--- sys/sys/soundcard.h	2024-09-23 07:37:50.791528000 +0800
+++ sys/sys/soundcard.h	2024-11-29 15:33:15.817113000 +0800
@@ -184,6 +184,7 @@
 #define AFMT_S24_BE	0x00020000	/* Big endian signed 24-bit */
 #define AFMT_U24_LE	0x00040000	/* Little endian unsigned 24-bit */
 #define AFMT_U24_BE	0x00080000	/* Big endian unsigned 24-bit */
+#define AFMT_FLOAT	0x10000000	/* 32-bit floating point */
 
 /* Machine dependent AFMT_* definitions. */
 #if BYTE_ORDER == LITTLE_ENDIAN
--- sys/dev/sound/pcm/channel.c	2024-11-27 07:37:35.185838000 +0800
+++ sys/dev/sound/pcm/channel.c	2024-11-29 15:33:15.817529000 +0800
@@ -980,6 +980,7 @@
 	{ "u32le",  NULL, NULL, AFMT_U32_LE },
 	{ "u32be",  NULL, NULL, AFMT_U32_BE },
 	{   "ac3",  NULL, NULL, AFMT_AC3    },
+	{ "float",  NULL, NULL, AFMT_FLOAT  },
 	{    NULL,  NULL, NULL, 0           }
 };
 
--- sys/dev/sound/pcm/feeder_format.c	2024-11-29 08:19:33.277658000 +0800
+++ sys/dev/sound/pcm/feeder_format.c	2024-11-29 15:35:04.228247000 +0800
@@ -35,6 +35,11 @@
 #ifdef HAVE_KERNEL_OPTION_HEADERS
 #include "opt_snd.h"
 #endif
+/* XXX for future opposite/odd endianess support */
+#undef SND_IEEE754_OE
+#ifdef SND_IEEE754_OE
+#include <sys/endian.h>
+#endif
 #include <dev/sound/pcm/sound.h>
 #include <dev/sound/pcm/g711.h>
 #include "feeder_if.h"
@@ -172,6 +177,92 @@
 	PCM_WRITE_S16_NE(dst, 0);
 }
 
+static __inline intpcm_t
+intpcm_read_ieee754_32ne(uint8_t *src)
+{
+	uint32_t v;
+	int32_t s, e, m;
+
+	v = *((uint32_t *)src);
+
+	e = (v >> 23) & 0xff;
+
+	/* NaN, +/- Inf  or too small */
+	if (e == 0xff || e < 96)
+		return (INTPCM_T(0));
+
+	s = ((v & 0x80000000U) != 0) ? 1 : 0;
+
+	if (e > 126)
+		return (INTPCM_T((s == 0) ? PCM_S32_MAX : PCM_S32_MIN));
+
+	m = 0x800000 | (v & 0x7fffff);
+	e += 8 - 127;
+
+	if (e < 0)
+		m >>= -e;
+	else
+		m <<= e;
+
+	return (INTPCM_T((s == 0) ? m : -m));
+}
+
+static __inline void
+intpcm_write_ieee754_32ne(uint8_t *dst, intpcm_t v)
+{
+	uint32_t r;
+	int32_t e;
+
+	if (v == 0)
+		r = 0;
+	else if (v == PCM_S32_MAX)
+		r = 0x3f800000;
+	else if (v == PCM_S32_MIN)
+		r = 0x80000000U | 0x3f800000; 
+	else {
+		r = 0;
+		if (v < 0) {
+			r |= 0x80000000U;
+			v = -v;
+		}
+	
+		e = 127 - 8;
+		while ((v & 0x7f000000) != 0) {
+			v >>= 1;
+			e++;
+		}
+		while ((v & 0x7f800000) == 0) {
+			v <<= 1;
+			e--;
+		}
+	
+		r |= (e & 0xff) << 23;
+		r |= v & 0x7fffff;
+	}
+
+	*((uint32_t *)dst) = r;
+}
+
+#ifdef SND_IEEE754_OE
+static __inline intpcm_t
+intpcm_read_ieee754_32oe(uint8_t *src)
+{
+	uint32_t v;
+
+	v = bswap32(*((uint32_t *)src));
+
+	return (intpcm_read_ieee754_32ne((uint8_t *)&v));
+}
+
+static __inline void
+intpcm_write_ieee754_32oe(uint8_t *dst, intpcm_t v)
+{
+
+	intpcm_write_ieee754_32ne(dst, v);
+	*((uint32_t *)dst) = bswap32(*((uint32_t *)dst));
+}
+#endif
+
 #define FEEDFORMAT_ENTRY(SIGN, BIT, ENDIAN)				\
 	{								\
 		AFMT_##SIGN##BIT##_##ENDIAN,				\
@@ -198,6 +289,10 @@
 	FEEDFORMAT_ENTRY(U, 16, BE),
 	FEEDFORMAT_ENTRY(U, 24, BE),
 	FEEDFORMAT_ENTRY(U, 32, BE),
+	{
+		AFMT_FLOAT,
+		intpcm_read_ieee754_32ne, intpcm_write_ieee754_32ne
+	},
 	{
 		AFMT_MU_LAW,
 		intpcm_read_ulaw, intpcm_write_ulaw
--- sys/dev/sound/pcm/sound.h	2024-11-27 07:37:35.187046000 +0800
+++ sys/dev/sound/pcm/sound.h	2024-11-29 15:33:15.817853000 +0800
@@ -148,21 +148,27 @@
 	(((var)<(low))? (low) : ((var)>(high))? (high) : (var))
 
 /* make figuring out what a format is easier. got AFMT_STEREO already */
-#define AFMT_32BIT (AFMT_S32_LE | AFMT_S32_BE | AFMT_U32_LE | AFMT_U32_BE)
+#define AFMT_32BIT (AFMT_S32_LE | AFMT_S32_BE | AFMT_U32_LE | AFMT_U32_BE | \
+			AFMT_FLOAT)
 #define AFMT_24BIT (AFMT_S24_LE | AFMT_S24_BE | AFMT_U24_LE | AFMT_U24_BE)
 #define AFMT_16BIT (AFMT_S16_LE | AFMT_S16_BE | AFMT_U16_LE | AFMT_U16_BE)
 #define AFMT_G711  (AFMT_MU_LAW | AFMT_A_LAW)
 #define AFMT_8BIT (AFMT_G711 | AFMT_U8 | AFMT_S8)
 #define AFMT_SIGNED (AFMT_S32_LE | AFMT_S32_BE | AFMT_S24_LE | AFMT_S24_BE | \
-			AFMT_S16_LE | AFMT_S16_BE | AFMT_S8)
-#define AFMT_BIGENDIAN (AFMT_S32_BE | AFMT_U32_BE | AFMT_S24_BE | AFMT_U24_BE | \
+			AFMT_S16_LE | AFMT_S16_BE | AFMT_S8 | AFMT_FLOAT)
+#define _AFMT_BIGENDIAN (AFMT_S32_BE | AFMT_U32_BE | AFMT_S24_BE | AFMT_U24_BE | \
 			AFMT_S16_BE | AFMT_U16_BE)
+#if BYTE_ORDER == LITTLE_ENDIAN
+#define AFMT_BIGENDIAN	_AFMT_BIGENDIAN
+#else  /* !LITTLE_ENDIAN */
+#define AFMT_BIGENDIAN	(_AFMT_BIGENDIAN | AFMT_FLOAT)
+#endif /* LITTLE_ENDIAN */
 
 #define AFMT_CONVERTIBLE	(AFMT_8BIT | AFMT_16BIT | AFMT_24BIT |	\
 				 AFMT_32BIT)
 
 /* Supported vchan mixing formats */
-#define AFMT_VCHAN		(AFMT_CONVERTIBLE & ~AFMT_G711)
+#define AFMT_VCHAN		(AFMT_CONVERTIBLE & ~(AFMT_G711 | AFMT_FLOAT))
 
 #define AFMT_PASSTHROUGH		AFMT_AC3
 #define AFMT_PASSTHROUGH_RATE		48000