Change how kernel version is given to the script - use arguments, to
avoid confusion between pipeline level variables and job level ones.

The build-linux.sh now can take either just the kernel version (used to be
LINUX_VERSION variable), or git branch/tag/commit name + git URL (new feature).
Go with "git init" + "git fetch" instead of "git clone" to support any
of branch/tag/commit.

This also defines optional linux-git-* jobs which will build the thing
if LINUX_GIT_VERSION and LINUX_GIT_URL variables are provided for the
pipeline.

The idea is to define separate CI schedules for the test-artifacts repo
with LINUX_GIT_URL/LINUX_GIT_VERSION pointing at Linux trees to be
tested (for example linux-next), and then trigger matching pipelines in
the xen repo for testing with that version.

Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
---
Changes in v3:
- pass kernel version via script arguments, not variables
---
 .gitlab-ci.yml         | 23 ++++++++++++++++++-----
 scripts/build-linux.sh | 21 ++++++++++++++++-----
 2 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 58f7571f5366..62b2a24e7faf 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,9 @@
 variables:
   REGISTRY: registry.gitlab.com/xen-project/hardware/test-artifacts
+  LINUX_GIT_VERSION:
+    description: "branch/tag/commit for the linux-git jobs"
+  LINUX_GIT_URL:
+    description: "git url for the linux-git jobs"
 
 stages:
   - build
@@ -49,9 +53,13 @@ alpine-3.22-arm64-rootfs:
 
 linux-6.6.86-arm64:
   extends: .arm64-artifacts
-  script: ./scripts/build-linux.sh
-  variables:
-    LINUX_VERSION: 6.6.86
+  script: ./scripts/build-linux.sh "6.6.86"
+
+linux-git-arm64:
+  extends: .arm64-artifacts
+  script: ./scripts/build-linux.sh "$LINUX_GIT_VERSION" "$LINUX_GIT_URL"
+  rules:
+  - if: $LINUX_GIT_VERSION && $LINUX_GIT_URL
 
 #
 # x86_64 artifacts
@@ -79,9 +87,8 @@ debian-13-x86_64-rootfs:
 
 linux-6.6.56-x86_64:
   extends: .x86_64-artifacts
-  script: ./scripts/build-linux.sh
+  script: ./scripts/build-linux.sh "6.6.56"
   variables:
-    LINUX_VERSION: 6.6.56
     ARGO_SHA: "cf73819cacc945baca1a7421e5836d1bd481739b"
     ARGOEXEC_SHA: "d900429f6640acc6f68a3d3a4c945d7da60625d8"
 
@@ -89,6 +96,12 @@ linux-6.12.60-x86_64:
   extends: .x86_64-artifacts
   script: ./scripts/build-linux.sh "6.12.60"
 
+linux-git-x86_64:
+  extends: .x86_64-artifacts
+  script: ./scripts/build-linux.sh "$LINUX_GIT_VERSION" "$LINUX_GIT_URL"
+  rules:
+  - if: $LINUX_GIT_VERSION && $LINUX_GIT_URL
+
 microcode-x86:
   extends: .x86_64-artifacts
   script: ./scripts/x86-microcode.sh
diff --git a/scripts/build-linux.sh b/scripts/build-linux.sh
index cf0e744bd232..882bac2189a6 100755
--- a/scripts/build-linux.sh
+++ b/scripts/build-linux.sh
@@ -1,5 +1,8 @@
 #!/usr/bin/env bash
 
+LINUX_VERSION="$1"
+LINUX_GIT_URL="$2"
+
 if test -z "${LINUX_VERSION}"
 then
     >&2 echo "LINUX_VERSION must be set"; exit 1
@@ -12,11 +15,19 @@ COPYDIR="${WORKDIR}/binaries"
 UNAME=$(uname -m)
 
 # Build Linux
-MAJOR=${LINUX_VERSION%%.*}
-curl -fsSLO \
-    https://cdn.kernel.org/pub/linux/kernel/v"${MAJOR}".x/linux-"${LINUX_VERSION}".tar.xz
-tar xf linux-"${LINUX_VERSION}".tar.xz
-cd linux-"${LINUX_VERSION}"
+if [[ -n "${LINUX_GIT_URL}" ]]; then
+    mkdir linux
+    cd linux
+    git init
+    git fetch --depth=1 "${LINUX_GIT_URL}" "${LINUX_VERSION}"
+    git checkout FETCH_HEAD
+else
+    MAJOR=${LINUX_VERSION%%.*}
+    curl -fsSLO \
+        https://cdn.kernel.org/pub/linux/kernel/v"${MAJOR}".x/linux-"${LINUX_VERSION}".tar.xz
+    tar xf linux-"${LINUX_VERSION}".tar.xz
+    cd linux-"${LINUX_VERSION}"
+fi
 
 make defconfig
 ./scripts/config --enable BRIDGE
-- 
git-series 0.9.1