Re-Orderingis a new attribute in ARMv8.
Can you explain Device-nGRE, and How to distinguish Device-nGRE and Device-nGnRE?
The three device attributes are G, R, and E, with the following definitions:
So with the above said:
I hope that helps,
in the case of Device-nGnRE, what does IMPLEMENTATION DEFINED block size means?
Is it related to (according to the Armv8 architecture specification)
A Memory-mapped peripheral occupies a memory region of IMPLEMENTATION DEFINED size andcan be accessed using load and store instructions.
My misunderstanding comes from the Armv7a specification which states:
in A3.8.2 Ordering requirements for memory accesses:
The size of a memory mapped peripheral, or a block of memory, is IMPLEMENTATION DEFINED, but is not smallerthan 1KByte.
Note: This implies that the maximum memory-mapped peripheral size for which the architecture guarantees order for allimplementations is 1KB.
If the pheriperal has a memory map greater than 1KB, the Armv7 architecture doesn't guarantee ordering? If true, does the same limitation
exist for Armv8, for the Device-nGnRE?