PKGBUILDs/alarm/dtc-overlay/0001-dtc-Symbol-and-local-fixup-generation-support.patch

From 78077bd72707579bffab6b1d3e7f1a8f5b2b127f Mon Sep 17 00:00:00 2001
From: Pantelis Antoniou
 <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
Date: Tue, 21 Oct 2014 22:39:57 +0300
Subject: [PATCH 1/3] dtc: Symbol and local fixup generation support

Enable the generation of symbols & local fixup information
for trees compiled with the -@ (--symbols) option.

Using this patch labels in the tree and their users emit information
in __symbols__ and __local_fixups__ nodes. Using this information
it is possible to implement run time dynamic tree loading.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou-OWPKS81ov/FWk0Htik3J/w@public.gmane.org>
---
 Documentation/manual.txt |   5 ++
 checks.c                 |  61 +++++++++++++++++++++
 dtc.c                    |   9 ++-
 dtc.h                    |  28 ++++++++++
 flattree.c               | 139 +++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 240 insertions(+), 2 deletions(-)

diff --git a/Documentation/manual.txt b/Documentation/manual.txt
index 398de32..4359958 100644
--- a/Documentation/manual.txt
+++ b/Documentation/manual.txt
@@ -119,6 +119,11 @@ Options:
 	Make space for <number> reserve map entries
 	Relevant for dtb and asm output only.
 
+    -@
+        Generates a __symbols__ node at the root node of the resulting blob
+	for any node labels used, and for any local references using phandles
+	it also generates a __local_fixups__ node that tracks them.
+
     -S <bytes>
 	Ensure the blob at least <bytes> long, adding additional
 	space if needed.
diff --git a/checks.c b/checks.c
index 3bf0fa4..f203986 100644
--- a/checks.c
+++ b/checks.c
@@ -457,6 +457,7 @@ 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_entry *fe, **fep;
 	struct node *refnode;
 	cell_t phandle;
 
@@ -470,9 +471,28 @@ static void fixup_phandle_references(struct check *c, struct node *dt,
 			continue;
 		}
 
+		/* if it's a local reference, we need to record it */
+		if (symbol_fixup_support) {
+
+			/* 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;
+		}
+
 		phandle = get_node_phandle(dt, refnode);
 		*((cell_t *)(prop->val.val + m->offset)) = cpu_to_fdt32(phandle);
 	}
+
 }
 ERROR(phandle_references, NULL, NULL, fixup_phandle_references, NULL,
       &duplicate_node_names, &explicit_phandles);
@@ -651,6 +671,45 @@ 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,
@@ -669,6 +728,8 @@ static struct check *check_table[] = {
 	&avoid_default_addr_size,
 	&obsolete_chosen_interrupt_controller,
 
+	&auto_label_phandles,
+
 	&always_fail,
 };
 
diff --git a/dtc.c b/dtc.c
index 8c4add6..91e91e7 100644
--- a/dtc.c
+++ b/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",	     no_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\tEnable symbols/fixup 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:
diff --git a/dtc.h b/dtc.h
index 56212c8..16354fa 100644
--- a/dtc.h
+++ b/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 +133,20 @@ struct label {
 	struct label *next;
 };
 
+struct fixup_entry {
+	int offset;
+	struct node *node;
+	struct property *prop;
+	struct fixup_entry *next;
+	bool local_fixup_generated;
+};
+
+struct symbol {
+	struct label *label;
+	struct node *node;
+	struct symbol *next;
+};
+
 struct property {
 	bool deleted;
 	char *name;
@@ -158,6 +173,10 @@ struct node {
 	int addr_cells, size_cells;
 
 	struct label *labels;
+
+	struct symbol *symbols;
+	struct fixup_entry *local_fixups;
+	bool emit_local_fixup_node;
 };
 
 #define for_each_label_withdel(l0, l) \
@@ -181,6 +200,15 @@ struct node {
 	for_each_child_withdel(n, c) \
 		if (!(c)->deleted)
 
+#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);
 
diff --git a/flattree.c b/flattree.c
index bd99fa2..3a58949 100644
--- a/flattree.c
+++ b/flattree.c
@@ -255,6 +255,142 @@ static int stringtable_insert(struct data *d, const char *str)
 	return i;
 }
 
+static void emit_local_fixups(struct node *tree, struct emitter *emit,
+		void *etarget, struct data *strbuf, struct version_info *vi,
+		struct node *node)
+{
+	struct fixup_entry *fe, *fen;
+	struct node *child;
+	int nameoff, count;
+	cell_t *buf;
+	struct data d;
+
+	if (node->emit_local_fixup_node) {
+
+		/* emit the external fixups (do not emit /) */
+		if (node != tree) {
+			emit->beginnode(etarget, NULL);
+			emit->string(etarget, node->name, 0);
+			emit->align(etarget, sizeof(cell_t));
+		}
+
+		for_each_local_fixup_entry(tree, fe) {
+			if (fe->node != node || fe->local_fixup_generated)
+				continue;
+
+			/* count the number of fixup entries */
+			count = 0;
+			for_each_local_fixup_entry(tree, fen) {
+				if (fen->prop != fe->prop)
+					continue;
+				fen->local_fixup_generated = true;
+				count++;
+			}
+
+			/* allocate buffer */
+			buf = xmalloc(count * sizeof(cell_t));
+
+			/* collect all the offsets in buffer */
+			count = 0;
+			for_each_local_fixup_entry(tree, fen) {
+				if (fen->prop != fe->prop)
+					continue;
+				fen->local_fixup_generated = true;
+				buf[count++] = cpu_to_fdt32(fen->offset);
+			}
+			d = empty_data;
+			d.len = count * sizeof(cell_t);
+			d.val = (char *)buf;
+
+			nameoff = stringtable_insert(strbuf, fe->prop->name);
+			emit->property(etarget, fe->prop->labels);
+			emit->cell(etarget, count * sizeof(cell_t));
+			emit->cell(etarget, nameoff);
+
+			if ((vi->flags & FTF_VARALIGN) &&
+					(count * sizeof(cell_t)) >= 8)
+				emit->align(etarget, 8);
+
+			emit->data(etarget, d);
+			emit->align(etarget, sizeof(cell_t));
+
+			free(buf);
+		}
+	}
+
+	for_each_child(node, child)
+		emit_local_fixups(tree, emit, etarget, strbuf, vi, child);
+
+	if (node->emit_local_fixup_node && node != tree)
+		emit->endnode(etarget, tree->labels);
+}
+
+static void emit_symbols_node(struct node *tree, struct emitter *emit,
+			      void *etarget, struct data *strbuf,
+			      struct version_info *vi)
+{
+	struct symbol *sym;
+	int nameoff, vallen;
+
+	/* do nothing if no symbols */
+	if (!tree->symbols)
+		return;
+
+	emit->beginnode(etarget, NULL);
+	emit->string(etarget, "__symbols__", 0);
+	emit->align(etarget, sizeof(cell_t));
+
+	for_each_symbol(tree, sym) {
+
+		vallen = strlen(sym->node->fullpath);
+
+		nameoff = stringtable_insert(strbuf, sym->label->label);
+
+		emit->property(etarget, NULL);
+		emit->cell(etarget, vallen + 1);
+		emit->cell(etarget, nameoff);
+
+		if ((vi->flags & FTF_VARALIGN) && vallen >= 8)
+			emit->align(etarget, 8);
+
+		emit->string(etarget, sym->node->fullpath,
+				strlen(sym->node->fullpath));
+		emit->align(etarget, sizeof(cell_t));
+	}
+
+	emit->endnode(etarget, NULL);
+}
+
+static void emit_local_fixups_node(struct node *tree, struct emitter *emit,
+				   void *etarget, struct data *strbuf,
+				   struct version_info *vi)
+{
+	struct fixup_entry *fe;
+	struct node *node;
+
+	/* do nothing if no local fixups */
+	if (!tree->local_fixups)
+		return;
+
+	/* mark all nodes that need a local fixup generated (and parents) */
+	for_each_local_fixup_entry(tree, fe) {
+		node = fe->node;
+		while (node != NULL && !node->emit_local_fixup_node) {
+			node->emit_local_fixup_node = true;
+			node = node->parent;
+		}
+	}
+
+	/* emit the local fixups node now */
+	emit->beginnode(etarget, NULL);
+	emit->string(etarget, "__local_fixups__", 0);
+	emit->align(etarget, sizeof(cell_t));
+
+	emit_local_fixups(tree, emit, etarget, strbuf, vi, tree);
+
+	emit->endnode(etarget, tree->labels);
+}
+
 static void flatten_tree(struct node *tree, struct emitter *emit,
 			 void *etarget, struct data *strbuf,
 			 struct version_info *vi)
@@ -310,6 +446,9 @@ static void flatten_tree(struct node *tree, struct emitter *emit,
 		flatten_tree(child, emit, etarget, strbuf, vi);
 	}
 
+	emit_symbols_node(tree, emit, etarget, strbuf, vi);
+	emit_local_fixups_node(tree, emit, etarget, strbuf, vi);
+
 	emit->endnode(etarget, tree->labels);
 }
 
-- 
2.2.2