[Pdbg] [PATCH 2/2] pdbg: Remove default_backend() selection

[Alistair Popple]

Now that libpdbg can automatically select the correct device-tree the
pdbg application doesn't need code to do the same thing. By default
pdbg can just rely on the device-tree selected by libpdbg.

Unfortunately to maintain backwards compatibility for users explicitly
selecting a device-tree and device-tree node we need to retain most of
the code and continue linking the device-trees into the
application. It would be good to remove these one day so print a
deprecation warning when a user does explicitly select a backend.

Signed-off-by: Alistair Popple <alistair at popple.id.au>
---
 src/main.c        | 41 ++++++++++++++++++++++++-----------------
 src/main.h        |  2 +-
 src/options.h     |  3 ---
 src/options_arm.c | 14 --------------
 src/options_def.c |  5 -----
 src/options_ppc.c |  5 -----
 6 files changed, 25 insertions(+), 45 deletions(-)

diff --git a/src/main.c b/src/main.c
index ad40d19..7cee57b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -64,7 +64,7 @@
 
 #define THREADS_PER_CORE	8
 
-static enum backend backend = KERNEL;
+static enum backend backend = DEFAULT_BACKEND;
 
 static char const *device_node;
 static int i2c_addr = 0x50;
@@ -607,17 +607,6 @@ static bool target_selection(void)
 		return false;
 	}
 
-	if (pathsel_count) {
-		if (!path_target_parse(pathsel, pathsel_count))
-			return false;
-	}
-
-	if (!path_target_present()) {
-		printf("No valid targets found or specified. Try adding -p/-c/-t options to specify a target.\n");
-		printf("Alternatively run 'pdbg -a probe' to get a list of all valid targets\n");
-		return false;
-	}
-
 	return true;
 }
 
@@ -677,9 +666,7 @@ int main(int argc, char *argv[])
 	optcmd_cmd_t *cmd;
 	struct pdbg_target *target;
 
-	backend = default_backend();
-
-	if (!device_node)
+	if (backend && !device_node)
 		device_node = default_target(backend);
 
 	if (!parse_options(argc, argv))
@@ -690,9 +677,29 @@ int main(int argc, char *argv[])
 		return 1;
 	}
 
-	/* Disable unselected targets */
-	if (!target_selection())
+	if (backend) {
+		fprintf(stderr, "WARNING: Explicit backend selection should no longer be required\n");
+		fprintf(stderr, "         and will be deprecated in a future release.\n");
+		fprintf(stderr, "         Removing -b/-d command line options will remove this warning.\n");
+		fprintf(stderr, "         An explicit device-tree can still be selected using the\n");
+		fprintf(stderr, "         LPDBG_DTB environment variable instead.\n");
+
+		if (!target_selection())
+			return 1;
+	} else {
+		pdbg_targets_init(NULL);
+	}
+
+	if (pathsel_count) {
+		if (!path_target_parse(pathsel, pathsel_count))
+			return false;
+	}
+
+	if (!path_target_present()) {
+		printf("No valid targets found or specified. Try adding -p/-c/-t options to specify a target.\n");
+		printf("Alternatively run 'pdbg -a probe' to get a list of all valid targets\n");
 		return 1;
+	}
 
 	/* Probe all selected targets */
 	for_each_path_target(target) {
diff --git a/src/main.h b/src/main.h
index 78b4d92..1d5913e 100644
--- a/src/main.h
+++ b/src/main.h
@@ -19,7 +19,7 @@
 
 #include <libpdbg.h>
 
-enum backend { FSI, I2C, KERNEL, FAKE, HOST };
+enum backend { DEFAULT_BACKEND = 0, FSI, I2C, KERNEL, FAKE, HOST };
 
 static inline bool target_is_disabled(struct pdbg_target *target)
 {
diff --git a/src/options.h b/src/options.h
index 67f15a8..cf63cbe 100644
--- a/src/options.h
+++ b/src/options.h
@@ -14,9 +14,6 @@
  * limitations under the License.
  */
 
-/* Default backend on this platform */
-enum backend default_backend(void);
-
 /* Print all possible backends on this platform */
 void print_backends(FILE *stream);
 
diff --git a/src/options_arm.c b/src/options_arm.c
index 0dbc731..99a2d3f 100644
--- a/src/options_arm.c
+++ b/src/options_arm.c
@@ -28,20 +28,6 @@
 #define CHIP_ID_P9  0xd1
 #define CHIP_ID_P8P 0xd3
 
-enum backend default_backend(void)
-{
-	int rc;
-	rc = access(AMI_BMC, F_OK);
-	if (rc == 0) /* AMI BMC */
-		return I2C;
-
-	rc = access(OPENFSI_BMC, F_OK);
-	if (rc == 0) /* Kernel interface. OpenBMC */
-		return KERNEL;
-
-	return FAKE;
-}
-
 void print_backends(FILE *stream)
 {
 	fprintf(stream, "Valid backends: i2c kernel fsi fake\n");
diff --git a/src/options_def.c b/src/options_def.c
index 4092cea..3fef60d 100644
--- a/src/options_def.c
+++ b/src/options_def.c
@@ -17,11 +17,6 @@
 #include <stdio.h>
 #include "main.h"
 
-enum backend default_backend(void)
-{
-	return FAKE;
-}
-
 void print_backends(FILE *stream)
 {
 	fprintf(stream, "Valid backends: fake\n");
diff --git a/src/options_ppc.c b/src/options_ppc.c
index 62eb7b0..82f410b 100644
--- a/src/options_ppc.c
+++ b/src/options_ppc.c
@@ -21,11 +21,6 @@
 static const char p8[] = "p8";
 static const char p9[] = "p9";
 
-enum backend default_backend(void)
-{
-	return HOST;
-}
-
 void print_backends(FILE *stream)
 {
 	fprintf(stream, "Valid backends: host fake\n");
-- 
2.11.0