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EDITING: Kconfig.cpu

# SPDX-License-Identifier: GPL-2.0
comment "Processor Type"

choice
	prompt "CPU/machine family support"
	default M68KCLASSIC if MMU
	default COLDFIRE if !MMU
	help
	  The Freescale (was Motorola) M68K family of processors implements
	  the full 68000 processor instruction set.
	  The Freescale ColdFire family of processors is a modern derivative
	  of the 68000 processor family. They are mainly targeted at embedded
	  applications, and are all System-On-Chip (SOC) devices, as opposed
	  to stand alone CPUs. They implement a subset of the original 68000
	  processor instruction set.
	  If you anticipate running this kernel on a computer with a classic
	  MC68xxx processor, select M68KCLASSIC.
	  If you anticipate running this kernel on a computer with a ColdFire
	  processor, select COLDFIRE.

config M68KCLASSIC
	bool "Classic M68K CPU/machine family support"
	select HAVE_ARCH_PFN_VALID
	select M68020 if MMU && !(M68030 || M68040 || M68060)

config COLDFIRE
	bool "Coldfire CPU family support"
	select CPU_HAS_NO_BITFIELDS
	select CPU_HAS_NO_CAS
	select CPU_HAS_NO_MULDIV64
	select GENERIC_CSUM
	select GPIOLIB
	select HAVE_LEGACY_CLK
	select HAVE_PAGE_SIZE_8KB if !MMU

config SUN3
	bool "Sun3 machine support"
	depends on MMU
	select HAVE_ARCH_PFN_VALID
	select LEGACY_TIMER_TICK
	select NO_DMA
	select M68020
	help
	  This option enables support for the Sun 3 series of workstations
	  (3/50, 3/60, 3/1xx, 3/2xx systems). These use a classic 68020 CPU
	  but the custom memory management unit makes them incompatible with
	  all other classic m68k machines, including Sun 3x.

endchoice

config M68000
	def_bool M68KCLASSIC && !MMU
	select CPU_HAS_NO_BITFIELDS
	select CPU_HAS_NO_CAS
	select CPU_HAS_NO_MULDIV64
	select CPU_HAS_NO_UNALIGNED
	select GENERIC_CSUM
	select CPU_NO_EFFICIENT_FFS
	select HAVE_ARCH_HASH
	select HAVE_PAGE_SIZE_4KB
	select LEGACY_TIMER_TICK
	help
	  The Freescale (was Motorola) 68000 CPU is the first generation of
	  the well known M68K family of processors. The CPU core as well as
	  being available as a stand alone CPU was also used in many
	  System-On-Chip devices (eg 68328, 68302, etc). It does not contain
	  a paging MMU.

config M68020
	bool "68020 support" if M68KCLASSIC
	depends on MMU
	select FPU
	select CPU_HAS_ADDRESS_SPACES
	help
	  If you anticipate running this kernel on a computer with a MC68020
	  processor, say Y. Otherwise, say N. Note that the 68020 requires a
	  68851 MMU (Memory Management Unit) to run Linux/m68k, except on the
	  Sun 3, which provides its own version.

if M68KCLASSIC && MMU

config M68030
	bool "68030 support"
	select FPU
	select CPU_HAS_ADDRESS_SPACES
	help
	  If you anticipate running this kernel on a computer with a MC68030
	  processor, say Y. Otherwise, say N. Note that a MC68EC030 will not
	  work, as it does not include an MMU (Memory Management Unit).

config M68040
	bool "68040 support"
	select FPU
	select CPU_HAS_ADDRESS_SPACES
	help
	  If you anticipate running this kernel on a computer with a MC68LC040
	  or MC68040 processor, say Y. Otherwise, say N. Note that an
	  MC68EC040 will not work, as it does not include an MMU (Memory
	  Management Unit).

config M68060
	bool "68060 support"
	select FPU
	select CPU_HAS_ADDRESS_SPACES
	help
	  If you anticipate running this kernel on a computer with a MC68060
	  processor, say Y. Otherwise, say N.

endif # M68KCLASSIC

config M68328
	bool
	depends on !MMU
	select M68000
	help
	  Motorola 68328 processor support.

config M68EZ328
	bool
	depends on !MMU
	select M68000
	help
	  Motorola 68EX328 processor support.

config M68VZ328
	bool
	depends on !MMU
	select M68000
	help
	  Motorola 68VZ328 processor support.

if COLDFIRE

choice
	prompt "ColdFire SoC type"
	default M520x
	help
	  Select the type of ColdFire System-on-Chip (SoC) that you want
	  to build for.

config M5206
	bool "MCF5206"
	depends on !MMU
	select COLDFIRE_SW_A7
	select COLDFIRE_TIMERS
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Motorola ColdFire 5206 processor support.

config M5206e
	bool "MCF5206e"
	depends on !MMU
	select COLDFIRE_SW_A7
	select COLDFIRE_TIMERS
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Motorola ColdFire 5206e processor support.

config M520x
	bool "MCF520x"
	depends on !MMU
	select COLDFIRE_PIT_TIMER
	select HAVE_CACHE_SPLIT
	help
	  Freescale Coldfire 5207/5208 processor support.

config M523x
	bool "MCF523x"
	depends on !MMU
	select COLDFIRE_PIT_TIMER
	select HAVE_CACHE_SPLIT
	select HAVE_IPSBAR
	help
	  Freescale Coldfire 5230/1/2/4/5 processor support

config M5249
	bool "MCF5249"
	depends on !MMU
	select COLDFIRE_SW_A7
	select COLDFIRE_TIMERS
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Motorola ColdFire 5249 processor support.

config M525x
	bool "MCF525x"
	depends on !MMU
	select COLDFIRE_SW_A7
	select COLDFIRE_TIMERS
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Freescale (Motorola) Coldfire 5251/5253 processor support.

config M5271
	bool "MCF5271"
	depends on !MMU
	select COLDFIRE_PIT_TIMER
	select M527x
	select HAVE_CACHE_SPLIT
	select HAVE_IPSBAR
	help
	  Freescale (Motorola) ColdFire 5270/5271 processor support.

config M5272
	bool "MCF5272"
	depends on !MMU
	select COLDFIRE_SW_A7
	select COLDFIRE_TIMERS
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Motorola ColdFire 5272 processor support.

config M5275
	bool "MCF5275"
	depends on !MMU
	select COLDFIRE_PIT_TIMER
	select M527x
	select HAVE_CACHE_SPLIT
	select HAVE_IPSBAR
	help
	  Freescale (Motorola) ColdFire 5274/5275 processor support.

config M528x
	bool "MCF528x"
	depends on !MMU
	select COLDFIRE_PIT_TIMER
	select HAVE_CACHE_SPLIT
	select HAVE_IPSBAR
	help
	  Motorola ColdFire 5280/5282 processor support.

config M5307
	bool "MCF5307"
	depends on !MMU
	select COLDFIRE_TIMERS
	select COLDFIRE_SW_A7
	select HAVE_CACHE_CB
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Motorola ColdFire 5307 processor support.

config M532x
	bool "MCF532x"
	depends on !MMU
	select COLDFIRE_TIMERS
	select M53xx
	select HAVE_CACHE_CB
	help
	  Freescale (Motorola) ColdFire 532x processor support.

config M537x
	bool "MCF537x"
	depends on !MMU
	select COLDFIRE_TIMERS
	select M53xx
	select HAVE_CACHE_CB
	help
	  Freescale ColdFire 537x processor support.

config M5407
	bool "MCF5407"
	depends on !MMU
	select COLDFIRE_SW_A7
	select COLDFIRE_TIMERS
	select HAVE_CACHE_CB
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Motorola ColdFire 5407 processor support.

config M547x
	bool "MCF547x"
	select M54xx
	select COLDFIRE_SLTIMERS
	select MMU_COLDFIRE if MMU
	select FPU if MMU
	select HAVE_CACHE_CB
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Freescale ColdFire 5470/5471/5472/5473/5474/5475 processor support.

config M548x
	bool "MCF548x"
	select COLDFIRE_SLTIMERS
	select MMU_COLDFIRE if MMU
	select FPU if MMU
	select M54xx
	select HAVE_CACHE_CB
	select HAVE_MBAR
	select CPU_NO_EFFICIENT_FFS
	help
	  Freescale ColdFire 5480/5481/5482/5483/5484/5485 processor support.

config M5441x
	bool "MCF5441x"
	select COLDFIRE_PIT_TIMER
	select MMU_COLDFIRE if MMU
	select HAVE_CACHE_CB
	help
	  Freescale Coldfire 54410/54415/54416/54417/54418 processor support.

endchoice

config M527x
	bool

config M53xx
	bool

config M54xx
	select HAVE_PCI
	bool

config COLDFIRE_PIT_TIMER
	bool

config COLDFIRE_TIMERS
	bool
	select LEGACY_TIMER_TICK

config COLDFIRE_SLTIMERS
	bool
	select LEGACY_TIMER_TICK

endif # COLDFIRE

comment "Processor Specific Options"

config M68KFPU_EMU
	bool "Math emulation support"
	depends on (M68KCLASSIC || SUN3) && FPU
	help
	  At some point in the future, this will cause floating-point math
	  instructions to be emulated by the kernel on machines that lack a
	  floating-point math coprocessor.  Thrill-seekers and chronically
	  sleep-deprived psychotic hacker types can say Y now, everyone else
	  should probably wait a while.

config M68KFPU_EMU_EXTRAPREC
	bool "Math emulation extra precision"
	depends on M68KFPU_EMU
	help
	  The fpu uses normally a few bit more during calculations for
	  correct rounding, the emulator can (often) do the same but this
	  extra calculation can cost quite some time, so you can disable
	  it here. The emulator will then "only" calculate with a 64 bit
	  mantissa and round slightly incorrect, what is more than enough
	  for normal usage.

config M68KFPU_EMU_ONLY
	bool "Math emulation only kernel"
	depends on M68KFPU_EMU
	help
	  This option prevents any floating-point instructions from being
	  compiled into the kernel, thereby the kernel doesn't save any
	  floating point context anymore during task switches, so this
	  kernel will only be usable on machines without a floating-point
	  math coprocessor. This makes the kernel a bit faster as no tests
	  needs to be executed whether a floating-point instruction in the
	  kernel should be executed or not.

config ADVANCED
	bool "Advanced configuration options"
	depends on MMU
	help
	  This gives you access to some advanced options for the CPU. The
	  defaults should be fine for most users, but these options may make
	  it possible for you to improve performance somewhat if you know what
	  you are doing.

Note that the answer to this question won't directly affect the
	  kernel: saying N will just cause the configurator to skip all
	  the questions about these options.

Most users should say N to this question.

config RMW_INSNS
	bool "Use read-modify-write instructions"
	depends on ADVANCED && !CPU_HAS_NO_CAS
	help
	  This allows to use certain instructions that work with indivisible
	  read-modify-write bus cycles. While this is faster than the
	  workaround of disabling interrupts, it can conflict with DMA
	  ( = direct memory access) on many Amiga systems, and it is also said
	  to destabilize other machines. It is very likely that this will
	  cause serious problems on any Amiga or Atari Medusa if set. The only
	  configuration where it should work are 68030-based Ataris, where it
	  apparently improves performance. But you've been warned! Unless you
	  really know what you are doing, say N. Try Y only if you're quite
	  adventurous.

config SINGLE_MEMORY_CHUNK
	bool "Use one physical chunk of memory only" if ADVANCED && !SUN3
	depends on MMU
	default y if SUN3 || MMU_COLDFIRE
	help
	  Ignore all but the first contiguous chunk of physical memory for VM
	  purposes.  This will save a few bytes kernel size and may speed up
	  some operations.
	  When this option os set to N, you may want to lower "Maximum zone
	  order" to save memory that could be wasted for unused memory map.
	  Say N if not sure.

config ARCH_FORCE_MAX_ORDER
	int "Order of maximal physically contiguous allocations" if ADVANCED
	depends on !SINGLE_MEMORY_CHUNK
	default "10"
	help
	  The kernel page allocator limits the size of maximal physically
	  contiguous allocations. The limit is called MAX_PAGE_ORDER and it
	  defines the maximal power of two of number of pages that can be
	  allocated as a single contiguous block. This option allows
	  overriding the default setting when ability to allocate very
	  large blocks of physically contiguous memory is required.

For systems that have holes in their physical address space this
	  value also defines the minimal size of the hole that allows
	  freeing unused memory map.

Don't change if unsure.

config 060_WRITETHROUGH
	bool "Use write-through caching for 68060 supervisor accesses"
	depends on ADVANCED && M68060
	help
	  The 68060 generally uses copyback caching of recently accessed data.
	  Copyback caching means that memory writes will be held in an on-chip
	  cache and only written back to memory some time later.  Saying Y
	  here will force supervisor (kernel) accesses to use writethrough
	  caching.  Writethrough caching means that data is written to memory
	  straight away, so that cache and memory data always agree.
	  Writethrough caching is less efficient, but is needed for some
	  drivers on 68060 based systems where the 68060 bus snooping signal
	  is hardwired on.  The 53c710 SCSI driver is known to suffer from
	  this problem.

config M68K_L2_CACHE
	bool
	depends on MAC
	default y

config CPU_HAS_NO_BITFIELDS
	bool

config CPU_HAS_NO_CAS
	bool

config CPU_HAS_NO_MULDIV64
	bool

config CPU_HAS_NO_UNALIGNED
	bool

config CPU_HAS_ADDRESS_SPACES
	bool
	select ALTERNATE_USER_ADDRESS_SPACE

config FPU
	bool

config COLDFIRE_SW_A7
	bool

config HAVE_CACHE_SPLIT
	bool

config HAVE_CACHE_CB
	bool

config HAVE_MBAR
	bool

config HAVE_IPSBAR
	bool

config CLOCK_FREQ
	int "Set the core clock frequency"
	default "25000000" if M5206
	default "54000000" if M5206e
	default "166666666" if M520x
	default "140000000" if M5249
	default "150000000" if M527x || M523x
	default "90000000" if M5307
	default "50000000" if M5407
	default "266000000" if M54xx
	default "66666666"
	depends on COLDFIRE
	help
	  Define the CPU clock frequency in use. This is the core clock
	  frequency, it may or may not be the same as the external clock
	  crystal fitted to your board. Some processors have an internal
	  PLL and can have their frequency programmed at run time, others
	  use internal dividers. In general the kernel won't setup a PLL
	  if it is fitted (there are some exceptions). This value will be
	  specific to the exact CPU that you are using.

config OLDMASK
	bool "Old mask 5307 (1H55J) silicon"
	depends on M5307
	help
	  Build support for the older revision ColdFire 5307 silicon.
	  Specifically this is the 1H55J mask revision.

if HAVE_CACHE_SPLIT
choice
	prompt "Split Cache Configuration"
	default CACHE_I

config CACHE_I
	bool "Instruction"
	help
	  Use all of the ColdFire CPU cache memory as an instruction cache.

config CACHE_D
	bool "Data"
	help
	  Use all of the ColdFire CPU cache memory as a data cache.

config CACHE_BOTH
	bool "Both"
	help
	  Split the ColdFire CPU cache, and use half as an instruction cache
	  and half as a data cache.
endchoice
endif # HAVE_CACHE_SPLIT

if HAVE_CACHE_CB
choice
	prompt "Data cache mode"
	default CACHE_WRITETHRU

config CACHE_WRITETHRU
	bool "Write-through"
	help
	  The ColdFire CPU cache is set into Write-through mode.

config CACHE_COPYBACK
	bool "Copy-back"
	help
	  The ColdFire CPU cache is set into Copy-back mode.
endchoice
endif # HAVE_CACHE_CB

# Coldfire cores that do not have a data cache configured can do coherent DMA.
config COLDFIRE_COHERENT_DMA
	bool
	default y
	depends on COLDFIRE
	depends on !HAVE_CACHE_CB && !CACHE_D && !CACHE_BOTH

config M68K_NONCOHERENT_DMA
	bool
	default y
	depends on HAS_DMA && !COLDFIRE_COHERENT_DMA

CANCEL

Name	Type	Size	Modified	Actions
↩ ..	DIR	—	—
📁 68000/	DIR	—	2026-03-10 17:30
📁 amiga/	DIR	—	2026-03-10 17:30
📁 apollo/	DIR	—	2026-03-10 17:30
📁 atari/	DIR	—	2026-03-10 17:30
📁 bvme6000/	DIR	—	2026-03-10 17:30
📁 coldfire/	DIR	—	2026-03-10 17:30
📁 emu/	DIR	—	2026-03-10 17:30
📁 fpsp040/	DIR	—	2026-03-10 17:30
📁 hp300/	DIR	—	2026-03-10 17:30
📁 ifpsp060/	DIR	—	2026-03-10 17:30
📁 include/	DIR	—	2026-03-10 17:30
📁 kernel/	DIR	—	2026-03-10 17:30
📁 lib/	DIR	—	2026-03-10 17:30
📁 mac/	DIR	—	2026-03-10 17:30
📁 math-emu/	DIR	—	2026-03-10 17:30
📁 mm/	DIR	—	2026-03-10 17:30
📁 mvme147/	DIR	—	2026-03-10 17:30
📁 mvme16x/	DIR	—	2026-03-10 17:30
📁 q40/	DIR	—	2026-03-10 17:30
📁 sun3/	DIR	—	2026-03-10 17:30
📁 sun3x/	DIR	—	2026-03-10 17:30
📁 tools/	DIR	—	2026-03-10 17:30
📁 virt/	DIR	—	2026-03-10 17:30
📄 install.sh	SH	667 B	2025-09-28 21:39	EDIT
📄 Kbuild	?	654 B	2025-09-28 21:39	EDIT
📄 Kconfig	?	2.9 KB	2025-09-28 21:39	EDIT
📄 Kconfig.bus	BUS	1.8 KB	2025-09-28 21:39	EDIT
📄 Kconfig.cpu	CPU	14.2 KB	2025-09-28 21:39	EDIT
📄 Kconfig.debug	DEBUG	1.1 KB	2025-09-28 21:39	EDIT
📄 Kconfig.devices	DEVICES	4.4 KB	2025-09-28 21:39	EDIT
📄 Kconfig.machine	MACHINE	12.2 KB	2025-09-28 21:39	EDIT
📄 Makefile	?	3.8 KB	2025-09-28 21:39	EDIT