Add generic IMU fusion and PMOD IRQ verification

soc/software/gps_system/Makefile

@@ -5,9 +5,41 @@ TARGET := gps_system
 # with the common 100 MHz fallback divider.
 BSP_UART_CLOCK_HZ ?= 50000000
 
+# Select one sensor backend, or keep the default read-only WHO_AM_I probe.
+# Accepted values: auto, tdk, st (stm is an alias for st).
+IMU_SENSOR ?= auto
+ifeq ($(IMU_SENSOR),auto)
+IMU_DRIVER_SRCS := src/tdk_icm42688.c src/st_lsm6dsox.c
+IMU_BACKEND_CFLAG := -DIMU_SENSOR_BUILD_AUTO=1
+else ifeq ($(IMU_SENSOR),tdk)
+IMU_DRIVER_SRCS := src/tdk_icm42688.c
+IMU_BACKEND_CFLAG := -DIMU_SENSOR_BUILD_TDK=1
+else ifeq ($(IMU_SENSOR),st)
+IMU_DRIVER_SRCS := src/st_lsm6dsox.c
+IMU_BACKEND_CFLAG := -DIMU_SENSOR_BUILD_ST=1
+else ifeq ($(IMU_SENSOR),stm)
+IMU_DRIVER_SRCS := src/st_lsm6dsox.c
+IMU_BACKEND_CFLAG := -DIMU_SENSOR_BUILD_ST=1
+else
+$(error IMU_SENSOR must be auto, tdk, st or stm)
+endif
+
+# Zero means use the selected backend's default. The legacy TDK variable is
+# accepted so existing build commands remain valid.
+ifdef TDK_IMU_ODR_HZ
+IMU_ODR_HZ ?= $(TDK_IMU_ODR_HZ)
+else
+IMU_ODR_HZ ?= 0
+endif
+IMU_ACCEL_FS_G ?= 0
+IMU_GYRO_FS_DPS ?= 0
+
 APP_SRCS := \
 	gps_test.c \
-	src/tdk_icm42688.c \
+	src/imu_calibration.c \
+	src/imu_sensor.c \
+	src/imu_sensor_profile.c \
+	$(IMU_DRIVER_SRCS) \
 	src/eskf.c \
 	src/fusion_motion.c \
 	src/fusion_engine.c \
@@ -25,13 +57,15 @@ APP_SRCS := \
 
 BSP_SRCS := init.c uart.c plic.c irq.c spi_flash.c pmod_spi.c
 
-TDK_IMU_ODR_HZ ?= 500
 GPS_NAV_SOLVE_TIMER_TICKS ?= 50
 
 include ../common/app.mk
 
 CFLAGS += -Iheader
-CFLAGS += -DTDK_IMU_ODR_HZ=$(TDK_IMU_ODR_HZ) \
+CFLAGS += $(IMU_BACKEND_CFLAG) \
+	-DIMU_ODR_HZ=$(IMU_ODR_HZ) \
+	-DIMU_ACCEL_FS_G=$(IMU_ACCEL_FS_G) \
+	-DIMU_GYRO_FS_DPS=$(IMU_GYRO_FS_DPS) \
 	-DGPS_NAV_SOLVE_TIMER_TICKS=$(GPS_NAV_SOLVE_TIMER_TICKS)
 LDLIBS += -lm