implement kernel symbol neutral method to select audio addon boards

Config.in

@@ -24,6 +24,7 @@ source "target/config/Config.in.systemopts"
 source "target/config/Config.in.subsystem"
 source "target/config/Config.in.qemuopts"
 source "target/config/Config.in.cpu"
+source "target/config/Config.in.addons"
 
 comment "After you saved your configuration once, you shouldn't change anything above"
 	depends on ADK_TARGET_OS_LINUX && !ADK_APPLIANCE_TOOLCHAIN && !ADK_TARGET_CHOOSE_ARCH

package/bcm28xx-bootloader/Makefile

@@ -57,27 +57,27 @@ ifeq ($(ADK_PACKAGE_BCM28XX_BOOTLOADER_CUTDOWN),y)
 endif
 	printf "gpu_mem=$(ADK_TARGET_GPU_MEM)\n" >> \
 		$(IDIR_BCM28XX_BOOTLOADER)/boot/config.txt
-ifneq ($(ADK_KERNEL_SND_BCM2708_SOC_HIFIBERRY_AMP),)
+ifneq ($(ADK_TARGET_HARDWARE_HIFIBERRY_AMP),)
 	printf "dtoverlay=hifiberry-amp\n" >> \
 		$(IDIR_BCM28XX_BOOTLOADER)/boot/config.txt
 endif
-ifneq ($(ADK_KERNEL_SND_BCM2708_SOC_HIFIBERRY_DAC),)
+ifneq ($(ADK_TARGET_HARDWARE_HIFIBERRY_DAC),)
 	printf "dtoverlay=hifiberry-dac\n" >> \
 		$(IDIR_BCM28XX_BOOTLOADER)/boot/config.txt
 endif
-ifneq ($(ADK_KERNEL_SND_BCM2708_SOC_HIFIBERRY_DIGI),)
+ifneq ($(ADK_TARGET_HARDWARE_HIFIBERRY_DIGI),)
 	printf "dtoverlay=hifiberry-digi\n" >> \
 		$(IDIR_BCM28XX_BOOTLOADER)/boot/config.txt
 endif
-ifneq ($(ADK_KERNEL_SND_BCM2708_SOC_RPI_DAC),)
+ifneq ($(ADK_TARGET_HARDWARE_RPI_DAC),)
 	printf "dtoverlay=rpi-dac\n" >> \
 		$(IDIR_BCM28XX_BOOTLOADER)/boot/config.txt
 endif
-ifneq ($(ADK_KERNEL_SND_BCM2708_SOC_IQAUDIO_DAC),)
+ifneq ($(ADK_TARGET_HARDWARE_IQAUDIO_DAC),)
 	printf "dtoverlay=iqaudio-dac\n" >> \
 		$(IDIR_BCM28XX_BOOTLOADER)/boot/config.txt
 endif
-ifneq ($(ADK_KERNEL_SND_BCM2708_SOC_RPI_PROTO),)
+ifneq ($(ADK_TARGET_HARDWARE_RPI_PROTO),)
 	printf "dtoverlay=rpi-proto\n" >> \
 		$(IDIR_BCM28XX_BOOTLOADER)/boot/config.txt
 endif

target/config/Config.in.addons

@@ -0,0 +1,35 @@
+# This file is part of the OpenADK project. OpenADK is copyrighted
+# material, please see the LICENCE file in the top-level directory.
+
+choice
+prompt "Audio Board"
+depends on ADK_TARGET_OS_LINUX && ADK_TARGET_BOARD_BCM28XX
+
+config ADK_TARGET_HARDWARE_NONE
+	bool "No audio addon board"
+
+config ADK_TARGET_HARDWARE_HIFIBERRY_AMP
+	bool "Hifiberry AMP"
+	select ADK_KERNEL_SND_BCM2708_SOC_HIFIBERRY_AMP
+
+config ADK_TARGET_HARDWARE_HIFIBERRY_DAC
+	bool "Hifiberry DAC"
+	select ADK_KERNEL_SND_BCM2708_SOC_HIFIBERRY_DAC
+
+config ADK_TARGET_HARDWARE_HIFIBERRY_DIGI
+	bool "Hifiberry DIGI"
+	select ADK_KERNEL_SND_BCM2708_SOC_HIFIBERRY_DIGI
+
+config ADK_TARGET_HARDWARE_RPI_DAC
+	bool "RPI-DAC"
+	select ADK_KERNEL_SND_BCM2708_SOC_RPI_DAC
+
+config ADK_TARGET_HARDWARE_IQAUDIO_DAC
+	bool "IQAudio-DAC"
+	select ADK_KERNEL_SND_BCM2708_SOC_IQAUDIO_DAC
+
+config ADK_TARGET_HARDWARE_RPI_PROTO
+	bool "Rpi-Proto"
+	select ADK_KERNEL_SND_BCM2708_SOC_RPI_PROTO
+
+endchoice