dtc: Add -i option to support search paths

It is often inconvenient to place device tree files in the same directory
as their includes, or to specify the full path to include files.

An example of this is in U-Boot where we have a .dtsi file for each SOC
type, and this is included by the board .dts file. We need to either use
a mechanism like:

/include/ ARCH_CPU_DTS

with sed or cpp to perform the replacement with the correct path, or
we must specify the full path in the file:

/include/ "../../arch/arm/dts/tegra20.dtsi"

The first option is not desirable since it requires anyone compiling the
file to first pre-process it. The second is not desirable since it
introduces a path which is project-specific into a file which is supposed
to be a hardware description. For example Linux and U-Boot are unlikely to
put these include files in the same place.

It is much more convenient to specify the search patch on the command line
as is done with C pre-processors, for example.

Introduce a -i option to add to the list of search paths used to find
source and include files.

We cannot use -I as it is already in use. Other suggestions welcome.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/dtc.c b/dtc.c
index 7a0c605..83aef32 100644
--- a/dtc.c
+++ b/dtc.c
@@ -82,6 +82,8 @@ static void  __attribute__ ((noreturn)) usage(void)
 	fprintf(stderr, "\t\tSet the physical boot cpu\n");
 	fprintf(stderr, "\t-f\n");
 	fprintf(stderr, "\t\tForce - try to produce output even if the input tree has errors\n");
+	fprintf(stderr, "\t-i\n");
+	fprintf(stderr, "\t\tAdd a path to search for include files\n");
 	fprintf(stderr, "\t-s\n");
 	fprintf(stderr, "\t\tSort nodes and properties before outputting (only useful for\n\t\tcomparing trees)\n");
 	fprintf(stderr, "\t-v\n");
@@ -113,7 +115,8 @@ int main(int argc, char *argv[])
 	minsize    = 0;
 	padsize    = 0;
 
-	while ((opt = getopt(argc, argv, "hI:O:o:V:d:R:S:p:fqb:vH:s")) != EOF) {
+	while ((opt = getopt(argc, argv, "hI:O:o:V:d:R:S:p:fqb:i:vH:s"))
+			!= EOF) {
 		switch (opt) {
 		case 'I':
 			inform = optarg;
@@ -148,6 +151,9 @@ int main(int argc, char *argv[])
 		case 'b':
 			cmdline_boot_cpuid = strtoll(optarg, NULL, 0);
 			break;
+		case 'i':
+			srcfile_add_search_path(optarg);
+			break;
 		case 'v':
 			printf("Version: %s\n", DTC_VERSION);
 			exit(0);