From 44ae2a75e44a7e6d1b83e8151bcd4bda03a69aee Mon Sep 17 00:00:00 2001
From: Richard Hughes <richard@hughsie.com>
Date: Fri, 25 Sep 2020 18:00:21 +0100
Subject: [PATCH] trivial: Add CRC8 as well

---
 libfwupdplugin/fu-common.c         | 26 ++++++++++++++++++++++++++
 libfwupdplugin/fu-common.h         |  2 ++
 libfwupdplugin/fu-self-test.c      |  1 +
 libfwupdplugin/fwupdplugin.map     |  1 +
 plugins/vli/fu-vli-common.c        | 15 ---------------
 plugins/vli/fu-vli-common.h        |  3 ---
 plugins/vli/fu-vli-usbhub-common.c |  2 +-
 7 files changed, 31 insertions(+), 19 deletions(-)

diff --git a/libfwupdplugin/fu-common.c b/libfwupdplugin/fu-common.c
index ee8969260..13db2afa5 100644
--- a/libfwupdplugin/fu-common.c
+++ b/libfwupdplugin/fu-common.c
@@ -2336,6 +2336,32 @@ fu_common_get_esp_for_path (const gchar *esp_path, GError **error)
 	return NULL;
 }
 
+/**
+ * fu_common_crc8:
+ * @buf: memory buffer
+ * @bufsz: sizeof buf
+ *
+ * Returns the cyclic redundancy check value for the given memory buffer.
+ *
+ * Returns: CRC value
+ *
+ * Since: 1.5.0
+ **/
+guint8
+fu_common_crc8 (const guint8 *buf, gsize bufsz)
+{
+	guint32 crc = 0;
+	for (gsize j = bufsz; j > 0; j--) {
+		crc ^= (*(buf++) << 8);
+		for (guint32 i = 8; i; i--) {
+			if (crc & 0x8000)
+				crc ^= (0x1070 << 3);
+			crc <<= 1;
+		}
+	}
+	return ~((guint8) (crc >> 8));
+}
+
 /**
  * fu_common_crc16:
  * @buf: memory buffer
diff --git a/libfwupdplugin/fu-common.h b/libfwupdplugin/fu-common.h
index 2d15f41c2..c65dafa7c 100644
--- a/libfwupdplugin/fu-common.h
+++ b/libfwupdplugin/fu-common.h
@@ -240,6 +240,8 @@ FuVolume	*fu_common_get_esp_for_path	(const gchar	*esp_path,
 						 GError		**error);
 FuVolume	*fu_common_get_esp_default	(GError		**error);
 
+guint8		 fu_common_crc8			(const guint8	*buf,
+						 gsize		 bufsz);
 guint16		 fu_common_crc16		(const guint8	*buf,
 						 gsize		 bufsz);
 guint32		 fu_common_crc32		(const guint8	*buf,
diff --git a/libfwupdplugin/fu-self-test.c b/libfwupdplugin/fu-self-test.c
index e6cb49ffc..383788f9d 100644
--- a/libfwupdplugin/fu-self-test.c
+++ b/libfwupdplugin/fu-self-test.c
@@ -111,6 +111,7 @@ static void
 fu_common_crc_func (void)
 {
 	guint8 buf[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09 };
+	g_assert_cmpint (fu_common_crc8 (buf, sizeof(buf)), ==, 0x7A);
 	g_assert_cmpint (fu_common_crc16 (buf, sizeof(buf)), ==, 0x4DF1);
 	g_assert_cmpint (fu_common_crc32 (buf, sizeof(buf)), ==, 0x40EFAB9E);
 }
diff --git a/libfwupdplugin/fwupdplugin.map b/libfwupdplugin/fwupdplugin.map
index 6a1910db9..7164d61b3 100644
--- a/libfwupdplugin/fwupdplugin.map
+++ b/libfwupdplugin/fwupdplugin.map
@@ -616,6 +616,7 @@ LIBFWUPDPLUGIN_1.5.0 {
     fu_common_crc16;
     fu_common_crc32;
     fu_common_crc32_full;
+    fu_common_crc8;
     fu_common_filename_glob;
     fu_common_is_cpu_intel;
     fu_device_bind_driver;
diff --git a/plugins/vli/fu-vli-common.c b/plugins/vli/fu-vli-common.c
index 38e93537a..c5b7fda1b 100644
--- a/plugins/vli/fu-vli-common.c
+++ b/plugins/vli/fu-vli-common.c
@@ -9,21 +9,6 @@
 
 #include "fu-vli-common.h"
 
-guint8
-fu_vli_common_crc8 (const guint8 *buf, gsize bufsz)
-{
-	guint32 crc = 0;
-	for (gsize j = bufsz; j > 0; j--) {
-		crc ^= (*(buf++) << 8);
-		for (guint32 i = 8; i; i--) {
-			if (crc & 0x8000)
-				crc ^= (0x1070 << 3);
-			crc <<= 1;
-		}
-	}
-	return (guint8) (crc >> 8);
-}
-
 const gchar *
 fu_vli_common_device_kind_to_string (FuVliDeviceKind device_kind)
 {
diff --git a/plugins/vli/fu-vli-common.h b/plugins/vli/fu-vli-common.h
index e3c2c9e35..30d964835 100644
--- a/plugins/vli/fu-vli-common.h
+++ b/plugins/vli/fu-vli-common.h
@@ -43,6 +43,3 @@ const gchar	*fu_vli_common_device_kind_to_string	(FuVliDeviceKind	 device_kind);
 FuVliDeviceKind	 fu_vli_common_device_kind_from_string	(const gchar		*device_kind);
 guint32		 fu_vli_common_device_kind_get_size	(FuVliDeviceKind	 device_kind);
 guint32		 fu_vli_common_device_kind_get_offset	(FuVliDeviceKind	 device_kind);
-
-guint8		 fu_vli_common_crc8			(const guint8		*buf,
-							 gsize			 bufsz);
diff --git a/plugins/vli/fu-vli-usbhub-common.c b/plugins/vli/fu-vli-usbhub-common.c
index e45ee85d8..3fa77f964 100644
--- a/plugins/vli/fu-vli-usbhub-common.c
+++ b/plugins/vli/fu-vli-usbhub-common.c
@@ -12,7 +12,7 @@
 guint8
 fu_vli_usbhub_header_crc8 (FuVliUsbhubHeader *hdr)
 {
-	return fu_vli_common_crc8 ((const guint8 *) hdr, sizeof(*hdr) - 1);
+	return ~fu_common_crc8 ((const guint8 *) hdr, sizeof(*hdr) - 1);
 }
 
 void