SPRUIV7B May 2022 – September 2023 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP
All the A53 cores use the common 36b SoC memory map shown in Section 2.1 for its physical address map. Since A53 natively supports up to 44b physical address, if A53 issues any transaction with non-zero upper 8 physical address bits, those upper 8 address bits are ignored by SoC address decoding logic.
Sitara’s SoC memory map is constructed to allow software utilizing bigger MMU page. The majority of the peripherals are put at 64KB aligned boundary. This is to allow A53 software to use 64KB MMU page to manage individual peripherals instead of using 4KB MMU page. There are a few exceptions.
Main domain GPIO is implemented by using two GPIO modules. However, these two GPIO modules are putting back to back together. Software needs to manage two GPIO modules using a single MMU page. Since each GPIO pin is managed by a single bit inside GPIO registers, there is no virtual machine or OS isolation implemented.
SoC also contains multiple DCC modules and they are put at 4KB boundary instead of 64KB. A53 software can still use 64KB MMU page to manage those DCC modules. If any of the DCC needs to be allocated for other processors, the region-based firewall can provide the additional isolation needed. The firewall granularity is at 4KB boundary, which allows each DDC is assigned individually.
Firewall, QoS, ISC configurations are not on 64KB boundary. And each individual firewall module, QoS module and ISC module are put at 1KB boundary.