See a https://github.com/konradwilk/sha1 for the full git history of this code. Branch name is submission-mpw-two.
This is an implementation of [https://www.rfc-editor.org/rfc/inline-errata/rfc3174.html](RFC 3174) of SHA-1 engine.
It is not the most secure one nowadays (it is still used for git commit ids and TPM PCR values), but it looked like the easiest of the SHA engines to implement. The communication channel is via WishBone commands to provide sixteen words after which the engine starts and computes the digest in about 160 cycles. Then digest can be retrieved via the wishbone. There is a IRQ line so when it has completed it will bring it high if that is enabled.
To create the GDS files, there are macros that are being ingested. The best way to do is by checking out the SHA-1 engine https://github.com/konradwilk/sha1:
git clone https://github.com/konradwilk/sha1
And then there are some pre-requisities:
open_mpw_checkerinstalled as well (and the docker container).
From within the
sha1 directory execute:
which after running tests will generate the GDS, LEF, etc files. It will also copy them in the
gds sub-directory. Those files should then be in caravel_user_project, which can either be done manually, or with automatic way. To do that:
which will copy the appropiate files, run the OpenLANE to create the user_project_wrapper macro together, and run the checkers.
The best way is to look at the test-cases and run them:
which will use the various WishBone commands to program it.