Wire up orphaned GPS NMEA service into build and test suite

services/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_subdirectory(crypto)
+add_subdirectory(gps)
 add_subdirectory(security)
 add_subdirectory(os)
 add_subdirectory(linux)

services/gps/CMakeLists.txt

@@ -0,0 +1,10 @@
+add_library(eos_gps STATIC
+    src/gps_nmea.c
+)
+
+target_compile_definitions(eos_gps PUBLIC EOS_ENABLE_GPS=1)
+
+target_include_directories(eos_gps PUBLIC
+    ${CMAKE_CURRENT_SOURCE_DIR}/include
+    ${CMAKE_SOURCE_DIR}/include
+)

services/gps/include/eos/gps_nmea.h

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2026 EoS Project
+// ISO/IEC 25000 | ISO/IEC/IEEE 15288:2023
+
+/**
+ * @file gps_nmea.h
+ * @brief EoS GPS Service — NMEA 0183 sentence parsing
+ *
+ * Provides parsing of standard NMEA GPRMC sentences into a structured
+ * position/velocity fix usable by higher-level location services.
+ */
+
+#ifndef EOS_GPS_NMEA_H
+#define EOS_GPS_NMEA_H
+
+#include <stdbool.h>
+#include <eos/eos_config.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    double latitude;
+    double longitude;
+    float altitude;
+    float speed_knots;
+    int satellites;
+    bool fix_valid;
+} eos_gps_data_t;
+
+/**
+ * Parse a standard NMEA $GPRMC sentence.
+ *
+ * @param nmea NUL-terminated NMEA sentence, e.g.
+ *             "$GPRMC,092750.000,A,3746.4949,N,12225.1644,W,0.00,0.00,270526,,,A*7B"
+ * @param data Output struct populated on success.
+ * @return 0 on success (data->fix_valid indicates whether the fix is valid),
+ *         -1 on invalid arguments or sentence type, -2 if the sentence has
+ *         too few fields to parse.
+ */
+int eos_gps_parse_gprmc(const char *nmea, eos_gps_data_t *data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* EOS_GPS_NMEA_H */

services/gps/src/gps_nmea.c

@@ -1,17 +1,14 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2026 EoS Project
+// ISO/IEC 25000 | ISO/IEC/IEEE 15288:2023
 
+#include <eos/gps_nmea.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdbool.h>
 
-typedef struct {
-    double latitude;
-    double longitude;
-    float altitude;
-    float speed_knots;
-    int satellites;
-    bool fix_valid;
-} eos_gps_data_t;
+#if EOS_ENABLE_GPS
 
 /* Parse standard NMEA $GPRMC sentence */
 int eos_gps_parse_gprmc(const char *nmea, eos_gps_data_t *data) {
@@ -62,3 +59,5 @@ int eos_gps_parse_gprmc(const char *nmea, eos_gps_data_t *data) {
     data->fix_valid = true;
     return 0;
 }
+
+#endif /* EOS_ENABLE_GPS */

tests/CMakeLists.txt

@@ -106,6 +106,14 @@ add_executable(test_service test_service.c)
 target_link_libraries(test_service PRIVATE eos_service)
 add_test(NAME test_service COMMAND test_service)
 
+# --- test_gps: GPS NMEA sentence parsing ---
+add_executable(test_gps test_gps.c)
+target_link_libraries(test_gps PRIVATE eos_gps)
+if(UNIX AND NOT APPLE)
+    target_link_libraries(test_gps PRIVATE m)
+endif()
+add_test(NAME test_gps COMMAND test_gps)
+
 # --- test_debug: GDB stub + core dump ---
 add_executable(test_debug test_debug.c)
 target_include_directories(test_debug PRIVATE
@@ -173,4 +181,4 @@ add_test(NAME test_devicetree COMMAND test_devicetree)
 
 # --- Fuzz targets ---
 # Opt-in (-DEOS_ENABLE_FUZZING=ON, Clang only); the subdirectory guards itself.
-add_subdirectory(fuzz)
+add_subdirectory(fuzz)

tests/test_gps.c

@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2026 EoS Project
+// ISO/IEC 25000 | ISO/IEC/IEEE 15288:2023
+
+#include <stdio.h>
+#include <math.h>
+#include <assert.h>
+#include "eos/gps_nmea.h"
+
+static void test_gprmc_valid_fix(void) {
+    const char *nmea =
+        "$GPRMC,092750.000,A,3746.4949,N,12225.1644,W,0.00,0.00,270526,,,A*7B";
+    eos_gps_data_t data;
+
+    assert(eos_gps_parse_gprmc(nmea, &data) == 0);
+    assert(data.fix_valid);
+    assert(fabs(data.latitude - 37.7749) < 0.01);
+    assert(fabs(data.longitude - (-122.4194)) < 0.01);
+    printf("[PASS] gps gprmc valid fix\n");
+}
+
+static void test_gprmc_void_fix(void) {
+    const char *nmea =
+        "$GPRMC,092750.000,V,3746.4949,N,12225.1644,W,0.00,0.00,270526,,,A*7B";
+    eos_gps_data_t data;
+
+    assert(eos_gps_parse_gprmc(nmea, &data) == 0);
+    assert(!data.fix_valid);
+    printf("[PASS] gps gprmc void fix\n");
+}
+
+static void test_gprmc_rejects_wrong_sentence(void) {
+    eos_gps_data_t data;
+    assert(eos_gps_parse_gprmc("$GPGGA,092750.000,3746.4949,N", &data) == -1);
+    printf("[PASS] gps gprmc rejects non-GPRMC sentence\n");
+}
+
+static void test_gprmc_rejects_null_args(void) {
+    eos_gps_data_t data;
+    assert(eos_gps_parse_gprmc(NULL, &data) == -1);
+    assert(eos_gps_parse_gprmc("$GPRMC,...", NULL) == -1);
+    printf("[PASS] gps gprmc rejects null args\n");
+}
+
+static void test_gprmc_rejects_short_sentence(void) {
+    eos_gps_data_t data;
+    assert(eos_gps_parse_gprmc("$GPRMC,092750.000,A", &data) == -2);
+    printf("[PASS] gps gprmc rejects short sentence\n");
+}
+
+int main(void) {
+    test_gprmc_valid_fix();
+    test_gprmc_void_fix();
+    test_gprmc_rejects_wrong_sentence();
+    test_gprmc_rejects_null_args();
+    test_gprmc_rejects_short_sentence();
+    printf("All GPS NMEA tests passed.\n");
+    return 0;
+}