xref: /openbmc/linux/arch/xtensa/Kconfig (revision 9eda7c1f)
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_USE_QUEUED_RWLOCKS
11	select ARCH_USE_QUEUED_SPINLOCKS
12	select ARCH_WANT_FRAME_POINTERS
13	select ARCH_WANT_IPC_PARSE_VERSION
14	select BUILDTIME_TABLE_SORT
15	select CLONE_BACKWARDS
16	select COMMON_CLK
17	select DMA_REMAP if MMU
18	select GENERIC_ATOMIC64
19	select GENERIC_CLOCKEVENTS
20	select GENERIC_IRQ_SHOW
21	select GENERIC_PCI_IOMAP
22	select GENERIC_SCHED_CLOCK
23	select GENERIC_STRNCPY_FROM_USER if KASAN
24	select HAVE_ARCH_AUDITSYSCALL
25	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
26	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
27	select HAVE_ARCH_SECCOMP_FILTER
28	select HAVE_ARCH_TRACEHOOK
29	select HAVE_DEBUG_KMEMLEAK
30	select HAVE_DMA_CONTIGUOUS
31	select HAVE_EXIT_THREAD
32	select HAVE_FUNCTION_TRACER
33	select HAVE_FUTEX_CMPXCHG if !MMU
34	select HAVE_HW_BREAKPOINT if PERF_EVENTS
35	select HAVE_IRQ_TIME_ACCOUNTING
36	select HAVE_OPROFILE
37	select HAVE_PCI
38	select HAVE_PERF_EVENTS
39	select HAVE_STACKPROTECTOR
40	select HAVE_SYSCALL_TRACEPOINTS
41	select IRQ_DOMAIN
42	select MODULES_USE_ELF_RELA
43	select PERF_USE_VMALLOC
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 TRACE_IRQFLAGS_SUPPORT
76	def_bool y
77
78config MMU
79	def_bool n
80
81config HAVE_XTENSA_GPIO32
82	def_bool n
83
84config KASAN_SHADOW_OFFSET
85	hex
86	default 0x6e400000
87
88menu "Processor type and features"
89
90choice
91	prompt "Xtensa Processor Configuration"
92	default XTENSA_VARIANT_FSF
93
94config XTENSA_VARIANT_FSF
95	bool "fsf - default (not generic) configuration"
96	select MMU
97
98config XTENSA_VARIANT_DC232B
99	bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
100	select MMU
101	select HAVE_XTENSA_GPIO32
102	help
103	  This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).
104
105config XTENSA_VARIANT_DC233C
106	bool "dc233c - Diamond 233L Standard Core Rev.C (LE)"
107	select MMU
108	select HAVE_XTENSA_GPIO32
109	help
110	  This variant refers to Tensilica's Diamond 233L Standard core Rev.C (LE).
111
112config XTENSA_VARIANT_CUSTOM
113	bool "Custom Xtensa processor configuration"
114	select HAVE_XTENSA_GPIO32
115	help
116	  Select this variant to use a custom Xtensa processor configuration.
117	  You will be prompted for a processor variant CORENAME.
118endchoice
119
120config XTENSA_VARIANT_CUSTOM_NAME
121	string "Xtensa Processor Custom Core Variant Name"
122	depends on XTENSA_VARIANT_CUSTOM
123	help
124	  Provide the name of a custom Xtensa processor variant.
125	  This CORENAME selects arch/xtensa/variant/CORENAME.
126	  Don't forget you have to select MMU if you have one.
127
128config XTENSA_VARIANT_NAME
129	string
130	default "dc232b"			if XTENSA_VARIANT_DC232B
131	default "dc233c"			if XTENSA_VARIANT_DC233C
132	default "fsf"				if XTENSA_VARIANT_FSF
133	default XTENSA_VARIANT_CUSTOM_NAME	if XTENSA_VARIANT_CUSTOM
134
135config XTENSA_VARIANT_MMU
136	bool "Core variant has a Full MMU (TLB, Pages, Protection, etc)"
137	depends on XTENSA_VARIANT_CUSTOM
138	default y
139	select MMU
140	help
141	  Build a Conventional Kernel with full MMU support,
142	  ie: it supports a TLB with auto-loading, page protection.
143
144config XTENSA_VARIANT_HAVE_PERF_EVENTS
145	bool "Core variant has Performance Monitor Module"
146	depends on XTENSA_VARIANT_CUSTOM
147	default n
148	help
149	  Enable if core variant has Performance Monitor Module with
150	  External Registers Interface.
151
152	  If unsure, say N.
153
154config XTENSA_FAKE_NMI
155	bool "Treat PMM IRQ as NMI"
156	depends on XTENSA_VARIANT_HAVE_PERF_EVENTS
157	default n
158	help
159	  If PMM IRQ is the only IRQ at EXCM level it is safe to
160	  treat it as NMI, which improves accuracy of profiling.
161
162	  If there are other interrupts at or above PMM IRQ priority level
163	  but not above the EXCM level, PMM IRQ still may be treated as NMI,
164	  but only if these IRQs are not used. There will be a build warning
165	  saying that this is not safe, and a bugcheck if one of these IRQs
166	  actually fire.
167
168	  If unsure, say N.
169
170config XTENSA_UNALIGNED_USER
171	bool "Unaligned memory access in user space"
172	help
173	  The Xtensa architecture currently does not handle unaligned
174	  memory accesses in hardware but through an exception handler.
175	  Per default, unaligned memory accesses are disabled in user space.
176
177	  Say Y here to enable unaligned memory access in user space.
178
179config HAVE_SMP
180	bool "System Supports SMP (MX)"
181	depends on XTENSA_VARIANT_CUSTOM
182	select XTENSA_MX
183	help
184	  This option is used to indicate that the system-on-a-chip (SOC)
185	  supports Multiprocessing. Multiprocessor support implemented above
186	  the CPU core definition and currently needs to be selected manually.
187
188	  Multiprocessor support is implemented with external cache and
189	  interrupt controllers.
190
191	  The MX interrupt distributer adds Interprocessor Interrupts
192	  and causes the IRQ numbers to be increased by 4 for devices
193	  like the open cores ethernet driver and the serial interface.
194
195	  You still have to select "Enable SMP" to enable SMP on this SOC.
196
197config SMP
198	bool "Enable Symmetric multi-processing support"
199	depends on HAVE_SMP
200	select GENERIC_SMP_IDLE_THREAD
201	help
202	  Enabled SMP Software; allows more than one CPU/CORE
203	  to be activated during startup.
204
205config NR_CPUS
206	depends on SMP
207	int "Maximum number of CPUs (2-32)"
208	range 2 32
209	default "4"
210
211config HOTPLUG_CPU
212	bool "Enable CPU hotplug support"
213	depends on SMP
214	help
215	  Say Y here to allow turning CPUs off and on. CPUs can be
216	  controlled through /sys/devices/system/cpu.
217
218	  Say N if you want to disable CPU hotplug.
219
220config SECCOMP
221	bool
222	prompt "Enable seccomp to safely compute untrusted bytecode"
223	help
224	  This kernel feature is useful for number crunching applications
225	  that may need to compute untrusted bytecode during their
226	  execution. By using pipes or other transports made available to
227	  the process as file descriptors supporting the read/write
228	  syscalls, it's possible to isolate those applications in
229	  their own address space using seccomp. Once seccomp is
230	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
231	  and the task is only allowed to execute a few safe syscalls
232	  defined by each seccomp mode.
233
234config FAST_SYSCALL_XTENSA
235	bool "Enable fast atomic syscalls"
236	default n
237	help
238	  fast_syscall_xtensa is a syscall that can make atomic operations
239	  on UP kernel when processor has no s32c1i support.
240
241	  This syscall is deprecated. It may have issues when called with
242	  invalid arguments. It is provided only for backwards compatibility.
243	  Only enable it if your userspace software requires it.
244
245	  If unsure, say N.
246
247config FAST_SYSCALL_SPILL_REGISTERS
248	bool "Enable spill registers syscall"
249	default n
250	help
251	  fast_syscall_spill_registers is a syscall that spills all active
252	  register windows of a calling userspace task onto its stack.
253
254	  This syscall is deprecated. It may have issues when called with
255	  invalid arguments. It is provided only for backwards compatibility.
256	  Only enable it if your userspace software requires it.
257
258	  If unsure, say N.
259
260config USER_ABI_CALL0
261	bool
262
263choice
264	prompt "Userspace ABI"
265	default USER_ABI_DEFAULT
266	help
267	  Select supported userspace ABI.
268
269	  If unsure, choose the default ABI.
270
271config USER_ABI_DEFAULT
272	bool "Default ABI only"
273	help
274	  Assume default userspace ABI. For XEA2 cores it is windowed ABI.
275	  call0 ABI binaries may be run on such kernel, but signal delivery
276	  will not work correctly for them.
277
278config USER_ABI_CALL0_ONLY
279	bool "Call0 ABI only"
280	select USER_ABI_CALL0
281	help
282	  Select this option to support only call0 ABI in userspace.
283	  Windowed ABI binaries will crash with a segfault caused by
284	  an illegal instruction exception on the first 'entry' opcode.
285
286	  Choose this option if you're planning to run only user code
287	  built with call0 ABI.
288
289config USER_ABI_CALL0_PROBE
290	bool "Support both windowed and call0 ABI by probing"
291	select USER_ABI_CALL0
292	help
293	  Select this option to support both windowed and call0 userspace
294	  ABIs. When enabled all processes are started with PS.WOE disabled
295	  and a fast user exception handler for an illegal instruction is
296	  used to turn on PS.WOE bit on the first 'entry' opcode executed by
297	  the userspace.
298
299	  This option should be enabled for the kernel that must support
300	  both call0 and windowed ABIs in userspace at the same time.
301
302	  Note that Xtensa ISA does not guarantee that entry opcode will
303	  raise an illegal instruction exception on cores with XEA2 when
304	  PS.WOE is disabled, check whether the target core supports it.
305
306endchoice
307
308endmenu
309
310config XTENSA_CALIBRATE_CCOUNT
311	def_bool n
312	help
313	  On some platforms (XT2000, for example), the CPU clock rate can
314	  vary.  The frequency can be determined, however, by measuring
315	  against a well known, fixed frequency, such as an UART oscillator.
316
317config SERIAL_CONSOLE
318	def_bool n
319
320config PLATFORM_HAVE_XIP
321	def_bool n
322
323menu "Platform options"
324
325choice
326	prompt "Xtensa System Type"
327	default XTENSA_PLATFORM_ISS
328
329config XTENSA_PLATFORM_ISS
330	bool "ISS"
331	select XTENSA_CALIBRATE_CCOUNT
332	select SERIAL_CONSOLE
333	help
334	  ISS is an acronym for Tensilica's Instruction Set Simulator.
335
336config XTENSA_PLATFORM_XT2000
337	bool "XT2000"
338	select HAVE_IDE
339	help
340	  XT2000 is the name of Tensilica's feature-rich emulation platform.
341	  This hardware is capable of running a full Linux distribution.
342
343config XTENSA_PLATFORM_XTFPGA
344	bool "XTFPGA"
345	select ETHOC if ETHERNET
346	select PLATFORM_WANT_DEFAULT_MEM if !MMU
347	select SERIAL_CONSOLE
348	select XTENSA_CALIBRATE_CCOUNT
349	select PLATFORM_HAVE_XIP
350	help
351	  XTFPGA is the name of Tensilica board family (LX60, LX110, LX200, ML605).
352	  This hardware is capable of running a full Linux distribution.
353
354endchoice
355
356config PLATFORM_NR_IRQS
357	int
358	default 3 if XTENSA_PLATFORM_XT2000
359	default 0
360
361config XTENSA_CPU_CLOCK
362	int "CPU clock rate [MHz]"
363	depends on !XTENSA_CALIBRATE_CCOUNT
364	default 16
365
366config GENERIC_CALIBRATE_DELAY
367	bool "Auto calibration of the BogoMIPS value"
368	help
369	  The BogoMIPS value can easily be derived from the CPU frequency.
370
371config CMDLINE_BOOL
372	bool "Default bootloader kernel arguments"
373
374config CMDLINE
375	string "Initial kernel command string"
376	depends on CMDLINE_BOOL
377	default "console=ttyS0,38400 root=/dev/ram"
378	help
379	  On some architectures (EBSA110 and CATS), there is currently no way
380	  for the boot loader to pass arguments to the kernel. For these
381	  architectures, you should supply some command-line options at build
382	  time by entering them here. As a minimum, you should specify the
383	  memory size and the root device (e.g., mem=64M root=/dev/nfs).
384
385config USE_OF
386	bool "Flattened Device Tree support"
387	select OF
388	select OF_EARLY_FLATTREE
389	help
390	  Include support for flattened device tree machine descriptions.
391
392config BUILTIN_DTB_SOURCE
393	string "DTB to build into the kernel image"
394	depends on OF
395
396config PARSE_BOOTPARAM
397	bool "Parse bootparam block"
398	default y
399	help
400	  Parse parameters passed to the kernel from the bootloader. It may
401	  be disabled if the kernel is known to run without the bootloader.
402
403	  If unsure, say Y.
404
405config BLK_DEV_SIMDISK
406	tristate "Host file-based simulated block device support"
407	default n
408	depends on XTENSA_PLATFORM_ISS && BLOCK
409	help
410	  Create block devices that map to files in the host file system.
411	  Device binding to host file may be changed at runtime via proc
412	  interface provided the device is not in use.
413
414config BLK_DEV_SIMDISK_COUNT
415	int "Number of host file-based simulated block devices"
416	range 1 10
417	depends on BLK_DEV_SIMDISK
418	default 2
419	help
420	  This is the default minimal number of created block devices.
421	  Kernel/module parameter 'simdisk_count' may be used to change this
422	  value at runtime. More file names (but no more than 10) may be
423	  specified as parameters, simdisk_count grows accordingly.
424
425config SIMDISK0_FILENAME
426	string "Host filename for the first simulated device"
427	depends on BLK_DEV_SIMDISK = y
428	default ""
429	help
430	  Attach a first simdisk to a host file. Conventionally, this file
431	  contains a root file system.
432
433config SIMDISK1_FILENAME
434	string "Host filename for the second simulated device"
435	depends on BLK_DEV_SIMDISK = y && BLK_DEV_SIMDISK_COUNT != 1
436	default ""
437	help
438	  Another simulated disk in a host file for a buildroot-independent
439	  storage.
440
441config XTFPGA_LCD
442	bool "Enable XTFPGA LCD driver"
443	depends on XTENSA_PLATFORM_XTFPGA
444	default n
445	help
446	  There's a 2x16 LCD on most of XTFPGA boards, kernel may output
447	  progress messages there during bootup/shutdown. It may be useful
448	  during board bringup.
449
450	  If unsure, say N.
451
452config XTFPGA_LCD_BASE_ADDR
453	hex "XTFPGA LCD base address"
454	depends on XTFPGA_LCD
455	default "0x0d0c0000"
456	help
457	  Base address of the LCD controller inside KIO region.
458	  Different boards from XTFPGA family have LCD controller at different
459	  addresses. Please consult prototyping user guide for your board for
460	  the correct address. Wrong address here may lead to hardware lockup.
461
462config XTFPGA_LCD_8BIT_ACCESS
463	bool "Use 8-bit access to XTFPGA LCD"
464	depends on XTFPGA_LCD
465	default n
466	help
467	  LCD may be connected with 4- or 8-bit interface, 8-bit access may
468	  only be used with 8-bit interface. Please consult prototyping user
469	  guide for your board for the correct interface width.
470
471comment "Kernel memory layout"
472
473config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
474	bool "Initialize Xtensa MMU inside the Linux kernel code"
475	depends on !XTENSA_VARIANT_FSF && !XTENSA_VARIANT_DC232B
476	default y if XTENSA_VARIANT_DC233C || XTENSA_VARIANT_CUSTOM
477	help
478	  Earlier version initialized the MMU in the exception vector
479	  before jumping to _startup in head.S and had an advantage that
480	  it was possible to place a software breakpoint at 'reset' and
481	  then enter your normal kernel breakpoints once the MMU was mapped
482	  to the kernel mappings (0XC0000000).
483
484	  This unfortunately won't work for U-Boot and likely also wont
485	  work for using KEXEC to have a hot kernel ready for doing a
486	  KDUMP.
487
488	  So now the MMU is initialized in head.S but it's necessary to
489	  use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
490	  xt-gdb can't place a Software Breakpoint in the  0XD region prior
491	  to mapping the MMU and after mapping even if the area of low memory
492	  was mapped gdb wouldn't remove the breakpoint on hitting it as the
493	  PC wouldn't match. Since Hardware Breakpoints are recommended for
494	  Linux configurations it seems reasonable to just assume they exist
495	  and leave this older mechanism for unfortunate souls that choose
496	  not to follow Tensilica's recommendation.
497
498	  Selecting this will cause U-Boot to set the KERNEL Load and Entry
499	  address at 0x00003000 instead of the mapped std of 0xD0003000.
500
501	  If in doubt, say Y.
502
503config XIP_KERNEL
504	bool "Kernel Execute-In-Place from ROM"
505	depends on PLATFORM_HAVE_XIP
506	help
507	  Execute-In-Place allows the kernel to run from non-volatile storage
508	  directly addressable by the CPU, such as NOR flash. This saves RAM
509	  space since the text section of the kernel is not loaded from flash
510	  to RAM. Read-write sections, such as the data section and stack,
511	  are still copied to RAM. The XIP kernel is not compressed since
512	  it has to run directly from flash, so it will take more space to
513	  store it. The flash address used to link the kernel object files,
514	  and for storing it, is configuration dependent. Therefore, if you
515	  say Y here, you must know the proper physical address where to
516	  store the kernel image depending on your own flash memory usage.
517
518	  Also note that the make target becomes "make xipImage" rather than
519	  "make Image" or "make uImage". The final kernel binary to put in
520	  ROM memory will be arch/xtensa/boot/xipImage.
521
522	  If unsure, say N.
523
524config MEMMAP_CACHEATTR
525	hex "Cache attributes for the memory address space"
526	depends on !MMU
527	default 0x22222222
528	help
529	  These cache attributes are set up for noMMU systems. Each hex digit
530	  specifies cache attributes for the corresponding 512MB memory
531	  region: bits 0..3 -- for addresses 0x00000000..0x1fffffff,
532	  bits 4..7 -- for addresses 0x20000000..0x3fffffff, and so on.
533
534	  Cache attribute values are specific for the MMU type.
535	  For region protection MMUs:
536	    1: WT cached,
537	    2: cache bypass,
538	    4: WB cached,
539	    f: illegal.
540	  For ful MMU:
541	    bit 0: executable,
542	    bit 1: writable,
543	    bits 2..3:
544	      0: cache bypass,
545	      1: WB cache,
546	      2: WT cache,
547	      3: special (c and e are illegal, f is reserved).
548	  For MPU:
549	    0: illegal,
550	    1: WB cache,
551	    2: WB, no-write-allocate cache,
552	    3: WT cache,
553	    4: cache bypass.
554
555config KSEG_PADDR
556	hex "Physical address of the KSEG mapping"
557	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX && MMU
558	default 0x00000000
559	help
560	  This is the physical address where KSEG is mapped. Please refer to
561	  the chosen KSEG layout help for the required address alignment.
562	  Unpacked kernel image (including vectors) must be located completely
563	  within KSEG.
564	  Physical memory below this address is not available to linux.
565
566	  If unsure, leave the default value here.
567
568config KERNEL_VIRTUAL_ADDRESS
569	hex "Kernel virtual address"
570	depends on MMU && XIP_KERNEL
571	default 0xd0003000
572	help
573	  This is the virtual address where the XIP kernel is mapped.
574	  XIP kernel may be mapped into KSEG or KIO region, virtual address
575	  provided here must match kernel load address provided in
576	  KERNEL_LOAD_ADDRESS.
577
578config KERNEL_LOAD_ADDRESS
579	hex "Kernel load address"
580	default 0x60003000 if !MMU
581	default 0x00003000 if MMU && INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
582	default 0xd0003000 if MMU && !INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
583	help
584	  This is the address where the kernel is loaded.
585	  It is virtual address for MMUv2 configurations and physical address
586	  for all other configurations.
587
588	  If unsure, leave the default value here.
589
590choice
591	prompt "Relocatable vectors location"
592	default XTENSA_VECTORS_IN_TEXT
593	help
594	  Choose whether relocatable vectors are merged into the kernel .text
595	  or placed separately at runtime. This option does not affect
596	  configurations without VECBASE register where vectors are always
597	  placed at their hardware-defined locations.
598
599config XTENSA_VECTORS_IN_TEXT
600	bool "Merge relocatable vectors into kernel text"
601	depends on !MTD_XIP
602	help
603	  This option puts relocatable vectors into the kernel .text section
604	  with proper alignment.
605	  This is a safe choice for most configurations.
606
607config XTENSA_VECTORS_SEPARATE
608	bool "Put relocatable vectors at fixed address"
609	help
610	  This option puts relocatable vectors at specific virtual address.
611	  Vectors are merged with the .init data in the kernel image and
612	  are copied into their designated location during kernel startup.
613	  Use it to put vectors into IRAM or out of FLASH on kernels with
614	  XIP-aware MTD support.
615
616endchoice
617
618config VECTORS_ADDR
619	hex "Kernel vectors virtual address"
620	default 0x00000000
621	depends on XTENSA_VECTORS_SEPARATE
622	help
623	  This is the virtual address of the (relocatable) vectors base.
624	  It must be within KSEG if MMU is used.
625
626config XIP_DATA_ADDR
627	hex "XIP kernel data virtual address"
628	depends on XIP_KERNEL
629	default 0x00000000
630	help
631	  This is the virtual address where XIP kernel data is copied.
632	  It must be within KSEG if MMU is used.
633
634config PLATFORM_WANT_DEFAULT_MEM
635	def_bool n
636
637config DEFAULT_MEM_START
638	hex
639	prompt "PAGE_OFFSET/PHYS_OFFSET" if !MMU && PLATFORM_WANT_DEFAULT_MEM
640	default 0x60000000 if PLATFORM_WANT_DEFAULT_MEM
641	default 0x00000000
642	help
643	  This is the base address used for both PAGE_OFFSET and PHYS_OFFSET
644	  in noMMU configurations.
645
646	  If unsure, leave the default value here.
647
648choice
649	prompt "KSEG layout"
650	depends on MMU
651	default XTENSA_KSEG_MMU_V2
652
653config XTENSA_KSEG_MMU_V2
654	bool "MMUv2: 128MB cached + 128MB uncached"
655	help
656	  MMUv2 compatible kernel memory map: TLB way 5 maps 128MB starting
657	  at KSEG_PADDR to 0xd0000000 with cache and to 0xd8000000
658	  without cache.
659	  KSEG_PADDR must be aligned to 128MB.
660
661config XTENSA_KSEG_256M
662	bool "256MB cached + 256MB uncached"
663	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
664	help
665	  TLB way 6 maps 256MB starting at KSEG_PADDR to 0xb0000000
666	  with cache and to 0xc0000000 without cache.
667	  KSEG_PADDR must be aligned to 256MB.
668
669config XTENSA_KSEG_512M
670	bool "512MB cached + 512MB uncached"
671	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
672	help
673	  TLB way 6 maps 512MB starting at KSEG_PADDR to 0xa0000000
674	  with cache and to 0xc0000000 without cache.
675	  KSEG_PADDR must be aligned to 256MB.
676
677endchoice
678
679config HIGHMEM
680	bool "High Memory Support"
681	depends on MMU
682	help
683	  Linux can use the full amount of RAM in the system by
684	  default. However, the default MMUv2 setup only maps the
685	  lowermost 128 MB of memory linearly to the areas starting
686	  at 0xd0000000 (cached) and 0xd8000000 (uncached).
687	  When there are more than 128 MB memory in the system not
688	  all of it can be "permanently mapped" by the kernel.
689	  The physical memory that's not permanently mapped is called
690	  "high memory".
691
692	  If you are compiling a kernel which will never run on a
693	  machine with more than 128 MB total physical RAM, answer
694	  N here.
695
696	  If unsure, say Y.
697
698config FORCE_MAX_ZONEORDER
699	int "Maximum zone order"
700	default "11"
701	help
702	  The kernel memory allocator divides physically contiguous memory
703	  blocks into "zones", where each zone is a power of two number of
704	  pages.  This option selects the largest power of two that the kernel
705	  keeps in the memory allocator.  If you need to allocate very large
706	  blocks of physically contiguous memory, then you may need to
707	  increase this value.
708
709	  This config option is actually maximum order plus one. For example,
710	  a value of 11 means that the largest free memory block is 2^10 pages.
711
712endmenu
713
714menu "Power management options"
715
716source "kernel/power/Kconfig"
717
718endmenu
719