The invention relates to an
upgrade method for a vehicle-mounted
multimedia system. Based on an SoC (
System on
Chip) and an MCU (
Microcontroller Unit) which includes an FBL (First Bootloader), an SBL(Second Bootloader) and an application program, the method comprises the following steps of S1, enabling a vehicle-mounted
multimedia system to receive a corresponding
upgrade request through a safetyaccess, identifying the
upgrade request, going to the step S2 if a request for upgrade of the SBL and / or the application program is received, and going to the step S3 if a request for upgrade of theFBL and / or the SoC is received; S2, enabling the vehicle-mounted
multimedia system to upgrade the SBL and / or the application program through the FBL; and S3, enabling the vehicle-mounted
multimedia system to upgrade the FBL and the SoC through the SBL. According to the abovementioned upgrade scheme, the FBL and the SBL are introduced into the MCU, the FBL can upgrade the SBL and / or the applicationprogram, the SBL can upgrade the FBL and / or the SoC, a mutual refresh mechanism between the FBL and the SBL is formed so as to update the FBL and the SBL in real time, and the reliability and expandability of the vehicle-mounted
multimedia system are improved to a certain degree. Furthermore, an unlocking CAN (Controller
Area Network) diagnosis safety access step is introduced in an upgrade process, thereby improving the safety of system upgrade.