int PwStmNvsBackendSync(void)
int PwStmNvsBackendRead(uint32_t abs_addr, void *buf, size_t len)
int PwStmNvsBackendErase(uint32_t abs_addr, size_t len)
Erase [abs_addr, abs_addr+len) for compaction (4 KiB aligned OK).
int PwStmNvsBackendWrite(uint32_t abs_addr, const void *buf, size_t len)