COREV-DV

COREV-DV is the name given to a library of extensions to the Google riscv-dv instructuion stream generator. Riscv-dv is implemented as a collection SystemVerilog classes extending from uvm_object, so extending riscv-dv classes to modify its behavior is straightforward. For those cases where a specific instruction stream is required, it is implemented as an extension of an existing riscv-dv class. Thus, riscv-dv is not modified allowing core-v-verif to easily take advantage of updates to the Google project.

Note that for the most part, core-v-verif uses riscv-dv “as is” and each core that is verified in core-v-verif is free to use whatever version of riscv-dv that suits the core’s needs:

  • riscv-dv “as is”.

  • corev-dv (extensions at $CORE_V_VERIF/lib/corev-dv

  • core-specific extensions at $CORE_V_VERIF/$COREV_CORE)/env/corev-dv

A non-core-specific version of corev-dv resides at $CORE_V_VERIF/lib/corev-dv. Here you will find a set of extensions to riscv-dv that are intended to be common across all (or at least most) CORE-V cores.

Using COREV-DV

When a Make target requires it, a specific hash of riscv-dv is cloned to $CORE_V_VERIF/$COREV_CORE/vendor_lib/riscv-dv. The compile Makefiles will compile in the required extensions to generate the core-specific version of corev-dv needed for a test. The README at $CORE_V_VERIF/mk/uvmt provides instructions for building and running a corev-dv generated test-program.

Extending COREV-DV

It is to be expected that each unique core will require multiple extensions to riscv-dv. These should be placed in $CORE_V_VERIF/$COREV_CORE/env/corev-dv.

For example $CORE_V_VERIF/lib/corev-dv/corev_asm_program_gen.sv implements an override of riscv_gen_program_header::gen_program_header() to enforce the use of common symbols required by the board support package. Since each core’s verification environment is likely to use a core-specific BSP, it is expected that each core will need to implement core-specific extensions to corev_asm_program_gen.sv.

Below is simplifed view of the core-v-verif directory tree showing the locations of riscv-dv and the base corev-dv extensions plus an example of core-specific extensions for the CV32E40P.