scripts/dtc: Add overlay support

Author: Phil Elwell

scripts/dtc/checks.c

@@ -458,21 +458,91 @@ static void fixup_phandle_references(struct check *c, struct node *dt,
 				     struct node *node, struct property *prop)
 {
 	struct marker *m = prop->val.markers;
+	struct fixup *f, **fp;
+	struct fixup_entry *fe, **fep;
 	struct node *refnode;
 	cell_t phandle;
+	int has_phandle_refs;
+
+	has_phandle_refs = 0;
+	for_each_marker_of_type(m, REF_PHANDLE) {
+		has_phandle_refs = 1;
+		break;
+	}
+
+	if (!has_phandle_refs)
+		return;
 
 	for_each_marker_of_type(m, REF_PHANDLE) {
 		assert(m->offset + sizeof(cell_t) <= prop->val.len);
 
 		refnode = get_node_by_ref(dt, m->ref);
-		if (! refnode) {
+		if (!refnode && !symbol_fixup_support) {
 			FAIL(c, "Reference to non-existent node or label \"%s\"\n",
-			     m->ref);
+				m->ref);
 			continue;
 		}
 
-		phandle = get_node_phandle(dt, refnode);
-		*((cell_t *)(prop->val.val + m->offset)) = cpu_to_fdt32(phandle);
+		if (!refnode) {
+			/* allocate fixup entry */
+			fe = xmalloc(sizeof(*fe));
+
+			fe->node = node;
+			fe->prop = prop;
+			fe->offset = m->offset;
+			fe->next = NULL;
+
+			/* search for an already existing fixup */
+			for_each_fixup(dt, f)
+				if (strcmp(f->ref, m->ref) == 0)
+					break;
+
+			/* no fixup found, add new */
+			if (f == NULL) {
+				f = xmalloc(sizeof(*f));
+				f->ref = m->ref;
+				f->entries = NULL;
+				f->next = NULL;
+
+				/* add it to the tree */
+				fp = &dt->fixups;
+				while (*fp)
+					fp = &(*fp)->next;
+				*fp = f;
+			}
+
+			/* and now append fixup entry */
+			fep = &f->entries;
+			while (*fep)
+				fep = &(*fep)->next;
+			*fep = fe;
+
+			/* mark the entry as unresolved */
+			phandle = 0xdeadbeef;
+		} else {
+			phandle = get_node_phandle(dt, refnode);
+
+			/* if it's a plugin, we need to record it */
+			if (symbol_fixup_support && dt->is_plugin) {
+
+				/* allocate a new local fixup entry */
+				fe = xmalloc(sizeof(*fe));
+
+				fe->node = node;
+				fe->prop = prop;
+				fe->offset = m->offset;
+				fe->next = NULL;
+
+				/* append it to the local fixups */
+				fep = &dt->local_fixups;
+				while (*fep)
+					fep = &(*fep)->next;
+				*fep = fe;
+			}
+		}
+
+		*((cell_t *)(prop->val.val + m->offset)) =
+			cpu_to_fdt32(phandle);
 	}
 }
 ERROR(phandle_references, NULL, NULL, fixup_phandle_references, NULL,
@@ -652,6 +722,45 @@ static void check_obsolete_chosen_interrupt_controller(struct check *c,
 }
 TREE_WARNING(obsolete_chosen_interrupt_controller, NULL);
 
+static void check_auto_label_phandles(struct check *c, struct node *dt,
+				       struct node *node)
+{
+	struct label *l;
+	struct symbol *s, **sp;
+	int has_label;
+
+	if (!symbol_fixup_support)
+		return;
+
+	has_label = 0;
+	for_each_label(node->labels, l) {
+		has_label = 1;
+		break;
+	}
+
+	if (!has_label)
+		return;
+
+	/* force allocation of a phandle for this node */
+	(void)get_node_phandle(dt, node);
+
+	/* add the symbol */
+	for_each_label(node->labels, l) {
+
+		s = xmalloc(sizeof(*s));
+		s->label = l;
+		s->node = node;
+		s->next = NULL;
+
+		/* add it to the symbols list */
+		sp = &dt->symbols;
+		while (*sp)
+			sp = &((*sp)->next);
+		*sp = s;
+	}
+}
+NODE_WARNING(auto_label_phandles, NULL);
+
 static struct check *check_table[] = {
 	&duplicate_node_names, &duplicate_property_names,
 	&node_name_chars, &node_name_format, &property_name_chars,
@@ -670,6 +779,8 @@ static struct check *check_table[] = {
 	&avoid_default_addr_size,
 	&obsolete_chosen_interrupt_controller,
 
+	&auto_label_phandles,
+
 	&always_fail,
 };
 

scripts/dtc/dtc-lexer.l

@@ -113,6 +113,11 @@ static void lexical_error(const char *fmt, ...);
 			return DT_V1;
 		}
 
+<*>"/plugin/"	{
+			DPRINT("Keyword: /plugin/\n");
+			return DT_PLUGIN;
+		}
+
 <*>"/memreserve/"	{
 			DPRINT("Keyword: /memreserve/\n");
 			BEGIN_DEFAULT();

scripts/dtc/dtc-parser.y

@@ -19,6 +19,7 @@
  */
 %{
 #include <stdio.h>
+#include <inttypes.h>
 
 #include "dtc.h"
 #include "srcpos.h"
@@ -52,9 +53,11 @@ extern bool treesource_error;
 	struct node *nodelist;
 	struct reserve_info *re;
 	uint64_t integer;
+	int is_plugin;
 }
 
 %token DT_V1
+%token DT_PLUGIN
 %token DT_MEMRESERVE
 %token DT_LSHIFT DT_RSHIFT DT_LE DT_GE DT_EQ DT_NE DT_AND DT_OR
 %token DT_BITS
@@ -71,6 +74,7 @@ extern bool treesource_error;
 
 %type <data> propdata
 %type <data> propdataprefix
+%type <is_plugin> plugindecl
 %type <re> memreserve
 %type <re> memreserves
 %type <array> arrayprefix
@@ -101,10 +105,23 @@ extern bool treesource_error;
 %%
 
 sourcefile:
-	  DT_V1 ';' memreserves devicetree
+	  DT_V1 ';' plugindecl memreserves devicetree
 		{
-			the_boot_info = build_boot_info($3, $4,
-							guess_boot_cpuid($4));
+			$5->is_plugin = $3;
+			$5->is_root = 1;
+			the_boot_info = build_boot_info($4, $5,
+							guess_boot_cpuid($5));
+		}
+	;
+
+plugindecl:
+	/* empty */
+		{
+			$$ = 0;
+		}
+	| DT_PLUGIN ';'
+		{
+			$$ = 1;
 		}
 	;
 

scripts/dtc/dtc.c

@@ -29,6 +29,7 @@ int reservenum;		/* Number of memory reservation slots */
 int minsize;		/* Minimum blob size */
 int padsize;		/* Additional padding to blob */
 int phandle_format = PHANDLE_BOTH;	/* Use linux,phandle or phandle properties */
+int symbol_fixup_support = 0;
 
 static void fill_fullpaths(struct node *tree, const char *prefix)
 {
@@ -51,7 +52,7 @@ static void fill_fullpaths(struct node *tree, const char *prefix)
 #define FDT_VERSION(version)	_FDT_VERSION(version)
 #define _FDT_VERSION(version)	#version
 static const char usage_synopsis[] = "dtc [options] <input file>";
-static const char usage_short_opts[] = "qI:O:o:V:d:R:S:p:fb:i:H:sW:E:hv";
+static const char usage_short_opts[] = "qI:O:o:V:d:R:S:p:fb:i:H:sW:E:hv@";
 static struct option const usage_long_opts[] = {
 	{"quiet",            no_argument, NULL, 'q'},
 	{"in-format",         a_argument, NULL, 'I'},
@@ -69,6 +70,7 @@ static struct option const usage_long_opts[] = {
 	{"phandle",           a_argument, NULL, 'H'},
 	{"warning",           a_argument, NULL, 'W'},
 	{"error",             a_argument, NULL, 'E'},
+	{"symbols",           a_argument, NULL, '@'},
 	{"help",             no_argument, NULL, 'h'},
 	{"version",          no_argument, NULL, 'v'},
 	{NULL,               no_argument, NULL, 0x0},
@@ -99,6 +101,7 @@ static const char * const usage_opts_help[] = {
 	 "\t\tboth   - Both \"linux,phandle\" and \"phandle\" properties",
 	"\n\tEnable/disable warnings (prefix with \"no-\")",
 	"\n\tEnable/disable errors (prefix with \"no-\")",
+	"\n\tSymbols and Fixups support",
 	"\n\tPrint this help and exit",
 	"\n\tPrint version and exit",
 	NULL,
@@ -186,7 +189,9 @@ int main(int argc, char *argv[])
 		case 'E':
 			parse_checks_option(false, true, optarg);
 			break;
-
+		case '@':
+			symbol_fixup_support = 1;
+			break;
 		case 'h':
 			usage(NULL);
 		default:

scripts/dtc/dtc.h

@@ -54,6 +54,7 @@ extern int reservenum;		/* Number of memory reservation slots */
 extern int minsize;		/* Minimum blob size */
 extern int padsize;		/* Additional padding to blob */
 extern int phandle_format;	/* Use linux,phandle or phandle properties */
+extern int symbol_fixup_support;/* enable symbols & fixup support */
 
 #define PHANDLE_LEGACY	0x1
 #define PHANDLE_EPAPR	0x2
@@ -132,6 +133,25 @@ struct label {
 	struct label *next;
 };
 
+struct fixup_entry {
+	int offset;
+	struct node *node;
+	struct property *prop;
+	struct fixup_entry *next;
+};
+
+struct fixup {
+	char *ref;
+	struct fixup_entry *entries;
+	struct fixup *next;
+};
+
+struct symbol {
+	struct label *label;
+	struct node *node;
+	struct symbol *next;
+};
+
 struct property {
 	bool deleted;
 	char *name;
@@ -158,6 +178,12 @@ struct node {
 	int addr_cells, size_cells;
 
 	struct label *labels;
+
+	int is_root;
+	int is_plugin;
+	struct fixup *fixups;
+	struct symbol *symbols;
+	struct fixup_entry *local_fixups;
 };
 
 #define for_each_label_withdel(l0, l) \
@@ -181,6 +207,18 @@ struct node {
 	for_each_child_withdel(n, c) \
 		if (!(c)->deleted)
 
+#define for_each_fixup(n, f) \
+	for ((f) = (n)->fixups; (f); (f) = (f)->next)
+
+#define for_each_fixup_entry(f, fe) \
+	for ((fe) = (f)->entries; (fe); (fe) = (fe)->next)
+
+#define for_each_symbol(n, s) \
+	for ((s) = (n)->symbols; (s); (s) = (s)->next)
+
+#define for_each_local_fixup_entry(n, fe) \
+	for ((fe) = (n)->local_fixups; (fe); (fe) = (fe)->next)
+
 void add_label(struct label **labels, char *label);
 void delete_labels(struct label **labels);