[PATCH] dtc: Basic integer expressions

[PATCH] dtc: Basic integer expressions

[Stephen Warren]

Written by David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>. Additions by me:
* Ported to ToT dtc.
* Renamed cell to integer throughout.
* Implemented value range checks.
* Allow U/L/UL/LL/ULL suffix on literals.
* Enabled the commented test.

Signed-off-by: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
---
v3:
* Fix printf warning by s/%ld/%zd/
* Support plain "U" as an integer literal suffix
* Fix misplaced semi-colons in grammar
* Support integer expressions for /memreserve/ and /incbin/ too
* Modify eval_literal to check U/L suffixes after strtoull call,
  using strspn/strlen
* Remove mention of libfdt from comment in tests/integer-expressions.c
* Add comment to explain integer_prim range check
v2:
* s/cell/integer/ throughout.
* Allow signed-extended values to pass the overall cell range check.
* Allow L/UL/LL/ULL suffix on literals. This is purely for compatibility
  with C, and has no effect on dtc's processing.
* Enabled the 3 disabled tests.
---
 dtc-lexer.l                 |   11 +++-
 dtc-parser.y                |  156 ++++++++++++++++++++++++++++++++++++-------
 tests/Makefile.tests        |    3 +-
 tests/integer-expressions.c |  117 ++++++++++++++++++++++++++++++++
 tests/run_tests.sh          |    5 ++
 5 files changed, 266 insertions(+), 26 deletions(-)
 create mode 100644 tests/integer-expressions.c

diff --git a/dtc-lexer.l b/dtc-lexer.l
index 73d190c..4715f31 100644
--- a/dtc-lexer.l
+++ b/dtc-lexer.l
@@ -110,7 +110,7 @@ static int pop_input_file(void);
 			return DT_LABEL;
 		}
 
-<V1>[0-9]+|0[xX][0-9a-fA-F]+      {
+<V1>([0-9]+|0[xX][0-9a-fA-F]+)(U|L|UL|LL|ULL)? {
 			yylval.literal = xstrdup(yytext);
 			DPRINT("Literal: '%s'\n", yylval.literal);
 			return DT_LITERAL;
@@ -164,6 +164,15 @@ static int pop_input_file(void);
 <*>{COMMENT}+	/* eat C-style comments */
 <*>{LINECOMMENT}+ /* eat C++-style comments */
 
+<*>"<<"		{ return DT_LSHIFT; };
+<*>">>"		{ return DT_RSHIFT; };
+<*>"<="		{ return DT_LE; };
+<*>">="		{ return DT_GE; };
+<*>"=="		{ return DT_EQ; };
+<*>"!="		{ return DT_NE; };
+<*>"&&"		{ return DT_AND; };
+<*>"||"		{ return DT_OR; };
+
 <*>.		{
 			DPRINT("Char: %c (\\x%02x)\n", yytext[0],
 				(unsigned)yytext[0]);
diff --git a/dtc-parser.y b/dtc-parser.y
index 348616b..6d5c2c2 100644
--- a/dtc-parser.y
+++ b/dtc-parser.y
@@ -50,16 +50,17 @@ static unsigned char eval_char_literal(const char *s);
 		int		bits;
 	} array;
 
-	uint64_t addr;
 	struct property *prop;
 	struct property *proplist;
 	struct node *node;
 	struct node *nodelist;
 	struct reserve_info *re;
+	uint64_t integer;
 }
 
 %token DT_V1
 %token DT_MEMRESERVE
+%token DT_LSHIFT DT_RSHIFT DT_LE DT_GE DT_EQ DT_NE DT_AND DT_OR
 %token DT_BITS
 %token <propnodename> DT_PROPNODENAME
 %token <literal> DT_LITERAL
@@ -75,7 +76,6 @@ static unsigned char eval_char_literal(const char *s);
 %type <data> propdataprefix
 %type <re> memreserve
 %type <re> memreserves
-%type <addr> addr
 %type <array> arrayprefix
 %type <data> bytestring
 %type <prop> propdef
@@ -86,6 +86,21 @@ static unsigned char eval_char_literal(const char *s);
 %type <node> subnode
 %type <nodelist> subnodes
 
+%type <integer> integer_prim
+%type <integer> integer_unary
+%type <integer> integer_mul
+%type <integer> integer_add
+%type <integer> integer_shift
+%type <integer> integer_rela
+%type <integer> integer_eq
+%type <integer> integer_bitand
+%type <integer> integer_bitxor
+%type <integer> integer_bitor
+%type <integer> integer_and
+%type <integer> integer_or
+%type <integer> integer_trinary
+%type <integer> integer_expr
+
 %%
 
 sourcefile:
@@ -108,7 +123,7 @@ memreserves:
 	;
 
 memreserve:
-	  DT_MEMRESERVE addr addr ';'
+	  DT_MEMRESERVE integer_prim integer_prim ';'
 		{
 			$$ = build_reserve_entry($2, $3);
 		}
@@ -119,13 +134,6 @@ memreserve:
 		}
 	;
 
-addr:
-	  DT_LITERAL
-		{
-			$$ = eval_literal($1, 0, 64);
-		}
-	  ;
-
 devicetree:
 	  '/' nodedef
 		{
@@ -198,7 +206,7 @@ propdata:
 		{
 			$$ = data_add_marker($1, REF_PATH, $2);
 		}
-	| propdataprefix DT_INCBIN '(' DT_STRING ',' addr ',' addr ')'
+	| propdataprefix DT_INCBIN '(' DT_STRING ',' integer_prim ',' integer_prim ')'
 		{
 			FILE *f = srcfile_relative_open($4.val, NULL);
 			struct data d;
@@ -267,17 +275,25 @@ arrayprefix:
 			$$.data = empty_data;
 			$$.bits = 32;
 		}
-	| arrayprefix DT_LITERAL
-		{
-			uint64_t val = eval_literal($2, 0, $1.bits);
-
-			$$.data = data_append_integer($1.data, val, $1.bits);
-		}
-	| arrayprefix DT_CHAR_LITERAL
-		{
-			uint64_t val = eval_char_literal($2);
+	| arrayprefix integer_prim
+		{
+			if ($1.bits < 64) {
+				uint64_t mask = (1ULL << $1.bits) - 1;
+				/*
+				 * Bits above mask must either be all zero
+				 * (positive within range of mask) or all one
+				 * (negative and sign-extended). The second
+				 * condition is true if when we set all bits
+				 * within the mask to one (i.e. | in the
+				 * mask), all bits are one.
+				 */
+				if (($2 > mask) && (($2 | mask) != -1ULL))
+					print_error(
+						"integer value out of range "
+						"%016lx (%d bits)", $1.bits);
+			}
 
-			$$.data = data_append_integer($1.data, val, $1.bits);
+			$$.data = data_append_integer($1.data, $2, $1.bits);
 		}
 	| arrayprefix DT_REF
 		{
@@ -299,6 +315,95 @@ arrayprefix:
 		}
 	;
 
+integer_prim:
+	  DT_LITERAL
+		{
+			$$ = eval_literal($1, 0, 64);
+		}
+	| DT_CHAR_LITERAL
+		{
+			$$ = eval_char_literal($1);
+		}
+	| '(' integer_expr ')'
+		{
+			$$ = $2;
+		}
+	;
+
+integer_expr:
+	integer_trinary
+	;
+
+integer_trinary:
+	  integer_or
+	| integer_or '?' integer_expr ':' integer_trinary { $$ = $1 ? $3 : $5; }
+	;
+
+integer_or:
+	  integer_and
+	| integer_or DT_OR integer_and { $$ = $1 || $3; }
+	;
+
+integer_and:
+	  integer_bitor
+	| integer_and DT_AND integer_bitor { $$ = $1 && $3; }
+	;
+
+integer_bitor:
+	  integer_bitxor
+	| integer_bitor '|' integer_bitxor { $$ = $1 | $3; }
+	;
+
+integer_bitxor:
+	  integer_bitand
+	| integer_bitxor '^' integer_bitand { $$ = $1 ^ $3; }
+	;
+
+integer_bitand:
+	  integer_eq
+	| integer_bitand '&' integer_eq { $$ = $1 & $3; }
+	;
+
+integer_eq:
+	  integer_rela
+	| integer_eq DT_EQ integer_rela { $$ = $1 == $3; }
+	| integer_eq DT_NE integer_rela { $$ = $1 != $3; }
+	;
+
+integer_rela:
+	  integer_shift
+	| integer_rela '<' integer_shift { $$ = $1 < $3; }
+	| integer_rela '>' integer_shift { $$ = $1 > $3; }
+	| integer_rela DT_LE integer_shift { $$ = $1 <= $3; }
+	| integer_rela DT_GE integer_shift { $$ = $1 >= $3; }
+	;
+
+integer_shift:
+	  integer_shift DT_LSHIFT integer_add { $$ = $1 << $3; }
+	| integer_shift DT_RSHIFT integer_add { $$ = $1 >> $3; }
+	| integer_add
+	;
+
+integer_add:
+	  integer_add '+' integer_mul { $$ = $1 + $3; }
+	| integer_add '-' integer_mul { $$ = $1 - $3; }
+	| integer_mul
+	;
+
+integer_mul:
+	  integer_mul '*' integer_unary { $$ = $1 * $3; }
+	| integer_mul '/' integer_unary { $$ = $1 / $3; }
+	| integer_mul '%' integer_unary { $$ = $1 % $3; }
+	| integer_unary
+	;
+
+integer_unary:
+	  integer_prim
+	| '-' integer_unary { $$ = -$2; }
+	| '~' integer_unary { $$ = ~$2; }
+	| '!' integer_unary { $$ = !$2; }
+	;
+
 bytestring:
 	  /* empty */
 		{
@@ -366,9 +471,12 @@ static unsigned long long eval_literal(const char *s, int base, int bits)
 
 	errno = 0;
 	val = strtoull(s, &e, base);
-	if (*e)
-		print_error("bad characters in literal");
-	else if ((errno == ERANGE)
+	if (*e) {
+		size_t uls = strspn(e, "UL");
+		if (e[uls])
+			print_error("bad characters in literal");
+	}
+	if ((errno == ERANGE)
 		 || ((bits < 64) && (val >= (1ULL << bits))))
 		print_error("literal out of range");
 	else if (errno != 0)
diff --git a/tests/Makefile.tests b/tests/Makefile.tests
index 2eee708..1795466 100644
--- a/tests/Makefile.tests
+++ b/tests/Makefile.tests
@@ -19,7 +19,8 @@ LIB_TESTS_L = get_mem_rsv \
 	dtbs_equal_ordered \
 	dtb_reverse dtbs_equal_unordered \
 	add_subnode_with_nops path_offset_aliases \
-	utilfdt_test
+	utilfdt_test \
+	integer-expressions
 LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%)
 
 LIBTREE_TESTS_L = truncated_property
diff --git a/tests/integer-expressions.c b/tests/integer-expressions.c
new file mode 100644
index 0000000..5ba1566
--- /dev/null
+++ b/tests/integer-expressions.c
@@ -0,0 +1,117 @@
+/*
+ * Testcase for dtc expression support
+ *
+ * Copyright (C) 2008 David Gibson, IBM Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "tests.h"
+#include "testdata.h"
+
+struct test_expr {
+	const char *expr;
+	uint32_t result;
+} expr_table[] = {
+#define TE(expr)	{ #expr, (expr) }
+	TE(0xdeadbeef),
+	TE(-0x21524111),
+	TE(1+1),
+	TE(2*3),
+	TE(4/2),
+	TE(10/3),
+	TE(19%4),
+	TE(1 << 13),
+	TE(0x1000 >> 4),
+	TE(3*2+1), TE(3*(2+1)),
+	TE(1+2*3), TE((1+2)*3),
+	TE(1 < 2), TE(2 < 1), TE(1 < 1),
+	TE(1 <= 2), TE(2 <= 1), TE(1 <= 1),
+	TE(1 > 2), TE(2 > 1), TE(1 > 1),
+	TE(1 >= 2), TE(2 >= 1), TE(1 >= 1),
+	TE(1 == 1), TE(1 == 2),
+	TE(1 != 1), TE(1 != 2),
+	TE(0xabcdabcd & 0xffff0000),
+	TE(0xdead4110 ^ 0xf0f0f0f0),
+	TE(0xabcd0000 | 0x0000abcd),
+	TE(~0x21524110),
+	TE(~~0xdeadbeef),
+	TE(0 && 0), TE(17 && 0), TE(0 && 17), TE(17 && 17),
+	TE(0 || 0), TE(17 || 0), TE(0 || 17), TE(17 || 17),
+	TE(!0), TE(!1), TE(!17), TE(!!0), TE(!!17),
+	TE(0 ? 17 : 39), TE(1 ? 17 : 39), TE(17 ? 0xdeadbeef : 0xabcd1234),
+	TE(11 * 257 * 1321517ULL),
+	TE(123456790 - 4/2 + 17%4),
+};
+
+#define ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
+
+int main(int argc, char *argv[])
+{
+	void *fdt;
+	const uint32_t *res;
+	int reslen;
+	int i;
+
+	test_init(argc, argv);
+
+	if ((argc == 3) && (strcmp(argv[1], "-g") == 0)) {
+		FILE *f = fopen(argv[2], "w");
+
+		if (!f)
+			FAIL("Couldn't open \"%s\" for output: %s\n",
+			     argv[2], strerror(errno));
+
+		fprintf(f, "/dts-v1/;\n");
+		fprintf(f, "/ {\n");
+		fprintf(f, "\texpressions = <\n");
+		for (i = 0; i < ARRAY_SIZE(expr_table); i++)
+			fprintf(f, "\t\t(%s)\n", expr_table[i].expr);
+		fprintf(f, "\t>;\n");
+		fprintf(f, "};\n");
+		fclose(f);
+	} else {
+		fdt = load_blob_arg(argc, argv);
+
+		res = fdt_getprop(fdt, 0, "expressions", &reslen);
+
+		if (!res)
+			FAIL("Error retreiving expression results: %s\n",
+		     fdt_strerror(reslen));
+
+		if (reslen != (ARRAY_SIZE(expr_table) * sizeof(uint32_t)))
+			FAIL("Unexpected length of results %d instead of %zd\n",
+			     reslen, ARRAY_SIZE(expr_table) * sizeof(uint32_t));
+
+		for (i = 0; i < ARRAY_SIZE(expr_table); i++)
+			if (fdt32_to_cpu(res[i]) != expr_table[i].result)
+				FAIL("Incorrect result for expression \"%s\","
+				     " 0x%x instead of 0x%x\n",
+				     expr_table[i].expr, fdt32_to_cpu(res[i]),
+				     expr_table[i].result);
+	}
+
+	PASS();
+}
diff --git a/tests/run_tests.sh b/tests/run_tests.sh
index e470b82..ab8133c 100755
--- a/tests/run_tests.sh
+++ b/tests/run_tests.sh
@@ -404,6 +404,11 @@ dtc_tests () {
     run_dtc_test -I dtb -O dts -o stdin_odts_test_tree1.dtb.test.dts - < test_tree1.dtb
     run_wrap_test cmp stdin_odts_test_tree1.dtb.test.dts odts_test_tree1.dtb.test.dts
 
+    # Check integer expresisons
+    run_test integer-expressions -g integer-expressions.test.dts
+    run_dtc_test -I dts -O dtb -o integer-expressions.test.dtb integer-expressions.test.dts
+    run_test integer-expressions integer-expressions.test.dtb
+
     # Check for graceful failure in some error conditions
     run_sh_test dtc-fatal.sh -I dts -O dtb nosuchfile.dts
     run_sh_test dtc-fatal.sh -I dtb -O dtb nosuchfile.dtb
-- 
1.7.5.4

Re: [PATCH] dtc: Basic integer expressions

[Jon Loeliger]

> Written by David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>. Additions by me:
> * Ported to ToT dtc.
> * Renamed cell to integer throughout.
> * Implemented value range checks.
> * Allow U/L/UL/LL/ULL suffix on literals.
> * Enabled the commented test.
> 
> Signed-off-by: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
> ---
> v3:
> * Fix printf warning by s/%ld/%zd/
> * Support plain "U" as an integer literal suffix
> * Fix misplaced semi-colons in grammar
> * Support integer expressions for /memreserve/ and /incbin/ too
> * Modify eval_literal to check U/L suffixes after strtoull call,
>   using strspn/strlen
> * Remove mention of libfdt from comment in tests/integer-expressions.c
> * Add comment to explain integer_prim range check
> v2:
> * s/cell/integer/ throughout.
> * Allow signed-extended values to pass the overall cell range check.
> * Allow L/UL/LL/ULL suffix on literals. This is purely for compatibility
>   with C, and has no effect on dtc's processing.
> * Enabled the 3 disabled tests.


Applied.

jdl

Re: [PATCH] dtc: Basic integer expressions

[Jean-Christophe PLAGNIOL-VILLARD]

On 08:43 Mon 09 Apr     , Jon Loeliger wrote:
> > Written by David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>. Additions by me:
> > * Ported to ToT dtc.
> > * Renamed cell to integer throughout.
> > * Implemented value range checks.
> > * Allow U/L/UL/LL/ULL suffix on literals.
> > * Enabled the commented test.
> > 
> > Signed-off-by: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
> > ---
> > v3:
> > * Fix printf warning by s/%ld/%zd/
> > * Support plain "U" as an integer literal suffix
> > * Fix misplaced semi-colons in grammar
> > * Support integer expressions for /memreserve/ and /incbin/ too
> > * Modify eval_literal to check U/L suffixes after strtoull call,
> >   using strspn/strlen
> > * Remove mention of libfdt from comment in tests/integer-expressions.c
> > * Add comment to explain integer_prim range check
> > v2:
> > * s/cell/integer/ throughout.
> > * Allow signed-extended values to pass the overall cell range check.
> > * Allow L/UL/LL/ULL suffix on literals. This is purely for compatibility
> >   with C, and has no effect on dtc's processing.
> > * Enabled the 3 disabled tests.
> 
> 
> Applied.
can we update the kernel with it in next I'm goint to use it for at91 too

Best Regards,
J.
> 
> jdl
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org
> https://lists.ozlabs.org/listinfo/devicetree-discuss

Re: [PATCH] dtc: Basic integer expressions

[Jean-Christophe PLAGNIOL-VILLARD]

On 20:56 Tue 03 Apr     , Stephen Warren wrote:
> Written by David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>. Additions by me:
> * Ported to ToT dtc.
> * Renamed cell to integer throughout.
> * Implemented value range checks.
> * Allow U/L/UL/LL/ULL suffix on literals.
> * Enabled the commented test.
> 
> Signed-off-by: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
> ---
> v3:
> * Fix printf warning by s/%ld/%zd/
> * Support plain "U" as an integer literal suffix
> * Fix misplaced semi-colons in grammar
> * Support integer expressions for /memreserve/ and /incbin/ too
> * Modify eval_literal to check U/L suffixes after strtoull call,
>   using strspn/strlen
> * Remove mention of libfdt from comment in tests/integer-expressions.c
> * Add comment to explain integer_prim range check
> v2:
> * s/cell/integer/ throughout.
> * Allow signed-extended values to pass the overall cell range check.
> * Allow L/UL/LL/ULL suffix on literals. This is purely for compatibility
>   with C, and has no effect on dtc's processing.
> * Enabled the 3 disabled tests.
Stephen what is the status of the define value?

Best Regards,
J.

Re: [PATCH] dtc: Basic integer expressions

[Stephen Warren]

On 04/09/2012 08:38 PM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 20:56 Tue 03 Apr     , Stephen Warren wrote:
>> Written by David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>. Additions by me:
>> * Ported to ToT dtc.
>> * Renamed cell to integer throughout.
>> * Implemented value range checks.
>> * Allow U/L/UL/LL/ULL suffix on literals.
>> * Enabled the commented test.
>>
>> Signed-off-by: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
>> ---
>> v3:
>> * Fix printf warning by s/%ld/%zd/
>> * Support plain "U" as an integer literal suffix
>> * Fix misplaced semi-colons in grammar
>> * Support integer expressions for /memreserve/ and /incbin/ too
>> * Modify eval_literal to check U/L suffixes after strtoull call,
>>   using strspn/strlen
>> * Remove mention of libfdt from comment in tests/integer-expressions.c
>> * Add comment to explain integer_prim range check
>> v2:
>> * s/cell/integer/ throughout.
>> * Allow signed-extended values to pass the overall cell range check.
>> * Allow L/UL/LL/ULL suffix on literals. This is purely for compatibility
>>   with C, and has no effect on dtc's processing.
>> * Enabled the 3 disabled tests.
>
> Stephen what is the status of the define value?

You mean /define/ VAR VALUE? It's on hold right now; I've been waiting
for this patch to be merged before trying to push that, since one of the
objections against the /define/ patch was that we didn't know what the
future dtc expressions syntax would look like, and hence couldn't tell
whether /define/ fit into it. Now at least we know what integer
expressions look like, so can perhaps start thinking about /define/
syntax again...

Re: [PATCH] dtc: Basic integer expressions

[Stephen Warren]

On 04/09/2012 08:29 PM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> On 08:43 Mon 09 Apr     , Jon Loeliger wrote:
>>> Written by David Gibson <david-xT8FGy+AXnRB3Ne2BGzF6laj5H9X9Tb+@public.gmane.org>. Additions by me:
>>> * Ported to ToT dtc.
>>> * Renamed cell to integer throughout.
>>> * Implemented value range checks.
>>> * Allow U/L/UL/LL/ULL suffix on literals.
>>> * Enabled the commented test.
...
>>
>> Applied.
>
> can we update the kernel with it in next I'm goint to use it for at91 too

Sure.

Grant,

Should I just port this individual patch, or pull in the whole of ToT
dtc? I vaguely recall you advocating the latter sometime recently.

Re: [PATCH] dtc: Basic integer expressions

[Jon Loeliger]

> >
> > can we update the kernel with it in next I'm goint to use it for at91 too
> 
> Sure.
> 
> Grant,
> 
> Should I just port this individual patch, or pull in the whole of ToT
> dtc? I vaguely recall you advocating the latter sometime recently.

We should wait and include the recently posted patch:

    From:    Andrej Krutak
    Subject: Re: [PATCH] Rename _B to _XBYTE in libfdt_env.h.

jdl

Re: [PATCH] dtc: Basic integer expressions

[Stephen Warren]

On 04/10/2012 08:43 AM, Jon Loeliger wrote:
>>>
>>> can we update the kernel with it in next I'm goint to use it for at91 too
>>
>> Sure.
>>
>> Grant,
>>
>> Should I just port this individual patch, or pull in the whole of ToT
>> dtc? I vaguely recall you advocating the latter sometime recently.
> 
> We should wait and include the recently posted patch:
> 
>     From:    Andrej Krutak
>     Subject: Re: [PATCH] Rename _B to _XBYTE in libfdt_env.h.

Oh, I see this actually is there already in upstream dtc, although the
patch subject ended up being something different.

In general, do you recommend just copying upstream dtc over the top of
the kernel copy, or streaming in patches individually, or something
else? Is there someone who usually does this; I see a lot of different
committers to scripts/dtc in the kernel.