Disable cache when reading flash user signature area on SAM4E

Duet3D · Aug 13, 2022 · 45b9920 · 45b9920
1 parent 21735eb
commit 45b9920
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/src/SAM4S_4E_E70/Flash.cpp b/src/SAM4S_4E_E70/Flash.cpp
@@ -482,10 +482,20 @@ bool Flash::ReadUserSignature(uint32_t *p_data, uint32_t ul_size) noexcept
 
 	// dc42 bug fix: must disable interrupts while executing the EFC read command
 	const irqflags_t flags = IrqSave();
+#if SAM4E
+	// On the SAM4E we get a crash if we try to read the user signature with cache enabled
+	const bool cacheWasEnabled = Cache::Disable();
+	const uint32_t rc = efc_perform_read_sequence(EFC, EFC_FCMD_STUS, EFC_FCMD_SPUS, p_data, ul_size);
+	if (cacheWasEnabled)
+	{
+		Cache::Enable();
+	}
+#else
 	// Ideally the cache invalidate call would be inside function efc_perform_read_sequence,
 	// but here will do because we have disabled interrupts and this code won't be within 512b of the start of flash memory
 	Cache::InvalidateAfterDMAReceive(reinterpret_cast<const void*>(IFLASH_ADDR), FLASH_USER_SIG_SIZE);
 	const uint32_t rc = efc_perform_read_sequence(EFC, EFC_FCMD_STUS, EFC_FCMD_SPUS, p_data, ul_size);
+#endif
 	IrqRestore(flags);
 	return rc == 0;
 }