forked from u-boot/u-boot
-
-
Notifications
You must be signed in to change notification settings - Fork 0
/
README
2473 lines (1910 loc) · 85.3 KB
/
README
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
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
# SPDX-License-Identifier: GPL-2.0+
#
# (C) Copyright 2000 - 2013
# Wolfgang Denk, DENX Software Engineering, [email protected].
Summary:
========
This directory contains the source code for U-Boot, a boot loader for
Embedded boards based on PowerPC, ARM, MIPS and several other
processors, which can be installed in a boot ROM and used to
initialize and test the hardware or to download and run application
code.
The development of U-Boot is closely related to Linux: some parts of
the source code originate in the Linux source tree, we have some
header files in common, and special provision has been made to
support booting of Linux images.
Some attention has been paid to make this software easily
configurable and extendable. For instance, all monitor commands are
implemented with the same call interface, so that it's very easy to
add new commands. Also, instead of permanently adding rarely used
code (for instance hardware test utilities) to the monitor, you can
load and run it dynamically.
Status:
=======
In general, all boards for which a default configuration file exists in the
configs/ directory have been tested to some extent and can be considered
"working". In fact, many of them are used in production systems.
In case of problems you can use
scripts/get_maintainer.pl <path>
to identify the people or companies responsible for various boards and
subsystems. Or have a look at the git log.
Where to get help:
==================
In case you have questions about, problems with or contributions for
U-Boot, you should send a message to the U-Boot mailing list at
<[email protected]>. There is also an archive of previous traffic
on the mailing list - please search the archive before asking FAQ's.
Please see https://lists.denx.de/pipermail/u-boot and
https://marc.info/?l=u-boot
Where to get source code:
=========================
The U-Boot source code is maintained in the Git repository at
https://source.denx.de/u-boot/u-boot.git ; you can browse it online at
https://source.denx.de/u-boot/u-boot
The "Tags" links on this page allow you to download tarballs of
any version you might be interested in. Official releases are also
available from the DENX file server through HTTPS or FTP.
https://ftp.denx.de/pub/u-boot/
ftp://ftp.denx.de/pub/u-boot/
Where we come from:
===================
- start from 8xxrom sources
- create PPCBoot project (https://sourceforge.net/projects/ppcboot)
- clean up code
- make it easier to add custom boards
- make it possible to add other [PowerPC] CPUs
- extend functions, especially:
* Provide extended interface to Linux boot loader
* S-Record download
* network boot
* ATA disk / SCSI ... boot
- create ARMBoot project (https://sourceforge.net/projects/armboot)
- add other CPU families (starting with ARM)
- create U-Boot project (https://sourceforge.net/projects/u-boot)
- current project page: see https://www.denx.de/wiki/U-Boot
Names and Spelling:
===================
The "official" name of this project is "Das U-Boot". The spelling
"U-Boot" shall be used in all written text (documentation, comments
in source files etc.). Example:
This is the README file for the U-Boot project.
File names etc. shall be based on the string "u-boot". Examples:
include/asm-ppc/u-boot.h
#include <asm/u-boot.h>
Variable names, preprocessor constants etc. shall be either based on
the string "u_boot" or on "U_BOOT". Example:
U_BOOT_VERSION u_boot_logo
IH_OS_U_BOOT u_boot_hush_start
Software Configuration:
=======================
Selection of Processor Architecture and Board Type:
---------------------------------------------------
For all supported boards there are ready-to-use default
configurations available; just type "make <board_name>_defconfig".
Example: For a TQM823L module type:
cd u-boot
make TQM823L_defconfig
Note: If you're looking for the default configuration file for a board
you're sure used to be there but is now missing, check the file
doc/README.scrapyard for a list of no longer supported boards.
Sandbox Environment:
--------------------
U-Boot can be built natively to run on a Linux host using the 'sandbox'
board. This allows feature development which is not board- or architecture-
specific to be undertaken on a native platform. The sandbox is also used to
run some of U-Boot's tests.
See doc/arch/sandbox/sandbox.rst for more details.
The following options need to be configured:
- CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
- Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
- 85xx CPU Options:
CONFIG_SYS_PPC64
Specifies that the core is a 64-bit PowerPC implementation (implements
the "64" category of the Power ISA). This is necessary for ePAPR
compliance, among other possible reasons.
CONFIG_SYS_FSL_ERRATUM_A004510
Enables a workaround for erratum A004510. If set,
then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
CFG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
Defines one or two SoC revisions (low 8 bits of SVR)
for which the A004510 workaround should be applied.
The rest of SVR is either not relevant to the decision
of whether the erratum is present (e.g. p2040 versus
p2041) or is implied by the build target, which controls
whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
See Freescale App Note 4493 for more information about
this erratum.
CFG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
This is the value to write into CCSR offset 0x18600
according to the A004510 workaround.
CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
Single Source Clock is clocking mode present in some of FSL SoC's.
In this mode, a single differential clock is used to supply
clocks to the sysclock, ddrclock and usbclock.
- Generic CPU options:
CONFIG_SYS_FSL_DDR
Freescale DDR driver in use. This type of DDR controller is
found in mpc83xx, mpc85xx as well as some ARM core SoCs.
CFG_SYS_FSL_DDR_ADDR
Freescale DDR memory-mapped register base.
CONFIG_SYS_FSL_IFC_CLK_DIV
Defines divider of platform clock(clock input to IFC controller).
CONFIG_SYS_FSL_LBC_CLK_DIV
Defines divider of platform clock(clock input to eLBC controller).
CFG_SYS_FSL_DDR_SDRAM_BASE_PHY
Physical address from the view of DDR controllers. It is the
same as CFG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
it could be different for ARM SoCs.
- ARM options:
CFG_SYS_EXCEPTION_VECTORS_HIGH
Select high exception vectors of the ARM core, e.g., do not
clear the V bit of the c1 register of CP15.
COUNTER_FREQUENCY
Generic timer clock source frequency.
COUNTER_FREQUENCY_REAL
Generic timer clock source frequency if the real clock is
different from COUNTER_FREQUENCY, and can only be determined
at run time.
- Linux Kernel Interface:
CONFIG_OF_LIBFDT
New kernel versions are expecting firmware settings to be
passed using flattened device trees (based on open firmware
concepts).
CONFIG_OF_LIBFDT
* New libfdt-based support
* Adds the "fdt" command
* The bootm command automatically updates the fdt
OF_TBCLK - The timebase frequency.
boards with QUICC Engines require OF_QE to set UCC MAC
addresses
CONFIG_OF_IDE_FIXUP
U-Boot can detect if an IDE device is present or not.
If not, and this new config option is activated, U-Boot
removes the ATA node from the DTS before booting Linux,
so the Linux IDE driver does not probe the device and
crash. This is needed for buggy hardware (uc101) where
no pull down resistor is connected to the signal IDE5V_DD7.
- vxWorks boot parameters:
bootvx constructs a valid bootline using the following
environments variables: bootdev, bootfile, ipaddr, netmask,
serverip, gatewayip, hostname, othbootargs.
It loads the vxWorks image pointed bootfile.
Note: If a "bootargs" environment is defined, it will override
the defaults discussed just above.
- Cache Configuration for ARM:
CFG_SYS_PL310_BASE - Physical base address of PL310
controller register space
- Serial Ports:
CFG_PL011_CLOCK
If you have Amba PrimeCell PL011 UARTs, set this variable to
the clock speed of the UARTs.
CFG_PL01x_PORTS
If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
define this to a list of base addresses for each (supported)
port. See e.g. include/configs/versatile.h
CONFIG_SERIAL_HW_FLOW_CONTROL
Define this variable to enable hw flow control in serial driver.
Current user of this option is drivers/serial/nsl16550.c driver
- Removal of commands
If no commands are needed to boot, you can disable
CONFIG_CMDLINE to remove them. In this case, the command line
will not be available, and when U-Boot wants to execute the
boot command (on start-up) it will call board_run_command()
instead. This can reduce image size significantly for very
simple boot procedures.
- Regular expression support:
CONFIG_REGEX
If this variable is defined, U-Boot is linked against
the SLRE (Super Light Regular Expression) library,
which adds regex support to some commands, as for
example "env grep" and "setexpr".
- Watchdog:
CFG_SYS_WATCHDOG_FREQ
Some platforms automatically call WATCHDOG_RESET()
from the timer interrupt handler every
CFG_SYS_WATCHDOG_FREQ interrupts. If not set by the
board configuration file, a default of CONFIG_SYS_HZ/2
(i.e. 500) is used. Setting CFG_SYS_WATCHDOG_FREQ
to 0 disables calling WATCHDOG_RESET() from the timer
interrupt.
- GPIO Support:
The CFG_SYS_I2C_PCA953X_WIDTH option specifies a list of
chip-ngpio pairs that tell the PCA953X driver the number of
pins supported by a particular chip.
Note that if the GPIO device uses I2C, then the I2C interface
must also be configured. See I2C Support, below.
- I/O tracing:
When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
accesses and can checksum them or write a list of them out
to memory. See the 'iotrace' command for details. This is
useful for testing device drivers since it can confirm that
the driver behaves the same way before and after a code
change. Currently this is supported on sandbox and arm. To
add support for your architecture, add '#include <iotrace.h>'
to the bottom of arch/<arch>/include/asm/io.h and test.
Example output from the 'iotrace stats' command is below.
Note that if the trace buffer is exhausted, the checksum will
still continue to operate.
iotrace is enabled
Start: 10000000 (buffer start address)
Size: 00010000 (buffer size)
Offset: 00000120 (current buffer offset)
Output: 10000120 (start + offset)
Count: 00000018 (number of trace records)
CRC32: 9526fb66 (CRC32 of all trace records)
- Timestamp Support:
When CONFIG_TIMESTAMP is selected, the timestamp
(date and time) of an image is printed by image
commands like bootm or iminfo. This option is
automatically enabled when you select CONFIG_CMD_DATE .
- Partition Labels (disklabels) Supported:
Zero or more of the following:
CONFIG_MAC_PARTITION Apple's MacOS partition table.
CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
bootloader. Note 2TB partition limit; see
disk/part_efi.c
CONFIG_SCSI) you must configure support for at
least one non-MTD partition type as well.
- NETWORK Support (PCI):
CONFIG_E1000_SPI
Utility code for direct access to the SPI bus on Intel 8257x.
This does not do anything useful unless you set at least one
of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
CONFIG_NATSEMI
Support for National dp83815 chips.
CONFIG_NS8382X
Support for National dp8382[01] gigabit chips.
- NETWORK Support (other):
CONFIG_CALXEDA_XGMAC
Support for the Calxeda XGMAC device
CONFIG_LAN91C96
Support for SMSC's LAN91C96 chips.
CONFIG_LAN91C96_USE_32_BIT
Define this to enable 32 bit addressing
CFG_SYS_DAVINCI_EMAC_PHY_COUNT
Define this if you have more then 3 PHYs.
CONFIG_FTGMAC100
Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
CONFIG_FTGMAC100_EGIGA
Define this to use GE link update with gigabit PHY.
Define this if FTGMAC100 is connected to gigabit PHY.
If your system has 10/100 PHY only, it might not occur
wrong behavior. Because PHY usually return timeout or
useless data when polling gigabit status and gigabit
control registers. This behavior won't affect the
correctnessof 10/100 link speed update.
CONFIG_SH_ETHER
Support for Renesas on-chip Ethernet controller
CFG_SH_ETHER_USE_PORT
Define the number of ports to be used
CFG_SH_ETHER_PHY_ADDR
Define the ETH PHY's address
CFG_SH_ETHER_CACHE_WRITEBACK
If this option is set, the driver enables cache flush.
- TPM Support:
CONFIG_TPM
Support TPM devices.
CONFIG_TPM_TIS_INFINEON
Support for Infineon i2c bus TPM devices. Only one device
per system is supported at this time.
CONFIG_TPM_TIS_I2C_BURST_LIMITATION
Define the burst count bytes upper limit
CONFIG_TPM_ST33ZP24
Support for STMicroelectronics TPM devices. Requires DM_TPM support.
CONFIG_TPM_ST33ZP24_I2C
Support for STMicroelectronics ST33ZP24 I2C devices.
Requires TPM_ST33ZP24 and I2C.
CONFIG_TPM_ST33ZP24_SPI
Support for STMicroelectronics ST33ZP24 SPI devices.
Requires TPM_ST33ZP24 and SPI.
CONFIG_TPM_ATMEL_TWI
Support for Atmel TWI TPM device. Requires I2C support.
CONFIG_TPM_TIS_LPC
Support for generic parallel port TPM devices. Only one device
per system is supported at this time.
CONFIG_TPM
Define this to enable the TPM support library which provides
functional interfaces to some TPM commands.
Requires support for a TPM device.
CONFIG_TPM_AUTH_SESSIONS
Define this to enable authorized functions in the TPM library.
Requires CONFIG_TPM and CONFIG_SHA1.
- USB Support:
At the moment only the UHCI host controller is
supported (PIP405, MIP405); define
CONFIG_USB_UHCI to enable it.
define CONFIG_USB_KEYBOARD to enable the USB Keyboard
and define CONFIG_USB_STORAGE to enable the USB
storage devices.
Note:
Supported are USB Keyboards and USB Floppy drives
(TEAC FD-05PUB).
CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
HW module registers.
- USB Device:
Define the below if you wish to use the USB console.
Once firmware is rebuilt from a serial console issue the
command "setenv stdin usbtty; setenv stdout usbtty" and
attach your USB cable. The Unix command "dmesg" should print
it has found a new device. The environment variable usbtty
can be set to gserial or cdc_acm to enable your device to
appear to a USB host as a Linux gserial device or a
Common Device Class Abstract Control Model serial device.
If you select usbtty = gserial you should be able to enumerate
a Linux host by
# modprobe usbserial vendor=0xVendorID product=0xProductID
else if using cdc_acm, simply setting the environment
variable usbtty to be cdc_acm should suffice. The following
might be defined in YourBoardName.h
If you have a USB-IF assigned VendorID then you may wish to
define your own vendor specific values either in BoardName.h
or directly in usbd_vendor_info.h. If you don't define
CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
should pretend to be a Linux device to it's target host.
CONFIG_USBD_MANUFACTURER
Define this string as the name of your company for
- CONFIG_USBD_MANUFACTURER "my company"
CONFIG_USBD_PRODUCT_NAME
Define this string as the name of your product
- CONFIG_USBD_PRODUCT_NAME "acme usb device"
CONFIG_USBD_VENDORID
Define this as your assigned Vendor ID from the USB
Implementors Forum. This *must* be a genuine Vendor ID
to avoid polluting the USB namespace.
- CONFIG_USBD_VENDORID 0xFFFF
CONFIG_USBD_PRODUCTID
Define this as the unique Product ID
for your device
- CONFIG_USBD_PRODUCTID 0xFFFF
- ULPI Layer Support:
The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
the generic ULPI layer. The generic layer accesses the ULPI PHY
via the platform viewport, so you need both the genric layer and
the viewport enabled. Currently only Chipidea/ARC based
viewport is supported.
To enable the ULPI layer support, define CONFIG_USB_ULPI and
CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
If your ULPI phy needs a different reference clock than the
standard 24 MHz then you have to define CFG_ULPI_REF_CLK to
the appropriate value in Hz.
- MMC Support:
CONFIG_SH_MMCIF
Support for Renesas on-chip MMCIF controller
CONFIG_SH_MMCIF_ADDR
Define the base address of MMCIF registers
CONFIG_SH_MMCIF_CLK
Define the clock frequency for MMCIF
- USB Device Firmware Update (DFU) class support:
CONFIG_DFU_OVER_USB
This enables the USB portion of the DFU USB class
CONFIG_DFU_NAND
This enables support for exposing NAND devices via DFU.
CONFIG_DFU_RAM
This enables support for exposing RAM via DFU.
Note: DFU spec refer to non-volatile memory usage, but
allow usages beyond the scope of spec - here RAM usage,
one that would help mostly the developer.
CONFIG_SYS_DFU_DATA_BUF_SIZE
Dfu transfer uses a buffer before writing data to the
raw storage device. Make the size (in bytes) of this buffer
configurable. The size of this buffer is also configurable
through the "dfu_bufsiz" environment variable.
CONFIG_SYS_DFU_MAX_FILE_SIZE
When updating files rather than the raw storage device,
we use a static buffer to copy the file into and then write
the buffer once we've been given the whole file. Define
this to the maximum filesize (in bytes) for the buffer.
Default is 4 MiB if undefined.
DFU_DEFAULT_POLL_TIMEOUT
Poll timeout [ms], is the timeout a device can send to the
host. The host must wait for this timeout before sending
a subsequent DFU_GET_STATUS request to the device.
DFU_MANIFEST_POLL_TIMEOUT
Poll timeout [ms], which the device sends to the host when
entering dfuMANIFEST state. Host waits this timeout, before
sending again an USB request to the device.
- Keyboard Support:
See Kconfig help for available keyboard drivers.
- MII/PHY support:
CONFIG_PHY_CLOCK_FREQ (ppc4xx)
The clock frequency of the MII bus
CONFIG_PHY_CMD_DELAY (ppc4xx)
Some PHY like Intel LXT971A need extra delay after
command issued before MII status register can be read
- BOOTP Recovery Mode:
CONFIG_BOOTP_RANDOM_DELAY
If you have many targets in a network that try to
boot using BOOTP, you may want to avoid that all
systems send out BOOTP requests at precisely the same
moment (which would happen for instance at recovery
from a power failure, when all systems will try to
boot, thus flooding the BOOTP server. Defining
CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
inserted before sending out BOOTP requests. The
following delays are inserted then:
1st BOOTP request: delay 0 ... 1 sec
2nd BOOTP request: delay 0 ... 2 sec
3rd BOOTP request: delay 0 ... 4 sec
4th and following
BOOTP requests: delay 0 ... 8 sec
CFG_BOOTP_ID_CACHE_SIZE
BOOTP packets are uniquely identified using a 32-bit ID. The
server will copy the ID from client requests to responses and
U-Boot will use this to determine if it is the destination of
an incoming response. Some servers will check that addresses
aren't in use before handing them out (usually using an ARP
ping) and therefore take up to a few hundred milliseconds to
respond. Network congestion may also influence the time it
takes for a response to make it back to the client. If that
time is too long, U-Boot will retransmit requests. In order
to allow earlier responses to still be accepted after these
retransmissions, U-Boot's BOOTP client keeps a small cache of
IDs. The CFG_BOOTP_ID_CACHE_SIZE controls the size of this
cache. The default is to keep IDs for up to four outstanding
requests. Increasing this will allow U-Boot to accept offers
from a BOOTP client in networks with unusually high latency.
- DHCP Advanced Options:
- Link-local IP address negotiation:
Negotiate with other link-local clients on the local network
for an address that doesn't require explicit configuration.
This is especially useful if a DHCP server cannot be guaranteed
to exist in all environments that the device must operate.
See doc/README.link-local for more information.
- MAC address from environment variables
FDT_SEQ_MACADDR_FROM_ENV
Fix-up device tree with MAC addresses fetched sequentially from
environment variables. This config work on assumption that
non-usable ethernet node of device-tree are either not present
or their status has been marked as "disabled".
- CDP Options:
CONFIG_CDP_DEVICE_ID
The device id used in CDP trigger frames.
CONFIG_CDP_DEVICE_ID_PREFIX
A two character string which is prefixed to the MAC address
of the device.
CONFIG_CDP_PORT_ID
A printf format string which contains the ascii name of
the port. Normally is set to "eth%d" which sets
eth0 for the first Ethernet, eth1 for the second etc.
CONFIG_CDP_CAPABILITIES
A 32bit integer which indicates the device capabilities;
0x00000010 for a normal host which does not forwards.
CONFIG_CDP_VERSION
An ascii string containing the version of the software.
CONFIG_CDP_PLATFORM
An ascii string containing the name of the platform.
CONFIG_CDP_TRIGGER
A 32bit integer sent on the trigger.
CONFIG_CDP_POWER_CONSUMPTION
A 16bit integer containing the power consumption of the
device in .1 of milliwatts.
CONFIG_CDP_APPLIANCE_VLAN_TYPE
A byte containing the id of the VLAN.
- Status LED: CONFIG_LED_STATUS
Several configurations allow to display the current
status using a LED. For instance, the LED will blink
fast while running U-Boot code, stop blinking as
soon as a reply to a BOOTP request was received, and
start blinking slow once the Linux kernel is running
(supported by a status LED driver in the Linux
kernel). Defining CONFIG_LED_STATUS enables this
feature in U-Boot.
Additional options:
CONFIG_LED_STATUS_GPIO
The status LED can be connected to a GPIO pin.
In such cases, the gpio_led driver can be used as a
status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
to include the gpio_led driver in the U-Boot binary.
CFG_GPIO_LED_INVERTED_TABLE
Some GPIO connected LEDs may have inverted polarity in which
case the GPIO high value corresponds to LED off state and
GPIO low value corresponds to LED on state.
In such cases CFG_GPIO_LED_INVERTED_TABLE may be defined
with a list of GPIO LEDs that have inverted polarity.
- I2C Support:
CFG_SYS_NUM_I2C_BUSES
Hold the number of i2c buses you want to use.
CFG_SYS_I2C_BUSES
hold a list of buses you want to use
CFG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
{0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
{0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
{0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
{0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
{0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
{1, {I2C_NULL_HOP}}, \
{1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
{1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
}
which defines
bus 0 on adapter 0 without a mux
bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
bus 6 on adapter 1 without a mux
bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
If you do not have i2c muxes on your board, omit this define.
- Legacy I2C Support:
If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
then the following macros need to be defined (examples are
from include/configs/lwmon.h):
I2C_INIT
(Optional). Any commands necessary to enable the I2C
controller or configure ports.
eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
I2C_ACTIVE
The code necessary to make the I2C data line active
(driven). If the data line is open collector, this
define can be null.
eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
I2C_TRISTATE
The code necessary to make the I2C data line tri-stated
(inactive). If the data line is open collector, this
define can be null.
eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
I2C_READ
Code that returns true if the I2C data line is high,
false if it is low.
eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
I2C_SDA(bit)
If <bit> is true, sets the I2C data line high. If it
is false, it clears it (low).
eg: #define I2C_SDA(bit) \
if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
else immr->im_cpm.cp_pbdat &= ~PB_SDA
I2C_SCL(bit)
If <bit> is true, sets the I2C clock line high. If it
is false, it clears it (low).
eg: #define I2C_SCL(bit) \
if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
else immr->im_cpm.cp_pbdat &= ~PB_SCL
I2C_DELAY
This delay is invoked four times per clock cycle so this
controls the rate of data transfer. The data rate thus
is 1 / (I2C_DELAY * 4). Often defined to be something
like:
#define I2C_DELAY udelay(2)
CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
If your arch supports the generic GPIO framework (asm/gpio.h),
then you may alternatively define the two GPIOs that are to be
used as SCL / SDA. Any of the previous I2C_xxx macros will
have GPIO-based defaults assigned to them as appropriate.
You should define these to the GPIO value as given directly to
the generic GPIO functions.
CFG_SYS_I2C_NOPROBES
This option specifies a list of I2C devices that will be skipped
when the 'i2c probe' command is issued.
e.g.
#define CFG_SYS_I2C_NOPROBES {0x50,0x68}
will skip addresses 0x50 and 0x68 on a board with one I2C bus
CONFIG_SOFT_I2C_READ_REPEATED_START
defining this will force the i2c_read() function in
the soft_i2c driver to perform an I2C repeated start
between writing the address pointer and reading the
data. If this define is omitted the default behaviour
of doing a stop-start sequence will be used. Most I2C
devices can use either method, but some require one or
the other.
- SPI Support: CONFIG_SPI
Enables SPI driver (so far only tested with
SPI EEPROM, also an instance works with Crystal A/D and
D/As on the SACSng board)
CFG_SYS_SPI_MXC_WAIT
Timeout for waiting until spi transfer completed.
default: (CONFIG_SYS_HZ/100) /* 10 ms */
- FPGA Support: CONFIG_FPGA
Enables FPGA subsystem.
CONFIG_FPGA_<vendor>
Enables support for specific chip vendors.
(ALTERA, XILINX)
CONFIG_FPGA_<family>
Enables support for FPGA family.
(SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
CONFIG_SYS_FPGA_CHECK_BUSY
Enable checks on FPGA configuration interface busy
status by the configuration function. This option
will require a board or device specific function to
be written.
CFG_FPGA_DELAY
If defined, a function that provides delays in the FPGA
configuration driver.
CFG_SYS_FPGA_CHECK_ERROR
Check for configuration errors during FPGA bitfile
loading. For example, abort during Virtex II
configuration if the INIT_B line goes low (which
indicated a CRC error).
CFG_SYS_FPGA_WAIT_INIT
Maximum time to wait for the INIT_B line to de-assert
after PROB_B has been de-asserted during a Virtex II
FPGA configuration sequence. The default time is 500
ms.
CFG_SYS_FPGA_WAIT_BUSY
Maximum time to wait for BUSY to de-assert during
Virtex II FPGA configuration. The default is 5 ms.
CFG_SYS_FPGA_WAIT_CONFIG
Time to wait after FPGA configuration. The default is
200 ms.
- Vendor Parameter Protection:
U-Boot considers the values of the environment
variables "serial#" (Board Serial Number) and
"ethaddr" (Ethernet Address) to be parameters that
are set once by the board vendor / manufacturer, and
protects these variables from casual modification by
the user. Once set, these variables are read-only,
and write or delete attempts are rejected. You can
change this behaviour:
If CONFIG_ENV_OVERWRITE is #defined in your config
file, the write protection for vendor parameters is
completely disabled. Anybody can change or delete
these parameters.
The same can be accomplished in a more flexible way
for any variable by configuring the type of access
to allow for those variables in the ".flags" variable
or define CFG_ENV_FLAGS_LIST_STATIC.
- Protected RAM:
CFG_PRAM
Define this variable to enable the reservation of
"protected RAM", i. e. RAM which is not overwritten
by U-Boot. Define CFG_PRAM to hold the number of
kB you want to reserve for pRAM. You can overwrite
this default value by defining an environment
variable "pram" to the number of kB you want to
reserve. Note that the board info structure will
still show the full amount of RAM. If pRAM is
reserved, a new environment variable "mem" will
automatically be defined to hold the amount of
remaining RAM in a form that can be passed as boot
argument to Linux, for instance like that:
setenv bootargs ... mem=\${mem}
saveenv
This way you can tell Linux not to use this memory,
either, which results in a memory region that will
not be affected by reboots.
*WARNING* If your board configuration uses automatic
detection of the RAM size, you must make sure that
this memory test is non-destructive. So far, the
following board configurations are known to be
"pRAM-clean":
IVMS8, IVML24, SPD8xx,
HERMES, IP860, RPXlite, LWMON,
FLAGADM
- Error Recovery:
Note:
In the current implementation, the local variables
space and global environment variables space are
separated. Local variables are those you define by
simply typing `name=value'. To access a local
variable later on, you have write `$name' or
`${name}'; to execute the contents of a variable
directly type `$name' at the command prompt.
Global environment variables are those you use
setenv/printenv to work with. To run a command stored
in such a variable, you need to use the run command,
and you must not use the '$' sign to access them.
To store commands and special characters in a
variable, please use double quotation marks
surrounding the whole text of the variable, instead
of the backslashes before semicolons and special
symbols.
- Default Environment:
CFG_EXTRA_ENV_SETTINGS
Define this to contain any number of null terminated
strings (variable = value pairs) that will be part of
the default environment compiled into the boot image.
For example, place something like this in your
board's config file:
#define CFG_EXTRA_ENV_SETTINGS \
"myvar1=value1\0" \
"myvar2=value2\0"
Warning: This method is based on knowledge about the
internal format how the environment is stored by the
U-Boot code. This is NOT an official, exported
interface! Although it is unlikely that this format
will change soon, there is no guarantee either.
You better know what you are doing here.
Note: overly (ab)use of the default environment is
discouraged. Make sure to check other ways to preset
the environment like the "source" command or the
boot command first.
CONFIG_DELAY_ENVIRONMENT
Normally the environment is loaded when the board is
initialised so that it is available to U-Boot. This inhibits
that so that the environment is not available until
explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
this is instead controlled by the value of
/config/load-environment.
- Automatic software updates via TFTP server
CONFIG_UPDATE_TFTP
CONFIG_UPDATE_TFTP_CNT_MAX
CONFIG_UPDATE_TFTP_MSEC_MAX
These options enable and control the auto-update feature;
for a more detailed description refer to doc/README.update.
- MTD Support (mtdparts command, UBI support)
CONFIG_MTD_UBI_WL_THRESHOLD
This parameter defines the maximum difference between the highest
erase counter value and the lowest erase counter value of eraseblocks
of UBI devices. When this threshold is exceeded, UBI starts performing
wear leveling by means of moving data from eraseblock with low erase
counter to eraseblocks with high erase counter.
The default value should be OK for SLC NAND flashes, NOR flashes and
other flashes which have eraseblock life-cycle 100000 or more.
However, in case of MLC NAND flashes which typically have eraseblock
life-cycle less than 10000, the threshold should be lessened (e.g.,
to 128 or 256, although it does not have to be power of 2).
default: 4096
CONFIG_MTD_UBI_BEB_LIMIT
This option specifies the maximum bad physical eraseblocks UBI
expects on the MTD device (per 1024 eraseblocks). If the