From: Steven Stallion <stallion@squareup.com>
Date: Tue, 21 Mar 2017 15:33:09 +0000 (-0500)
Subject: gdb_server: add support for architecture element
X-Git-Tag: v0.11.0-rc1~978
X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=commitdiff_plain;h=e65acd889c61a424c7bd72fdee5d6a3aee1d8504

gdb_server: add support for architecture element

This change adds optional support for a target to report architecture
information in the target description to GDB. This is needed by some GDB
implementations to properly support remote target with custom behavior.
More information on the architecture element can be found here:

    https://sourceware.org/gdb/onlinedocs/gdb/Target-Description-Format.html#Target-Description-Format

Change-Id: I57b19cae5ac3496256e4e5cc52cf6526ca5c322d
Signed-off-by: Steven Stallion <stallion@squareup.com>
Reviewed-on: http://openocd.zylin.com/4078
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>
---

diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index 2b3057a1a9..13e5aca6a4 100644
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -2196,6 +2196,7 @@ static int gdb_generate_target_description(struct target *target, char **tdesc_o
 	int retval = ERROR_OK;
 	struct reg **reg_list = NULL;
 	int reg_list_size;
+	char const *architecture;
 	char const **features = NULL;
 	char const **arch_defined_types = NULL;
 	int feature_list_size = 0;
@@ -2237,6 +2238,12 @@ static int gdb_generate_target_description(struct target *target, char **tdesc_o
 			"<!DOCTYPE target SYSTEM \"gdb-target.dtd\">\n"
 			"<target version=\"1.0\">\n");
 
+	/* generate architecture element if supported by target */
+	architecture = target_get_gdb_arch(target);
+	if (architecture != NULL)
+		xml_printf(&retval, &tdesc, &pos, &size,
+				"<architecture>%s</architecture>\n", architecture);
+
 	/* generate target description according to register list */
 	if (features != NULL) {
 		while (features[current_feature]) {
@@ -2386,6 +2393,8 @@ static int gdb_target_description_supported(struct target *target, int *supporte
 	char const **features = NULL;
 	int feature_list_size = 0;
 
+	char const *architecture = target_get_gdb_arch(target);
+
 	retval = target_get_gdb_reg_list(target, &reg_list,
 			&reg_list_size, REG_CLASS_ALL);
 	if (retval != ERROR_OK) {
@@ -2407,7 +2416,7 @@ static int gdb_target_description_supported(struct target *target, int *supporte
 	}
 
 	if (supported) {
-		if (feature_list_size)
+		if (architecture || feature_list_size)
 			*supported = 1;
 		else
 			*supported = 0;
diff --git a/src/target/target.c b/src/target/target.c
index 3aaebcd49f..c1ccf962e9 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -1199,6 +1199,13 @@ int target_hit_watchpoint(struct target *target,
 	return target->type->hit_watchpoint(target, hit_watchpoint);
 }
 
+const char *target_get_gdb_arch(struct target *target)
+{
+	if (target->type->get_gdb_arch == NULL)
+		return NULL;
+	return target->type->get_gdb_arch(target);
+}
+
 int target_get_gdb_reg_list(struct target *target,
 		struct reg **reg_list[], int *reg_list_size,
 		enum target_register_class reg_class)
diff --git a/src/target/target.h b/src/target/target.h
index fe7e1a7db8..5457f0abf6 100644
--- a/src/target/target.h
+++ b/src/target/target.h
@@ -472,6 +472,13 @@ int target_remove_watchpoint(struct target *target,
 int target_hit_watchpoint(struct target *target,
 		struct watchpoint **watchpoint);
 
+/**
+ * Obtain the architecture for GDB.
+ *
+ * This routine is a wrapper for target->type->get_gdb_arch.
+ */
+const char *target_get_gdb_arch(struct target *target);
+
 /**
  * Obtain the registers for GDB.
  *
diff --git a/src/target/target_type.h b/src/target/target_type.h
index fbbd57d980..a8928911f6 100644
--- a/src/target/target_type.h
+++ b/src/target/target_type.h
@@ -88,6 +88,15 @@ struct target_type {
 	int (*deassert_reset)(struct target *target);
 	int (*soft_reset_halt)(struct target *target);
 
+	/**
+	 * Target architecture for GDB.
+	 *
+	 * The string returned by this function will not be automatically freed;
+	 * if dynamic allocation is used for this value, it must be managed by
+	 * the target, ideally by caching the result for subsequent calls.
+	 */
+	const char *(*get_gdb_arch)(struct target *target);
+
 	/**
 	 * Target register access for GDB.  Do @b not call this function
 	 * directly, use target_get_gdb_reg_list() instead.