plugins/coreboot: Improve version detection

Only on Lenovo devices the DMI version string is prefixed with
CBETxxxx to make the thinkpad_acpi kernel module happy.

Add a new quirk called "CorebootVersionQuirks" to detect platforms
that need to cut of the prefix.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>

plugins/coreboot/README.md

@@ -20,13 +20,24 @@ coreboot can be detected the following ways:
 coreboot version string
 -----------------------
 
-The coreboot version string always starts with `CBET`.
+The coreboot version string can have an optional prefix (see below).
-After the prefix the *version*, *major*, *minor* string follows and finally
+After the optional prefix the *major*, *minor* string follows and finally
 the *build string*, containing the exact commit and repository state, follows.
 
+For example:
+> 4.10-989-gc8a4e4b9c5-dirty
+
+**Exception on Lenovo devices:**
+
+The thinkpad_acpi kernel module requires a specific pattern in the DMI version
+string. To satisfy those requirements coreboot adds the CBETxxxx prefix to the
+DMI version string on all Lenovo devices.
+
 For example:
 > CBET4000 4.10-989-gc8a4e4b9c5-dirty
 
+The coreboot DMI version string always starts with `CBET`.
+
 GUID Generation
 ---------------
 

plugins/coreboot/coreboot.quirk

@@ -0,0 +1,2 @@
+[SmbiosManufacturer=LENOVO]
+CorebootVersionQuirks = lenovo-cbet-prefix

plugins/coreboot/fu-coreboot-common.c

@@ -11,20 +11,37 @@
 
 #include "fu-plugin-coreboot.h"
 
+/**
+ * FU_QUIRKS_COREBOOT_VERSION:
+ * @key: The SMBIOS manufacturer name
+ * @value: One of the following: "lenovo-cbet-prefix"
+ *
+ * "lenovo-cbet-prefix" quirk:
+ * The thinkpad_acpi kernel module requires a specific pattern
+ * in the DMI version string. To satisfy those requirements
+ * coreboot adds the CBETxxxx prefix to the DMI version string
+ * on all Lenovo devices. The prefix isn't present in the
+ * version string found in coreboot tables, or on other
+ * coreboot enabled devices.
+ *
+ * Since: 1.3.5
+ */
+#define	FU_QUIRKS_COREBOOT_VERSION	"CorebootVersionQuirks"
+#define	FU_QUIRK_CBET_PREFIX		"lenovo-cbet-prefix"
+
 /* Tries to convert the coreboot version string to a triplet string.
  * Returns NULL on error. */
 gchar *
 fu_plugin_coreboot_version_string_to_triplet (const gchar *coreboot_version,
 					      GError **error)
 {
-	guint cb_version = 0;
 	guint cb_major = 0;
 	guint cb_minor = 0;
 	guint cb_build = 0;
 	gint rc;
 
-	rc = sscanf (coreboot_version, "CBET%u %u.%u-%u", &cb_version, &cb_major,
+	rc = sscanf (coreboot_version, "%u.%u-%u", &cb_major, &cb_minor, &cb_build);
-			&cb_minor, &cb_build);
+
 	if (rc < 0) {
 		g_set_error (error,
 			     G_IO_ERROR,
@@ -34,7 +51,7 @@ fu_plugin_coreboot_version_string_to_triplet (const gchar *coreboot_version,
 	}
 
 	/* Sanity check */
-	if (cb_major == 0 || cb_version == 0) {
+	if (cb_major == 0) {
 		g_set_error (error,
 			     G_IO_ERROR,
 			     G_IO_ERROR_INVALID_DATA,
@@ -62,3 +79,37 @@ fu_plugin_coreboot_get_name_for_type (FuPlugin *plugin,
 	g_string_prepend (display_name, "coreboot System Firmware");
 	return g_string_free (display_name, FALSE);
 }
+
+/* Returns the version string with possible quirks applied */
+gchar *
+fu_plugin_coreboot_get_version_string (FuPlugin *plugin)
+{
+	const gchar *version;
+	const gchar *manufacturer;
+	const gchar *quirk = NULL;
+
+	version = fu_plugin_get_dmi_value (plugin, FU_HWIDS_KEY_BIOS_VERSION);
+	if (version == NULL)
+		return NULL;
+
+	manufacturer = fu_plugin_get_dmi_value (plugin, FU_HWIDS_KEY_MANUFACTURER);
+	if (manufacturer != NULL) {
+		g_autofree gchar *group = NULL;
+
+		/* any quirks match */
+		group = g_strdup_printf ("SmbiosManufacturer=%s", manufacturer);
+		quirk = fu_plugin_lookup_quirk_by_id (plugin, group,
+						      FU_QUIRKS_COREBOOT_VERSION);
+	}
+
+	if (quirk == NULL)
+		return version;
+
+	if (g_strcmp0(quirk, FU_QUIRK_CBET_PREFIX) == 0) {
+		if (strlen (version) > 9 && g_str_has_prefix (version, "CBET"))
+			version += 9;
+		return version;
+	}
+
+	return version;
+}

plugins/coreboot/fu-plugin-coreboot.c

@@ -44,7 +44,7 @@ fu_plugin_coldplug (FuPlugin *plugin, GError **error)
 		"HardwareID-10",
 	};
 
-	version = fu_plugin_get_dmi_value (plugin, FU_HWIDS_KEY_BIOS_VERSION);
+	version = fu_plugin_coreboot_get_version_string (plugin);
 	if (version != NULL)
 		triplet = fu_plugin_coreboot_version_string_to_triplet (version, error);
 

plugins/coreboot/fu-plugin-coreboot.h

@@ -13,3 +13,4 @@ gchar		*fu_plugin_coreboot_version_string_to_triplet	(const gchar	*coreboot_vers
 								 GError		**error);
 gchar		*fu_plugin_coreboot_get_name_for_type		(FuPlugin	*plugin,
 								const gchar	*vboot_partition);
+gchar		*fu_plugin_coreboot_get_version_string		(FuPlugin	*plugin);

plugins/coreboot/meson.build

@@ -1,5 +1,9 @@
 cargs = ['-DG_LOG_DOMAIN="FuPluginCoreboot"']
 
+install_data(['coreboot.quirk'],
+  install_dir: join_paths(datadir, 'fwupd', 'quirks.d')
+)
+
 shared_module('fu_plugin_coreboot',
   sources : [
     'fu-plugin-coreboot.c',