physical memory location

基本解释

For example, one PPE-side mailbox register appears as a write-only physical memory location.
例如，一个 PPE 端的邮箱寄存器会作为一个只写的物理内存位置出现。
Past that is unmapped memory -- memory for which no corresponding physical location has been assigned either in RAM or on disk.
该地址之后是未被映射的内存 —— 用于在 RAM 或者硬盘中没有分配相应物理位置的内存。
frenchen.blog.163.com
This way we did not have to care about the physical location of our data within memory, we simply used its identifier whenever we wanted to refer to our variable.
这样我们就不必关心我们的数据在内存中的实际物理位置，我们每次想引用我们的变量时只需使用它的标识符即可。
xcf-007.blog.163.com