--- a/grub.SlackBuild	2021-02-10 17:20:35.117832543 +0200
+++ b/grub.SlackBuild	2021-02-10 17:21:13.221805372 +0200
@@ -77,6 +77,12 @@
 elif [ "$ARCH" = "armv7hl" ]; then
   SLKCFLAGS="-O3 -march=armv7-a -mfpu=vfpv3-d16"
   LIBDIRSUFFIX=""
+elif [ "$ARCH" = "aarch64" ]; then
+  SLKCFLAGS="-O3"
+  LIBDIRSUFFIX="64"
+elif [ "$ARCH" = "riscv64" ]; then
+  SLKCFLAGS="-O3"
+  LIBDIRSUFFIX="64"
 else
   SLKCFLAGS="-O2"
   LIBDIRSUFFIX=""
@@ -118,6 +124,7 @@
 build_grub() {
   EFI_DO="$*"
   # Configure:
+  ac_cv_header_sys_sysmacros_h=yes \
   CFLAGS="$SLKCFLAGS" \
   ./configure \
     --prefix=/usr \