xref: /openbmc/linux/arch/xtensa/Kconfig (revision 6b342707)
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 SET_FS
44	select TRACE_IRQFLAGS_SUPPORT
45	select VIRT_TO_BUS
46	help
47	  Xtensa processors are 32-bit RISC machines designed by Tensilica
48	  primarily for embedded systems.  These processors are both
49	  configurable and extensible.  The Linux port to the Xtensa
50	  architecture supports all processor configurations and extensions,
51	  with reasonable minimum requirements.  The Xtensa Linux project has
52	  a home page at <http://www.linux-xtensa.org/>.
53
54config GENERIC_HWEIGHT
55	def_bool y
56
57config ARCH_HAS_ILOG2_U32
58	def_bool n
59
60config ARCH_HAS_ILOG2_U64
61	def_bool n
62
63config NO_IOPORT_MAP
64	def_bool n
65
66config HZ
67	int
68	default 100
69
70config LOCKDEP_SUPPORT
71	def_bool y
72
73config STACKTRACE_SUPPORT
74	def_bool y
75
76config MMU
77	def_bool n
78
79config HAVE_XTENSA_GPIO32
80	def_bool n
81
82config KASAN_SHADOW_OFFSET
83	hex
84	default 0x6e400000
85
86config CPU_BIG_ENDIAN
87	def_bool $(success,test "$(shell,echo __XTENSA_EB__ | $(CC) -E -P -)" = 1)
88
89config CPU_LITTLE_ENDIAN
90	def_bool !CPU_BIG_ENDIAN
91
92menu "Processor type and features"
93
94choice
95	prompt "Xtensa Processor Configuration"
96	default XTENSA_VARIANT_FSF
97
98config XTENSA_VARIANT_FSF
99	bool "fsf - default (not generic) configuration"
100	select MMU
101
102config XTENSA_VARIANT_DC232B
103	bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
104	select MMU
105	select HAVE_XTENSA_GPIO32
106	help
107	  This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
108
109config XTENSA_VARIANT_DC233C
110	bool "dc233c - Diamond 233L Standard Core Rev.C (LE)"
111	select MMU
112	select HAVE_XTENSA_GPIO32
113	help
114	  This variant refers to Tensilica's Diamond 233L Standard core Rev.C (LE).
115
116config XTENSA_VARIANT_CUSTOM
117	bool "Custom Xtensa processor configuration"
118	select HAVE_XTENSA_GPIO32
119	help
120	  Select this variant to use a custom Xtensa processor configuration.
121	  You will be prompted for a processor variant CORENAME.
122endchoice
123
124config XTENSA_VARIANT_CUSTOM_NAME
125	string "Xtensa Processor Custom Core Variant Name"
126	depends on XTENSA_VARIANT_CUSTOM
127	help
128	  Provide the name of a custom Xtensa processor variant.
129	  This CORENAME selects arch/xtensa/variant/CORENAME.
130	  Don't forget you have to select MMU if you have one.
131
132config XTENSA_VARIANT_NAME
133	string
134	default "dc232b"			if XTENSA_VARIANT_DC232B
135	default "dc233c"			if XTENSA_VARIANT_DC233C
136	default "fsf"				if XTENSA_VARIANT_FSF
137	default XTENSA_VARIANT_CUSTOM_NAME	if XTENSA_VARIANT_CUSTOM
138
139config XTENSA_VARIANT_MMU
140	bool "Core variant has a Full MMU (TLB, Pages, Protection, etc)"
141	depends on XTENSA_VARIANT_CUSTOM
142	default y
143	select MMU
144	help
145	  Build a Conventional Kernel with full MMU support,
146	  ie: it supports a TLB with auto-loading, page protection.
147
148config XTENSA_VARIANT_HAVE_PERF_EVENTS
149	bool "Core variant has Performance Monitor Module"
150	depends on XTENSA_VARIANT_CUSTOM
151	default n
152	help
153	  Enable if core variant has Performance Monitor Module with
154	  External Registers Interface.
155
156	  If unsure, say N.
157
158config XTENSA_FAKE_NMI
159	bool "Treat PMM IRQ as NMI"
160	depends on XTENSA_VARIANT_HAVE_PERF_EVENTS
161	default n
162	help
163	  If PMM IRQ is the only IRQ at EXCM level it is safe to
164	  treat it as NMI, which improves accuracy of profiling.
165
166	  If there are other interrupts at or above PMM IRQ priority level
167	  but not above the EXCM level, PMM IRQ still may be treated as NMI,
168	  but only if these IRQs are not used. There will be a build warning
169	  saying that this is not safe, and a bugcheck if one of these IRQs
170	  actually fire.
171
172	  If unsure, say N.
173
174config XTENSA_UNALIGNED_USER
175	bool "Unaligned memory access in user space"
176	help
177	  The Xtensa architecture currently does not handle unaligned
178	  memory accesses in hardware but through an exception handler.
179	  Per default, unaligned memory accesses are disabled in user space.
180
181	  Say Y here to enable unaligned memory access in user space.
182
183config HAVE_SMP
184	bool "System Supports SMP (MX)"
185	depends on XTENSA_VARIANT_CUSTOM
186	select XTENSA_MX
187	help
188	  This option is used to indicate that the system-on-a-chip (SOC)
189	  supports Multiprocessing. Multiprocessor support implemented above
190	  the CPU core definition and currently needs to be selected manually.
191
192	  Multiprocessor support is implemented with external cache and
193	  interrupt controllers.
194
195	  The MX interrupt distributer adds Interprocessor Interrupts
196	  and causes the IRQ numbers to be increased by 4 for devices
197	  like the open cores ethernet driver and the serial interface.
198
199	  You still have to select "Enable SMP" to enable SMP on this SOC.
200
201config SMP
202	bool "Enable Symmetric multi-processing support"
203	depends on HAVE_SMP
204	select GENERIC_SMP_IDLE_THREAD
205	help
206	  Enabled SMP Software; allows more than one CPU/CORE
207	  to be activated during startup.
208
209config NR_CPUS
210	depends on SMP
211	int "Maximum number of CPUs (2-32)"
212	range 2 32
213	default "4"
214
215config HOTPLUG_CPU
216	bool "Enable CPU hotplug support"
217	depends on SMP
218	help
219	  Say Y here to allow turning CPUs off and on. CPUs can be
220	  controlled through /sys/devices/system/cpu.
221
222	  Say N if you want to disable CPU hotplug.
223
224config FAST_SYSCALL_XTENSA
225	bool "Enable fast atomic syscalls"
226	default n
227	help
228	  fast_syscall_xtensa is a syscall that can make atomic operations
229	  on UP kernel when processor has no s32c1i support.
230
231	  This syscall is deprecated. It may have issues when called with
232	  invalid arguments. It is provided only for backwards compatibility.
233	  Only enable it if your userspace software requires it.
234
235	  If unsure, say N.
236
237config FAST_SYSCALL_SPILL_REGISTERS
238	bool "Enable spill registers syscall"
239	default n
240	help
241	  fast_syscall_spill_registers is a syscall that spills all active
242	  register windows of a calling userspace task onto its stack.
243
244	  This syscall is deprecated. It may have issues when called with
245	  invalid arguments. It is provided only for backwards compatibility.
246	  Only enable it if your userspace software requires it.
247
248	  If unsure, say N.
249
250config USER_ABI_CALL0
251	bool
252
253choice
254	prompt "Userspace ABI"
255	default USER_ABI_DEFAULT
256	help
257	  Select supported userspace ABI.
258
259	  If unsure, choose the default ABI.
260
261config USER_ABI_DEFAULT
262	bool "Default ABI only"
263	help
264	  Assume default userspace ABI. For XEA2 cores it is windowed ABI.
265	  call0 ABI binaries may be run on such kernel, but signal delivery
266	  will not work correctly for them.
267
268config USER_ABI_CALL0_ONLY
269	bool "Call0 ABI only"
270	select USER_ABI_CALL0
271	help
272	  Select this option to support only call0 ABI in userspace.
273	  Windowed ABI binaries will crash with a segfault caused by
274	  an illegal instruction exception on the first 'entry' opcode.
275
276	  Choose this option if you're planning to run only user code
277	  built with call0 ABI.
278
279config USER_ABI_CALL0_PROBE
280	bool "Support both windowed and call0 ABI by probing"
281	select USER_ABI_CALL0
282	help
283	  Select this option to support both windowed and call0 userspace
284	  ABIs. When enabled all processes are started with PS.WOE disabled
285	  and a fast user exception handler for an illegal instruction is
286	  used to turn on PS.WOE bit on the first 'entry' opcode executed by
287	  the userspace.
288
289	  This option should be enabled for the kernel that must support
290	  both call0 and windowed ABIs in userspace at the same time.
291
292	  Note that Xtensa ISA does not guarantee that entry opcode will
293	  raise an illegal instruction exception on cores with XEA2 when
294	  PS.WOE is disabled, check whether the target core supports it.
295
296endchoice
297
298endmenu
299
300config XTENSA_CALIBRATE_CCOUNT
301	def_bool n
302	help
303	  On some platforms (XT2000, for example), the CPU clock rate can
304	  vary.  The frequency can be determined, however, by measuring
305	  against a well known, fixed frequency, such as an UART oscillator.
306
307config SERIAL_CONSOLE
308	def_bool n
309
310config PLATFORM_HAVE_XIP
311	def_bool n
312
313menu "Platform options"
314
315choice
316	prompt "Xtensa System Type"
317	default XTENSA_PLATFORM_ISS
318
319config XTENSA_PLATFORM_ISS
320	bool "ISS"
321	select XTENSA_CALIBRATE_CCOUNT
322	select SERIAL_CONSOLE
323	help
324	  ISS is an acronym for Tensilica's Instruction Set Simulator.
325
326config XTENSA_PLATFORM_XT2000
327	bool "XT2000"
328	help
329	  XT2000 is the name of Tensilica's feature-rich emulation platform.
330	  This hardware is capable of running a full Linux distribution.
331
332config XTENSA_PLATFORM_XTFPGA
333	bool "XTFPGA"
334	select ETHOC if ETHERNET
335	select PLATFORM_WANT_DEFAULT_MEM if !MMU
336	select SERIAL_CONSOLE
337	select XTENSA_CALIBRATE_CCOUNT
338	select PLATFORM_HAVE_XIP
339	help
340	  XTFPGA is the name of Tensilica board family (LX60, LX110, LX200, ML605).
341	  This hardware is capable of running a full Linux distribution.
342
343endchoice
344
345config PLATFORM_NR_IRQS
346	int
347	default 3 if XTENSA_PLATFORM_XT2000
348	default 0
349
350config XTENSA_CPU_CLOCK
351	int "CPU clock rate [MHz]"
352	depends on !XTENSA_CALIBRATE_CCOUNT
353	default 16
354
355config GENERIC_CALIBRATE_DELAY
356	bool "Auto calibration of the BogoMIPS value"
357	help
358	  The BogoMIPS value can easily be derived from the CPU frequency.
359
360config CMDLINE_BOOL
361	bool "Default bootloader kernel arguments"
362
363config CMDLINE
364	string "Initial kernel command string"
365	depends on CMDLINE_BOOL
366	default "console=ttyS0,38400 root=/dev/ram"
367	help
368	  On some architectures (EBSA110 and CATS), there is currently no way
369	  for the boot loader to pass arguments to the kernel. For these
370	  architectures, you should supply some command-line options at build
371	  time by entering them here. As a minimum, you should specify the
372	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
373
374config USE_OF
375	bool "Flattened Device Tree support"
376	select OF
377	select OF_EARLY_FLATTREE
378	help
379	  Include support for flattened device tree machine descriptions.
380
381config BUILTIN_DTB_SOURCE
382	string "DTB to build into the kernel image"
383	depends on OF
384
385config PARSE_BOOTPARAM
386	bool "Parse bootparam block"
387	default y
388	help
389	  Parse parameters passed to the kernel from the bootloader. It may
390	  be disabled if the kernel is known to run without the bootloader.
391
392	  If unsure, say Y.
393
394choice
395	prompt "Semihosting interface"
396	default XTENSA_SIMCALL_ISS
397	depends on XTENSA_PLATFORM_ISS
398	help
399	  Choose semihosting interface that will be used for serial port,
400	  block device and networking.
401
402config XTENSA_SIMCALL_ISS
403	bool "simcall"
404	help
405	  Use simcall instruction. simcall is only available on simulators,
406	  it does nothing on hardware.
407
408config XTENSA_SIMCALL_GDBIO
409	bool "GDBIO"
410	help
411	  Use break instruction. It is available on real hardware when GDB
412	  is attached to it via JTAG.
413
414endchoice
415
416config BLK_DEV_SIMDISK
417	tristate "Host file-based simulated block device support"
418	default n
419	depends on XTENSA_PLATFORM_ISS && BLOCK
420	help
421	  Create block devices that map to files in the host file system.
422	  Device binding to host file may be changed at runtime via proc
423	  interface provided the device is not in use.
424
425config BLK_DEV_SIMDISK_COUNT
426	int "Number of host file-based simulated block devices"
427	range 1 10
428	depends on BLK_DEV_SIMDISK
429	default 2
430	help
431	  This is the default minimal number of created block devices.
432	  Kernel/module parameter 'simdisk_count' may be used to change this
433	  value at runtime. More file names (but no more than 10) may be
434	  specified as parameters, simdisk_count grows accordingly.
435
436config SIMDISK0_FILENAME
437	string "Host filename for the first simulated device"
438	depends on BLK_DEV_SIMDISK = y
439	default ""
440	help
441	  Attach a first simdisk to a host file. Conventionally, this file
442	  contains a root file system.
443
444config SIMDISK1_FILENAME
445	string "Host filename for the second simulated device"
446	depends on BLK_DEV_SIMDISK = y && BLK_DEV_SIMDISK_COUNT != 1
447	default ""
448	help
449	  Another simulated disk in a host file for a buildroot-independent
450	  storage.
451
452config XTFPGA_LCD
453	bool "Enable XTFPGA LCD driver"
454	depends on XTENSA_PLATFORM_XTFPGA
455	default n
456	help
457	  There's a 2x16 LCD on most of XTFPGA boards, kernel may output
458	  progress messages there during bootup/shutdown. It may be useful
459	  during board bringup.
460
461	  If unsure, say N.
462
463config XTFPGA_LCD_BASE_ADDR
464	hex "XTFPGA LCD base address"
465	depends on XTFPGA_LCD
466	default "0x0d0c0000"
467	help
468	  Base address of the LCD controller inside KIO region.
469	  Different boards from XTFPGA family have LCD controller at different
470	  addresses. Please consult prototyping user guide for your board for
471	  the correct address. Wrong address here may lead to hardware lockup.
472
473config XTFPGA_LCD_8BIT_ACCESS
474	bool "Use 8-bit access to XTFPGA LCD"
475	depends on XTFPGA_LCD
476	default n
477	help
478	  LCD may be connected with 4- or 8-bit interface, 8-bit access may
479	  only be used with 8-bit interface. Please consult prototyping user
480	  guide for your board for the correct interface width.
481
482comment "Kernel memory layout"
483
484config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
485	bool "Initialize Xtensa MMU inside the Linux kernel code"
486	depends on !XTENSA_VARIANT_FSF && !XTENSA_VARIANT_DC232B
487	default y if XTENSA_VARIANT_DC233C || XTENSA_VARIANT_CUSTOM
488	help
489	  Earlier version initialized the MMU in the exception vector
490	  before jumping to _startup in head.S and had an advantage that
491	  it was possible to place a software breakpoint at 'reset' and
492	  then enter your normal kernel breakpoints once the MMU was mapped
493	  to the kernel mappings (0XC0000000).
494
495	  This unfortunately won't work for U-Boot and likely also won't
496	  work for using KEXEC to have a hot kernel ready for doing a
497	  KDUMP.
498
499	  So now the MMU is initialized in head.S but it's necessary to
500	  use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
501	  xt-gdb can't place a Software Breakpoint in the  0XD region prior
502	  to mapping the MMU and after mapping even if the area of low memory
503	  was mapped gdb wouldn't remove the breakpoint on hitting it as the
504	  PC wouldn't match. Since Hardware Breakpoints are recommended for
505	  Linux configurations it seems reasonable to just assume they exist
506	  and leave this older mechanism for unfortunate souls that choose
507	  not to follow Tensilica's recommendation.
508
509	  Selecting this will cause U-Boot to set the KERNEL Load and Entry
510	  address at 0x00003000 instead of the mapped std of 0xD0003000.
511
512	  If in doubt, say Y.
513
514config XIP_KERNEL
515	bool "Kernel Execute-In-Place from ROM"
516	depends on PLATFORM_HAVE_XIP
517	help
518	  Execute-In-Place allows the kernel to run from non-volatile storage
519	  directly addressable by the CPU, such as NOR flash. This saves RAM
520	  space since the text section of the kernel is not loaded from flash
521	  to RAM. Read-write sections, such as the data section and stack,
522	  are still copied to RAM. The XIP kernel is not compressed since
523	  it has to run directly from flash, so it will take more space to
524	  store it. The flash address used to link the kernel object files,
525	  and for storing it, is configuration dependent. Therefore, if you
526	  say Y here, you must know the proper physical address where to
527	  store the kernel image depending on your own flash memory usage.
528
529	  Also note that the make target becomes "make xipImage" rather than
530	  "make Image" or "make uImage". The final kernel binary to put in
531	  ROM memory will be arch/xtensa/boot/xipImage.
532
533	  If unsure, say N.
534
535config MEMMAP_CACHEATTR
536	hex "Cache attributes for the memory address space"
537	depends on !MMU
538	default 0x22222222
539	help
540	  These cache attributes are set up for noMMU systems. Each hex digit
541	  specifies cache attributes for the corresponding 512MB memory
542	  region: bits 0..3 -- for addresses 0x00000000..0x1fffffff,
543	  bits 4..7 -- for addresses 0x20000000..0x3fffffff, and so on.
544
545	  Cache attribute values are specific for the MMU type.
546	  For region protection MMUs:
547	    1: WT cached,
548	    2: cache bypass,
549	    4: WB cached,
550	    f: illegal.
551	  For full MMU:
552	    bit 0: executable,
553	    bit 1: writable,
554	    bits 2..3:
555	      0: cache bypass,
556	      1: WB cache,
557	      2: WT cache,
558	      3: special (c and e are illegal, f is reserved).
559	  For MPU:
560	    0: illegal,
561	    1: WB cache,
562	    2: WB, no-write-allocate cache,
563	    3: WT cache,
564	    4: cache bypass.
565
566config KSEG_PADDR
567	hex "Physical address of the KSEG mapping"
568	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX && MMU
569	default 0x00000000
570	help
571	  This is the physical address where KSEG is mapped. Please refer to
572	  the chosen KSEG layout help for the required address alignment.
573	  Unpacked kernel image (including vectors) must be located completely
574	  within KSEG.
575	  Physical memory below this address is not available to linux.
576
577	  If unsure, leave the default value here.
578
579config KERNEL_VIRTUAL_ADDRESS
580	hex "Kernel virtual address"
581	depends on MMU && XIP_KERNEL
582	default 0xd0003000
583	help
584	  This is the virtual address where the XIP kernel is mapped.
585	  XIP kernel may be mapped into KSEG or KIO region, virtual address
586	  provided here must match kernel load address provided in
587	  KERNEL_LOAD_ADDRESS.
588
589config KERNEL_LOAD_ADDRESS
590	hex "Kernel load address"
591	default 0x60003000 if !MMU
592	default 0x00003000 if MMU && INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
593	default 0xd0003000 if MMU && !INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
594	help
595	  This is the address where the kernel is loaded.
596	  It is virtual address for MMUv2 configurations and physical address
597	  for all other configurations.
598
599	  If unsure, leave the default value here.
600
601choice
602	prompt "Relocatable vectors location"
603	default XTENSA_VECTORS_IN_TEXT
604	help
605	  Choose whether relocatable vectors are merged into the kernel .text
606	  or placed separately at runtime. This option does not affect
607	  configurations without VECBASE register where vectors are always
608	  placed at their hardware-defined locations.
609
610config XTENSA_VECTORS_IN_TEXT
611	bool "Merge relocatable vectors into kernel text"
612	depends on !MTD_XIP
613	help
614	  This option puts relocatable vectors into the kernel .text section
615	  with proper alignment.
616	  This is a safe choice for most configurations.
617
618config XTENSA_VECTORS_SEPARATE
619	bool "Put relocatable vectors at fixed address"
620	help
621	  This option puts relocatable vectors at specific virtual address.
622	  Vectors are merged with the .init data in the kernel image and
623	  are copied into their designated location during kernel startup.
624	  Use it to put vectors into IRAM or out of FLASH on kernels with
625	  XIP-aware MTD support.
626
627endchoice
628
629config VECTORS_ADDR
630	hex "Kernel vectors virtual address"
631	default 0x00000000
632	depends on XTENSA_VECTORS_SEPARATE
633	help
634	  This is the virtual address of the (relocatable) vectors base.
635	  It must be within KSEG if MMU is used.
636
637config XIP_DATA_ADDR
638	hex "XIP kernel data virtual address"
639	depends on XIP_KERNEL
640	default 0x00000000
641	help
642	  This is the virtual address where XIP kernel data is copied.
643	  It must be within KSEG if MMU is used.
644
645config PLATFORM_WANT_DEFAULT_MEM
646	def_bool n
647
648config DEFAULT_MEM_START
649	hex
650	prompt "PAGE_OFFSET/PHYS_OFFSET" if !MMU && PLATFORM_WANT_DEFAULT_MEM
651	default 0x60000000 if PLATFORM_WANT_DEFAULT_MEM
652	default 0x00000000
653	help
654	  This is the base address used for both PAGE_OFFSET and PHYS_OFFSET
655	  in noMMU configurations.
656
657	  If unsure, leave the default value here.
658
659choice
660	prompt "KSEG layout"
661	depends on MMU
662	default XTENSA_KSEG_MMU_V2
663
664config XTENSA_KSEG_MMU_V2
665	bool "MMUv2: 128MB cached + 128MB uncached"
666	help
667	  MMUv2 compatible kernel memory map: TLB way 5 maps 128MB starting
668	  at KSEG_PADDR to 0xd0000000 with cache and to 0xd8000000
669	  without cache.
670	  KSEG_PADDR must be aligned to 128MB.
671
672config XTENSA_KSEG_256M
673	bool "256MB cached + 256MB uncached"
674	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
675	help
676	  TLB way 6 maps 256MB starting at KSEG_PADDR to 0xb0000000
677	  with cache and to 0xc0000000 without cache.
678	  KSEG_PADDR must be aligned to 256MB.
679
680config XTENSA_KSEG_512M
681	bool "512MB cached + 512MB uncached"
682	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
683	help
684	  TLB way 6 maps 512MB starting at KSEG_PADDR to 0xa0000000
685	  with cache and to 0xc0000000 without cache.
686	  KSEG_PADDR must be aligned to 256MB.
687
688endchoice
689
690config HIGHMEM
691	bool "High Memory Support"
692	depends on MMU
693	select KMAP_LOCAL
694	help
695	  Linux can use the full amount of RAM in the system by
696	  default. However, the default MMUv2 setup only maps the
697	  lowermost 128 MB of memory linearly to the areas starting
698	  at 0xd0000000 (cached) and 0xd8000000 (uncached).
699	  When there are more than 128 MB memory in the system not
700	  all of it can be "permanently mapped" by the kernel.
701	  The physical memory that's not permanently mapped is called
702	  "high memory".
703
704	  If you are compiling a kernel which will never run on a
705	  machine with more than 128 MB total physical RAM, answer
706	  N here.
707
708	  If unsure, say Y.
709
710config FORCE_MAX_ZONEORDER
711	int "Maximum zone order"
712	default "11"
713	help
714	  The kernel memory allocator divides physically contiguous memory
715	  blocks into "zones", where each zone is a power of two number of
716	  pages.  This option selects the largest power of two that the kernel
717	  keeps in the memory allocator.  If you need to allocate very large
718	  blocks of physically contiguous memory, then you may need to
719	  increase this value.
720
721	  This config option is actually maximum order plus one. For example,
722	  a value of 11 means that the largest free memory block is 2^10 pages.
723
724endmenu
725
726menu "Power management options"
727
728source "kernel/power/Kconfig"
729
730endmenu
731