xref: /rk3399_rockchip-uboot/dts/Kconfig (revision 39d40ad54eb2274a86419000e0e087673f86508a)
1783e6a72SMasahiro Yamada#
2783e6a72SMasahiro Yamada# Device Tree Control
3783e6a72SMasahiro Yamada#
4783e6a72SMasahiro Yamada
5783e6a72SMasahiro Yamadaconfig SUPPORT_OF_CONTROL
6783e6a72SMasahiro Yamada	bool
7783e6a72SMasahiro Yamada
85821df21STom Riniconfig DTC
95821df21STom Rini	bool
105821df21STom Rini
11ec821af4SMasahiro Yamadaconfig PYLIBFDT
12ec821af4SMasahiro Yamada	bool
13ec821af4SMasahiro Yamada
14ec821af4SMasahiro Yamadaconfig DTOC
15ec821af4SMasahiro Yamada	bool
16ec821af4SMasahiro Yamada	select PYLIBFDT
17ec821af4SMasahiro Yamada
18ec821af4SMasahiro Yamadaconfig BINMAN
19ec821af4SMasahiro Yamada	bool
20ec821af4SMasahiro Yamada	select DTOC
21ec821af4SMasahiro Yamada
22783e6a72SMasahiro Yamadamenu "Device Tree Control"
23783e6a72SMasahiro Yamada	depends on SUPPORT_OF_CONTROL
24783e6a72SMasahiro Yamada
25783e6a72SMasahiro Yamadaconfig OF_CONTROL
26783e6a72SMasahiro Yamada	bool "Run-time configuration via Device Tree"
275821df21STom Rini	select DTC
28783e6a72SMasahiro Yamada	help
29783e6a72SMasahiro Yamada	  This feature provides for run-time configuration of U-Boot
30783e6a72SMasahiro Yamada	  via a flattened device tree.
31783e6a72SMasahiro Yamada
32*39d40ad5SJoseph Chenconfig OF_ADDR_SIZE_AUTO_NOPARENT
33*39d40ad5SJoseph Chen	bool "FDT get address/size cell auto from parent node"
34*39d40ad5SJoseph Chen	depends on OF_CONTROL && ARM64
35*39d40ad5SJoseph Chen	help
36*39d40ad5SJoseph Chen	  Enable this to use 'fdtdec_get_addr_size_auto_noparent' instead of
37*39d40ad5SJoseph Chen	  'fdtdec_get_addr_size_fixed' in case of 64-bit U-Boot use 32-bit
38*39d40ad5SJoseph Chen	  platform dtb.
39*39d40ad5SJoseph Chen
402a792753Smario.six@gdsys.ccconfig OF_BOARD_FIXUP
412a792753Smario.six@gdsys.cc	bool "Board-specific manipulation of Device Tree"
422a792753Smario.six@gdsys.cc	help
432a792753Smario.six@gdsys.cc	  In certain circumstances it is necessary to be able to modify
442a792753Smario.six@gdsys.cc	  U-Boot's device tree (e.g. to delete device from it). This option
452a792753Smario.six@gdsys.cc	  make the Device Tree writeable and provides a board-specific
462a792753Smario.six@gdsys.cc	  "board_fix_fdt" callback (called during pre-relocation time), which
472a792753Smario.six@gdsys.cc	  enables the board initialization to modifiy the Device Tree. The
482a792753Smario.six@gdsys.cc	  modified copy is subsequently used by U-Boot after relocation.
492a792753Smario.six@gdsys.cc
50dffb86e4SMasahiro Yamadaconfig SPL_OF_CONTROL
51dffb86e4SMasahiro Yamada	bool "Enable run-time configuration via Device Tree in SPL"
52dffb86e4SMasahiro Yamada	depends on SPL && OF_CONTROL
532860f03bSSimon Glass	help
542860f03bSSimon Glass	  Some boards use device tree in U-Boot but only have 4KB of SRAM
552860f03bSSimon Glass	  which is not enough to support device tree. Enable this option to
562860f03bSSimon Glass	  allow such boards to be supported by U-Boot SPL.
572860f03bSSimon Glass
584447bf16SJoseph Chenconfig SPL_DTB_MINIMUM
594447bf16SJoseph Chen	bool "Provide a minimum SPL DTB "
604447bf16SJoseph Chen	depends on SPL_OF_CONTROL
614447bf16SJoseph Chen	default n
624447bf16SJoseph Chen	help
634447bf16SJoseph Chen	  Some boards need a SPL DTB as smaller as possible to save dm scan
644447bf16SJoseph Chen	  time and space. It provides a SPL DTB only include the node with
654447bf16SJoseph Chen	  property "u-boot,dm-spl". The property "u-boot,pre-reloc" doesn't
664447bf16SJoseph Chen	  work any more.
674447bf16SJoseph Chen
68f291ce12SPhilipp Tomsichconfig TPL_OF_CONTROL
69f291ce12SPhilipp Tomsich	bool "Enable run-time configuration via Device Tree in TPL"
70f291ce12SPhilipp Tomsich	depends on TPL && OF_CONTROL
71f291ce12SPhilipp Tomsich	help
72f291ce12SPhilipp Tomsich	  Some boards use device tree in U-Boot but only have 4KB of SRAM
73f291ce12SPhilipp Tomsich	  which is not enough to support device tree. Enable this option to
74f291ce12SPhilipp Tomsich	  allow such boards to be supported by U-Boot TPL.
75f291ce12SPhilipp Tomsich
765e060d8bSSimon Glassconfig OF_LIVE
775e060d8bSSimon Glass	bool "Enable use of a live tree"
785e060d8bSSimon Glass	depends on OF_CONTROL
795e060d8bSSimon Glass	help
805e060d8bSSimon Glass	  Normally U-Boot uses a flat device tree which saves space and
815e060d8bSSimon Glass	  avoids the need to unpack the tree before use. However a flat
825e060d8bSSimon Glass	  tree does not support modifcation from within U-Boot since it
835e060d8bSSimon Glass	  can invalidate driver-model device tree offsets. This option
845e060d8bSSimon Glass	  enables a live tree which is available after relocation,
855e060d8bSSimon Glass	  and can be adjusted as needed.
865e060d8bSSimon Glass
87783e6a72SMasahiro Yamadachoice
88783e6a72SMasahiro Yamada	prompt "Provider of DTB for DT control"
89783e6a72SMasahiro Yamada	depends on OF_CONTROL
90783e6a72SMasahiro Yamada
91783e6a72SMasahiro Yamadaconfig OF_SEPARATE
92783e6a72SMasahiro Yamada	bool "Separate DTB for DT control"
93783e6a72SMasahiro Yamada	depends on !SANDBOX
94783e6a72SMasahiro Yamada	help
95783e6a72SMasahiro Yamada	  If this option is enabled, the device tree will be built and
96783e6a72SMasahiro Yamada	  placed as a separate u-boot.dtb file alongside the U-Boot image.
97783e6a72SMasahiro Yamada
98783e6a72SMasahiro Yamadaconfig OF_EMBED
99783e6a72SMasahiro Yamada	bool "Embedded DTB for DT control"
100783e6a72SMasahiro Yamada	help
101783e6a72SMasahiro Yamada	  If this option is enabled, the device tree will be picked up and
1023d3f60cbSSimon Glass	  built into the U-Boot image. This is suitable for local debugging
1033d3f60cbSSimon Glass	  and development only and is not recommended for production devices.
1043d3f60cbSSimon Glass	  Boards in the mainline U-Boot tree should not use it.
105783e6a72SMasahiro Yamada
10682f766d1SAlex Deymoconfig OF_BOARD
10782f766d1SAlex Deymo	bool "Provided by the board at runtime"
10882f766d1SAlex Deymo	depends on !SANDBOX
10982f766d1SAlex Deymo	help
11082f766d1SAlex Deymo	  If this option is enabled, the device tree will be provided by
11182f766d1SAlex Deymo	  the board at runtime if the board supports it, instead of being
11282f766d1SAlex Deymo	  bundled with the image.
11382f766d1SAlex Deymo
114783e6a72SMasahiro Yamadaconfig OF_HOSTFILE
115783e6a72SMasahiro Yamada	bool "Host filed DTB for DT control"
116783e6a72SMasahiro Yamada	depends on SANDBOX
117783e6a72SMasahiro Yamada	help
118783e6a72SMasahiro Yamada	  If this option is enabled, DTB will be read from a file on startup.
119783e6a72SMasahiro Yamada	  This is only useful for Sandbox.  Use the -d flag to U-Boot to
120783e6a72SMasahiro Yamada	  specify the file to read.
121783e6a72SMasahiro Yamada
122f36ea2f6SThomas Fitzsimmonsconfig OF_PRIOR_STAGE
123f36ea2f6SThomas Fitzsimmons	bool "Prior stage bootloader DTB for DT control"
124f36ea2f6SThomas Fitzsimmons	help
125f36ea2f6SThomas Fitzsimmons	  If this option is enabled, the device tree used for DT
126f36ea2f6SThomas Fitzsimmons	  control will be read from a device tree binary, at a memory
127f36ea2f6SThomas Fitzsimmons	  location passed to U-Boot by the prior stage bootloader.
128f36ea2f6SThomas Fitzsimmons
129783e6a72SMasahiro Yamadaendchoice
130783e6a72SMasahiro Yamada
131f1ef2b62SMasahiro Yamadaconfig DEFAULT_DEVICE_TREE
132f1ef2b62SMasahiro Yamada	string "Default Device Tree for DT control"
13370d41093SSimon Glass	depends on OF_CONTROL
134f1ef2b62SMasahiro Yamada	help
135f1ef2b62SMasahiro Yamada	  This option specifies the default Device Tree used for DT control.
1365699ea6dSRobert P. J. Day	  It can be overridden from the command line:
137f1ef2b62SMasahiro Yamada	  $ make DEVICE_TREE=<device-tree-name>
138f1ef2b62SMasahiro Yamada
139cdf17246SSimon Glassconfig OF_LIST
140cdf17246SSimon Glass	string "List of device tree files to include for DT control"
1412bbcffb1SJean-Jacques Hiblot	depends on SPL_LOAD_FIT || MULTI_DTB_FIT
142c409bd01SMichal Simek	default DEFAULT_DEVICE_TREE
143cdf17246SSimon Glass	help
144cdf17246SSimon Glass	  This option specifies a list of device tree files to use for DT
145d9797409SCooper Jr., Franklin	  control. These will be packaged into a FIT. At run-time, U-boot
146d9797409SCooper Jr., Franklin	  or SPL will select the correct DT to use by examining the
147d9797409SCooper Jr., Franklin	  hardware (e.g. reading a board ID value). This is a list of
148d9797409SCooper Jr., Franklin	  device tree files (without the directory or .dtb suffix)
149d9797409SCooper Jr., Franklin	  separated by <space>.
150cdf17246SSimon Glass
1512bbcffb1SJean-Jacques Hiblot
1522bbcffb1SJean-Jacques Hiblotconfig DTB_RESELECT
1532bbcffb1SJean-Jacques Hiblot	bool "Support swapping dtbs at a later point in boot"
1542bbcffb1SJean-Jacques Hiblot	depends on MULTI_DTB_FIT
1552bbcffb1SJean-Jacques Hiblot	help
1562bbcffb1SJean-Jacques Hiblot	  It is possible during initial boot you may need to use a generic
1572bbcffb1SJean-Jacques Hiblot	  dtb until you can fully determine the board your running on. This
1582bbcffb1SJean-Jacques Hiblot	  config allows boards to implement a function at a later point
1592bbcffb1SJean-Jacques Hiblot	  during boot to switch to the "correct" dtb.
1602bbcffb1SJean-Jacques Hiblot
1612bbcffb1SJean-Jacques Hiblotconfig MULTI_DTB_FIT
1622bbcffb1SJean-Jacques Hiblot	bool "Support embedding several DTBs in a FIT image for u-boot"
1632bbcffb1SJean-Jacques Hiblot	help
1642bbcffb1SJean-Jacques Hiblot	  This option provides hooks to allow U-boot to parse an
1652bbcffb1SJean-Jacques Hiblot	  appended FIT image and enable board specific code to then select
1662bbcffb1SJean-Jacques Hiblot	  the correct DTB to be used. Use this if you need to support
1672bbcffb1SJean-Jacques Hiblot	  multiple DTBs but don't use the SPL.
1682bbcffb1SJean-Jacques Hiblot
169476f6045SJean-Jacques Hiblot
170476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT
171476f6045SJean-Jacques Hiblot	depends on SPL_LOAD_FIT && SPL_OF_CONTROL && !SPL_OF_PLATDATA
172476f6045SJean-Jacques Hiblot	bool "Support embedding several DTBs in a FIT image for the SPL"
173476f6045SJean-Jacques Hiblot	help
174476f6045SJean-Jacques Hiblot	  This option provides the SPL with the ability to select its own
175476f6045SJean-Jacques Hiblot	  DTB at runtime from an appended FIT image containing several DTBs.
176476f6045SJean-Jacques Hiblot	  This allows using the same SPL binary on multiple platforms.
177476f6045SJean-Jacques Hiblot	  The primary purpose is to handle different versions of
178476f6045SJean-Jacques Hiblot	  the same platform without tweaking the platform code if the
179476f6045SJean-Jacques Hiblot	  differences can be expressed in the DTBs (common examples are: bus
180476f6045SJean-Jacques Hiblot	  capabilities, pad configurations).
181476f6045SJean-Jacques Hiblot
182476f6045SJean-Jacques Hiblotconfig SPL_OF_LIST
183476f6045SJean-Jacques Hiblot	string "List of device tree files to include for DT control in SPL"
184476f6045SJean-Jacques Hiblot	depends on SPL_MULTI_DTB_FIT
185476f6045SJean-Jacques Hiblot	default OF_LIST
186476f6045SJean-Jacques Hiblot	help
187476f6045SJean-Jacques Hiblot	  This option specifies a list of device tree files to use for DT
188476f6045SJean-Jacques Hiblot	  control in the SPL. These will be packaged into a FIT. At run-time,
189476f6045SJean-Jacques Hiblot	  the SPL will select the correct DT to use by examining the
190476f6045SJean-Jacques Hiblot	  hardware (e.g. reading a board ID value). This is a list of
191476f6045SJean-Jacques Hiblot	  device tree files (without the directory or .dtb suffix)
192476f6045SJean-Jacques Hiblot	  separated by <space>.
193476f6045SJean-Jacques Hiblot
194476f6045SJean-Jacques Hiblotchoice
195476f6045SJean-Jacques Hiblot	prompt "SPL OF LIST compression"
196476f6045SJean-Jacques Hiblot	depends on SPL_MULTI_DTB_FIT
197476f6045SJean-Jacques Hiblot	default SPL_MULTI_DTB_FIT_LZO
198476f6045SJean-Jacques Hiblot
199476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT_LZO
200476f6045SJean-Jacques Hiblot	bool "LZO"
201476f6045SJean-Jacques Hiblot	depends on SYS_MALLOC_F
202476f6045SJean-Jacques Hiblot	select SPL_LZO
203476f6045SJean-Jacques Hiblot	help
204476f6045SJean-Jacques Hiblot	  Compress the FIT image containing the DTBs available for the SPL
205476f6045SJean-Jacques Hiblot	  using LZO compression. (requires lzop on host).
206476f6045SJean-Jacques Hiblot
207476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT_GZIP
208476f6045SJean-Jacques Hiblot	bool "GZIP"
209476f6045SJean-Jacques Hiblot	depends on SYS_MALLOC_F
210476f6045SJean-Jacques Hiblot	select SPL_GZIP
211476f6045SJean-Jacques Hiblot	help
212476f6045SJean-Jacques Hiblot	  Compress the FIT image containing the DTBs available for the SPL
213476f6045SJean-Jacques Hiblot	  using GZIP compression. (requires gzip on host)
214476f6045SJean-Jacques Hiblot
215476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT_NO_COMPRESSION
216476f6045SJean-Jacques Hiblot	bool "No compression"
217476f6045SJean-Jacques Hiblot	help
218476f6045SJean-Jacques Hiblot	  Do not compress the FIT image containing the DTBs available for the SPL.
219476f6045SJean-Jacques Hiblot	  Use this options only if LZO is not available and the DTBs are very small.
220476f6045SJean-Jacques Hiblotendchoice
221476f6045SJean-Jacques Hiblot
222476f6045SJean-Jacques Hiblotchoice
223476f6045SJean-Jacques Hiblot	prompt "Location of uncompressed DTBs "
224476f6045SJean-Jacques Hiblot	depends on (SPL_MULTI_DTB_FIT_GZIP || SPL_MULTI_DTB_FIT_LZO)
225476f6045SJean-Jacques Hiblot	default SPL_MULTI_DTB_FIT_DYN_ALLOC if SYS_MALLOC_F
226476f6045SJean-Jacques Hiblot
227476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT_DYN_ALLOC
228476f6045SJean-Jacques Hiblot	bool "Dynamically allocate the memory"
229476f6045SJean-Jacques Hiblot	depends on SYS_MALLOC_F
230476f6045SJean-Jacques Hiblot
231476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT_USER_DEFINED_AREA
232476f6045SJean-Jacques Hiblot	bool "User-defined location"
233476f6045SJean-Jacques Hiblotendchoice
234476f6045SJean-Jacques Hiblot
235476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT_UNCOMPRESS_SZ
236476f6045SJean-Jacques Hiblot	hex "Size of memory reserved to uncompress the DTBs"
237476f6045SJean-Jacques Hiblot	depends on (SPL_MULTI_DTB_FIT_GZIP || SPL_MULTI_DTB_FIT_LZO)
238476f6045SJean-Jacques Hiblot	default 0x8000
239476f6045SJean-Jacques Hiblot	help
240476f6045SJean-Jacques Hiblot	   This is the size of this area where the DTBs are uncompressed.
241476f6045SJean-Jacques Hiblot	   If this area is dynamically allocated, make sure that
242476f6045SJean-Jacques Hiblot	   SPL_SYS_MALLOC_F_LEN is big enough to contain it.
243476f6045SJean-Jacques Hiblot
244476f6045SJean-Jacques Hiblotconfig SPL_MULTI_DTB_FIT_USER_DEF_ADDR
245476f6045SJean-Jacques Hiblot	hex "Address of memory where dtbs are uncompressed"
246476f6045SJean-Jacques Hiblot	depends on SPL_MULTI_DTB_FIT_USER_DEFINED_AREA
247476f6045SJean-Jacques Hiblot	help
248476f6045SJean-Jacques Hiblot	   the FIT image containing the DTBs is uncompressed in an area defined
249476f6045SJean-Jacques Hiblot	   at compilation time. This is the address of this area. It must be
250476f6045SJean-Jacques Hiblot	   aligned on 2-byte boundary.
251476f6045SJean-Jacques Hiblot
252fa78e0a3SSimon Glassconfig OF_SPL_REMOVE_PROPS
253fa78e0a3SSimon Glass	string "List of device tree properties to drop for SPL"
254239ae4a9SVikas Manocha	default "interrupt-parent" if SPL_PINCTRL && SPL_CLK
255239ae4a9SVikas Manocha	default "clocks clock-names interrupt-parent" if SPL_PINCTRL
2565f3f7b79SMasahiro Yamada	default "pinctrl-0 pinctrl-names interrupt-parent" if SPL_CLK
257fa78e0a3SSimon Glass	default "pinctrl-0 pinctrl-names clocks clock-names interrupt-parent"
258fa78e0a3SSimon Glass	help
259fa78e0a3SSimon Glass	  Since SPL normally runs in a reduced memory space, the device tree
260fa78e0a3SSimon Glass	  is cut down to only what is needed to load and start U-Boot. Only
261fa78e0a3SSimon Glass	  nodes marked with the property "u-boot,dm-pre-reloc" will be
262fa78e0a3SSimon Glass	  included. In addition, some properties are not used by U-Boot and
263fa78e0a3SSimon Glass	  can be discarded. This option defines the list of properties to
264fa78e0a3SSimon Glass	  discard.
265fa78e0a3SSimon Glass
266c48a3a80SJoseph Chenconfig OF_U_BOOT_REMOVE_PROPS
267c48a3a80SJoseph Chen	string "List of device tree properties to drop for U-Boot"
268c48a3a80SJoseph Chen	depends on USING_KERNEL_DTB
269c48a3a80SJoseph Chen	default ""
270c48a3a80SJoseph Chen	help
271c48a3a80SJoseph Chen	  Since kernel dtb feature is enabled, U-Boot prop use the same device tree as SPL.
272c48a3a80SJoseph Chen	  At sometimes there is different require for list of device tree properties to drop
273c48a3a80SJoseph Chen	  for U-Boot prop, so providing this configure which has higher priority, that if it
274c48a3a80SJoseph Chen	  is defined empty string, fallback to use OF_SPL_REMOVE_PROPS.
275c48a3a80SJoseph Chen
2762789ddb9SSimon Glassconfig SPL_OF_PLATDATA
2772789ddb9SSimon Glass	bool "Generate platform data for use in SPL"
2782789ddb9SSimon Glass	depends on SPL_OF_CONTROL
279ec821af4SMasahiro Yamada	select DTOC
2802789ddb9SSimon Glass	help
2812789ddb9SSimon Glass	  For very constrained SPL environments the overhead of decoding
2822789ddb9SSimon Glass	  device tree nodes and converting their contents into platform data
2832789ddb9SSimon Glass	  is too large. This overhead includes libfdt code as well as the
2842789ddb9SSimon Glass	  device tree contents itself. The latter is fairly compact, but the
2852789ddb9SSimon Glass	  former can add 3KB or more to a Thumb 2 Image.
2862789ddb9SSimon Glass
2872789ddb9SSimon Glass	  This option enables generation of platform data from the device
2882789ddb9SSimon Glass	  tree as C code. This code creates devices using U_BOOT_DEVICE()
2892789ddb9SSimon Glass	  declarations. The benefit is that it allows driver code to access
2902789ddb9SSimon Glass	  the platform data directly in C structures, avoidin the libfdt
2912789ddb9SSimon Glass	  overhead.
2922789ddb9SSimon Glass
2932789ddb9SSimon Glass	  This option works by generating C structure declarations for each
2942789ddb9SSimon Glass	  compatible string, then adding platform data and U_BOOT_DEVICE
2952789ddb9SSimon Glass	  declarations for each node. See README.platdata for more
2962789ddb9SSimon Glass	  information.
2972789ddb9SSimon Glass
298f291ce12SPhilipp Tomsichconfig TPL_OF_PLATDATA
299f291ce12SPhilipp Tomsich	bool "Generate platform data for use in TPL"
300f291ce12SPhilipp Tomsich	depends on TPL_OF_CONTROL
301ec821af4SMasahiro Yamada	select DTOC
302f291ce12SPhilipp Tomsich	help
303f291ce12SPhilipp Tomsich	  For very constrained SPL environments the overhead of decoding
304f291ce12SPhilipp Tomsich	  device tree nodes and converting their contents into platform data
305f291ce12SPhilipp Tomsich	  is too large. This overhead includes libfdt code as well as the
306f291ce12SPhilipp Tomsich	  device tree contents itself. The latter is fairly compact, but the
307f291ce12SPhilipp Tomsich	  former can add 3KB or more to a Thumb 2 Image.
308f291ce12SPhilipp Tomsich
309f291ce12SPhilipp Tomsich	  This option enables generation of platform data from the device
310f291ce12SPhilipp Tomsich	  tree as C code. This code creates devices using U_BOOT_DEVICE()
311f291ce12SPhilipp Tomsich	  declarations. The benefit is that it allows driver code to access
312f291ce12SPhilipp Tomsich	  the platform data directly in C structures, avoidin the libfdt
313f291ce12SPhilipp Tomsich	  overhead.
314f291ce12SPhilipp Tomsich
315f291ce12SPhilipp Tomsich	  This option works by generating C structure declarations for each
316f291ce12SPhilipp Tomsich	  compatible string, then adding platform data and U_BOOT_DEVICE
317f291ce12SPhilipp Tomsich	  declarations for each node. See README.platdata for more
318f291ce12SPhilipp Tomsich	  information.
319f291ce12SPhilipp Tomsich
320783e6a72SMasahiro Yamadaendmenu
321f8470aeeSTom Rini
322f8470aeeSTom Riniconfig MKIMAGE_DTC_PATH
323f8470aeeSTom Rini	string "Path to dtc binary for use within mkimage"
324f8470aeeSTom Rini	default "dtc"
325f8470aeeSTom Rini	help
326f8470aeeSTom Rini	  The mkimage host tool will, in order to generate FIT images make
327f8470aeeSTom Rini	  calls to the dtc application in order to create the output.  In
328f8470aeeSTom Rini	  some cases the system dtc may not support all required features
329f8470aeeSTom Rini	  and the path to a different version should be given here.
330