SNIP_CLASSIC_NVDATAHANDLING_SECTION_4_3_Initialization_of_RAM_Blocks_from_NVRAM

4.3 Initialization of RAM Blocks from NVRAM There are different strategies in AUTOSAR to restore RAM blocks to their previous values i.e. the values held before going into last shutdown. Individual blocks can be explicitly read one-by-one using NvM_ReadBlock/NvM_ReadPRAMBlock from the Initialization runnables called using InitEvent during Rte_Init(). A more optimized approach is to read all such blocks where data persistence is required using a single NvM request NvM_ReadAll. All such NvM blocks are configured to be applicable for NvM_ReadAll. Any block to be read during NvM_ReadAll has to either have explicit synchronization or have a permanent RAM block. Figure 4 shows the process of restoration of RAM block using NvM_ReadAll. Further information about the AUTOSAR startup process is mentioned in [4]. NV Data Handling Guideline Figure 4: Sequence diagram for Initialization of RAM block BswM NvM BSW Cyclic Task RTE SWC1 AppVar = Rte_RamBlock Rte_RamBlock = NvMBuffer Rte and SWC Initialized BswM_MainFunction() Rte_SetMirror_NvMB_BlkDesc0 (&NvMBuffer) *NvM_MainFunction() BswM_NvM_CurrentJobMode(SID_NvM_ReadAll,NVM_REQ_OK) Multi Block Request Received NvM_ReadAll() First Call after Init Rte_Read_PR_NvD_Data0(&AppVar) BswM_MainFunction() [if NvM_ReadAll Finished]: Rte_Start() NV Data Handling Guideline