The AP startup code simply jumps into this code with the CpuDxe driver
without setting up a stack for the processor.
Therefore, this code must setup the stack before calling into C code.
This is the basic flow:
* AP enters CpuDxe driver code (AsmApEntryPoint) without stack
- AP grabs a lock
- AP sets up stack
- AP calls CpuMp.c:ApEntryPointInC
- If ApEntryPointInC returns, the lock is freed, and another AP may
run
- The AP C code may call AsmApDoneWithCommonStack to indicate that
the AP is no longer using the stack, and another may therefore
proceed to use the stack and then call ApEntryPointInC
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16347 6f19259b-4bc3-4df7-8a09-765794883524
Jordan Justen