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Default Memory Attribute with Cortex-A7 on memory space and disabled MMU

Stephan Cadene

Hi All,

After the reset, I would know the default memory attribute of the memory space, of course, wihout any MMU setting?

Thank you,

Stephan

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    Cortex-A7 is Armv7-A.  In the v7 Arm ARM, you want chapter B3.2 (The effects of disabling MMUs on VMSA behavior)

    https://developer.arm.com/documentation/ddi0406/cd/?lang=en

    The summary is that Data accesses will be treated as Strongly Ordered.

    But it's a little more complicate than that.  For example, when you're in NS PL1/0, those default attributes can be overridden via HCR even without enabling the MMU.  And the attributes of instruction fetches depend on the instruction cache enable.  So I'd recommend reading the referenced chapter for the full answer.

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    Cortex-A7 is Armv7-A.  In the v7 Arm ARM, you want chapter B3.2 (The effects of disabling MMUs on VMSA behavior)

    https://developer.arm.com/documentation/ddi0406/cd/?lang=en

    The summary is that Data accesses will be treated as Strongly Ordered.

    But it's a little more complicate than that.  For example, when you're in NS PL1/0, those default attributes can be overridden via HCR even without enabling the MMU.  And the attributes of instruction fetches depend on the instruction cache enable.  So I'd recommend reading the referenced chapter for the full answer.

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