diff --git a/m1/patches/rtems/milkymist-audio-add-support-mic-boost.patch b/m1/patches/rtems/milkymist-audio-add-support-mic-boost.patch
new file mode 100644
index 0000000..8cb4846
--- /dev/null
+++ b/m1/patches/rtems/milkymist-audio-add-support-mic-boost.patch
@@ -0,0 +1,73 @@
+Index: rtems/c/src/lib/libbsp/lm32/shared/milkymist_ac97/ac97.c
+===================================================================
+--- rtems.orig/c/src/lib/libbsp/lm32/shared/milkymist_ac97/ac97.c	2012-03-20 17:11:20.087160002 +0800
++++ rtems/c/src/lib/libbsp/lm32/shared/milkymist_ac97/ac97.c	2012-03-20 17:12:23.731160001 +0800
+@@ -372,6 +372,39 @@
+   return sc;
+ }
+ 
++static rtems_status_code ioctl_read_mic_boost(void *buf, unsigned int chan)
++{
++  unsigned int *val = (unsigned int *)buf;
++  int codec;
++
++  codec = read_cr(chan);
++  if (codec < 0)
++    return RTEMS_UNSATISFIED;
++
++  *val = (codec & (1 << 6)) >> 6;
++  return RTEMS_SUCCESSFUL;
++}
++
++static rtems_status_code ioctl_write_mic_boost(void *buf, unsigned int chan)
++{
++  unsigned int *val = (unsigned int *)buf;
++  int codec;
++
++  codec = read_cr(chan);
++  if (codec < 0)
++    return RTEMS_UNSATISFIED;
++
++  if (*val)
++    codec |= (1 << 6);
++  else
++    codec &= ~(1 << 6);
++
++  if (!write_cr(chan, codec))
++    return RTEMS_UNSATISFIED;
++
++  return RTEMS_SUCCESSFUL;
++}
++
+ rtems_device_driver ac97_control(
+   rtems_device_major_number major,
+   rtems_device_minor_number minor,
+@@ -419,6 +452,16 @@
+         if(sc == RTEMS_SUCCESSFUL)
+           args->ioctl_return = 0;
+         return sc;
++      case SOUND_MIXER_READ(SOUND_MIXER_MIC_BOOST):
++	sc = ioctl_read_mic_boost(args->buffer, 0x0e);
++        if(sc == RTEMS_SUCCESSFUL)
++          args->ioctl_return = 0;
++        return sc;
++      case SOUND_MIXER_WRITE(SOUND_MIXER_MIC_BOOST):
++	sc = ioctl_write_mic_boost(args->buffer, 0x0e);
++        if(sc == RTEMS_SUCCESSFUL)
++          args->ioctl_return = 0;
++        return sc;
+       default:
+         return RTEMS_UNSATISFIED;
+     }
+Index: rtems/c/src/lib/libbsp/lm32/shared/milkymist_ac97/milkymist_ac97.h
+===================================================================
+--- rtems.orig/c/src/lib/libbsp/lm32/shared/milkymist_ac97/milkymist_ac97.h	2012-03-20 17:11:23.791160002 +0800
++++ rtems/c/src/lib/libbsp/lm32/shared/milkymist_ac97/milkymist_ac97.h	2012-03-20 17:12:23.731160001 +0800
+@@ -21,6 +21,7 @@
+ /* Ioctls. 0x41 is 'A' */
+ #define SOUND_MIXER_MIC             0x0
+ #define SOUND_MIXER_LINE            0x1
++#define SOUND_MIXER_MIC_BOOST       0x2
+ #define SOUND_MIXER_READ(x)         (0x4100+x)
+ #define SOUND_MIXER_WRITE(x)        (0x4110+x)
+ 
diff --git a/m1/patches/rtems/series b/m1/patches/rtems/series
index d3f535a..0b9b16d 100644
--- a/m1/patches/rtems/series
+++ b/m1/patches/rtems/series
@@ -24,3 +24,4 @@ export-shell-fns.patch		# https://www.rtems.org/bugzilla/show_bug.cgi?id=2030
 bootp-dhcp-cleanup.patch	# https://www.rtems.org/bugzilla/show_bug.cgi?id=2031
 # usb-firmware-ioctl.patch	- applied 2012-03-04
 # fix-pmem-size.patch		- applied 2012-03-06
+milkymist-audio-add-support-mic-boost.patch