[HAL][CRC] Add filter in HAL_CRCEx_Polynomial_Set() to exclude even polynomials
diff --git a/Src/stm32l4xx_hal_crc_ex.c b/Src/stm32l4xx_hal_crc_ex.c
index 6f66833..17a5851 100644
--- a/Src/stm32l4xx_hal_crc_ex.c
+++ b/Src/stm32l4xx_hal_crc_ex.c
@@ -94,44 +94,53 @@
/* Check the parameters */
assert_param(IS_CRC_POL_LENGTH(PolyLength));
- /* check polynomial definition vs polynomial size:
- * polynomial length must be aligned with polynomial
- * definition. HAL_ERROR is reported if Pol degree is
- * larger than that indicated by PolyLength.
- * Look for MSB position: msb will contain the degree of
- * the second to the largest polynomial member. E.g., for
- * X^7 + X^6 + X^5 + X^2 + 1, msb = 6. */
- while ((msb-- > 0U) && ((Pol & ((uint32_t)(0x1U) << (msb & 0x1FU))) == 0U))
+ /* Ensure that the generating polynomial is odd */
+ if ((Pol & (uint32_t)(0x1U)) == 0U)
{
+ status = HAL_ERROR;
}
-
- switch (PolyLength)
+ else
{
- case CRC_POLYLENGTH_7B:
- if (msb >= HAL_CRC_LENGTH_7B)
- {
- status = HAL_ERROR;
- }
- break;
- case CRC_POLYLENGTH_8B:
- if (msb >= HAL_CRC_LENGTH_8B)
- {
- status = HAL_ERROR;
- }
- break;
- case CRC_POLYLENGTH_16B:
- if (msb >= HAL_CRC_LENGTH_16B)
- {
- status = HAL_ERROR;
- }
- break;
+ /* check polynomial definition vs polynomial size:
+ * polynomial length must be aligned with polynomial
+ * definition. HAL_ERROR is reported if Pol degree is
+ * larger than that indicated by PolyLength.
+ * Look for MSB position: msb will contain the degree of
+ * the second to the largest polynomial member. E.g., for
+ * X^7 + X^6 + X^5 + X^2 + 1, msb = 6. */
+ while ((msb-- > 0U) && ((Pol & ((uint32_t)(0x1U) << (msb & 0x1FU))) == 0U))
+ {
+ }
- case CRC_POLYLENGTH_32B:
- /* no polynomial definition vs. polynomial length issue possible */
- break;
- default:
- status = HAL_ERROR;
- break;
+ switch (PolyLength)
+ {
+
+ case CRC_POLYLENGTH_7B:
+ if (msb >= HAL_CRC_LENGTH_7B)
+ {
+ status = HAL_ERROR;
+ }
+ break;
+ case CRC_POLYLENGTH_8B:
+ if (msb >= HAL_CRC_LENGTH_8B)
+ {
+ status = HAL_ERROR;
+ }
+ break;
+ case CRC_POLYLENGTH_16B:
+ if (msb >= HAL_CRC_LENGTH_16B)
+ {
+ status = HAL_ERROR;
+ }
+ break;
+
+ case CRC_POLYLENGTH_32B:
+ /* no polynomial definition vs. polynomial length issue possible */
+ break;
+ default:
+ status = HAL_ERROR;
+ break;
+ }
}
if (status == HAL_OK)
{
