tests/functional: Add the LinuxKernelTest for testing the Linux boot process

Copy the LinuxKernelTest from tests/acceptance/boot_linux_console.py
to be able to convert the related tests to the functional test framework
in the following patches.

Message-ID: <20240906180549.792832-2-thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/functional/qemu_test/__init__.py

@@ -12,3 +12,4 @@ from .cmd import has_cmd, has_cmds, run_cmd, is_readable_executable_file, \
     interrupt_interactive_console_until_pattern, wait_for_console_pattern, \
     exec_command, exec_command_and_wait_for_pattern, get_qemu_img
 from .testcase import QemuBaseTest, QemuUserTest, QemuSystemTest
+from .linuxkernel import LinuxKernelTest

tests/functional/qemu_test/linuxkernel.py

@@ -0,0 +1,41 @@
+# Test class for testing the boot process of a Linux kernel
+#
+# This work is licensed under the terms of the GNU GPL, version 2 or
+# later.  See the COPYING file in the top-level directory.
+
+import os
+
+from .testcase import QemuSystemTest
+from .cmd import run_cmd, wait_for_console_pattern
+from .utils import archive_extract
+
+class LinuxKernelTest(QemuSystemTest):
+    KERNEL_COMMON_COMMAND_LINE = 'printk.time=0 '
+
+    def wait_for_console_pattern(self, success_message, vm=None):
+        wait_for_console_pattern(self, success_message,
+                                 failure_message='Kernel panic - not syncing',
+                                 vm=vm)
+
+    def extract_from_deb(self, deb_path, path):
+        """
+        Extracts a file from a deb package into the test workdir
+
+        :param deb_path: path to the deb archive
+        :param path: path within the deb archive of the file to be extracted
+        :returns: path of the extracted file
+        """
+        cwd = os.getcwd()
+        os.chdir(self.workdir)
+        (stdout, stderr, ret) = run_cmd(['ar', 't', deb_path])
+        file_path = stdout.split()[2]
+        run_cmd(['ar', 'x', deb_path, file_path])
+        archive_extract(file_path, self.workdir)
+        os.chdir(cwd)
+        # Return complete path to extracted file.  Because callers to
+        # extract_from_deb() specify 'path' with a leading slash, it is
+        # necessary to use os.path.relpath() as otherwise os.path.join()
+        # interprets it as an absolute path and drops the self.workdir part.
+        return os.path.normpath(os.path.join(self.workdir,
+                                             os.path.relpath(path, '/')))
+