU is the first generation of
42 the well known M68K family of processors. The CPU core as well as
43 being available as a stand alone CPU was also used in many
44 System-On-Chip devices (eg 68328, 68302, etc). It does not contain
49 select CPU_HAS_NO_BITFIELDS
51 The Freescale (was then Motorola) CPU32 is a CPU core that is
52 based on the 68020 processor. For the most part it is used in
53 System-On-Chip parts, and does not contain a paging MMU.
58 select GENERIC_ATOMIC64
59 select CPU_HAS_ADDRESS_SPACES
61 If you anticipate running this kernel on a computer with a MC68020
62 processor, say Y. Otherwise, say N. Note that the 68020 requires a
63 68851 MMU (Memory Management Unit) to run Linux/m68k, except on the
64 Sun 3, which provides its own version.
68 depends on MMU && !MMU_SUN3
69 select GENERIC_ATOMIC64
70 select CPU_HAS_ADDRESS_SPACES
72 If you anticipate running this kernel on a computer with a MC68030
73 processor, say Y. Otherwise, say N. Note that a MC68EC030 will not
74 work, as it does not include an MMU (Memory Management Unit).
78 depends on MMU && !MMU_SUN3
79 select GENERIC_ATOMIC64
80 select CPU_HAS_ADDRESS_SPACES
82 If you anticipate running this kernel on a computer with a MC68LC040
83 or MC68040 processor, say Y. Otherwise, say N. Note that an
84 MC68EC040 will not work, as it does not include an MMU (Memory
89 depends on MMU && !MMU_SUN3
90 select GENERIC_ATOMIC64
91 select CPU_HAS_ADDRESS_SPACES
93 If you anticipate running this kernel on a computer with a MC68060
94 processor, say Y. Otherwise, say N.
101 Motorola 68328 processor support.
108 Motorola 68EX328 processor support.
115 Motorola 68VZ328 processor support.
122 Motorola 68360 processor support.
131 select COLDFIRE_SW_A7
134 Motorola ColdFire 5206 processor support.
139 select COLDFIRE_SW_A7
142 Motorola ColdFire 5206e processor support.
147 select GENERIC_CLOCKEVENTS
148 select HAVE_CACHE_SPLIT
150 Freescale Coldfire 5207/5208 processor support.
155 select GENERIC_CLOCKEVENTS
156 select HAVE_CACHE_SPLIT
159 Freescale Coldfire 5230/1/2/4/5 processor support
164 select COLDFIRE_SW_A7
167 Motorola ColdFire 5249 processor support.
176 select HAVE_CACHE_SPLIT
178 select GENERIC_CLOCKEVENTS
180 Freescale (Motorola) ColdFire 5270/5271 processor support.
185 select COLDFIRE_SW_A7
188 Motorola ColdFire 5272 processor support.
194 select HAVE_CACHE_SPLIT
196 select GENERIC_CLOCKEVENTS
198 Freescale (Motorola) ColdFire 5274/5275 processor support.
203 select GENERIC_CLOCKEVENTS
204 select HAVE_CACHE_SPLIT
207 Motorola ColdFire 5280/5282 processor support.
212 select COLDFIRE_SW_A7
216 Motorola ColdFire 5307 processor support.
223 Freescale (Motorola) ColdFire 532x processor support.
228 select COLDFIRE_SW_A7
232 Motorola ColdFire 5407 processor support.
240 select MMU_COLDFIRE if MMU
244 Freescale ColdFire 5470/5471/5472/5473/5474/5475 processor support.
248 select MMU_COLDFIRE if MMU
253 Freescale ColdFire 5480/5481/5482/5483/5484/5485 processor support.
258 comment "Processor Specific Options"
261 bool "Math emulation support (EXPERIMENTAL)"
263 depends on EXPERIMENTAL
265 At some point in the future, this will cause floating-point math
266 instructions to be emulated by the kernel on machines that lack a
267 floating-point math coprocessor. Thrill-seekers and chronically
268 sleep-deprived psychotic hacker types can say Y now, everyone else
269 should probably wait a while.
271 config M68KFPU_EMU_EXTRAPREC
272 bool "Math emulation extra precision"
273 depends on M68KFPU_EMU
275 The fpu uses normally a few bit more during calculations for
276 correct rounding, the emulator can (often) do the same but this
277 extra calculation can cost quite some time, so you can disable
278 it here. The emulator will then "only" calculate with a 64 bit
279 mantissa and round slightly incorrect, what is more than enough
282 config M68KFPU_EMU_ONLY
283 bool "Math emulation only kernel"
284 depends on M68KFPU_EMU
286 This option prevents any floating-point instructions from being
287 compiled into the kernel, thereby the kernel doesn't save any
288 floating point context anymore during task switches, so this
289 kernel will only be usable on machines without a floating-point
290 math coprocessor. This makes the kernel a bit faster as no tests
291 needs to be executed whether a floating-point instruction in the
292 kernel should be executed or not.
295 bool "Advanced configuration options"
298 This gives you access to some advanced options for the CPU. The
299 defaults should be fine for most users, but these options may make
300 it possible for you to improve performance somewhat if you know what
303 Note that the answer to this question won't directly affect the
304 kernel: saying N will just cause the configurator to skip all
305 the questions about these options.
307 Most users should say N to this question.
310 bool "Use read-modify-write instructions"
313 This allows to use certain instructions that work with indivisible
314 read-modify-write bus cycles. While this is faster than the
315 workaround of disabling interrupts, it can conflict with DMA
316 ( = direct memory access) on many Amiga systems, and it is also said
317 to destabilize other machines. It is very likely that this will
318 cause serious problems on any Amiga or Atari Medusa if set. The only
319 configuration where it should work are 68030-based Ataris, where it
320 apparently improves performance. But you've been warned! Unless you
321 really know what you are doing, say N. Try Y only if you're quite
324 config SINGLE_MEMORY_CHUNK
325 bool "Use one physical chunk of memory only" if ADVANCED && !SUN3
328 select NEED_MULTIPLE_NODES
330 Ignore all but the first contiguous chunk of physical memory for VM
331 purposes. This will save a few bytes kernel size and may speed up
332 some operations. Say N if not sure.
334 config ARCH_DISCONTIGMEM_ENABLE
335 def_bool MMU && !SINGLE_MEMORY_CHUNK
337 config 060_WRITETHROUGH
338 bool "Use write-through caching for 68060 supervisor accesses"
339 depends on ADVANCED && M68060
341 The 68060 generally uses copyback caching of recently accessed data.
342 Copyback caching means that memory writes will be held in an on-chip
343 cache and only written back to memory some time later. Saying Y
344 here will force supervisor (kernel) accesses to use writethrough
345 caching. Writethrough caching means that data is written to memory
346 straight away, so that cache and memory data always agree.
347 Writethrough caching is less efficient, but is needed for some
348 drivers on 68060 based systems where the 68060 bus snooping signal
349 is hardwired on. The 53c710 SCSI driver is known to suffer from
360 depends on !SINGLE_MEMORY_CHUNK
365 config COLDFIRE_SW_A7
368 config HAVE_CACHE_SPLIT
381 bool "Enable setting the CPU clock frequency"
385 On some CPU's you do not need to know what the core CPU clock
386 frequency is. On these you can disable clock setting. On some
387 traditional 68K parts, and on all ColdFire parts you need to set
388 the appropriate CPU clock frequency. On these devices many of the
389 onboard peripherals derive their timing from the master CPU clock
393 int "Set the core clock frequency"
397 Define the CPU clock frequency in use. This is the core clock
398 frequency, it may or may not be the same as the external clock
399 crystal fitted to your board. Some processors have an internal
400 PLL and can have their frequency programmed at run time, others
401 use internal dividers. In general the kernel won't setup a PLL
402 if it is fitted (there are some exceptions). This value will be
403 specific to the exact CPU that you are using.
406 bool "Old mask 5307 (1H55J) silicon"
409 Build support for the older revision ColdFire 5307 silicon.
410 Specifically this is the 1H55J mask revision.
414 prompt "Split Cache Configuration"
420 Use all of the ColdFire CPU cache memory as an instruction cache.
425 Use all of the ColdFire CPU cache memory as a data cache.
430 Split the ColdFire CPU cache, and use half as an instruction cache
431 and half as a data cache.
437 prompt "Data cache mode"
438 default CACHE_WRITETHRU
440 config CACHE_WRITETHRU
443 The ColdFire CPU cache is set into Write-through mode.
445 config CACHE_COPYBACK
448 The ColdFire CPU cache is set into Copy-back mode.