ARMv8的MMU支持4KB和64KB两种page size。
● 4KB and 4 levels => 48-bit VA
● 64KB and 3 levels => 48-bit VA (top table partially populated)
● 4KB and 3 levels => 39-bit VA (currently used by AArch64 Linux)
● 64KB and 2 levels => 42-bit VA
Security
AArch64中的EL3类似于ARM32的MON模式,用于secure和non-secure的trust zone切换。Secure EL1可以运行在AArch64或者AArch32,后者可以作为兼容以前的ARM32的Trusted OS使用。
ARM Trusted Firmware
EL3级别安全管理firmware,可负责CPU上下电,大小核迁移等。