xref: /openbmc/linux/arch/xtensa/Kconfig (revision aec499c7)
1# SPDX-License-Identifier: GPL-2.0
2config XTENSA
3	def_bool y
4	select ARCH_32BIT_OFF_T
5	select ARCH_HAS_BINFMT_FLAT if !MMU
6	select ARCH_HAS_DMA_PREP_COHERENT if MMU
7	select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU
8	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU
9	select ARCH_HAS_DMA_SET_UNCACHED if MMU
10	select ARCH_HAS_STRNCPY_FROM_USER if !KASAN
11	select ARCH_HAS_STRNLEN_USER
12	select ARCH_USE_MEMTEST
13	select ARCH_USE_QUEUED_RWLOCKS
14	select ARCH_USE_QUEUED_SPINLOCKS
15	select ARCH_WANT_FRAME_POINTERS
16	select ARCH_WANT_IPC_PARSE_VERSION
17	select BUILDTIME_TABLE_SORT
18	select CLONE_BACKWARDS
19	select COMMON_CLK
20	select DMA_REMAP if MMU
21	select GENERIC_ATOMIC64
22	select GENERIC_IRQ_SHOW
23	select GENERIC_PCI_IOMAP
24	select GENERIC_SCHED_CLOCK
25	select HAVE_ARCH_AUDITSYSCALL
26	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
27	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
28	select HAVE_ARCH_SECCOMP_FILTER
29	select HAVE_ARCH_TRACEHOOK
30	select HAVE_DEBUG_KMEMLEAK
31	select HAVE_DMA_CONTIGUOUS
32	select HAVE_EXIT_THREAD
33	select HAVE_FUNCTION_TRACER
34	select HAVE_HW_BREAKPOINT if PERF_EVENTS
35	select HAVE_IRQ_TIME_ACCOUNTING
36	select HAVE_PCI
37	select HAVE_PERF_EVENTS
38	select HAVE_STACKPROTECTOR
39	select HAVE_SYSCALL_TRACEPOINTS
40	select IRQ_DOMAIN
41	select MODULES_USE_ELF_RELA
42	select PERF_USE_VMALLOC
43	select TRACE_IRQFLAGS_SUPPORT
44	select VIRT_TO_BUS
45	help
46	  Xtensa processors are 32-bit RISC machines designed by Tensilica
47	  primarily for embedded systems.  These processors are both
48	  configurable and extensible.  The Linux port to the Xtensa
49	  architecture supports all processor configurations and extensions,
50	  with reasonable minimum requirements.  The Xtensa Linux project has
51	  a home page at <http://www.linux-xtensa.org/>.
52
53config GENERIC_HWEIGHT
54	def_bool y
55
56config ARCH_HAS_ILOG2_U32
57	def_bool n
58
59config ARCH_HAS_ILOG2_U64
60	def_bool n
61
62config NO_IOPORT_MAP
63	def_bool n
64
65config HZ
66	int
67	default 100
68
69config LOCKDEP_SUPPORT
70	def_bool y
71
72config STACKTRACE_SUPPORT
73	def_bool y
74
75config MMU
76	def_bool n
77
78config HAVE_XTENSA_GPIO32
79	def_bool n
80
81config KASAN_SHADOW_OFFSET
82	hex
83	default 0x6e400000
84
85config CPU_BIG_ENDIAN
86	def_bool $(success,test "$(shell,echo __XTENSA_EB__ | $(CC) -E -P -)" = 1)
87
88config CPU_LITTLE_ENDIAN
89	def_bool !CPU_BIG_ENDIAN
90
91menu "Processor type and features"
92
93choice
94	prompt "Xtensa Processor Configuration"
95	default XTENSA_VARIANT_FSF
96
97config XTENSA_VARIANT_FSF
98	bool "fsf - default (not generic) configuration"
99	select MMU
100
101config XTENSA_VARIANT_DC232B
102	bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
103	select MMU
104	select HAVE_XTENSA_GPIO32
105	help
106	  This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
107
108config XTENSA_VARIANT_DC233C
109	bool "dc233c - Diamond 233L Standard Core Rev.C (LE)"
110	select MMU
111	select HAVE_XTENSA_GPIO32
112	help
113	  This variant refers to Tensilica's Diamond 233L Standard core Rev.C (LE).
114
115config XTENSA_VARIANT_CUSTOM
116	bool "Custom Xtensa processor configuration"
117	select HAVE_XTENSA_GPIO32
118	help
119	  Select this variant to use a custom Xtensa processor configuration.
120	  You will be prompted for a processor variant CORENAME.
121endchoice
122
123config XTENSA_VARIANT_CUSTOM_NAME
124	string "Xtensa Processor Custom Core Variant Name"
125	depends on XTENSA_VARIANT_CUSTOM
126	help
127	  Provide the name of a custom Xtensa processor variant.
128	  This CORENAME selects arch/xtensa/variant/CORENAME.
129	  Don't forget you have to select MMU if you have one.
130
131config XTENSA_VARIANT_NAME
132	string
133	default "dc232b"			if XTENSA_VARIANT_DC232B
134	default "dc233c"			if XTENSA_VARIANT_DC233C
135	default "fsf"				if XTENSA_VARIANT_FSF
136	default XTENSA_VARIANT_CUSTOM_NAME	if XTENSA_VARIANT_CUSTOM
137
138config XTENSA_VARIANT_MMU
139	bool "Core variant has a Full MMU (TLB, Pages, Protection, etc)"
140	depends on XTENSA_VARIANT_CUSTOM
141	default y
142	select MMU
143	help
144	  Build a Conventional Kernel with full MMU support,
145	  ie: it supports a TLB with auto-loading, page protection.
146
147config XTENSA_VARIANT_HAVE_PERF_EVENTS
148	bool "Core variant has Performance Monitor Module"
149	depends on XTENSA_VARIANT_CUSTOM
150	default n
151	help
152	  Enable if core variant has Performance Monitor Module with
153	  External Registers Interface.
154
155	  If unsure, say N.
156
157config XTENSA_FAKE_NMI
158	bool "Treat PMM IRQ as NMI"
159	depends on XTENSA_VARIANT_HAVE_PERF_EVENTS
160	default n
161	help
162	  If PMM IRQ is the only IRQ at EXCM level it is safe to
163	  treat it as NMI, which improves accuracy of profiling.
164
165	  If there are other interrupts at or above PMM IRQ priority level
166	  but not above the EXCM level, PMM IRQ still may be treated as NMI,
167	  but only if these IRQs are not used. There will be a build warning
168	  saying that this is not safe, and a bugcheck if one of these IRQs
169	  actually fire.
170
171	  If unsure, say N.
172
173config XTENSA_UNALIGNED_USER
174	bool "Unaligned memory access in user space"
175	help
176	  The Xtensa architecture currently does not handle unaligned
177	  memory accesses in hardware but through an exception handler.
178	  Per default, unaligned memory accesses are disabled in user space.
179
180	  Say Y here to enable unaligned memory access in user space.
181
182config HAVE_SMP
183	bool "System Supports SMP (MX)"
184	depends on XTENSA_VARIANT_CUSTOM
185	select XTENSA_MX
186	help
187	  This option is used to indicate that the system-on-a-chip (SOC)
188	  supports Multiprocessing. Multiprocessor support implemented above
189	  the CPU core definition and currently needs to be selected manually.
190
191	  Multiprocessor support is implemented with external cache and
192	  interrupt controllers.
193
194	  The MX interrupt distributer adds Interprocessor Interrupts
195	  and causes the IRQ numbers to be increased by 4 for devices
196	  like the open cores ethernet driver and the serial interface.
197
198	  You still have to select "Enable SMP" to enable SMP on this SOC.
199
200config SMP
201	bool "Enable Symmetric multi-processing support"
202	depends on HAVE_SMP
203	select GENERIC_SMP_IDLE_THREAD
204	help
205	  Enabled SMP Software; allows more than one CPU/CORE
206	  to be activated during startup.
207
208config NR_CPUS
209	depends on SMP
210	int "Maximum number of CPUs (2-32)"
211	range 2 32
212	default "4"
213
214config HOTPLUG_CPU
215	bool "Enable CPU hotplug support"
216	depends on SMP
217	help
218	  Say Y here to allow turning CPUs off and on. CPUs can be
219	  controlled through /sys/devices/system/cpu.
220
221	  Say N if you want to disable CPU hotplug.
222
223config FAST_SYSCALL_XTENSA
224	bool "Enable fast atomic syscalls"
225	default n
226	help
227	  fast_syscall_xtensa is a syscall that can make atomic operations
228	  on UP kernel when processor has no s32c1i support.
229
230	  This syscall is deprecated. It may have issues when called with
231	  invalid arguments. It is provided only for backwards compatibility.
232	  Only enable it if your userspace software requires it.
233
234	  If unsure, say N.
235
236config FAST_SYSCALL_SPILL_REGISTERS
237	bool "Enable spill registers syscall"
238	default n
239	help
240	  fast_syscall_spill_registers is a syscall that spills all active
241	  register windows of a calling userspace task onto its stack.
242
243	  This syscall is deprecated. It may have issues when called with
244	  invalid arguments. It is provided only for backwards compatibility.
245	  Only enable it if your userspace software requires it.
246
247	  If unsure, say N.
248
249config USER_ABI_CALL0
250	bool
251
252choice
253	prompt "Userspace ABI"
254	default USER_ABI_DEFAULT
255	help
256	  Select supported userspace ABI.
257
258	  If unsure, choose the default ABI.
259
260config USER_ABI_DEFAULT
261	bool "Default ABI only"
262	help
263	  Assume default userspace ABI. For XEA2 cores it is windowed ABI.
264	  call0 ABI binaries may be run on such kernel, but signal delivery
265	  will not work correctly for them.
266
267config USER_ABI_CALL0_ONLY
268	bool "Call0 ABI only"
269	select USER_ABI_CALL0
270	help
271	  Select this option to support only call0 ABI in userspace.
272	  Windowed ABI binaries will crash with a segfault caused by
273	  an illegal instruction exception on the first 'entry' opcode.
274
275	  Choose this option if you're planning to run only user code
276	  built with call0 ABI.
277
278config USER_ABI_CALL0_PROBE
279	bool "Support both windowed and call0 ABI by probing"
280	select USER_ABI_CALL0
281	help
282	  Select this option to support both windowed and call0 userspace
283	  ABIs. When enabled all processes are started with PS.WOE disabled
284	  and a fast user exception handler for an illegal instruction is
285	  used to turn on PS.WOE bit on the first 'entry' opcode executed by
286	  the userspace.
287
288	  This option should be enabled for the kernel that must support
289	  both call0 and windowed ABIs in userspace at the same time.
290
291	  Note that Xtensa ISA does not guarantee that entry opcode will
292	  raise an illegal instruction exception on cores with XEA2 when
293	  PS.WOE is disabled, check whether the target core supports it.
294
295endchoice
296
297endmenu
298
299config XTENSA_CALIBRATE_CCOUNT
300	def_bool n
301	help
302	  On some platforms (XT2000, for example), the CPU clock rate can
303	  vary.  The frequency can be determined, however, by measuring
304	  against a well known, fixed frequency, such as an UART oscillator.
305
306config SERIAL_CONSOLE
307	def_bool n
308
309config PLATFORM_HAVE_XIP
310	def_bool n
311
312menu "Platform options"
313
314choice
315	prompt "Xtensa System Type"
316	default XTENSA_PLATFORM_ISS
317
318config XTENSA_PLATFORM_ISS
319	bool "ISS"
320	select XTENSA_CALIBRATE_CCOUNT
321	select SERIAL_CONSOLE
322	help
323	  ISS is an acronym for Tensilica's Instruction Set Simulator.
324
325config XTENSA_PLATFORM_XT2000
326	bool "XT2000"
327	help
328	  XT2000 is the name of Tensilica's feature-rich emulation platform.
329	  This hardware is capable of running a full Linux distribution.
330
331config XTENSA_PLATFORM_XTFPGA
332	bool "XTFPGA"
333	select ETHOC if ETHERNET
334	select PLATFORM_WANT_DEFAULT_MEM if !MMU
335	select SERIAL_CONSOLE
336	select XTENSA_CALIBRATE_CCOUNT
337	select PLATFORM_HAVE_XIP
338	help
339	  XTFPGA is the name of Tensilica board family (LX60, LX110, LX200, ML605).
340	  This hardware is capable of running a full Linux distribution.
341
342endchoice
343
344config PLATFORM_NR_IRQS
345	int
346	default 3 if XTENSA_PLATFORM_XT2000
347	default 0
348
349config XTENSA_CPU_CLOCK
350	int "CPU clock rate [MHz]"
351	depends on !XTENSA_CALIBRATE_CCOUNT
352	default 16
353
354config GENERIC_CALIBRATE_DELAY
355	bool "Auto calibration of the BogoMIPS value"
356	help
357	  The BogoMIPS value can easily be derived from the CPU frequency.
358
359config CMDLINE_BOOL
360	bool "Default bootloader kernel arguments"
361
362config CMDLINE
363	string "Initial kernel command string"
364	depends on CMDLINE_BOOL
365	default "console=ttyS0,38400 root=/dev/ram"
366	help
367	  On some architectures (EBSA110 and CATS), there is currently no way
368	  for the boot loader to pass arguments to the kernel. For these
369	  architectures, you should supply some command-line options at build
370	  time by entering them here. As a minimum, you should specify the
371	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
372
373config USE_OF
374	bool "Flattened Device Tree support"
375	select OF
376	select OF_EARLY_FLATTREE
377	help
378	  Include support for flattened device tree machine descriptions.
379
380config BUILTIN_DTB_SOURCE
381	string "DTB to build into the kernel image"
382	depends on OF
383
384config PARSE_BOOTPARAM
385	bool "Parse bootparam block"
386	default y
387	help
388	  Parse parameters passed to the kernel from the bootloader. It may
389	  be disabled if the kernel is known to run without the bootloader.
390
391	  If unsure, say Y.
392
393choice
394	prompt "Semihosting interface"
395	default XTENSA_SIMCALL_ISS
396	depends on XTENSA_PLATFORM_ISS
397	help
398	  Choose semihosting interface that will be used for serial port,
399	  block device and networking.
400
401config XTENSA_SIMCALL_ISS
402	bool "simcall"
403	help
404	  Use simcall instruction. simcall is only available on simulators,
405	  it does nothing on hardware.
406
407config XTENSA_SIMCALL_GDBIO
408	bool "GDBIO"
409	help
410	  Use break instruction. It is available on real hardware when GDB
411	  is attached to it via JTAG.
412
413endchoice
414
415config BLK_DEV_SIMDISK
416	tristate "Host file-based simulated block device support"
417	default n
418	depends on XTENSA_PLATFORM_ISS && BLOCK
419	help
420	  Create block devices that map to files in the host file system.
421	  Device binding to host file may be changed at runtime via proc
422	  interface provided the device is not in use.
423
424config BLK_DEV_SIMDISK_COUNT
425	int "Number of host file-based simulated block devices"
426	range 1 10
427	depends on BLK_DEV_SIMDISK
428	default 2
429	help
430	  This is the default minimal number of created block devices.
431	  Kernel/module parameter 'simdisk_count' may be used to change this
432	  value at runtime. More file names (but no more than 10) may be
433	  specified as parameters, simdisk_count grows accordingly.
434
435config SIMDISK0_FILENAME
436	string "Host filename for the first simulated device"
437	depends on BLK_DEV_SIMDISK = y
438	default ""
439	help
440	  Attach a first simdisk to a host file. Conventionally, this file
441	  contains a root file system.
442
443config SIMDISK1_FILENAME
444	string "Host filename for the second simulated device"
445	depends on BLK_DEV_SIMDISK = y && BLK_DEV_SIMDISK_COUNT != 1
446	default ""
447	help
448	  Another simulated disk in a host file for a buildroot-independent
449	  storage.
450
451config XTFPGA_LCD
452	bool "Enable XTFPGA LCD driver"
453	depends on XTENSA_PLATFORM_XTFPGA
454	default n
455	help
456	  There's a 2x16 LCD on most of XTFPGA boards, kernel may output
457	  progress messages there during bootup/shutdown. It may be useful
458	  during board bringup.
459
460	  If unsure, say N.
461
462config XTFPGA_LCD_BASE_ADDR
463	hex "XTFPGA LCD base address"
464	depends on XTFPGA_LCD
465	default "0x0d0c0000"
466	help
467	  Base address of the LCD controller inside KIO region.
468	  Different boards from XTFPGA family have LCD controller at different
469	  addresses. Please consult prototyping user guide for your board for
470	  the correct address. Wrong address here may lead to hardware lockup.
471
472config XTFPGA_LCD_8BIT_ACCESS
473	bool "Use 8-bit access to XTFPGA LCD"
474	depends on XTFPGA_LCD
475	default n
476	help
477	  LCD may be connected with 4- or 8-bit interface, 8-bit access may
478	  only be used with 8-bit interface. Please consult prototyping user
479	  guide for your board for the correct interface width.
480
481comment "Kernel memory layout"
482
483config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
484	bool "Initialize Xtensa MMU inside the Linux kernel code"
485	depends on !XTENSA_VARIANT_FSF && !XTENSA_VARIANT_DC232B
486	default y if XTENSA_VARIANT_DC233C || XTENSA_VARIANT_CUSTOM
487	help
488	  Earlier version initialized the MMU in the exception vector
489	  before jumping to _startup in head.S and had an advantage that
490	  it was possible to place a software breakpoint at 'reset' and
491	  then enter your normal kernel breakpoints once the MMU was mapped
492	  to the kernel mappings (0XC0000000).
493
494	  This unfortunately won't work for U-Boot and likely also won't
495	  work for using KEXEC to have a hot kernel ready for doing a
496	  KDUMP.
497
498	  So now the MMU is initialized in head.S but it's necessary to
499	  use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
500	  xt-gdb can't place a Software Breakpoint in the  0XD region prior
501	  to mapping the MMU and after mapping even if the area of low memory
502	  was mapped gdb wouldn't remove the breakpoint on hitting it as the
503	  PC wouldn't match. Since Hardware Breakpoints are recommended for
504	  Linux configurations it seems reasonable to just assume they exist
505	  and leave this older mechanism for unfortunate souls that choose
506	  not to follow Tensilica's recommendation.
507
508	  Selecting this will cause U-Boot to set the KERNEL Load and Entry
509	  address at 0x00003000 instead of the mapped std of 0xD0003000.
510
511	  If in doubt, say Y.
512
513config XIP_KERNEL
514	bool "Kernel Execute-In-Place from ROM"
515	depends on PLATFORM_HAVE_XIP
516	help
517	  Execute-In-Place allows the kernel to run from non-volatile storage
518	  directly addressable by the CPU, such as NOR flash. This saves RAM
519	  space since the text section of the kernel is not loaded from flash
520	  to RAM. Read-write sections, such as the data section and stack,
521	  are still copied to RAM. The XIP kernel is not compressed since
522	  it has to run directly from flash, so it will take more space to
523	  store it. The flash address used to link the kernel object files,
524	  and for storing it, is configuration dependent. Therefore, if you
525	  say Y here, you must know the proper physical address where to
526	  store the kernel image depending on your own flash memory usage.
527
528	  Also note that the make target becomes "make xipImage" rather than
529	  "make Image" or "make uImage". The final kernel binary to put in
530	  ROM memory will be arch/xtensa/boot/xipImage.
531
532	  If unsure, say N.
533
534config MEMMAP_CACHEATTR
535	hex "Cache attributes for the memory address space"
536	depends on !MMU
537	default 0x22222222
538	help
539	  These cache attributes are set up for noMMU systems. Each hex digit
540	  specifies cache attributes for the corresponding 512MB memory
541	  region: bits 0..3 -- for addresses 0x00000000..0x1fffffff,
542	  bits 4..7 -- for addresses 0x20000000..0x3fffffff, and so on.
543
544	  Cache attribute values are specific for the MMU type.
545	  For region protection MMUs:
546	    1: WT cached,
547	    2: cache bypass,
548	    4: WB cached,
549	    f: illegal.
550	  For full MMU:
551	    bit 0: executable,
552	    bit 1: writable,
553	    bits 2..3:
554	      0: cache bypass,
555	      1: WB cache,
556	      2: WT cache,
557	      3: special (c and e are illegal, f is reserved).
558	  For MPU:
559	    0: illegal,
560	    1: WB cache,
561	    2: WB, no-write-allocate cache,
562	    3: WT cache,
563	    4: cache bypass.
564
565config KSEG_PADDR
566	hex "Physical address of the KSEG mapping"
567	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX && MMU
568	default 0x00000000
569	help
570	  This is the physical address where KSEG is mapped. Please refer to
571	  the chosen KSEG layout help for the required address alignment.
572	  Unpacked kernel image (including vectors) must be located completely
573	  within KSEG.
574	  Physical memory below this address is not available to linux.
575
576	  If unsure, leave the default value here.
577
578config KERNEL_VIRTUAL_ADDRESS
579	hex "Kernel virtual address"
580	depends on MMU && XIP_KERNEL
581	default 0xd0003000
582	help
583	  This is the virtual address where the XIP kernel is mapped.
584	  XIP kernel may be mapped into KSEG or KIO region, virtual address
585	  provided here must match kernel load address provided in
586	  KERNEL_LOAD_ADDRESS.
587
588config KERNEL_LOAD_ADDRESS
589	hex "Kernel load address"
590	default 0x60003000 if !MMU
591	default 0x00003000 if MMU && INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
592	default 0xd0003000 if MMU && !INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
593	help
594	  This is the address where the kernel is loaded.
595	  It is virtual address for MMUv2 configurations and physical address
596	  for all other configurations.
597
598	  If unsure, leave the default value here.
599
600choice
601	prompt "Relocatable vectors location"
602	default XTENSA_VECTORS_IN_TEXT
603	help
604	  Choose whether relocatable vectors are merged into the kernel .text
605	  or placed separately at runtime. This option does not affect
606	  configurations without VECBASE register where vectors are always
607	  placed at their hardware-defined locations.
608
609config XTENSA_VECTORS_IN_TEXT
610	bool "Merge relocatable vectors into kernel text"
611	depends on !MTD_XIP
612	help
613	  This option puts relocatable vectors into the kernel .text section
614	  with proper alignment.
615	  This is a safe choice for most configurations.
616
617config XTENSA_VECTORS_SEPARATE
618	bool "Put relocatable vectors at fixed address"
619	help
620	  This option puts relocatable vectors at specific virtual address.
621	  Vectors are merged with the .init data in the kernel image and
622	  are copied into their designated location during kernel startup.
623	  Use it to put vectors into IRAM or out of FLASH on kernels with
624	  XIP-aware MTD support.
625
626endchoice
627
628config VECTORS_ADDR
629	hex "Kernel vectors virtual address"
630	default 0x00000000
631	depends on XTENSA_VECTORS_SEPARATE
632	help
633	  This is the virtual address of the (relocatable) vectors base.
634	  It must be within KSEG if MMU is used.
635
636config XIP_DATA_ADDR
637	hex "XIP kernel data virtual address"
638	depends on XIP_KERNEL
639	default 0x00000000
640	help
641	  This is the virtual address where XIP kernel data is copied.
642	  It must be within KSEG if MMU is used.
643
644config PLATFORM_WANT_DEFAULT_MEM
645	def_bool n
646
647config DEFAULT_MEM_START
648	hex
649	prompt "PAGE_OFFSET/PHYS_OFFSET" if !MMU && PLATFORM_WANT_DEFAULT_MEM
650	default 0x60000000 if PLATFORM_WANT_DEFAULT_MEM
651	default 0x00000000
652	help
653	  This is the base address used for both PAGE_OFFSET and PHYS_OFFSET
654	  in noMMU configurations.
655
656	  If unsure, leave the default value here.
657
658choice
659	prompt "KSEG layout"
660	depends on MMU
661	default XTENSA_KSEG_MMU_V2
662
663config XTENSA_KSEG_MMU_V2
664	bool "MMUv2: 128MB cached + 128MB uncached"
665	help
666	  MMUv2 compatible kernel memory map: TLB way 5 maps 128MB starting
667	  at KSEG_PADDR to 0xd0000000 with cache and to 0xd8000000
668	  without cache.
669	  KSEG_PADDR must be aligned to 128MB.
670
671config XTENSA_KSEG_256M
672	bool "256MB cached + 256MB uncached"
673	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
674	help
675	  TLB way 6 maps 256MB starting at KSEG_PADDR to 0xb0000000
676	  with cache and to 0xc0000000 without cache.
677	  KSEG_PADDR must be aligned to 256MB.
678
679config XTENSA_KSEG_512M
680	bool "512MB cached + 512MB uncached"
681	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
682	help
683	  TLB way 6 maps 512MB starting at KSEG_PADDR to 0xa0000000
684	  with cache and to 0xc0000000 without cache.
685	  KSEG_PADDR must be aligned to 256MB.
686
687endchoice
688
689config HIGHMEM
690	bool "High Memory Support"
691	depends on MMU
692	select KMAP_LOCAL
693	help
694	  Linux can use the full amount of RAM in the system by
695	  default. However, the default MMUv2 setup only maps the
696	  lowermost 128 MB of memory linearly to the areas starting
697	  at 0xd0000000 (cached) and 0xd8000000 (uncached).
698	  When there are more than 128 MB memory in the system not
699	  all of it can be "permanently mapped" by the kernel.
700	  The physical memory that's not permanently mapped is called
701	  "high memory".
702
703	  If you are compiling a kernel which will never run on a
704	  machine with more than 128 MB total physical RAM, answer
705	  N here.
706
707	  If unsure, say Y.
708
709config FORCE_MAX_ZONEORDER
710	int "Maximum zone order"
711	default "11"
712	help
713	  The kernel memory allocator divides physically contiguous memory
714	  blocks into "zones", where each zone is a power of two number of
715	  pages.  This option selects the largest power of two that the kernel
716	  keeps in the memory allocator.  If you need to allocate very large
717	  blocks of physically contiguous memory, then you may need to
718	  increase this value.
719
720	  This config option is actually maximum order plus one. For example,
721	  a value of 11 means that the largest free memory block is 2^10 pages.
722
723endmenu
724
725menu "Power management options"
726
727source "kernel/power/Kconfig"
728
729endmenu
730