handle being on an arm64 system

scripts/bootstrap-repo.sh

@@ -4,18 +4,26 @@ set -ex
 # bootstrap _this_ repo (toes-image-builder), not the image itself.
 # should only have to do this once per host we run this on.
 
-sudo apt-get update
-sudo apt-get install -y \
-	qemu-user-static \
-	binfmt-support \
-	qemu-system-arm \
-	qemu-utils \
-	kpartx \
-	parted \
-	fdisk \
-	dosfstools \
-	e2fsprogs \
-	xz-utils \
-	rsync \
-	curl \
+packages=(
+	kpartx
+	parted
+	fdisk
+	dosfstools
+	e2fsprogs
+	xz-utils
+	rsync
+	curl
 	ca-certificates
+)
+
+case "$(uname -m)" in
+	aarch64|arm64)
+		echo "native arm64 host detected; skipping qemu user emulation packages"
+		;;
+	*)
+		packages=(qemu-user-static binfmt-support "${packages[@]}")
+		;;
+esac
+
+sudo apt-get update
+sudo apt-get install -y "${packages[@]}"

scripts/build-in-chroot.sh

@@ -1,7 +1,7 @@
 #! /bin/bash
 set -ex
 
-# runs setup commands inside the image, under qemu arm64.
+# runs setup commands inside the arm64 image rootfs.
 
 sudo tee mnt/root/tmp/image-build.sh >/dev/null <<'EOF'
 #! /bin/bash