请问这个表到底应该怎么解读呢，特别是后面两种，LowerEL 一直没弄明白，求大神指教
Exception can only take in current EL(except EL0) or higher EL.
For example, there is a IRQ when running in EL1, and the IRQ exception is routed to EL2. In this case, processor's EL changes to EL2, and uses the vector table in EL2 to handle the exception.
If EL1 is running in AArch32, then 'Lower Exception level, where the implemented level immediately lower than the target level is using AArch32' IRQ vector entry(table offset 0x680) of EL2 vector table is used.If EL1 is running in AArch64, then 'Lower Exception level, where the implemented level immediately lower than the target level is using AArch64' IRQ vector entry(table offset 0x480) of EL2 vector table is used.