Introduction
A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit that examines all memory references on the memory bus, translating these requests, known as virtual memory addresses, into physical addresses in main memory.
S32DS MMU Viewer has been added to support display the MMU configuration status for the A53 cores using the GDB custom command from S32Debugger to see all the descriptors created (decoded).
Prerequisites:
S32 Design Studio version 3.5.14 needs to be installed, for the feature to be available.
S32DS MMU Viewer is available only for A53 cores.
Enabling the S32DS MMU Viewer, can be done from the top menu, by going to Window => Show View => Other.
From the next menu, search for S32DS MMU Viewer, highlight it, and select Open.
After debugging a project created with an A53 core, the MMU Viewer will have information displayed.
By default, the selection for the S32DS MMU Viewer is clear. In order to have information displayed in the MMU Viewer tab, the desired thread needs to be selected, in the Project Explorer.
All values are displayed in bytes.
The S32DS MMU Viewer has 3 options, allowing the user to navigate and utilize the information:
Change Exception Level:
This option allows you to change the Exception Level for which the information should be displayed.
Currently only Exception Level 3 is supported, which is also the default setting:
- MMU Translation at Exception Level 3 involves converting visual memory addresses into physical addresses at a high privilege level.
Pause View:
This option will pause the view. The information is displayed dynamically. Using the Pause View option, will interrupt the flow of information coming in. This can be resumed at any time is needed, for the A53 core project utilized.
Translate Virtual Address to Physical Address:
Utilizing this option, the user can translate the virtual address from the table, to the physical address.
- Exception Level:
Modifying the exception level from the Translate Address table, will only affect the Exception Level of the translation table.
By default, the “Current running exception level” is selected.
- Virtual Address (HEX)
After adding the virtual address that requires translation, the “Translate” option can be clicked and the corresponding “Physical Address (HEX)” field will be automatically populated.
The physical address can then be copied to clipboard, by clicking the option on the right side.
For more information, please visit: https://developer.arm.com/documentation/101470/2024-0/Perspectives-and-Views/MMU-MPU-view.