There are 2 communication interfaces between the SPMC and StandaloneMM
1. SpmMM
2. FF-A
When SpmMM is enabled, TF-A acts as the SPMC at EL3 and the stack is setup
by TF-A for use by StandaloneMm. However, when FF-A is enabled, the SPMC
does not setup the stack for StandaloneMm and it is expected that the
StandaloneMm code will setup its own stack.
Therefore, reserve an area in the data region for use as the stack for
StandaloneMM. This stack will be used in both the scenarios described
above, i.e. when either SpmMM or FF-A is enabled.
Although the stack is reserved from the data section which is expected
to be Read-Write enabled, when TF-A maps the StandaloneMM binary into
the DRAM it configures the entire StandaloneMM memory as Read-Only.
Therefore, before the stack can be utilised, the PE Coff sections
need to be scanned to change the the stack region from Read-Only to
Read-Write.
Signed-off-by: Levi Yun <yeoreum.yun@arm.com>
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