util: add stm32 bootloader flash write utility (i2c only)
Change-Id: If432939a945d21ecc5d8c53bb2c0bfe0c65ca64d
diff --git a/util/stm32_flash/stm32f4_crc.c b/util/stm32_flash/stm32f4_crc.c
new file mode 100644
index 0000000..307514a
--- /dev/null
+++ b/util/stm32_flash/stm32f4_crc.c
@@ -0,0 +1,49 @@
+#include <stdint.h>
+
+/* Calculate CRC32 how the STM32F4xx family does */
+
+static unsigned int crc_table[] =
+{
+ 0x00000000, 0x04C11DB7, 0x09823B6E, 0x0D4326D9,
+ 0x130476DC ,0x17C56B6B ,0x1A864DB2 ,0x1E475005,
+ 0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6, 0x2B4BCB61,
+ 0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD
+};
+
+static uint32_t crc32_word(uint32_t crc, uint32_t data)
+{
+ crc = crc ^ data;
+
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+ crc = (crc << 4) ^ crc_table[crc >> 28];
+
+ return crc;
+}
+
+uint32_t stm32f4_crc32(uint8_t *buffer, int length)
+{
+ uint32_t *data = (uint32_t *)buffer;
+ uint32_t word;
+ uint32_t crc = ~0;
+ int i;
+
+ /* word by word crc32 */
+ for (i=0; i<(length>>2); i++) {
+ crc = crc32_word(crc, data[i]);
+ }
+
+ /* zero pad last word if required */
+ if (length & 0x3) {
+ for (i*=4, word=0; i<length; i++)
+ word |= buffer[i] << ((i & 0x3) * 8);
+ crc = crc32_word(crc, word);
+ }
+
+ return crc;
+}
