makefile: add ABSTRACT_SOURCE variable for generate-abstract

This can be used to generate an abstract using for instance
2_floorplan stage, which allows quickly previewing
floorplan changes at the top level.

When I tested it with MegaBoom, I could view the floorplan
after mpl2 in minutes instead of days.

Signed-off-by: Øyvind Harboe <[email protected]>

Author: oharboe

flow/scripts/generate_abstract.tcl

@@ -1,16 +1,21 @@
 source $::env(SCRIPTS_DIR)/load.tcl
-load_design 6_final.odb 6_final.sdc "Starting generation of abstract views"
 
-read_spef $::env(RESULTS_DIR)/6_final.spef
-set_propagated_clock [all_clocks]
+set stem [expr {[info exists ::env(ABSTRACT_SOURCE)] ? $::env(ABSTRACT_SOURCE) : "6_final"}]
+
+load_design $stem.odb $stem.sdc "Starting generation of abstract views"
+
+if {[file exists $::env(RESULTS_DIR)/$stem.spef]} {
+  read_spef $::env(RESULTS_DIR)/$stem.spef
+  set_propagated_clock [all_clocks]
+}
 
 puts "Starting generation of abstract views"
 write_timing_model $::env(RESULTS_DIR)/$::env(DESIGN_NAME).lib
 write_abstract_lef -bloat_occupied_layers $::env(RESULTS_DIR)/$::env(DESIGN_NAME).lef
 
 if {[info exist ::env(CDL_FILES)]} {
   cdl read_masters $::env(CDL_FILES)
-  cdl out $::env(RESULTS_DIR)/6_final.cdl
+  cdl out $::env(RESULTS_DIR)/$stem.cdl
 }
 
 if {![info exists standalone] || $standalone} {