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• Execution after reset starts at 0xfffffffc
  • A branch instruction (either b or ba; 26 bit range) to some boot code is loaded here
    • The Xilinx example branches to in block RAM (bram) at 0xffffff00
    • The RTEMS example branches to download_entry (but I'm not sure how)
  • Potentially a sc (system call) instruction could be loaded here? Any advantage to this?
    • Probably not as the corresponding ivor register (PPC 440) is not loaded yet
    • The PPC 405 doesn't have ivor registers, so it would continue executing at the system call vector

dlEntry.s (download_entry())

This file is considered part of an RTEMS BSP and can be found in $RTEMS_ROOT/src/c/src/lib/libbsp/powerpc/virtex5/dlentry. What's written here is written for the PPC 440 found in Xilinx Virtex 5 parts. The Virtex 4 version is similar.

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