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 derivative
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_WANT_OPTIONAL_GPIOLIB
27 select ARCH_HAVE_CUSTOM_GPIO_H
28 select CPU_HAS_NO_BITFIELDS
29 select CPU_HAS_NO_MULDIV64
39 select CPU_HAS_NO_BITFIELDS
40 select CPU_HAS_NO_MULDIV64
41 select CPU_HAS_NO_UNALIGNED
44 The Freescale (was Motorola) 68000 CPU is the first generation of
45 the well known M68K family of processors. The CPU core as well as
46 being available as a stand alone CPU was also used in many
47 System-On-Chip devices (eg 68328, 68302, etc). It does not contain
52 select CPU_HAS_NO_BITFIELDS
53 select CPU_HAS_NO_UNALIGNED
55 The Freescale (was then Motorola) CPU32 is a CPU core that is
56 based on the 68020 processor. For the most part it is used in
57 System-On-Chip parts, and does not contain a paging MMU.
62 select CPU_HAS_ADDRESS_SPACES
64 If you anticipate running this kernel on a computer with a MC68020
65 processor, say Y. Otherwise, say N. Note that the 68020 requires a
66 68851 MMU (Memory Management Unit) to run Linux/m68k, except on the
67 Sun 3, which provides its own version.
71 depends on MMU && !MMU_SUN3
72 select CPU_HAS_ADDRESS_SPACES
74 If you anticipate running this kernel on a computer with a MC68030
75 processor, say Y. Otherwise, say N. Note that a MC68EC030 will not
76 work, as it does not include an MMU (Memory Management Unit).
80 depends on MMU && !MMU_SUN3
81 select CPU_HAS_ADDRESS_SPACES
83 If you anticipate running this kernel on a computer with a MC68LC040
84 or MC68040 processor, say Y. Otherwise, say N. Note that an
85 MC68EC040 will not work, as it does not include an MMU (Memory
90 depends on MMU && !MMU_SUN3
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.
172 select COLDFIRE_SW_A7
175 Freescale (Motorola) Coldfire 5251/5253 processor support.
184 select HAVE_CACHE_SPLIT
186 select GENERIC_CLOCKEVENTS
188 Freescale (Motorola) ColdFire 5270/5271 processor support.
193 select COLDFIRE_SW_A7
196 Motorola ColdFire 5272 processor support.
202 select HAVE_CACHE_SPLIT
204 select GENERIC_CLOCKEVENTS
206 Freescale (Motorola) ColdFire 5274/5275 processor support.
211 select GENERIC_CLOCKEVENTS
212 select HAVE_CACHE_SPLIT
215 Motorola ColdFire 5280/5282 processor support.
220 select COLDFIRE_SW_A7
224 Motorola ColdFire 5307 processor support.
231 Freescale (Motorola) ColdFire 532x processor support.
236 select COLDFIRE_SW_A7
240 Motorola ColdFire 5407 processor support.
248 select MMU_COLDFIRE if MMU
252 Freescale ColdFire 5470/5471/5472/5473/5474/5475 processor support.
256 select MMU_COLDFIRE if MMU
261 Freescale ColdFire 5480/5481/5482/5483/5484/5485 processor support.
266 select GENERIC_CLOCKEVENTS
269 Freescale Coldfire 54410/54415/54416/54417/54418 processor support.
274 comment "Processor Specific Options"
277 bool "Math emulation support"
280 At some point in the future, this will cause floating-point math
281 instructions to be emulated by the kernel on machines that lack a
282 floating-point math coprocessor. Thrill-seekers and chronically
283 sleep-deprived psychotic hacker types can say Y now, everyone else
284 should probably wait a while.
286 config M68KFPU_EMU_EXTRAPREC
287 bool "Math emulation extra precision"
288 depends on M68KFPU_EMU
290 The fpu uses normally a few bit more during calculations for
291 correct rounding, the emulator can (often) do the same but this
292 extra calculation can cost quite some time, so you can disable
293 it here. The emulator will then "only" calculate with a 64 bit
294 mantissa and round slightly incorrect, what is more than enough
297 config M68KFPU_EMU_ONLY
298 bool "Math emulation only kernel"
299 depends on M68KFPU_EMU
301 This option prevents any floating-point instructions from being
302 compiled into the kernel, thereby the kernel doesn't save any
303 floating point context anymore during task switches, so this
304 kernel will only be usable on machines without a floating-point
305 math coprocessor. This makes the kernel a bit faster as no tests
306 needs to be executed whether a floating-point instruction in the
307 kernel should be executed or not.
310 bool "Advanced configuration options"
313 This gives you access to some advanced options for the CPU. The
314 defaults should be fine for most users, but these options may make
315 it possible for you to improve performance somewhat if you know what
318 Note that the answer to this question won't directly affect the
319 kernel: saying N will just cause the configurator to skip all
320 the questions about these options.
322 Most users should say N to this question.
325 bool "Use read-modify-write instructions"
328 This allows to use certain instructions that work with indivisible
329 read-modify-write bus cycles. While this is faster than the
330 workaround of disabling interrupts, it can conflict with DMA
331 ( = direct memory access) on many Amiga systems, and it is also said
332 to destabilize other machines. It is very likely that this will
333 cause serious problems on any Amiga or Atari Medusa if set. The only
334 configuration where it should work are 68030-based Ataris, where it
335 apparently improves performance. But you've been warned! Unless you
336 really know what you are doing, say N. Try Y only if you're quite
339 config SINGLE_MEMORY_CHUNK
340 bool "Use one physical chunk of memory only" if ADVANCED && !SUN3
343 select NEED_MULTIPLE_NODES
345 Ignore all but the first contiguous chunk of physical memory for VM
346 purposes. This will save a few bytes kernel size and may speed up
347 some operations. Say N if not sure.
349 config ARCH_DISCONTIGMEM_ENABLE
350 def_bool MMU && !SINGLE_MEMORY_CHUNK
352 config 060_WRITETHROUGH
353 bool "Use write-through caching for 68060 supervisor accesses"
354 depends on ADVANCED && M68060
356 The 68060 generally uses copyback caching of recently accessed data.
357 Copyback caching means that memory writes will be held in an on-chip
358 cache and only written back to memory some time later. Saying Y
359 here will force supervisor (kernel) accesses to use writethrough
360 caching. Writethrough caching means that data is written to memory
361 straight away, so that cache and memory data always agree.
362 Writethrough caching is less efficient, but is needed for some
363 drivers on 68060 based systems where the 68060 bus snooping signal
364 is hardwired on. The 53c710 SCSI driver is known to suffer from
375 depends on !SINGLE_MEMORY_CHUNK
377 config CPU_HAS_NO_BITFIELDS
380 config CPU_HAS_NO_MULDIV64
383 config CPU_HAS_NO_UNALIGNED
386 config CPU_HAS_ADDRESS_SPACES
392 config COLDFIRE_SW_A7
395 config HAVE_CACHE_SPLIT
408 bool "Enable setting the CPU clock frequency"
412 On some CPU's you do not need to know what the core CPU clock
413 frequency is. On these you can disable clock setting. On some
414 traditional 68K parts, and on all ColdFire parts you need to set
415 the appropriate CPU clock frequency. On these devices many of the
416 onboard peripherals derive their timing from the master CPU clock
420 int "Set the core clock frequency"
424 Define the CPU clock frequency in use. This is the core clock
425 frequency, it may or may not be the same as the external clock
426 crystal fitted to your board. Some processors have an internal
427 PLL and can have their frequency programmed at run time, others
428 use internal dividers. In general the kernel won't setup a PLL
429 if it is fitted (there are some exceptions). This value will be
430 specific to the exact CPU that you are using.
433 bool "Old mask 5307 (1H55J) silicon"
436 Build support for the older revision ColdFire 5307 silicon.
437 Specifically this is the 1H55J mask revision.
441 prompt "Split Cache Configuration"
447 Use all of the ColdFire CPU cache memory as an instruction cache.
452 Use all of the ColdFire CPU cache memory as a data cache.
457 Split the ColdFire CPU cache, and use half as an instruction cache
458 and half as a data cache.
464 prompt "Data cache mode"
465 default CACHE_WRITETHRU
467 config CACHE_WRITETHRU
470 The ColdFire CPU cache is set into Write-through mode.
472 config CACHE_COPYBACK
475 The ColdFire CPU cache is set into Copy-back mode.