diff --git a/tools/list-openwrt.sh b/tools/list-openwrt.sh
new file mode 100644
index 0000000000..c93a3ab7da
--- /dev/null
+++ b/tools/list-openwrt.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+# $version can be 21.02 or 19.07.
+version=19.07.7
+if [ ! -d /tmp/openwrt ]; then
+  cd /tmp
+  git clone https://github.com/openwrt/openwrt.git
+  cd openwrt
+fi
+cd /tmp/openwrt
+git -c advice.detachedHead=false checkout v$version
+export TOPDIR=$PWD
+cd target/linux
+>targets.git
+for target in *; do
+  [ -d $target ] || continue
+  subtargets=$(make -C $target --no-print-directory DUMP=1 TARGET_BUILD=1 val.SUBTARGETS 2>/dev/null)
+  [ "$subtargets" ] || subtargets=generic
+  for subtarget in $subtargets; do
+    echo $(make -C $target --no-print-directory DUMP=1 TARGET_BUILD=1 SUBTARGET=$subtarget 2>/dev/null | egrep '^(Target:|Target-Arch-Packages:)' | cut -d: -f2) >>targets.git
+  done
+done
+
+targets=$(curl -s https://downloads.openwrt.org/releases/$version/targets/ | grep '<td class="n"><a href=' | cut -d'"' -f4 | sed 's,/,,')
+>targets.sdk
+for target in $targets; do
+  subtargets=$(curl -s https://downloads.openwrt.org/releases/$version/targets/$target/ | grep '<td class="n"><a href=' | cut -d'"' -f4 | sed 's,/,,')
+  for subtarget in $subtargets; do
+    arch=$(curl -s https://downloads.openwrt.org/releases/$version/targets/$target/$subtarget/profiles.json | grep arch_packages | cut -d'"' -f4)
+    echo $target/$subtarget $arch >>targets.sdk
+  done
+done
+
+cat >parse-targets.py <<EOF
+arch_by_target_git = {}
+arch_by_target_sdk = {}
+for line in open('targets.git'):
+    fields = line.split()
+    if not fields:
+        continue
+    arch_by_target_git[fields[0]] = fields[1]
+for line in open('targets.sdk'):
+    fields = line.split()
+    if len(fields) == 2:
+        if arch_by_target_git[fields[0]] != fields[1]:
+            raise Exception(line + ': wrong arch')
+        arch_by_target_sdk[fields[0]] = fields[1]
+    else:
+        arch_by_target_sdk[fields[0]] = ''
+for arch in sorted(set(arch_by_target_git.values())):
+    targets = []
+    for t in arch_by_target_git:
+        if arch_by_target_git[t] != arch:
+            continue
+        if t in arch_by_target_sdk:
+            targets.append(t)
+        else:
+            targets.append('~~' + t + '~~')
+    print('|', arch, '|?|', ' '.join(sorted(set(targets))), '|')
+EOF
+python3 parse-targets.py