tests/functional: Test SD cards in SPI mode (using sifive_u machine)

Add a test which uses the sifive_u machine to boot a Linux
kernel from a SD card connected via a SPI interface.

Inspired from the command provided in:
- https://lore.kernel.org/qemu-devel/94b2c5bf-53d0-4c74-8264-f3021916f38c@roeck-us.net/
- https://lore.kernel.org/qemu-devel/840016d0-0d49-4ef4-8372-b62b3bcd0ac6@codethink.co.uk/

Inspired-by: Guenter Roeck <linux@roeck-us.net>
Inspired-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250804133406.17456-12-philmd@linaro.org>

MAINTAINERS

@@ -1695,6 +1695,7 @@ S: Supported
 F: docs/system/riscv/sifive_u.rst
 F: hw/*/*sifive*.c
 F: include/hw/*/*sifive*.h
+F: tests/functional/test_riscv64_sifive_u.py
 
 AMD Microblaze-V Generic Board
 M: Sai Pavan Boddu <sai.pavan.boddu@amd.com>

tests/functional/meson.build

@@ -274,6 +274,7 @@ tests_riscv64_system_quick = [
 ]
 
 tests_riscv64_system_thorough = [
+  'riscv64_sifive_u',
   'riscv64_tuxrun',
 ]
 

tests/functional/test_riscv64_sifive_u.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+#
+# Functional test that boots a Linux kernel on a Sifive U machine
+# and checks the console
+#
+# Copyright (c) Linaro Ltd.
+#
+# Author:
+#  Philippe Mathieu-Daudé
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import os
+
+from qemu_test import Asset, LinuxKernelTest
+from qemu_test import skipIfMissingCommands
+
+
+class SifiveU(LinuxKernelTest):
+
+    ASSET_KERNEL = Asset(
+        'https://storage.tuxboot.com/buildroot/20241119/riscv64/Image',
+        '2bd8132a3bf21570290042324fff48c987f42f2a00c08de979f43f0662ebadba')
+    ASSET_ROOTFS = Asset(
+        ('https://github.com/groeck/linux-build-test/raw/'
+         '9819da19e6eef291686fdd7b029ea00e764dc62f/rootfs/riscv64/'
+         'rootfs.ext2.gz'),
+        'b6ed95610310b7956f9bf20c4c9c0c05fea647900df441da9dfe767d24e8b28b')
+
+    def test_riscv64_sifive_u_mmc_spi(self):
+        self.set_machine('sifive_u')
+        kernel_path = self.ASSET_KERNEL.fetch()
+        rootfs_path = self.uncompress(self.ASSET_ROOTFS)
+
+        self.vm.set_console()
+        kernel_command_line = (self.KERNEL_COMMON_COMMAND_LINE +
+                               'root=/dev/mmcblk0 rootwait '
+                               'earlycon=sbi console=ttySIF0 '
+                               'panic=-1 noreboot')
+        self.vm.add_args('-kernel', kernel_path,
+                         '-drive', f'file={rootfs_path},if=sd,format=raw',
+                         '-append', kernel_command_line,
+                         '-no-reboot')
+        self.vm.launch()
+        self.wait_for_console_pattern('Boot successful.')
+
+        os.remove(rootfs_path)
+
+
+if __name__ == '__main__':
+    LinuxKernelTest.main()