ci: add FreeBSD cross CI job

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 914b29ca..dd262282 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -486,6 +486,12 @@ jobs:
             timeout-minutes: 120
             file-env: './ci/test/00_setup_env_mac_cross_intel.sh'
 
+          - name: 'FreeBSD Cross'
+            cirrus-runner: 'ghcr.io/cirruslabs/ubuntu-runner-amd64:24.04-md'
+            fallback-runner: 'ubuntu-24.04'
+            timeout-minutes: 120
+            file-env: './ci/test/00_setup_env_freebsd_cross.sh'
+
           - name: 'No wallet'
             cirrus-runner: 'ghcr.io/cirruslabs/ubuntu-runner-amd64:24.04-sm'
             fallback-runner: 'ubuntu-24.04'
diff --git a/ci/test/00_setup_env_freebsd_cross.sh b/ci/test/00_setup_env_freebsd_cross.sh
new file mode 100755
index 00000000..da7304d1
--- /dev/null
+++ b/ci/test/00_setup_env_freebsd_cross.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+#
+# Copyright (c) The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://opensource.org/license/mit.
+
+export LC_ALL=C.UTF-8
+
+export CONTAINER_NAME=ci_freebsd_cross
+export CI_IMAGE_NAME_TAG="mirror.gcr.io/ubuntu:24.04"
+export APT_LLVM_V="22"
+export FREEBSD_VERSION=15.0
+export PACKAGES="clang-${APT_LLVM_V} llvm-${APT_LLVM_V} lld"
+export HOST=x86_64-unknown-freebsd
+export DEP_OPTS="build_CC=clang build_CXX=clang++ AR=llvm-ar-${APT_LLVM_V} STRIP=llvm-strip-${APT_LLVM_V} NM=llvm-nm-${APT_LLVM_V} RANLIB=llvm-ranlib-${APT_LLVM_V}"
+export GOAL="install"
+export BITCOIN_CONFIG="\
+ --preset=dev-mode \
+ -DREDUCE_EXPORTS=ON \
+ -DWITH_USDT=OFF \
+"
+export RUN_UNIT_TESTS=false
+export RUN_FUNCTIONAL_TESTS=false
diff --git a/ci/test/01_base_install.sh b/ci/test/01_base_install.sh
index 308f7abe..0debf36f 100755
--- a/ci/test/01_base_install.sh
+++ b/ci/test/01_base_install.sh
@@ -104,4 +104,16 @@ if [ -n "$XCODE_VERSION" ] && [ ! -d "${DEPENDS_DIR}/SDKs/${OSX_SDK_BASENAME}" ]
   tar -C "${DEPENDS_DIR}/SDKs" -xf "$OSX_SDK_PATH"
 fi
 
+FREEBSD_SDK_BASENAME="freebsd-${HOST}-${FREEBSD_VERSION}"
+
+if [ -n "$FREEBSD_VERSION" ] && [ ! -d "${DEPENDS_DIR}/SDKs/${FREEBSD_SDK_BASENAME}" ]; then
+  FREEBSD_SDK_FILENAME="base-${FREEBSD_VERSION}.txz"
+  FREEBSD_SDK_PATH="${DEPENDS_DIR}/sdk-sources/${FREEBSD_SDK_FILENAME}"
+  if [ ! -f "$FREEBSD_SDK_PATH" ]; then
+    ${CI_RETRY_EXE} curl --location --fail "https://download.freebsd.org/releases/amd64/${FREEBSD_VERSION}-RELEASE/base.txz" -o "$FREEBSD_SDK_PATH"
+  fi
+  mkdir -p "${DEPENDS_DIR}/SDKs/${FREEBSD_SDK_BASENAME}"
+  tar -C "${DEPENDS_DIR}/SDKs/${FREEBSD_SDK_BASENAME}" -xf "$FREEBSD_SDK_PATH"
+fi
+
 echo -n "done" > "${CFG_DONE}"