From b7cc273db6bc828a7c5da8b0ae0d90b040f79bad Mon Sep 17 00:00:00 2001
From: Jacob Dahl <37091262+dakejahl@users.noreply.github.com>
Date: Thu, 20 Aug 2026 20:16:33 -0600
Subject: [PATCH] refactor(gps): shrink the GPS driver by ~4 KB of flash
 (#28309)

* refactor(gps): publish RTCM chunks without a per-topic template

publish_rtcm_chunks() was instantiated once for Publication and once for PublicationMulti, duplicating the chunking loop. Select the topic inside the loop instead.

px4_fmu-v6x_default: gps.cpp.obj 8744 -> 8590 B.

Assisted-by: Claude:claude-fable-5

* build(gps): bump GPSDrivers to 2b05a67

Pulls in the flash-diet refactor (#230) and the unsupported-config-key fixes (#225).

px4_fmu-v6x_default: -4,200 B from #230, +816 B from #225.
---
 src/drivers/gps/devices |  2 +-
 src/drivers/gps/gps.cpp | 45 +++++++++++++++++------------------------
 2 files changed, 20 insertions(+), 27 deletions(-)

diff --git a/src/drivers/gps/devices b/src/drivers/gps/devices
index 836094f4643..2b05a673610 160000
--- a/src/drivers/gps/devices
+++ b/src/drivers/gps/devices
@@ -1 +1 @@
-Subproject commit 836094f464334cbc683f165437eae9858e2cf668
+Subproject commit 2b05a673610e63f7db73dec7ef477f1275c96c8d
diff --git a/src/drivers/gps/gps.cpp b/src/drivers/gps/gps.cpp
index d1666d85b33..e77be3ee52b 100644
--- a/src/drivers/gps/gps.cpp
+++ b/src/drivers/gps/gps.cpp
@@ -1651,16 +1651,19 @@ GPS::publishSatelliteInfo()
 	}
 }
 
-// Chunk an RTCM byte stream into a uORB message and publish it. RTCM frames larger than the
-// message payload are split across consecutive publications (flags LSB = fragmented). Templated
-// on the publication so the same code serves both the corrections and moving-baseline topics.
-template <typename PubT>
-static void publish_rtcm_chunks(PubT &pub, const uint8_t *data, size_t len, hrt_abstime timestamp,
-				uint32_t device_id)
+// Chunk an RTCM byte stream into uORB messages. Frames larger than the message payload are split
+// across consecutive publications (flags LSB = fragmented).
+void
+GPS::publishRTCMCorrections(uint8_t *data, size_t len)
 {
+	// If this GPS is a moving base, its RTCM output is moving-baseline data for a rover (not
+	// external corrections). Route it to a dedicated topic so downstream consumers can tell it
+	// apart from fixed-base RTCM.
+	const bool moving_base = _helper && _helper->isMovingBase();
+
 	rtcm_data_s msg{};
-	msg.timestamp = timestamp;
-	msg.device_id = device_id;
+	msg.timestamp = hrt_absolute_time();
+	msg.device_id = get_device_id();
 
 	const size_t capacity = sizeof(msg.data);
 	msg.flags = (len > capacity) ? 1 : 0; // LSB: 1=fragmented
@@ -1671,28 +1674,18 @@ static void publish_rtcm_chunks(PubT &pub, const uint8_t *data, size_t len, hrt_
 		const size_t chunk = math::min(len - written, capacity);
 		msg.len = chunk;
 		memcpy(msg.data, &data[written], chunk);
-		pub.publish(msg);
+
+		if (moving_base) {
+			_rtcm_moving_baseline_pub.publish(msg);
+
+		} else {
+			_rtcm_corrections_pub.publish(msg);
+		}
+
 		written += chunk;
 	}
 }
 
-void
-GPS::publishRTCMCorrections(uint8_t *data, size_t len)
-{
-	const hrt_abstime timestamp = hrt_absolute_time();
-	const uint32_t device_id = get_device_id();
-
-	// If this GPS is a moving base, its RTCM output is moving-baseline data for a rover (not
-	// external corrections). Route it to a dedicated topic so downstream consumers can tell it
-	// apart from fixed-base RTCM.
-	if (_helper && _helper->isMovingBase()) {
-		publish_rtcm_chunks(_rtcm_moving_baseline_pub, data, len, timestamp, device_id);
-
-	} else {
-		publish_rtcm_chunks(_rtcm_corrections_pub, data, len, timestamp, device_id);
-	}
-}
-
 void
 GPS::publishRelativePosition(sensor_gnss_relative_s &gnss_relative)
 {