free electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
config ZONE_DMA
	def_bool y

config XTENSA
	def_bool y
	select ARCH_WANT_FRAME_POINTERS
	select ARCH_WANT_IPC_PARSE_VERSION
	select BUILDTIME_EXTABLE_SORT
	select CLONE_BACKWARDS
	select COMMON_CLK
	select GENERIC_ATOMIC64
	select GENERIC_CLOCKEVENTS
	select GENERIC_IRQ_SHOW
	select GENERIC_PCI_IOMAP
	select GENERIC_SCHED_CLOCK
	select HAVE_DEBUG_KMEMLEAK
	select HAVE_DMA_API_DEBUG
	select HAVE_DMA_CONTIGUOUS
	select HAVE_EXIT_THREAD
	select HAVE_FUNCTION_TRACER
	select HAVE_FUTEX_CMPXCHG if !MMU
	select HAVE_HW_BREAKPOINT if PERF_EVENTS
	select HAVE_IRQ_TIME_ACCOUNTING
	select HAVE_MEMBLOCK
	select HAVE_OPROFILE
	select HAVE_PERF_EVENTS
	select IRQ_DOMAIN
	select MODULES_USE_ELF_RELA
	select NO_BOOTMEM
	select PERF_USE_VMALLOC
	select VIRT_TO_BUS
	help
	  Xtensa processors are 32-bit RISC machines designed by Tensilica
	  primarily for embedded systems.  These processors are both
	  configurable and extensible.  The Linux port to the Xtensa
	  architecture supports all processor configurations and extensions,
	  with reasonable minimum requirements.  The Xtensa Linux project has
	  a home page at <http://www.linux-xtensa.org/>.

config RWSEM_XCHGADD_ALGORITHM
	def_bool y

config GENERIC_HWEIGHT
	def_bool y

config ARCH_HAS_ILOG2_U32
	def_bool n

config ARCH_HAS_ILOG2_U64
	def_bool n

config NO_IOPORT_MAP
	def_bool n

config HZ
	int
	default 100

source "init/Kconfig"
source "kernel/Kconfig.freezer"

config LOCKDEP_SUPPORT
	def_bool y

config STACKTRACE_SUPPORT
	def_bool y

config TRACE_IRQFLAGS_SUPPORT
	def_bool y

config MMU
	def_bool n

config VARIANT_IRQ_SWITCH
	def_bool n

config HAVE_XTENSA_GPIO32
	def_bool n

menu "Processor type and features"

choice
	prompt "Xtensa Processor Configuration"
	default XTENSA_VARIANT_FSF

config XTENSA_VARIANT_FSF
	bool "fsf - default (not generic) configuration"
	select MMU

config XTENSA_VARIANT_DC232B
	bool "dc232b - Diamond 232L Standard Core Rev.B (LE)"
	select MMU
	select HAVE_XTENSA_GPIO32
	help
	  This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE).

config XTENSA_VARIANT_DC233C
	bool "dc233c - Diamond 233L Standard Core Rev.C (LE)"
	select MMU
	select HAVE_XTENSA_GPIO32
	help
	  This variant refers to Tensilica's Diamond 233L Standard core Rev.C (LE).

config XTENSA_VARIANT_CUSTOM
	bool "Custom Xtensa processor configuration"
	select HAVE_XTENSA_GPIO32
	help
	  Select this variant to use a custom Xtensa processor configuration.
	  You will be prompted for a processor variant CORENAME.
endchoice

config XTENSA_VARIANT_CUSTOM_NAME
	string "Xtensa Processor Custom Core Variant Name"
	depends on XTENSA_VARIANT_CUSTOM
	help
	  Provide the name of a custom Xtensa processor variant.
	  This CORENAME selects arch/xtensa/variant/CORENAME.
	  Dont forget you have to select MMU if you have one.

config XTENSA_VARIANT_NAME
	string
	default "dc232b"			if XTENSA_VARIANT_DC232B
	default "dc233c"			if XTENSA_VARIANT_DC233C
	default "fsf"				if XTENSA_VARIANT_FSF
	default XTENSA_VARIANT_CUSTOM_NAME	if XTENSA_VARIANT_CUSTOM

config XTENSA_VARIANT_MMU
	bool "Core variant has a Full MMU (TLB, Pages, Protection, etc)"
	depends on XTENSA_VARIANT_CUSTOM
	default y
	select MMU
	help
	  Build a Conventional Kernel with full MMU support,
	  ie: it supports a TLB with auto-loading, page protection.

config XTENSA_VARIANT_HAVE_PERF_EVENTS
	bool "Core variant has Performance Monitor Module"
	depends on XTENSA_VARIANT_CUSTOM
	default n
	help
	  Enable if core variant has Performance Monitor Module with
	  External Registers Interface.

	  If unsure, say N.

config XTENSA_FAKE_NMI
	bool "Treat PMM IRQ as NMI"
	depends on XTENSA_VARIANT_HAVE_PERF_EVENTS
	default n
	help
	  If PMM IRQ is the only IRQ at EXCM level it is safe to
	  treat it as NMI, which improves accuracy of profiling.

	  If there are other interrupts at or above PMM IRQ priority level
	  but not above the EXCM level, PMM IRQ still may be treated as NMI,
	  but only if these IRQs are not used. There will be a build warning
	  saying that this is not safe, and a bugcheck if one of these IRQs
	  actually fire.

	  If unsure, say N.

config XTENSA_UNALIGNED_USER
	bool "Unaligned memory access in use space"
	help
	  The Xtensa architecture currently does not handle unaligned
	  memory accesses in hardware but through an exception handler.
	  Per default, unaligned memory accesses are disabled in user space.

	  Say Y here to enable unaligned memory access in user space.

source "kernel/Kconfig.preempt"

config HAVE_SMP
	bool "System Supports SMP (MX)"
	depends on XTENSA_VARIANT_CUSTOM
	select XTENSA_MX
	help
	  This option is use to indicate that the system-on-a-chip (SOC)
	  supports Multiprocessing. Multiprocessor support implemented above
	  the CPU core definition and currently needs to be selected manually.

	  Multiprocessor support in implemented with external cache and
	  interrupt controllers.

	  The MX interrupt distributer adds Interprocessor Interrupts
	  and causes the IRQ numbers to be increased by 4 for devices
	  like the open cores ethernet driver and the serial interface.

	  You still have to select "Enable SMP" to enable SMP on this SOC.

config SMP
	bool "Enable Symmetric multi-processing support"
	depends on HAVE_SMP
	select GENERIC_SMP_IDLE_THREAD
	help
	  Enabled SMP Software; allows more than one CPU/CORE
	  to be activated during startup.

config NR_CPUS
	depends on SMP
	int "Maximum number of CPUs (2-32)"
	range 2 32
	default "4"

config HOTPLUG_CPU
	bool "Enable CPU hotplug support"
	depends on SMP
	help
	  Say Y here to allow turning CPUs off and on. CPUs can be
	  controlled through /sys/devices/system/cpu.

	  Say N if you want to disable CPU hotplug.

config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
	bool "Initialize Xtensa MMU inside the Linux kernel code"
	depends on !XTENSA_VARIANT_FSF && !XTENSA_VARIANT_DC232B
	default y if XTENSA_VARIANT_DC233C || XTENSA_VARIANT_CUSTOM
	help
	  Earlier version initialized the MMU in the exception vector
	  before jumping to _startup in head.S and had an advantage that
	  it was possible to place a software breakpoint at 'reset' and
	  then enter your normal kernel breakpoints once the MMU was mapped
	  to the kernel mappings (0XC0000000).

	  This unfortunately doesn't work for U-Boot and likley also wont
	  work for using KEXEC to have a hot kernel ready for doing a
	  KDUMP.

	  So now the MMU is initialized in head.S but it's necessary to
	  use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup.
	  xt-gdb can't place a Software Breakpoint in the  0XD region prior
	  to mapping the MMU and after mapping even if the area of low memory
	  was mapped gdb wouldn't remove the breakpoint on hitting it as the
	  PC wouldn't match. Since Hardware Breakpoints are recommended for
	  Linux configurations it seems reasonable to just assume they exist
	  and leave this older mechanism for unfortunate souls that choose
	  not to follow Tensilica's recommendation.

	  Selecting this will cause U-Boot to set the KERNEL Load and Entry
	  address at 0x00003000 instead of the mapped std of 0xD0003000.

	  If in doubt, say Y.

config KSEG_PADDR
	hex "Physical address of the KSEG mapping"
	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX && MMU
	default 0x00000000
	help
	  This is the physical address where KSEG is mapped. Please refer to
	  the chosen KSEG layout help for the required address alignment.
	  Unpacked kernel image (including vectors) must be located completely
	  within KSEG.
	  Physical memory below this address is not available to linux.

	  If unsure, leave the default value here.

config KERNEL_LOAD_ADDRESS
	hex "Kernel load address"
	default 0x60003000 if !MMU
	default 0x00003000 if MMU && INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
	default 0xd0003000 if MMU && !INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
	help
	  This is the address where the kernel is loaded.
	  It is virtual address for MMUv2 configurations and physical address
	  for all other configurations.

	  If unsure, leave the default value here.

config VECTORS_OFFSET
	hex "Kernel vectors offset"
	default 0x00003000
	help
	  This is the offset of the kernel image from the relocatable vectors
	  base.

	  If unsure, leave the default value here.

choice
	prompt "KSEG layout"
	depends on MMU
	default XTENSA_KSEG_MMU_V2

config XTENSA_KSEG_MMU_V2
	bool "MMUv2: 128MB cached + 128MB uncached"
	help
	  MMUv2 compatible kernel memory map: TLB way 5 maps 128MB starting
	  at KSEG_PADDR to 0xd0000000 with cache and to 0xd8000000
	  without cache.
	  KSEG_PADDR must be aligned to 128MB.

config XTENSA_KSEG_256M
	bool "256MB cached + 256MB uncached"
	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
	help
	  TLB way 6 maps 256MB starting at KSEG_PADDR to 0xb0000000
	  with cache and to 0xc0000000 without cache.
	  KSEG_PADDR must be aligned to 256MB.

config XTENSA_KSEG_512M
	bool "512MB cached + 512MB uncached"
	depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
	help
	  TLB way 6 maps 512MB starting at KSEG_PADDR to 0xa0000000
	  with cache and to 0xc0000000 without cache.
	  KSEG_PADDR must be aligned to 256MB.

endchoice

config HIGHMEM
	bool "High Memory Support"
	depends on MMU
	help
	  Linux can use the full amount of RAM in the system by
	  default. However, the default MMUv2 setup only maps the
	  lowermost 128 MB of memory linearly to the areas starting
	  at 0xd0000000 (cached) and 0xd8000000 (uncached).
	  When there are more than 128 MB memory in the system not
	  all of it can be "permanently mapped" by the kernel.
	  The physical memory that's not permanently mapped is called
	  "high memory".

	  If you are compiling a kernel which will never run on a
	  machine with more than 128 MB total physical RAM, answer
	  N here.

	  If unsure, say Y.

config FAST_SYSCALL_XTENSA
	bool "Enable fast atomic syscalls"
	default n
	help
	  fast_syscall_xtensa is a syscall that can make atomic operations
	  on UP kernel when processor has no s32c1i support.

	  This syscall is deprecated. It may have issues when called with
	  invalid arguments. It is provided only for backwards compatibility.
	  Only enable it if your userspace software requires it.

	  If unsure, say N.

config FAST_SYSCALL_SPILL_REGISTERS
	bool "Enable spill registers syscall"
	default n
	help
	  fast_syscall_spill_registers is a syscall that spills all active
	  register windows of a calling userspace task onto its stack.

	  This syscall is deprecated. It may have issues when called with
	  invalid arguments. It is provided only for backwards compatibility.
	  Only enable it if your userspace software requires it.

	  If unsure, say N.

endmenu

config XTENSA_CALIBRATE_CCOUNT
	def_bool n
	help
	  On some platforms (XT2000, for example), the CPU clock rate can
	  vary.  The frequency can be determined, however, by measuring
	  against a well known, fixed frequency, such as an UART oscillator.

config SERIAL_CONSOLE
	def_bool n

menu "Bus options"

config PCI
	bool "PCI support"
	default y
	help
	  Find out whether you have a PCI motherboard. PCI is the name of a
	  bus system, i.e. the way the CPU talks to the other stuff inside
	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
	  VESA. If you have PCI, say Y, otherwise N.

source "drivers/pci/Kconfig"

endmenu

menu "Platform options"

choice
	prompt "Xtensa System Type"
	default XTENSA_PLATFORM_ISS

config XTENSA_PLATFORM_ISS
	bool "ISS"
	select XTENSA_CALIBRATE_CCOUNT
	select SERIAL_CONSOLE
	help
	  ISS is an acronym for Tensilica's Instruction Set Simulator.

config XTENSA_PLATFORM_XT2000
	bool "XT2000"
	select HAVE_IDE
	help
	  XT2000 is the name of Tensilica's feature-rich emulation platform.
	  This hardware is capable of running a full Linux distribution.

config XTENSA_PLATFORM_XTFPGA
	bool "XTFPGA"
	select ETHOC if ETHERNET
	select PLATFORM_WANT_DEFAULT_MEM if !MMU
	select SERIAL_CONSOLE
	select XTENSA_CALIBRATE_CCOUNT
	help
	  XTFPGA is the name of Tensilica board family (LX60, LX110, LX200, ML605).
	  This hardware is capable of running a full Linux distribution.

endchoice


config XTENSA_CPU_CLOCK
	int "CPU clock rate [MHz]"
	depends on !XTENSA_CALIBRATE_CCOUNT
	default 16

config GENERIC_CALIBRATE_DELAY
	bool "Auto calibration of the BogoMIPS value"
	help
	  The BogoMIPS value can easily be derived from the CPU frequency.

config CMDLINE_BOOL
	bool "Default bootloader kernel arguments"

config CMDLINE
	string "Initial kernel command string"
	depends on CMDLINE_BOOL
	default "console=ttyS0,38400 root=/dev/ram"
	help
	  On some architectures (EBSA110 and CATS), there is currently no way
	  for the boot loader to pass arguments to the kernel. For these
	  architectures, you should supply some command-line options at build
	  time by entering them here. As a minimum, you should specify the
	  memory size and the root device (e.g., mem=64M root=/dev/nfs).

config USE_OF
	bool "Flattened Device Tree support"
	select OF
	select OF_EARLY_FLATTREE
	select OF_RESERVED_MEM
	help
	  Include support for flattened device tree machine descriptions.

config BUILTIN_DTB
	string "DTB to build into the kernel image"
	depends on OF

config BLK_DEV_SIMDISK
	tristate "Host file-based simulated block device support"
	default n
	depends on XTENSA_PLATFORM_ISS && BLOCK
	help
	  Create block devices that map to files in the host file system.
	  Device binding to host file may be changed at runtime via proc
	  interface provided the device is not in use.

config BLK_DEV_SIMDISK_COUNT
	int "Number of host file-based simulated block devices"
	range 1 10
	depends on BLK_DEV_SIMDISK
	default 2
	help
	  This is the default minimal number of created block devices.
	  Kernel/module parameter 'simdisk_count' may be used to change this
	  value at runtime. More file names (but no more than 10) may be
	  specified as parameters, simdisk_count grows accordingly.

config SIMDISK0_FILENAME
	string "Host filename for the first simulated device"
	depends on BLK_DEV_SIMDISK = y
	default ""
	help
	  Attach a first simdisk to a host file. Conventionally, this file
	  contains a root file system.

config SIMDISK1_FILENAME
	string "Host filename for the second simulated device"
	depends on BLK_DEV_SIMDISK = y && BLK_DEV_SIMDISK_COUNT != 1
	default ""
	help
	  Another simulated disk in a host file for a buildroot-independent
	  storage.

source "mm/Kconfig"

config FORCE_MAX_ZONEORDER
	int "Maximum zone order"
	default "11"
	help
	  The kernel memory allocator divides physically contiguous memory
	  blocks into "zones", where each zone is a power of two number of
	  pages.  This option selects the largest power of two that the kernel
	  keeps in the memory allocator.  If you need to allocate very large
	  blocks of physically contiguous memory, then you may need to
	  increase this value.

	  This config option is actually maximum order plus one. For example,
	  a value of 11 means that the largest free memory block is 2^10 pages.

source "drivers/pcmcia/Kconfig"

config PLATFORM_WANT_DEFAULT_MEM
	def_bool n

config DEFAULT_MEM_START
	hex "Physical address of the default memory area start"
	depends on PLATFORM_WANT_DEFAULT_MEM
	default 0x00000000 if MMU
	default 0x60000000 if !MMU
	help
	  This is the base address of the default memory area.
	  Default memory area has platform-specific meaning, it may be used
	  for e.g. early cache initialization.

	  If unsure, leave the default value here.

config DEFAULT_MEM_SIZE
	hex "Maximal size of the default memory area"
	depends on PLATFORM_WANT_DEFAULT_MEM
	default 0x04000000
	help
	  This is the size of the default memory area.
	  Default memory area has platform-specific meaning, it may be used
	  for e.g. early cache initialization.

	  If unsure, leave the default value here.

config XTFPGA_LCD
	bool "Enable XTFPGA LCD driver"
	depends on XTENSA_PLATFORM_XTFPGA
	default n
	help
	  There's a 2x16 LCD on most of XTFPGA boards, kernel may output
	  progress messages there during bootup/shutdown. It may be useful
	  during board bringup.

	  If unsure, say N.

config XTFPGA_LCD_BASE_ADDR
	hex "XTFPGA LCD base address"
	depends on XTFPGA_LCD
	default "0x0d0c0000"
	help
	  Base address of the LCD controller inside KIO region.
	  Different boards from XTFPGA family have LCD controller at different
	  addresses. Please consult prototyping user guide for your board for
	  the correct address. Wrong address here may lead to hardware lockup.

config XTFPGA_LCD_8BIT_ACCESS
	bool "Use 8-bit access to XTFPGA LCD"
	depends on XTFPGA_LCD
	default n
	help
	  LCD may be connected with 4- or 8-bit interface, 8-bit access may
	  only be used with 8-bit interface. Please consult prototyping user
	  guide for your board for the correct interface width.

endmenu

menu "Executable file formats"

source "fs/Kconfig.binfmt"

endmenu

menu "Power management options"

source "kernel/power/Kconfig"

endmenu

source "net/Kconfig"

source "drivers/Kconfig"

source "fs/Kconfig"

source "arch/xtensa/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

source "lib/Kconfig"