Fix missing ftruncate on MacOS

mk/config.mk

@@ -33,6 +33,7 @@ ifeq ($(UNAME),Darwin)
 	VB_AUDIO=coreaudio
 	VBM=/Applications/VirtualBox.app/Contents/MacOS/VBoxManage
 	HOST_TARGET ?= $(HOST_ARCH)-apple-darwin
+	ALLOC_FILE=truncate -s "$(FILESYSTEM_SIZE)m"
 else ifeq ($(UNAME),FreeBSD)
 	FUMOUNT=sudo umount
 	export NPROC=sysctl -n hw.ncpu
@@ -41,6 +42,7 @@ else ifeq ($(UNAME),FreeBSD)
 	VB_AUDIO=pulse # To check, will probaly be OSS on most setups
 	VBM=VBoxManage
 	HOST_TARGET ?= $(HOST_ARCH)-unknown-freebsd
+	ALLOC_FILE=fallocate --posix --length "$(FILESYSTEM_SIZE)MiB"
 else
 	# Detect which version of the fusermount binary is available.
 	ifneq (, $(shell which fusermount3))
@@ -54,6 +56,7 @@ else
 	VB_AUDIO=pulse
 	VBM=VBoxManage
 	HOST_TARGET ?= $(HOST_ARCH)-unknown-linux-gnu
+	ALLOC_FILE=fallocate --posix --length "$(FILESYSTEM_SIZE)MiB"
 endif
 
 # Automatic variables

mk/disk.mk

@@ -2,7 +2,7 @@ $(BUILD)/harddrive.img: $(FSTOOLS_TAG) $(REPO_TAG)
 	mkdir -p $(BUILD)
 	rm -rf $@  $@.partial
 	-$(FUMOUNT) /tmp/redox_installer || true
-	fallocate --posix --length "$(FILESYSTEM_SIZE)MiB" $@.partial
+	${ALLOC_FILE} $@.partial
 	umask 002 && $(INSTALLER) -c $(FILESYSTEM_CONFIG) $@.partial
 	mv $@.partial $@
 
@@ -10,7 +10,7 @@ $(BUILD)/livedisk.iso: $(FSTOOLS_TAG) $(REPO_TAG)
 	mkdir -p $(BUILD)
 	rm -rf $@  $@.partial
 	-$(FUMOUNT) /tmp/redox_installer || true
-	fallocate --posix --length "$(FILESYSTEM_SIZE)MiB" $@.partial
+	${ALLOC_FILE} $@.partial
 	umask 002 && $(INSTALLER) -c $(FILESYSTEM_CONFIG) --live $@.partial
 	mv $@.partial $@
 
@@ -19,7 +19,7 @@ $(BUILD)/filesystem.img: $(FSTOOLS_TAG) $(REPO_TAG)
 	-$(FUMOUNT) $(BUILD)/filesystem/ || true
 	rm -rf $@  $@.partial $(BUILD)/filesystem/
 	-$(FUMOUNT) /tmp/redox_installer || true
-	fallocate --posix --length "$(FILESYSTEM_SIZE)MiB" $@.partial
+	${ALLOC_FILE} $@.partial
 	redoxfs/target/release/redoxfs-mkfs $(REDOXFS_MKFS_FLAGS) $@.partial
 	mkdir -p $(BUILD)/filesystem/
 	redoxfs/target/release/redoxfs $@.partial $(BUILD)/filesystem/