各位专家：
目前正在学习ARMv8 Arch Ref Manual.
D1.10.2 Exception vectors有点疑惑：
1. Table D1-6 定义了一个Vector Table应该具有的items
我们假定一个ARMv8 SOC实现了4个EL：EL0 / EL1 / EL2 / EL3
根据ARMv8 ARM手册：每一个EL，都有自己对应的Vector Table.
那么：
EL0 / EL1 / EL2 / EL3 :它们各自的Vector Table，应该是什么样的？
比如：
(1) EL0的Vector Table：应该有2个Block :
Current Exception level with SP_EL0
Current Exception level with SP_ELx, x>0
(2) EL1的Vector Table：应该有4个Block :
EL0 that is using AARCH64
EL0 that is using AARCH32
我的理解对吗？
> 1. 前2个block: Current EL with SP_EL0 / SP_ELx> 能举个例子吗？
"with SP_EL0" means using the application's SP."with SP_ELx" means using the current EL's SP.
As far as I know, the purpose of differentiating SP_EL0 and SP_ELx is that the OS can prevent its own stack from overflow (which is critical for the system) by using the application's stack pointer (which is not as critical).
> 2. 基于你回复的帖子中所举例子：> (1) EL2是hypervisor，运行在AARCH64。> VBAR_EL2的Vector table，它的4个block是：> Current EL with SP_EL0 > Current EL with SP_ELx> 第3个block是EL1 Aarch64吗？
Yes.
> 第4个block应该是EL1 Aarch32吗？
Yes. > (2) EL0中发生的IRQ，可以通过register来控制它的target_EL=EL2，即：它想让HyperVisor来处理？
Yes. See HCR_EL2:AMOIMOFMO
hi, feng:
Thanks a lot