Match Windows 11 arm64 ISO names on arm64 hosts

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

README.md

@@ -24,8 +24,9 @@ Download or check selected targets:
 
 The Windows installation ISO is not downloaded because Microsoft's temporary
 download URLs expire. Place it manually in `install-iso/`; the script finds it
-automatically by matching `Win`, `11`, `x64` and `.iso` in that order
+automatically by matching `Win`, `11`, the architecture (`x64`, or `arm64` on
-(`*Win*11*x64*.iso`, case-insensitive). If several files match, the highest
+arm64 hosts) and `.iso` in that order (`*Win*11*x64*.iso` or
+`*Win*11*arm64*.iso`, case-insensitive). If several files match, the highest
 version-sorted name is used. Check which file was picked with
 `./download-images.sh --print-path windows11 --iso`.
 
@@ -47,7 +48,7 @@ The Windows target prints the QCOW2 path by default. Add `--iso` to print its
 manually supplied installation ISO path. The QCOW2 is named after the detected
 ISO (for example `Win11_25H2_English_x64_v2.iso` →
 `base-qcow2/Win11_25H2_English_x64_v2.qcow2`); if no ISO is present, an
-existing `*Win*11*x64*.qcow2` in `base-qcow2/` is used instead.
+existing `*Win*11*x64*.qcow2` (`*Win*11*arm64*.qcow2` on arm64) in `base-qcow2/` is used instead.
 
 Download URLs can be overridden with `DEBIAN_IMAGE_URL`, `ALMA_IMAGE_URL`,
 `FEDORA_IMAGE_URL`, `UBUNTU_IMAGE_URL`, and `VIRTIO_WIN_ISO_URL`. Each may

download-images.sh

@@ -57,8 +57,17 @@ fi
 
 virtio_image="${tools_iso_dir}/virtio-win.iso"
 
-# Find a Windows 11 x64 file in a directory by matching "Win", "11", "x64" and
+# Windows 11 media is named after the architecture: x64 on amd64 hosts and
-# the extension in that order (case-insensitive). When several match, the
+# Arm64 on arm64 hosts.
+if [[ "$image_arch" == arm64 ]]; then
+  windows_arch=arm64
+else
+  windows_arch=x64
+fi
+
+# Find a Windows 11 file for the current architecture in a directory by
+# matching "Win", "11", the architecture and the extension in that order
+# (case-insensitive). When several match, the
 # highest version-sorted name wins.
 find_windows_image() {
   local dir="$1"
@@ -67,7 +76,7 @@ find_windows_image() {
 
   match="$(
     shopt -s nullglob nocaseglob
-    files=("${dir}"/*Win*11*x64*."${extension}")
+    files=("${dir}"/*Win*11*"${windows_arch}"*."${extension}")
     ((${#files[@]} == 0)) || printf '%s\n' "${files[@]}" | sort -V | tail -n 1
   )"
   [[ -n "$match" ]] && printf '%s\n' "$match"
@@ -75,7 +84,8 @@ find_windows_image() {
 
 windows_iso_path() {
   if ! find_windows_image "$install_iso_dir" iso; then
-    printf 'Error: no Windows 11 x64 ISO (*Win*11*x64*.iso) found in %s\n' "$install_iso_dir" >&2
+    printf 'Error: no Windows 11 %s ISO (*Win*11*%s*.iso) found in %s\n' \
+      "$windows_arch" "$windows_arch" "$install_iso_dir" >&2
     return 1
   fi
 }
@@ -88,7 +98,8 @@ windows_qcow2_path() {
     iso="$(basename -- "$iso")"
     printf '%s/%s.qcow2\n' "$base_qcow2_dir" "${iso%.*}"
   elif ! find_windows_image "$base_qcow2_dir" qcow2; then
-    printf 'Error: no Windows 11 x64 ISO (*Win*11*x64*.iso) found in %s\n' "$install_iso_dir" >&2
+    printf 'Error: no Windows 11 %s ISO (*Win*11*%s*.iso) found in %s\n' \
+      "$windows_arch" "$windows_arch" "$install_iso_dir" >&2
     return 1
   fi
 }
@@ -125,7 +136,7 @@ then downloads them again from the beginning.
 --print-path prints only the absolute image path without downloading it.
 For windows11 it prints the QCOW2 path by default; add --iso for the ISO path.
 The Windows ISO is found automatically in install-iso/ by matching
-*Win*11*x64*.iso; the QCOW2 path is named after that ISO.
+*Win*11*x64*.iso (*Win*11*arm64*.iso on arm64); the QCOW2 path is named after that ISO.
 EOF
 }