The contents of the Abstract Shell are determined by two main factors: the floorplan of the target RP and the connectivity to this module.
The floorplan for reconfigurable Pblocks in UltraScale+ devices by default creates an expanded routing region to improve routability and reduce congestion. This expansion creates the frameset to be captured as the programming contents for the partial bitstream. To implement any RM and generate the partial bitstream for this expanded region, the Abstract Shell contains some (but not all) of the placement and all of the routing information for this region. Any part of the static design included in a partial bitstream is reprogrammed while it continues to operate without disruption. Only the logic within the user-defined Pblock receives the GSR event for initialization at the end of partial bitstream delivery.
Use the hd_visual scripts to visualize the expanded region for a given RP. In the image below, the blue placement range aligns with the Pblock itself, while the yellow expanded region denotes the overall solution space and partial bitstream range for this RP.
For the RM implemented in the Abstract Shell, its placement is limited to the blue region, which is the Pblock as created by the designer and then snapped in to fundamental programmable unit boundaries. For this RM, the routing is limited to the yellow expanded routing region.