[PATCH] dtc: introduce label relative path references
Peter Robinson
pbrobinson at gmail.com
Fri Mar 28 18:06:09 CET 2025
On Fri, 28 Mar 2025 at 16:52, Patrice Chotard <patrice.chotard at foss.st.com>
wrote:
> Since introduction of OF_UPSTREAM flag, U-Boot's dtc must be able
> to compile Kernel's device tree.
>
> Since kernel commit 7de129f5389b ("ARM: dts: stm32: stm32mp151a-prtt1l:
> Fix QSPI configuration"), label relative path references has been
> introduced. These label relative path references is not supported
> by current U-Boot dtc version 1.5.0: (see mailing list discussion [1]).
>
> In order to support such label relative patch references
> adds following commit from upstream DTC tree:
>
Maybe we need to rebase to the latest upstream dtc, I'm not sure pulling in
a random set of bits from upstream is the right way to do things as it's
brings things selectively which may bring along other issues.
> commit 651410e54cb9 ("util: introduce xstrndup helper")
> commit ec7986e682cf ("dtc: introduce label relative path references")
>
> [1] https://lore.kernel.org/all/20250115144428.GZ3476@bill-the-cat/T/
>
> Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: Simon Glass <sjg at chromium.org>
> ---
>
> scripts/dtc/dtc-lexer.l | 2 +-
> scripts/dtc/dtc-parser.y | 13 +++++++++++++
> scripts/dtc/livetree.c | 33 ++++++++++++++++++++++++++++++---
> scripts/dtc/util.c | 11 +++++++++++
> scripts/dtc/util.h | 1 +
> 5 files changed, 56 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/dtc/dtc-lexer.l b/scripts/dtc/dtc-lexer.l
> index d3694d6cf20..d34e1b04220 100644
> --- a/scripts/dtc/dtc-lexer.l
> +++ b/scripts/dtc/dtc-lexer.l
> @@ -215,7 +215,7 @@ static void PRINTF(1, 2) lexical_error(const char
> *fmt, ...);
> return DT_REF;
> }
>
> -<*>"&{/"{PATHCHAR}*\} { /* new-style path reference */
> +<*>"&{"{PATHCHAR}*\} { /* new-style path reference */
> yytext[yyleng-1] = '\0';
> DPRINT("Ref: %s\n", yytext+2);
> yylval.labelref = xstrdup(yytext+2);
> diff --git a/scripts/dtc/dtc-parser.y b/scripts/dtc/dtc-parser.y
> index 011a5b25539..b3b9c83873d 100644
> --- a/scripts/dtc/dtc-parser.y
> +++ b/scripts/dtc/dtc-parser.y
> @@ -34,6 +34,12 @@ extern void yyerror(char const *s);
>
> extern struct dt_info *parser_output;
> extern bool treesource_error;
> +
> +static bool is_ref_relative(const char *ref)
> +{
> + return ref[0] != '/' && strchr(&ref[1], '/');
> +}
> +
> %}
>
> %union {
> @@ -176,12 +182,17 @@ devicetree:
> */
> if (!($<flags>-1 & DTSF_PLUGIN))
> ERROR(&@2, "Label or path %s not found",
> $1);
> + else if (is_ref_relative($1))
> + ERROR(&@2, "Label-relative reference %s
> not supported in plugin", $1);
> $$ = add_orphan_node(name_node(build_node(NULL,
> NULL), ""), $2, $1);
> }
> | devicetree DT_LABEL DT_REF nodedef
> {
> struct node *target = get_node_by_ref($1, $3);
>
> + if (($<flags>-1 & DTSF_PLUGIN) &&
> is_ref_relative($3))
> + ERROR(&@2, "Label-relative reference %s
> not supported in plugin", $3);
> +
> if (target) {
> add_label(&target->labels, $2);
> merge_nodes(target, $4);
> @@ -197,6 +208,8 @@ devicetree:
> * so $-1 is what we want (plugindecl)
> */
> if ($<flags>-1 & DTSF_PLUGIN) {
> + if (is_ref_relative($2))
> + ERROR(&@2, "Label-relative
> reference %s not supported in plugin", $2);
> add_orphan_node($1, $3, $2);
> } else {
> struct node *target = get_node_by_ref($1,
> $2);
> diff --git a/scripts/dtc/livetree.c b/scripts/dtc/livetree.c
> index ba06ef348be..4cfc2adccdd 100644
> --- a/scripts/dtc/livetree.c
> +++ b/scripts/dtc/livetree.c
> @@ -583,12 +583,39 @@ struct node *get_node_by_phandle(struct node *tree,
> cell_t phandle)
>
> struct node *get_node_by_ref(struct node *tree, const char *ref)
> {
> + struct node *target = tree;
> + const char *label = NULL, *path = NULL;
> +
> if (streq(ref, "/"))
> return tree;
> - else if (ref[0] == '/')
> - return get_node_by_path(tree, ref);
> +
> + if (ref[0] == '/')
> + path = ref;
> else
> - return get_node_by_label(tree, ref);
> + label = ref;
> +
> + if (label) {
> + const char *slash = strchr(label, '/');
> + char *buf = NULL;
> +
> + if (slash) {
> + buf = xstrndup(label, slash - label);
> + label = buf;
> + path = slash + 1;
> + }
> +
> + target = get_node_by_label(tree, label);
> +
> + free(buf);
> +
> + if (!target)
> + return NULL;
> + }
> +
> + if (path)
> + target = get_node_by_path(target, path);
> +
> + return target;
> }
>
> cell_t get_node_phandle(struct node *root, struct node *node)
> diff --git a/scripts/dtc/util.c b/scripts/dtc/util.c
> index 23334d39bb6..25d4db1e8c2 100644
> --- a/scripts/dtc/util.c
> +++ b/scripts/dtc/util.c
> @@ -46,6 +46,17 @@ char *xstrdup(const char *s)
> return d;
> }
>
> +char *xstrndup(const char *s, size_t n)
> +{
> + size_t len = strnlen(s, n) + 1;
> + char *d = xmalloc(len);
> +
> + memcpy(d, s, len - 1);
> + d[len - 1] = '\0';
> +
> + return d;
> +}
> +
> /* based in part from (3) vsnprintf */
> int xasprintf(char **strp, const char *fmt, ...)
> {
> diff --git a/scripts/dtc/util.h b/scripts/dtc/util.h
> index 211d584435d..23e32962385 100644
> --- a/scripts/dtc/util.h
> +++ b/scripts/dtc/util.h
> @@ -70,6 +70,7 @@ static inline void *xrealloc(void *p, size_t len)
> }
>
> extern char *xstrdup(const char *s);
> +extern char *xstrndup(const char *s, size_t len);
>
> extern int PRINTF(2, 3) xasprintf(char **strp, const char *fmt, ...);
> extern char *join_path(const char *path, const char *name);
> --
> 2.25.1
>
>
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