Bureaucrats, dave_user, Administrators
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→Limitations of traditional configurations
* <div id="REQ6">REQ6</div> ''Boot order'': W1 must be the first world to come up.
* <div id="REQ7">REQ7</div> ''Master-slave relationship'': once the system has completed boot process, a master-slave relationship must be established between W1 and W2, in the sense that W1 must have complete control of W2 world (for instance W1 must be able to force the complete reboot of the GPOS.
* <div id="REQ8">REQ8</div> ''L2 cache enabling availability on W2 side'': Basic AMP configurations does not support L2 cache. Generally speaking, this is not an issue on W1 side where because** typical code and data footprints are relatively limited** L2 may affect predictability of execution time significantly. This However this is not true for W2 world: in case L2 is not available, overall Linux in order to achieve, L2 cache must be enabled (at least) onsystem performances may decrease noticeably.
The [[AN-BELK-001:_Asymmetric_Multiprocessing_(AMP)_on_Bora_–_Linux_FreeRTOS|traditional AMP]]<ref name="AN-BELK-001"></ref> configuration satisfies REQ1 through REG4. REQ5 through RE7 REQ8 are not satisfied instead. About integrity, for example, an application with ''root'' privileges or code executed in linux kernel space could access memory regions that are supposed to be exclusively accessed by code executed in W1. This may lead to unpredictable behaviors and to potentially catastrophic consequences. This is where TrustZone technology comes to help: it creates a sort of barrier between the two worlds and prevents W2 code from unauthorized accesses to certain regions of the processor's addressing space.