xref: /openbmc/u-boot/arch/x86/Kconfig (revision a818704b)
1menu "x86 architecture"
2	depends on X86
3
4config SYS_ARCH
5	default "x86"
6
7choice
8	prompt "Run U-Boot in 32/64-bit mode"
9	default X86_RUN_32BIT
10	help
11	  U-Boot can be built as a 32-bit binary which runs in 32-bit mode
12	  even on 64-bit machines. In this case SPL is not used, and U-Boot
13	  runs directly from the reset vector (via 16-bit start-up).
14
15	  Alternatively it can be run as a 64-bit binary, thus requiring a
16	  64-bit machine. In this case SPL runs in 32-bit mode (via 16-bit
17	  start-up) then jumps to U-Boot in 64-bit mode.
18
19	  For now, 32-bit mode is recommended, as 64-bit is still
20	  experimental and is missing a lot of features.
21
22config X86_RUN_32BIT
23	bool "32-bit"
24	help
25	  Build U-Boot as a 32-bit binary with no SPL. This is the currently
26	  supported normal setup. U-Boot will stay in 32-bit mode even on
27	  64-bit machines. When booting a 64-bit kernel, U-Boot will switch
28	  to 64-bit just before starting the kernel. Only the bottom 4GB of
29	  memory can be accessed through normal means, although
30	  arch_phys_memset() can be used for basic access to other memory.
31
32config X86_RUN_64BIT
33	bool "64-bit"
34	select X86_64
35	select SUPPORT_SPL
36	select SPL
37	select SPL_SEPARATE_BSS
38	help
39	  Build U-Boot as a 64-bit binary with a 32-bit SPL. This is
40	  experimental and many features are missing. U-Boot SPL starts up,
41	  runs through the 16-bit and 32-bit init, then switches to 64-bit
42	  mode and jumps to U-Boot proper.
43
44endchoice
45
46config X86_64
47	bool
48
49config SPL_X86_64
50	bool
51	depends on SPL
52
53choice
54	prompt "Mainboard vendor"
55	default VENDOR_EMULATION
56
57config VENDOR_ADVANTECH
58	bool "advantech"
59
60config VENDOR_CONGATEC
61	bool "congatec"
62
63config VENDOR_COREBOOT
64	bool "coreboot"
65
66config VENDOR_DFI
67	bool "dfi"
68
69config VENDOR_EFI
70	bool "efi"
71
72config VENDOR_EMULATION
73	bool "emulation"
74
75config VENDOR_GOOGLE
76	bool "Google"
77
78config VENDOR_INTEL
79	bool "Intel"
80
81endchoice
82
83# subarchitectures-specific options below
84config INTEL_MID
85	bool "Intel MID platform support"
86	select REGMAP
87	select SYSCON
88	help
89	  Select to build a U-Boot capable of supporting Intel MID
90	  (Mobile Internet Device) platform systems which do not have
91	  the PCI legacy interfaces.
92
93	  If you are building for a PC class system say N here.
94
95	  Intel MID platforms are based on an Intel processor and
96	  chipset which consume less power than most of the x86
97	  derivatives.
98
99# board-specific options below
100source "board/advantech/Kconfig"
101source "board/congatec/Kconfig"
102source "board/coreboot/Kconfig"
103source "board/dfi/Kconfig"
104source "board/efi/Kconfig"
105source "board/emulation/Kconfig"
106source "board/google/Kconfig"
107source "board/intel/Kconfig"
108
109# platform-specific options below
110source "arch/x86/cpu/baytrail/Kconfig"
111source "arch/x86/cpu/broadwell/Kconfig"
112source "arch/x86/cpu/coreboot/Kconfig"
113source "arch/x86/cpu/ivybridge/Kconfig"
114source "arch/x86/cpu/qemu/Kconfig"
115source "arch/x86/cpu/quark/Kconfig"
116source "arch/x86/cpu/queensbay/Kconfig"
117source "arch/x86/cpu/tangier/Kconfig"
118
119# architecture-specific options below
120
121config AHCI
122	default y
123
124config SYS_MALLOC_F_LEN
125	default 0x800
126
127config RAMBASE
128	hex
129	default 0x100000
130
131config XIP_ROM_SIZE
132	hex
133	depends on X86_RESET_VECTOR
134	default ROM_SIZE
135
136config CPU_ADDR_BITS
137	int
138	default 36
139
140config HPET_ADDRESS
141	hex
142	default 0xfed00000 if !HPET_ADDRESS_OVERRIDE
143
144config SMM_TSEG
145	bool
146	default n
147
148config SMM_TSEG_SIZE
149	hex
150
151config X86_RESET_VECTOR
152	bool
153	default n
154
155# The following options control where the 16-bit and 32-bit init lies
156# If SPL is enabled then it normally holds this init code, and U-Boot proper
157# is normally a 64-bit build.
158#
159# The 16-bit init refers to the reset vector and the small amount of code to
160# get the processor into 32-bit mode. It may be in SPL or in U-Boot proper,
161# or missing altogether if U-Boot is started from EFI or coreboot.
162#
163# The 32-bit init refers to processor init, running binary blobs including
164# FSP, setting up interrupts and anything else that needs to be done in
165# 32-bit code. It is normally in the same place as 16-bit init if that is
166# enabled (i.e. they are both in SPL, or both in U-Boot proper).
167config X86_16BIT_INIT
168	bool
169	depends on X86_RESET_VECTOR
170	default y if X86_RESET_VECTOR && !SPL
171	help
172	  This is enabled when 16-bit init is in U-Boot proper
173
174config SPL_X86_16BIT_INIT
175	bool
176	depends on X86_RESET_VECTOR
177	default y if X86_RESET_VECTOR && SPL
178	help
179	  This is enabled when 16-bit init is in SPL
180
181config X86_32BIT_INIT
182	bool
183	depends on X86_RESET_VECTOR
184	default y if X86_RESET_VECTOR && !SPL
185	help
186	  This is enabled when 32-bit init is in U-Boot proper
187
188config SPL_X86_32BIT_INIT
189	bool
190	depends on X86_RESET_VECTOR
191	default y if X86_RESET_VECTOR && SPL
192	help
193	  This is enabled when 32-bit init is in SPL
194
195config RESET_SEG_START
196	hex
197	depends on X86_RESET_VECTOR
198	default 0xffff0000
199
200config RESET_SEG_SIZE
201	hex
202	depends on X86_RESET_VECTOR
203	default 0x10000
204
205config RESET_VEC_LOC
206	hex
207	depends on X86_RESET_VECTOR
208	default 0xfffffff0
209
210config SYS_X86_START16
211	hex
212	depends on X86_RESET_VECTOR
213	default 0xfffff800
214
215config X86_LOAD_FROM_32_BIT
216	bool "Boot from a 32-bit program"
217	help
218	  Define this to boot U-Boot from a 32-bit program which sets
219	  the GDT differently. This can be used to boot directly from
220	  any stage of coreboot, for example, bypassing the normal
221	  payload-loading feature.
222
223config BOARD_ROMSIZE_KB_512
224	bool
225config BOARD_ROMSIZE_KB_1024
226	bool
227config BOARD_ROMSIZE_KB_2048
228	bool
229config BOARD_ROMSIZE_KB_4096
230	bool
231config BOARD_ROMSIZE_KB_8192
232	bool
233config BOARD_ROMSIZE_KB_16384
234	bool
235
236choice
237	prompt "ROM chip size"
238	depends on X86_RESET_VECTOR
239	default UBOOT_ROMSIZE_KB_512 if BOARD_ROMSIZE_KB_512
240	default UBOOT_ROMSIZE_KB_1024 if BOARD_ROMSIZE_KB_1024
241	default UBOOT_ROMSIZE_KB_2048 if BOARD_ROMSIZE_KB_2048
242	default UBOOT_ROMSIZE_KB_4096 if BOARD_ROMSIZE_KB_4096
243	default UBOOT_ROMSIZE_KB_8192 if BOARD_ROMSIZE_KB_8192
244	default UBOOT_ROMSIZE_KB_16384 if BOARD_ROMSIZE_KB_16384
245	help
246	  Select the size of the ROM chip you intend to flash U-Boot on.
247
248	  The build system will take care of creating a u-boot.rom file
249	  of the matching size.
250
251config UBOOT_ROMSIZE_KB_512
252	bool "512 KB"
253	help
254	  Choose this option if you have a 512 KB ROM chip.
255
256config UBOOT_ROMSIZE_KB_1024
257	bool "1024 KB (1 MB)"
258	help
259	  Choose this option if you have a 1024 KB (1 MB) ROM chip.
260
261config UBOOT_ROMSIZE_KB_2048
262	bool "2048 KB (2 MB)"
263	help
264	  Choose this option if you have a 2048 KB (2 MB) ROM chip.
265
266config UBOOT_ROMSIZE_KB_4096
267	bool "4096 KB (4 MB)"
268	help
269	  Choose this option if you have a 4096 KB (4 MB) ROM chip.
270
271config UBOOT_ROMSIZE_KB_8192
272	bool "8192 KB (8 MB)"
273	help
274	  Choose this option if you have a 8192 KB (8 MB) ROM chip.
275
276config UBOOT_ROMSIZE_KB_16384
277	bool "16384 KB (16 MB)"
278	help
279	  Choose this option if you have a 16384 KB (16 MB) ROM chip.
280
281endchoice
282
283# Map the config names to an integer (KB).
284config UBOOT_ROMSIZE_KB
285	int
286	default 512 if UBOOT_ROMSIZE_KB_512
287	default 1024 if UBOOT_ROMSIZE_KB_1024
288	default 2048 if UBOOT_ROMSIZE_KB_2048
289	default 4096 if UBOOT_ROMSIZE_KB_4096
290	default 8192 if UBOOT_ROMSIZE_KB_8192
291	default 16384 if UBOOT_ROMSIZE_KB_16384
292
293# Map the config names to a hex value (bytes).
294config ROM_SIZE
295	hex
296	default 0x80000 if UBOOT_ROMSIZE_KB_512
297	default 0x100000 if UBOOT_ROMSIZE_KB_1024
298	default 0x200000 if UBOOT_ROMSIZE_KB_2048
299	default 0x400000 if UBOOT_ROMSIZE_KB_4096
300	default 0x800000 if UBOOT_ROMSIZE_KB_8192
301	default 0xc00000 if UBOOT_ROMSIZE_KB_12288
302	default 0x1000000 if UBOOT_ROMSIZE_KB_16384
303
304config HAVE_INTEL_ME
305	bool "Platform requires Intel Management Engine"
306	help
307	  Newer higher-end devices have an Intel Management Engine (ME)
308	  which is a very large binary blob (typically 1.5MB) which is
309	  required for the platform to work. This enforces a particular
310	  SPI flash format. You will need to supply the me.bin file in
311	  your board directory.
312
313config X86_RAMTEST
314	bool "Perform a simple RAM test after SDRAM initialisation"
315	help
316	  If there is something wrong with SDRAM then the platform will
317	  often crash within U-Boot or the kernel. This option enables a
318	  very simple RAM test that quickly checks whether the SDRAM seems
319	  to work correctly. It is not exhaustive but can save time by
320	  detecting obvious failures.
321
322config FLASH_DESCRIPTOR_FILE
323	string "Flash descriptor binary filename"
324	depends on HAVE_INTEL_ME
325	default "descriptor.bin"
326	help
327	  The filename of the file to use as flash descriptor in the
328	  board directory.
329
330config INTEL_ME_FILE
331	string "Intel Management Engine binary filename"
332	depends on HAVE_INTEL_ME
333	default "me.bin"
334	help
335	  The filename of the file to use as Intel Management Engine in the
336	  board directory.
337
338config HAVE_FSP
339	bool "Add an Firmware Support Package binary"
340	depends on !EFI
341	help
342	  Select this option to add an Firmware Support Package binary to
343	  the resulting U-Boot image. It is a binary blob which U-Boot uses
344	  to set up SDRAM and other chipset specific initialization.
345
346	  Note: Without this binary U-Boot will not be able to set up its
347	  SDRAM so will not boot.
348
349config FSP_FILE
350	string "Firmware Support Package binary filename"
351	depends on HAVE_FSP
352	default "fsp.bin"
353	help
354	  The filename of the file to use as Firmware Support Package binary
355	  in the board directory.
356
357config FSP_ADDR
358	hex "Firmware Support Package binary location"
359	depends on HAVE_FSP
360	default 0xfffc0000
361	help
362	  FSP is not Position Independent Code (PIC) and the whole FSP has to
363	  be rebased if it is placed at a location which is different from the
364	  perferred base address specified during the FSP build. Use Intel's
365	  Binary Configuration Tool (BCT) to do the rebase.
366
367	  The default base address of 0xfffc0000 indicates that the binary must
368	  be located at offset 0xc0000 from the beginning of a 1MB flash device.
369
370config FSP_TEMP_RAM_ADDR
371	hex
372	depends on HAVE_FSP
373	default 0x2000000
374	help
375	  Stack top address which is used in fsp_init() after DRAM is ready and
376	  CAR is disabled.
377
378config FSP_SYS_MALLOC_F_LEN
379	hex
380	depends on HAVE_FSP
381	default 0x100000
382	help
383	  Additional size of malloc() pool before relocation.
384
385config FSP_USE_UPD
386	bool
387	depends on HAVE_FSP
388	default y
389	help
390	  Most FSPs use UPD data region for some FSP customization. But there
391	  are still some FSPs that might not even have UPD. For such FSPs,
392	  override this to n in their platform Kconfig files.
393
394config FSP_BROKEN_HOB
395	bool
396	depends on HAVE_FSP
397	help
398	  Indicate some buggy FSPs that does not report memory used by FSP
399	  itself as reserved in the resource descriptor HOB. Select this to
400	  tell U-Boot to do some additional work to ensure U-Boot relocation
401	  do not overwrite the important boot service data which is used by
402	  FSP, otherwise the subsequent call to fsp_notify() will fail.
403
404config ENABLE_MRC_CACHE
405	bool "Enable MRC cache"
406	depends on !EFI && !SYS_COREBOOT
407	help
408	  Enable this feature to cause MRC data to be cached in NV storage
409	  to be used for speeding up boot time on future reboots and/or
410	  power cycles.
411
412	  For platforms that use Intel FSP for the memory initialization,
413	  please check FSP output HOB via U-Boot command 'fsp hob' to see
414	  if there is FSP_NON_VOLATILE_STORAGE_HOB_GUID (asm/fsp/fsp_hob.h).
415	  If such GUID does not exist, MRC cache is not avaiable on such
416	  platform (eg: Intel Queensbay), which means selecting this option
417	  here does not make any difference.
418
419config HAVE_MRC
420	bool "Add a System Agent binary"
421	depends on !HAVE_FSP
422	help
423	  Select this option to add a System Agent binary to
424	  the resulting U-Boot image. MRC stands for Memory Reference Code.
425	  It is a binary blob which U-Boot uses to set up SDRAM.
426
427	  Note: Without this binary U-Boot will not be able to set up its
428	  SDRAM so will not boot.
429
430config CACHE_MRC_BIN
431	bool
432	depends on HAVE_MRC
433	default n
434	help
435	  Enable caching for the memory reference code binary. This uses an
436	  MTRR (memory type range register) to turn on caching for the section
437	  of SPI flash that contains the memory reference code. This makes
438	  SDRAM init run faster.
439
440config CACHE_MRC_SIZE_KB
441	int
442	depends on HAVE_MRC
443	default 512
444	help
445	  Sets the size of the cached area for the memory reference code.
446	  This ends at the end of SPI flash (address 0xffffffff) and is
447	  measured in KB. Typically this is set to 512, providing for 0.5MB
448	  of cached space.
449
450config DCACHE_RAM_BASE
451	hex
452	depends on HAVE_MRC
453	help
454	  Sets the base of the data cache area in memory space. This is the
455	  start address of the cache-as-RAM (CAR) area and the address varies
456	  depending on the CPU. Once CAR is set up, read/write memory becomes
457	  available at this address and can be used temporarily until SDRAM
458	  is working.
459
460config DCACHE_RAM_SIZE
461	hex
462	depends on HAVE_MRC
463	default 0x40000
464	help
465	  Sets the total size of the data cache area in memory space. This
466	  sets the size of the cache-as-RAM (CAR) area. Note that much of the
467	  CAR space is required by the MRC. The CAR space available to U-Boot
468	  is normally at the start and typically extends to 1/4 or 1/2 of the
469	  available size.
470
471config DCACHE_RAM_MRC_VAR_SIZE
472	hex
473	depends on HAVE_MRC
474	help
475	  This is the amount of CAR (Cache as RAM) reserved for use by the
476	  memory reference code. This depends on the implementation of the
477	  memory reference code and must be set correctly or the board will
478	  not boot.
479
480config HAVE_REFCODE
481        bool "Add a Reference Code binary"
482        help
483          Select this option to add a Reference Code binary to the resulting
484          U-Boot image. This is an Intel binary blob that handles system
485          initialisation, in this case the PCH and System Agent.
486
487          Note: Without this binary (on platforms that need it such as
488          broadwell) U-Boot will be missing some critical setup steps.
489          Various peripherals may fail to work.
490
491config SMP
492	bool "Enable Symmetric Multiprocessing"
493	default n
494	help
495	  Enable use of more than one CPU in U-Boot and the Operating System
496	  when loaded. Each CPU will be started up and information can be
497	  obtained using the 'cpu' command. If this option is disabled, then
498	  only one CPU will be enabled regardless of the number of CPUs
499	  available.
500
501config MAX_CPUS
502	int "Maximum number of CPUs permitted"
503	depends on SMP
504	default 4
505	help
506	  When using multi-CPU chips it is possible for U-Boot to start up
507	  more than one CPU. The stack memory used by all of these CPUs is
508	  pre-allocated so at present U-Boot wants to know the maximum
509	  number of CPUs that may be present. Set this to at least as high
510	  as the number of CPUs in your system (it uses about 4KB of RAM for
511	  each CPU).
512
513config AP_STACK_SIZE
514	hex
515	depends on SMP
516	default 0x1000
517	help
518	  Each additional CPU started by U-Boot requires its own stack. This
519	  option sets the stack size used by each CPU and directly affects
520	  the memory used by this initialisation process. Typically 4KB is
521	  enough space.
522
523config HAVE_VGA_BIOS
524	bool "Add a VGA BIOS image"
525	help
526	  Select this option if you have a VGA BIOS image that you would
527	  like to add to your ROM.
528
529config VGA_BIOS_FILE
530	string "VGA BIOS image filename"
531	depends on HAVE_VGA_BIOS
532	default "vga.bin"
533	help
534	  The filename of the VGA BIOS image in the board directory.
535
536config VGA_BIOS_ADDR
537	hex "VGA BIOS image location"
538	depends on HAVE_VGA_BIOS
539	default 0xfff90000
540	help
541	  The location of VGA BIOS image in the SPI flash. For example, base
542	  address of 0xfff90000 indicates that the image will be put at offset
543	  0x90000 from the beginning of a 1MB flash device.
544
545config ROM_TABLE_ADDR
546	hex
547	default 0xf0000
548	help
549	  All x86 tables happen to like the address range from 0x0f0000
550	  to 0x100000. We use 0xf0000 as the starting address to store
551	  those tables, including PIRQ routing table, Multi-Processor
552	  table and ACPI table.
553
554config ROM_TABLE_SIZE
555	hex
556	default 0x10000
557
558menu "System tables"
559	depends on !EFI && !SYS_COREBOOT
560
561config GENERATE_PIRQ_TABLE
562	bool "Generate a PIRQ table"
563	default n
564	help
565	  Generate a PIRQ routing table for this board. The PIRQ routing table
566	  is generated by U-Boot in the system memory from 0xf0000 to 0xfffff
567	  at every 16-byte boundary with a PCI IRQ routing signature ("$PIR").
568	  It specifies the interrupt router information as well how all the PCI
569	  devices' interrupt pins are wired to PIRQs.
570
571config GENERATE_SFI_TABLE
572	bool "Generate a SFI (Simple Firmware Interface) table"
573	help
574	  The Simple Firmware Interface (SFI) provides a lightweight method
575	  for platform firmware to pass information to the operating system
576	  via static tables in memory.  Kernel SFI support is required to
577	  boot on SFI-only platforms.  If you have ACPI tables then these are
578	  used instead.
579
580	  U-Boot writes this table in write_sfi_table() just before booting
581	  the OS.
582
583	  For more information, see http://simplefirmware.org
584
585config GENERATE_MP_TABLE
586	bool "Generate an MP (Multi-Processor) table"
587	default n
588	help
589	  Generate an MP (Multi-Processor) table for this board. The MP table
590	  provides a way for the operating system to support for symmetric
591	  multiprocessing as well as symmetric I/O interrupt handling with
592	  the local APIC and I/O APIC.
593
594config GENERATE_ACPI_TABLE
595	bool "Generate an ACPI (Advanced Configuration and Power Interface) table"
596	default n
597	select QFW if QEMU
598	help
599	  The Advanced Configuration and Power Interface (ACPI) specification
600	  provides an open standard for device configuration and management
601	  by the operating system. It defines platform-independent interfaces
602	  for configuration and power management monitoring.
603
604endmenu
605
606config HAVE_ACPI_RESUME
607	bool "Enable ACPI S3 resume"
608	help
609	  Select this to enable ACPI S3 resume. S3 is an ACPI-defined sleeping
610	  state where all system context is lost except system memory. U-Boot
611	  is responsible for restoring the machine state as it was before sleep.
612	  It needs restore the memory controller, without overwriting memory
613	  which is not marked as reserved. For the peripherals which lose their
614	  registers, U-Boot needs to write the original value. When everything
615	  is done, U-Boot needs to find out the wakeup vector provided by OSes
616	  and jump there.
617
618config S3_VGA_ROM_RUN
619	bool "Re-run VGA option ROMs on S3 resume"
620	depends on HAVE_ACPI_RESUME
621	default y if HAVE_ACPI_RESUME
622	help
623	  Execute VGA option ROMs in U-Boot when resuming from S3. Normally
624	  this is needed when graphics console is being used in the kernel.
625
626	  Turning it off can reduce some resume time, but be aware that your
627	  graphics console won't work without VGA options ROMs. Set it to N
628	  if your kernel is only on a serial console.
629
630config STACK_SIZE
631	hex
632	depends on HAVE_ACPI_RESUME
633	default 0x1000
634	help
635	  Estimated U-Boot's runtime stack size that needs to be reserved
636	  during an ACPI S3 resume.
637
638config MAX_PIRQ_LINKS
639	int
640	default 8
641	help
642	  This variable specifies the number of PIRQ interrupt links which are
643	  routable. On most older chipsets, this is 4, PIRQA through PIRQD.
644	  Some newer chipsets offer more than four links, commonly up to PIRQH.
645
646config IRQ_SLOT_COUNT
647	int
648	default 128
649	help
650	  U-Boot can support up to 254 IRQ slot info in the PIRQ routing table
651	  which in turns forms a table of exact 4KiB. The default value 128
652	  should be enough for most boards. If this does not fit your board,
653	  change it according to your needs.
654
655config PCIE_ECAM_BASE
656	hex
657	default 0xe0000000
658	help
659	  This is the memory-mapped address of PCI configuration space, which
660	  is only available through the Enhanced Configuration Access
661	  Mechanism (ECAM) with PCI Express. It can be set up almost
662	  anywhere. Before it is set up, it is possible to access PCI
663	  configuration space through I/O access, but memory access is more
664	  convenient. Using this, PCI can be scanned and configured. This
665	  should be set to a region that does not conflict with memory
666	  assigned to PCI devices - i.e. the memory and prefetch regions, as
667	  passed to pci_set_region().
668
669config PCIE_ECAM_SIZE
670	hex
671	default 0x10000000
672	help
673	  This is the size of memory-mapped address of PCI configuration space,
674	  which is only available through the Enhanced Configuration Access
675	  Mechanism (ECAM) with PCI Express. Each bus consumes 1 MiB memory,
676	  so a default 0x10000000 size covers all of the 256 buses which is the
677	  maximum number of PCI buses as defined by the PCI specification.
678
679config I8259_PIC
680	bool
681	default y
682	help
683	  Intel 8259 ISA compatible chipset incorporates two 8259 (master and
684	  slave) interrupt controllers. Include this to have U-Boot set up
685	  the interrupt correctly.
686
687config I8254_TIMER
688	bool
689	default y
690	help
691	  Intel 8254 timer contains three counters which have fixed uses.
692	  Include this to have U-Boot set up the timer correctly.
693
694config SEABIOS
695	bool "Support booting SeaBIOS"
696	help
697	  SeaBIOS is an open source implementation of a 16-bit X86 BIOS.
698	  It can run in an emulator or natively on X86 hardware with the use
699	  of coreboot/U-Boot. By turning on this option, U-Boot prepares
700	  all the configuration tables that are necessary to boot SeaBIOS.
701
702	  Check http://www.seabios.org/SeaBIOS for details.
703
704config HIGH_TABLE_SIZE
705	hex "Size of configuration tables which reside in high memory"
706	default 0x10000
707	depends on SEABIOS
708	help
709	  SeaBIOS itself resides in E seg and F seg, where U-Boot puts all
710	  configuration tables like PIRQ/MP/ACPI. To avoid conflicts, U-Boot
711	  puts a copy of configuration tables in high memory region which
712	  is reserved on the stack before relocation. The region size is
713	  determined by this option.
714
715	  Increse it if the default size does not fit the board's needs.
716	  This is most likely due to a large ACPI DSDT table is used.
717
718source "arch/x86/lib/efi/Kconfig"
719
720endmenu
721