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Caliptra Hands-On Guide

Last Update: 2023/08/24

Tools Used

OS:

• Build instructions assume a Linux environment

Lint:

• Synopsys Spyglass
  • Version S-2021.09-1
• Real Intent AscentLint
  • Version 2019.A.p15 for RHEL 6.0-64, Rev 116515, Built On 12/18/2020

Simulation:

• Synopsys VCS with Verdi
  • Version R-2020.12-SP2-7_Full64
• Verilator
  • Version 5.012
• Mentor Graphics QVIP
  • Version 2021.2.1 of AHB/APB models
• UVM installation
  • Version 1.1d

Synthesis:

• Synopsys DC
  • Version 2020.09-SP1

GCC:

• RISCV Toolchain for generating memory initialization files
  • riscv64-unknown-elf-gcc-8.2.0-2019.02.0-x86_64-linux-centos6
• G++ Used to compile Verilator objects
  • g++ (GCC) 8.2.0

Other:

• Playbook (Microsoft Internal workflow management tool)

RISCV Toolchain installation

Note that there is significant configurability when installing the RISCV toolchain. These instructions may be used to create a RISCV installation that will be compatible with the provided Makefile for compiling test C programs.

1. Install from this repository:
   • https://github.com/riscv-collab/riscv-gnu-toolchain
   • Follow the included README in that repository for installation instructions
2. The most recently tested toolchain build that was confirmed to work was 2023-04-29
   • https://github.com/riscv-collab/riscv-gnu-toolchain/releases/tag/2023.04.29
3. A compatible tool installation requires newlib cross-compiler, multilib support, and the zicsr/zifencei extensions. Use this configure command:
   • ./configure --enable-multilib --prefix=/path/to/tools/riscv-gnu/2023.04.29 --with-multilib-generator="rv32imc-ilp32--a*zicsr*zifencei"
4. Use make instead of make linux to install the tool (using newlib option)

ENVIRONMENT VARIABLES

Required for simulation:
CALIPTRA_WORKSPACE: Defines the absolute path to the directory where the Verilator "scratch" output directory will be created. Recommended to define as the absolute path to the directory that contains the Project repository root (called "Caliptra" or "caliptra-rtl")
CALIPTRA_ROOT: Defines the absolute path to the Project repository root (called "Caliptra" or "caliptra-rtl"). Recommended to define as ${CALIPTRA_WORKSPACE}/Caliptra.

Required for Firmware (i.e. Test suites) makefile:
TESTNAME: Contains the name of one of the tests listed inside the src/integration/test_suites folder

Repository Overview

Caliptra
|-- LICENSE
|-- README.md
|-- Release_notes.txt
|-- docs
|   |-- Caliptra_Integration_Specification.pdf
|   |-- Caliptra_Hardware_Spec.pdf
|   |-- Caliptra_TestPlan_L1.pdf
|-- src
|   |-- aes
|   |-- ahb_lite_bus
|   |-- caliptra_prim
|   |-- caliptra_prim_generic
|   |-- csrng
|   |-- datavault
|   |-- doe
|   |-- ecc
|   |-- edn
|   |-- entropy_src
|   |-- hmac
|   |-- hmac_drbg
|   |-- integration
|   |-- keyvault
|   |-- kmac
|   |-- lc_ctrl
|   |-- libs
|   |-- pcrvault
|   |-- riscv_core
|   |-- sha256
|   |-- sha512
|   |-- sha512_masked
|   |-- soc_ifc
|   |-- spi_host
|   |-- uart
`-- tools
    |-- config
    |-- README
    `-- scripts

The root of the repository is structured as shown above, to a depth of 2 layers.
Each sub-component is accompanied by a file list summary (located in src//config/.vf) that comprises all the filenames required to compile the component, and an optional testbench filelist for unit-level simulation.
VF files provide absolute filepaths (prefixed by the CALIPTRA_ROOT environment variable) to each compile target for the associated component.
The "Integration" sub-component contains the top-level fileset for Caliptra. src/integration/config/compile.yml defines the required filesets and sub-component dependencies for this build target. All of the files/dependencies are explicitly listed in src/integration/config/caliptra_top_tb.vf. Users may compile the entire design using only this VF filelist.

Scripts Description

demo.rdl:Sample RDL file
Makefile: Makefile to generate SRAM initialization files from test firmware and to run Verilator simulation
reg_gen.py: Used to compile/export RDL files to register source code
reg_gen.sh: Wrapper used to call reg_gen.py for all IP cores in Caliptra
reg_doc_gen.py: Used to compile/export top-level RDL address map to register source code, defining complete Caliptra address space, and produces HTML documentation
reg_doc_gen.sh: Wrapper to invoke reg_doc_gen.py
reg_json.py:Used to import JSON register definition from OpenTitan and generate SystemRDL model
rdl_post_process.py: Post-processing functionality to make RDL generated SystemVerilog files compatible with lint/Verilator requirements
run_verilator_l0_regression.py: Wrapper to run the L0 smoke test regression suite using the Makefile flow in Verilator
integration_vector_gen.py: Generates test vectors for crypto core tests
veer_build_command.sh: Shell script used to generate the VeeR-EL2 repository present in src/riscv_core/veer_el2

Simulation Flow

VCS Steps:

1. Setup tools, add to PATH (ensure riscv64-unknown-elf-gcc is also available)
2. Define all environment variables above
   • For the initial test run after downloading repository, iccm_lock is recommended for TESTNAME
3. Create a run folder for build outputs (and cd to it)
4. [OPTIONAL] By default, this run flow will use the riscv64 toolchain to compile test firmware (according to TESTNAME) into program.hex, iccm.hex, dccm.hex, and mailbox.hex. As a first pass, integrators may alternatively use the pre-built hexfiles for convenience (available for iccm_lock test). To do this, copy iccm_lock.hex to the run directory and rename to program.hex. dccm.hex should also be copied to the run directory, as-is. Use touch iccm.hex mailbox.hex to create empty hex files, as these are unnecessary for iccm_lock test.
5. Invoke ${CALIPTRA_ROOT}/tools/scripts/Makefile with target 'program.hex' to produce SRAM initialization files from the firmware found in src/integration/test_suites/${TESTNAME}
   • E.g.: make -f ${CALIPTRA_ROOT}/tools/scripts/Makefile program.hex
6. Compile complete project using src/integration/config/caliptra_top_tb.vf as a compilation target in VCS. When running the vcs command to generate simv, users should ensure that caliptra_top_tb is explicitly specified as the top-level component in their command to ensure this is the sole "top" that gets simulated.
7. Simulate project with caliptra_top_tb as the top target

Verilator Steps:

1. Setup tools, add to PATH (ensure Verilator, GCC, and riscv64-unknown-elf-gcc are available)
2. Define all environment variables above
   • For the initial test run after downloading repository, iccm_lock is recommended for TESTNAME
3. Create a run folder for build outputs
   • Recommended to place run folder under ${CALIPTRA_WORKSPACE}/scratch/$USER/verilator/<date>
4. [OPTIONAL] By default, this run flow will use the riscv64 toolchain to compile test firmware (according to TESTNAME) into program.hex, iccm.hex, dccm.hex, and mailbox.hex. As a first pass, integrators may alternatively use the pre-built hexfiles for convenience (available for iccm_lock test). To do this, copy iccm_lock.hex to the run directory and rename to program.hex. dccm.hex should also be copied to the run directory, as-is. Use touch iccm.hex mailbox.hex to create empty hex files, as these are unnecessary for iccm_lock test.
5. Run Caliptra/tools/scripts/Makefile, which provides steps to run a top-level simulation in Verilator
   • Example command: make -C <path/to/run/folder> -f ${CALIPTRA_ROOT}/tools/scripts/Makefile TESTNAME=${TESTNAME} debug=1 verilator
   • NOTE: debug=1 is optional; if provided, the verilator run will produce a .vcd file with waveform information
   • NOTE: TESTNAME=${TESTNAME} is optional; if not provided, test defaults to value of TESTNAME environment variable, then to iccm_lock
   • NOTE: Users may wish to produce a run log by piping the make command to a tee command, e.g.: make ... <args> ... | tee <path/to/run/folder>/verilate.log
6. Users have the option to run the entire suite of smoke tests using the provided python script run_verilator_l0_regression.py
   1. Ensure Python 3.9.2 is available by adding to the $PATH variable
   2. Run the script with: python3 run_verilator_l0_regression.py
   3. NOTE: The script automatically creates run output folders at ${CALIPTRA_WORKSPACE}/scratch/$USER/verilator/<timestamp>/<testname> for each test run
   4. NOTE: The output folder is populated with a run log that reports the run results and pass/fail status

UVM Testbench Steps for caliptra_top:

Description:
The UVM Framework generation tool was used to create the baseline UVM testbench for verification of the top-level Caliptra image. The top-level bench leverages the soc_ifc_top testbench as a subenvironment, to reuse environment level sequences, agents, register models, and predictors.

Prerequisites:

• QVIP 2021.2.1 for Mentor Graphics (provides the AHB/APB VIP)
• UVM 1.1d installation

Steps:

1. Compile UVM 1.1d library
2. Compile the AHB/APB QVIP source
3. Compile the UVMF wrapper for APB/AHB in Caliptra/src/libs/uvmf
4. Compile the verification_ip provided for soc_ifc found in Caliptra/src/soc_ifc/uvmf_soc_ifc
5. Compile the caliptra_top testbench found in Caliptra/src/integration/uvmf_caliptra_top
6. Caliptra/src/integration/uvmf_caliptra_top/uvmf_template_output/project_benches/caliptra_top/tb/testbench/hdl_top.sv is the top-level TB wrapper for the system
7. Select a test to run from the set of tests in Caliptra/src/integration/uvmf_caliptra_top/uvmf_template_output/project_benches/caliptra_top/tb/tests/src
8. Provide +UVM_TESTNAME=<test> argument to simulation

Regression Tests

Only tests from the L0 Regression List should be run.

NOTES

• The internal registers are auto rendered at the GitHub page
• So are the external registers