Patrick Rudolph would like Patrick Rudolph to review this change.

View Change

lib/crc_byte: Add CRC32 implementation

* Add CRC32 using polynomial 0x04C11DB7
+ Add macro to caculate CRC of a buffer

Change-Id: If98e4e12bb53a6e5123e94e8cdffde1eb3bc4b4b
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
---
M src/include/crc_byte.h
M src/lib/crc_byte.c
2 files changed, 33 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/53/37753/1

diff --git a/src/include/crc_byte.h b/src/include/crc_byte.h
index 9315277..3740b4a 100644
--- a/src/include/crc_byte.h
+++ b/src/include/crc_byte.h
@@ -36,5 +36,24 @@
  */
 uint16_t crc16_byte(uint16_t prev_crc, uint8_t data);
 
+/* This function is used to calculate crc32 byte by byte, with polynomial
+ * x^32 + x^26 +  x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 +
+ * x^5 + x^4 + x^2 + x + 1
+ *
+ * prev_crc: old crc result (0 for first)
+ * data: new byte
+ * return value: new crc result
+ */
+uint32_t crc32_byte(uint32_t prev_crc, uint8_t data);
+
+#define CRC(buf, size, crc_func) ({ \
+	const uint8_t *_crc_local_buf = (const uint8_t *)buf; \
+	size_t _crc_local_size = size; \
+	__typeof__(crc_func(0, 0)) _crc_local_result = ~0; \
+	while (_crc_local_size--) { \
+		_crc_local_result = crc_func(_crc_local_result, *_crc_local_buf++); \
+	} \
+	~_crc_local_result; \
+})
 
 #endif /* CRC_BYTE_H */
diff --git a/src/lib/crc_byte.c b/src/lib/crc_byte.c
index 0ac0063..c04449d 100644
--- a/src/lib/crc_byte.c
+++ b/src/lib/crc_byte.c
@@ -36,3 +36,17 @@
 	prev_crc ^= ((prev_crc & 0xff) << 4) << 1;
 	return prev_crc;
 }
+
+uint32_t crc32_byte(uint32_t prev_crc, uint8_t data)
+{
+	prev_crc ^= (uint32_t)data << 24;
+
+	for (int i = 0; i < 8; i++) {
+		if ((prev_crc & 0x80000000UL) != 0)
+			prev_crc = ((prev_crc << 1) ^ 0x04C11DB7UL);
+		else
+			prev_crc <<= 1;
+	}
+
+	return prev_crc;
+}

To view, visit change 37753. To unsubscribe, or for help writing mail filters, visit settings.