Add types for tagged data chunks in SPI flash.

firmware/common/spi_image.hpp

@@ -30,6 +30,58 @@
 namespace portapack {
 namespace spi_flash {
 
+struct image_tag_t {
+	constexpr image_tag_t(
+	) : c { 0, 0, 0, 0 }
+	{
+	}
+
+	constexpr image_tag_t(
+		char c0, char c1, char c2, char c3
+	) : c { c0, c1, c2, c3 }
+	{
+	}
+
+	image_tag_t& operator=(const image_tag_t& other) {
+		c[0] = other.c[0];
+		c[1] = other.c[1];
+		c[2] = other.c[2];
+		c[3] = other.c[3];
+		return *this;
+	}
+
+	bool operator==(const image_tag_t& other) const {
+		return (c[0] == other.c[0]) && (c[1] == other.c[1]) && (c[2] == other.c[2]) && (c[3] == other.c[3]);
+	}
+
+	operator bool() const {
+		return (c[0] != 0) || (c[1] != 0) || (c[2] != 0) || (c[3] != 0);
+	}
+
+private:
+	char c[4];
+};
+
+constexpr image_tag_t image_tag_ais					{ 'P', 'A', 'I', 'S' };
+constexpr image_tag_t image_tag_am_audio			{ 'P', 'A', 'M', 'A' };
+constexpr image_tag_t image_tag_capture				{ 'P', 'C', 'A', 'P' };
+constexpr image_tag_t image_tag_ert					{ 'P', 'E', 'R', 'T' };
+constexpr image_tag_t image_tag_nfm_audio			{ 'P', 'N', 'F', 'M' };
+constexpr image_tag_t image_tag_tpms				{ 'P', 'T', 'P', 'M' };
+constexpr image_tag_t image_tag_wfm_audio			{ 'P', 'W', 'F', 'M' };
+constexpr image_tag_t image_tag_wideband_spectrum	{ 'P', 'S', 'P', 'E' };
+constexpr image_tag_t image_tag_hackrf				{ 'H', 'R', 'F', '1' };
+
+struct chunk_t {
+	const image_tag_t tag;
+	const uint32_t length;
+	const uint8_t data[];
+
+	const chunk_t* next() const {
+		return reinterpret_cast<const chunk_t*>(&data[length]);
+	}
+};
+
 struct region_t {
 	const size_t offset;
 	const size_t size;