Added kernel role

roles/kernel/tasks/main.yml

@@ -0,0 +1,84 @@
+- name: Add the bc250-cachyos pacman repository
+  become: true
+  ansible.builtin.blockinfile:
+    path: /etc/pacman.conf
+    marker: "# {mark} - Ansible managed"
+    prepend_newline: true
+    block: |
+      [bc250-cachyos]
+      SigLevel = Optional TrustAll
+      Server = https://github.com/MastaG/linux-cachyos-bc250/releases/download/repo
+  register: pacman_repo
+
+# Full upgrade first: installing from a freshly added repo without -Syu
+# would be a partial upgrade.
+- name: Perform a full system upgrade
+  become: true
+  community.general.pacman:
+    update_cache: "{{ pacman_repo.changed }}"
+    upgrade: true
+  register: sys_upgrade
+
+- name: Give the BC-250 kernel priority in BOOT_ORDER
+  become: true
+  ansible.builtin.lineinfile:
+    path: /etc/default/limine
+    regexp: '^BOOT_ORDER='
+    line: 'BOOT_ORDER="*bc250, *lts, *, *fallback, Snapshots"'
+  register: boot_order
+
+- name: Install the BC-250 kernel and the fallback
+  become: true
+  community.general.pacman:
+    name:
+      - linux-cachyos-bc250
+      - linux-cachyos-bc250-headers
+      - linux-cachyos
+      - linux-cachyos-headers
+    state: present
+  register: kernel_pkg
+
+- name: Regenerate Limine entries when only BOOT_ORDER changed
+  become: true
+  ansible.builtin.command: limine-mkinitcpio
+  when: boot_order.changed and not kernel_pkg.changed
+  changed_when: true
+
+- name: Preselect the BC-250 kernel for the next boot
+  become: true
+  ansible.builtin.shell:
+    executable: /bin/bash
+    cmd: |
+      set -eu
+      EFIVAR=$(ls /sys/firmware/efi/efivars/LimineLastBootedEntry-*)
+      [ "$(tail -c +5 "$EFIVAR" | tr -d '\0')" = 'CachyOS/linux-cachyos-bc250' ] && exit 90
+      chattr -i "$EFIVAR"
+      printf '\x07\x00\x00\x00CachyOS/linux-cachyos-bc250\x00' > "$EFIVAR"
+  register: efivar_write
+  changed_when: efivar_write.rc == 0
+  failed_when: efivar_write.rc not in [0, 90]
+
+- name: Reboot into the new kernel
+  become: true
+  ansible.builtin.reboot:
+    reboot_timeout: 600
+  when: kernel_pkg.changed or boot_order.changed or sys_upgrade.changed
+
+- name: Re-gather kernel facts after reboot
+  ansible.builtin.setup:
+    filter: ansible_kernel
+
+# Guards the removal below: never drop deckify unless we are already
+# running the BC-250 kernel.
+- name: Make sure the BC-250 kernel is the running one
+  ansible.builtin.assert:
+    that: "'bc250' in ansible_kernel"
+    fail_msg: "Running {{ ansible_kernel }}"
+
+- name: Remove the deckify kernel
+  become: true
+  community.general.pacman:
+    name:
+      - linux-cachyos-deckify
+      - linux-cachyos-deckify-headers
+    state: absent