Removed the custom technology LEF files, as these have been added
to the Google/SkyWater git repository. Added more complete
instructions for cloning and installing the Google/SkyWater
repository. Modified the Makefile and qflow setup file for use
with the technology LEF files from the repo.
diff --git a/sky130/README b/sky130/README
index ebbdb8b..34d89ae 100644
--- a/sky130/README
+++ b/sky130/README
@@ -26,7 +26,33 @@
git clone https://github.com/google/skywater-pdk
- Then follow the instructions below.
+ Note that many of the files in the PDK are too large for a single git
+ repository, and so each IP library in the PDK has been placed in a
+ submodule. There are multiple versions of each library, and it is
+ nearly certain that you will only want to deal with the "latest" version
+ of each. To make sure you have the submodules for the latest version of
+ each supported IP library, do:
+
+ cd skywater-pdk
+ git submodule init libraries/sky_fd_sc_hd/latest
+ git submodule init libraries/sky_fd_sc_hdll/latest
+ git submodule init libraries/sky_fd_sc_hs/latest
+ git submodule init libraries/sky_fd_sc_ms/latest
+ git submodule init libraries/sky_fd_sc_ls/latest
+ git submodule init libraries/sky_fd_sc_lp/latest
+ git submodule init libraries/sky_fd_sc_hvl/latest
+ git submodule update
+
+ The liberty (.lib) files are the largest of all and so individual files
+ are too large for the git repo and need to be assembled by script. To
+ do that, do:
+
+ make timing
+
+ That installs all of the Google/Skywater files.
+
+ Then follow the instructions below for generating the additional files
+ for supporting the open source EDA tool flows.
2. EDA tools:
