diff --git a/core/linux-aarch64-rc/PKGBUILD b/core/linux-aarch64-rc/PKGBUILD
index 233f65915..2d5a2122c 100644
--- a/core/linux-aarch64-rc/PKGBUILD
+++ b/core/linux-aarch64-rc/PKGBUILD
@@ -4,7 +4,7 @@
 buildarch=8
 
 _rcver=5.15
-_rcrel=3
+_rcrel=4
 
 pkgbase=linux-aarch64-rc
 _srcname=linux-${_rcver}-rc${_rcrel}
@@ -27,10 +27,10 @@ source=("https://git.kernel.org/torvalds/t/${_srcname}.tar.gz"
         'linux.preset'
         '60-linux.hook'
         '90-linux.hook')
-md5sums=('f996cb6694304111742d60480aafd522'
+md5sums=('00dd752ba53fed55793f07864cbedac8'
          '21d3e833437461aed3b6ca68b5d8afa0'
          'd679f49645578a193d6e3c220787a40d'
-         'bc04eb51ec83ca2cbeeed417d3fec453'
+         'c1062ce684ed1aaa197d8a30e7532e11'
          'e19fbe69f1258b99ee6bed21d7afcbce'
          '61c5ff73c136ed07a7aadbf58db3d96a'
          '584777ae88bce2c5659960151b64c7d8'
@@ -39,7 +39,7 @@ md5sums=('f996cb6694304111742d60480aafd522'
          '3dc88030a8f2f5a5f97266d99b149f77')
 
 prepare() {
-  cd "${srcdir}/${_srcname}"
+  cd ${_srcname}
 
   # ALARM patches
   git apply ../0001-net-smsc95xx-Allow-mac-address-to-be-set-as-a-parame.patch
@@ -55,7 +55,7 @@ prepare() {
 }
 
 build() {
-  cd "${srcdir}/${_srcname}"
+  cd ${_srcname}
 
   # get kernel version
   make prepare
@@ -83,6 +83,7 @@ build() {
   # build!
   unset LDFLAGS
   make ${MAKEFLAGS} Image Image.gz modules
+  # Generate device tree blobs with symbols to support applying device tree overlays in U-Boot
   make ${MAKEFLAGS} DTC_FLAGS="-@" dtbs
 }
 
@@ -124,9 +125,6 @@ _package() {
   # now we call depmod...
   depmod -b "${pkgdir}/usr" -F System.map "${_kernver}"
 
-  # add vmlinux
-  install -Dt "${pkgdir}/usr/lib/modules/${_kernver}/build" -m644 vmlinux
-
   # sed expression for following substitutions
   local _subst="
     s|%PKGBASE%|${pkgbase}|g
@@ -152,66 +150,76 @@ _package-headers() {
   conflicts=('linux-headers')
 
   cd ${_srcname}
-  local _builddir="${pkgdir}/usr/lib/modules/${_kernver}/build"
+  local builddir="${pkgdir}/usr/lib/modules/${_kernver}/build"
 
-  install -Dt "${_builddir}" -m644 Makefile .config Module.symvers
-  install -Dt "${_builddir}/kernel" -m644 kernel/Makefile
-
-  mkdir "${_builddir}/.tmp_versions"
-
-  cp -t "${_builddir}" -a include scripts
-
-  install -Dt "${_builddir}/arch/${KARCH}" -m644 arch/${KARCH}/Makefile
-  install -Dt "${_builddir}/arch/${KARCH}/kernel" -m644 arch/${KARCH}/kernel/asm-offsets.s
-
-  cp -t "${_builddir}/arch/${KARCH}" -a arch/${KARCH}/include
-  mkdir -p "${_builddir}/arch/arm"
-  cp -t "${_builddir}/arch/arm" -a arch/arm/include
-
-  install -Dt "${_builddir}/drivers/md" -m644 drivers/md/*.h
-  install -Dt "${_builddir}/net/mac80211" -m644 net/mac80211/*.h
-
-  # http://bugs.archlinux.org/task/13146
-  install -Dt "${_builddir}/drivers/media/i2c" -m644 drivers/media/i2c/msp3400-driver.h
-
-  # http://bugs.archlinux.org/task/20402
-  install -Dt "${_builddir}/drivers/media/usb/dvb-usb" -m644 drivers/media/usb/dvb-usb/*.h
-  install -Dt "${_builddir}/drivers/media/dvb-frontends" -m644 drivers/media/dvb-frontends/*.h
-  install -Dt "${_builddir}/drivers/media/tuners" -m644 drivers/media/tuners/*.h
+  echo "Installing build files..."
+  install -Dt "$builddir" -m644 .config Makefile Module.symvers System.map vmlinux
+  install -Dt "$builddir/kernel" -m644 kernel/Makefile
+  install -Dt "$builddir/arch/${KARCH}" -m644 arch/${KARCH}/Makefile
+  cp -t "$builddir" -a scripts
 
   # add xfs and shmem for aufs building
-  mkdir -p "${_builddir}"/{fs/xfs,mm}
+  mkdir -p "$builddir"/{fs/xfs,mm}
 
-  # copy in Kconfig files
-  find . -name Kconfig\* -exec install -Dm644 {} "${_builddir}/{}" \;
+  echo "Installing headers..."
+  cp -t "$builddir" -a include
+  cp -t "$builddir/arch/${KARCH}" -a arch/${KARCH}/include
+  install -Dt "$builddir/arch/${KARCH}/kernel" -m644 arch/${KARCH}/kernel/asm-offsets.s
+  mkdir -p "$builddir/arch/arm"
+  cp -t "$builddir/arch/arm" -a arch/arm/include
 
-  # remove unneeded architectures
-  local _arch
-  for _arch in "${_builddir}"/arch/*/; do
-    [[ ${_arch} == */${KARCH}/ || ${_arch} == */arm/ ]] && continue
-    rm -r "${_arch}"
+  install -Dt "$builddir/drivers/md" -m644 drivers/md/*.h
+  install -Dt "$builddir/net/mac80211" -m644 net/mac80211/*.h
+
+  # https://bugs.archlinux.org/task/13146
+  install -Dt "$builddir/drivers/media/i2c" -m644 drivers/media/i2c/msp3400-driver.h
+
+  # https://bugs.archlinux.org/task/20402
+  install -Dt "$builddir/drivers/media/usb/dvb-usb" -m644 drivers/media/usb/dvb-usb/*.h
+  install -Dt "$builddir/drivers/media/dvb-frontends" -m644 drivers/media/dvb-frontends/*.h
+  install -Dt "$builddir/drivers/media/tuners" -m644 drivers/media/tuners/*.h
+
+  # https://bugs.archlinux.org/task/71392
+  install -Dt "$builddir/drivers/iio/common/hid-sensors" -m644 drivers/iio/common/hid-sensors/*.h
+
+  echo "Installing KConfig files..."
+  find . -name 'Kconfig*' -exec install -Dm644 {} "$builddir/{}" \;
+
+  echo "Removing unneeded architectures..."
+  local arch
+  for arch in "$builddir"/arch/*/; do
+    [[ $arch = */${KARCH}/ || $arch == */arm/ ]] && continue
+    echo "Removing $(basename "$arch")"
+    rm -r "$arch"
   done
 
-  # remove files already in linux-docs package
-  rm -r "${_builddir}/Documentation"
+  echo "Removing documentation..."
+  rm -r "$builddir/Documentation"
 
-  # remove now broken symlinks
-  find -L "${_builddir}" -type l -printf 'Removing %P\n' -delete
+  echo "Removing broken symlinks..."
+  find -L "$builddir" -type l -printf 'Removing %P\n' -delete
 
-  # Fix permissions
-  chmod -R u=rwX,go=rX "${_builddir}"
+  echo "Removing loose objects..."
+  find "$builddir" -type f -name '*.o' -printf 'Removing %P\n' -delete
 
-  # strip scripts directory
-  local _binary _strip
-  while read -rd '' _binary; do
-    case "$(file -bi "${_binary}")" in
-      *application/x-sharedlib*)  _strip="${STRIP_SHARED}"   ;; # Libraries (.so)
-      *application/x-archive*)    _strip="${STRIP_STATIC}"   ;; # Libraries (.a)
-      *application/x-executable*) _strip="${STRIP_BINARIES}" ;; # Binaries
-      *) continue ;;
+  echo "Stripping build tools..."
+  local file
+  while read -rd '' file; do
+    case "$(file -bi "$file")" in
+      application/x-sharedlib\;*)      # Libraries (.so)
+        strip -v $STRIP_SHARED "$file" ;;
+      application/x-archive\;*)        # Libraries (.a)
+        strip -v $STRIP_STATIC "$file" ;;
+      application/x-executable\;*)     # Binaries
+        strip -v $STRIP_BINARIES "$file" ;;
+      application/x-pie-executable\;*) # Relocatable binaries
+        strip -v $STRIP_SHARED "$file" ;;
     esac
-    /usr/bin/strip ${_strip} "${_binary}"
-  done < <(find "${_builddir}/scripts" -type f -perm -u+w -print0 2>/dev/null)
+  done < <(find "$builddir" -type f -perm -u+x ! -name vmlinux -print0)
+
+  echo "Adding symlink..."
+  mkdir -p "$pkgdir/usr/src"
+  ln -sr "$builddir" "$pkgdir/usr/src/$pkgbase"
 }
 
 _package-chromebook() {
@@ -220,7 +228,7 @@ _package-chromebook() {
   conflicts=('linux-aarch64-chromebook')
   install=${pkgname}.install
 
-  cd "${srcdir}/${_srcname}"
+  cd ${_srcname}
 
   mkdir -p "${pkgdir}/boot"
 
diff --git a/core/linux-aarch64-rc/config b/core/linux-aarch64-rc/config
index 8cc257623..71bb6f3e5 100644
--- a/core/linux-aarch64-rc/config
+++ b/core/linux-aarch64-rc/config
@@ -1,6 +1,6 @@
 #
 # Automatically generated file; DO NOT EDIT.
-# Linux/arm64 5.15.0-rc3-1 Kernel Configuration
+# Linux/arm64 5.15.0-rc4-1 Kernel Configuration
 #
 CONFIG_CC_VERSION_TEXT="gcc (GCC) 10.2.0"
 CONFIG_CC_IS_GCC=y
@@ -873,8 +873,7 @@ CONFIG_MODULE_COMPRESS_GZIP=y
 # CONFIG_MODULE_COMPRESS_ZSTD is not set
 # CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS is not set
 CONFIG_MODPROBE_PATH="/sbin/modprobe"
-CONFIG_TRIM_UNUSED_KSYMS=y
-CONFIG_UNUSED_KSYMS_WHITELIST=""
+# CONFIG_TRIM_UNUSED_KSYMS is not set
 CONFIG_MODULES_TREE_LOOKUP=y
 CONFIG_BLOCK=y
 CONFIG_BLK_CGROUP_RWSTAT=y