RVVILogger Module to RVVI TEXT format for coverage

[SadhviNarayanan]

This is a very initial, foundational version of the RVVI logger module, which uses the RVVI Trace to extract internal hart signals and write them out to an RVVI TEXT file in the format it requires.
Note: the output has not been validated with the Python script, I just wanted to get some initial feedback on the module to see if it was even progressing in the right direction.

[jordancarlin]

This is looking like a great start! I left some initial comments. Let me know when you’ve had a chance to actually run it and validate it with the Python script and then I’ll take another look.

[jordancarlin]

Why is this else case needed?

[jordancarlin]

Global comment. A lot of if blocks seem to have unnecessary else cases.

[jordancarlin]

This comment doesn’t match what you’re actually printing.

[jordancarlin]

Is there any way to use FLEN in the format specifiers so we don’t need all of these if/else cases? Same applies to XLEN elsewhere.

[Copilot]

Pull request overview

This PR introduces a new SystemVerilog module rvviTextLogger that converts RVVI-TRACE interface signals to RVVI-TEXT format for use with coverage tools and reference models. This is an initial foundational version for early feedback.

Key Changes

• Adds a fully parameterized RVVI-TRACE to RVVI-TEXT converter module
• Implements file-based logging of instruction retirement, register changes, CSR updates, and processor state
• Provides support for multi-hart, superscalar processors with configurable parameters

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[Copilot]

The PC formatting uses %5h for 32-bit addresses and %6h for 64-bit addresses, but these format specifiers limit the output to 5 and 6 hex digits respectively. A 32-bit address requires 8 hex digits (0x00000000 to 0xFFFFFFFF), and a 64-bit address requires 16 hex digits. The current format will truncate leading digits.

Suggested change

	$fwrite(file, " %5h ", rvvi.pc_rdata[retire_slot][hart][31:0]);
	end else if (XLEN == 64) begin
	$fwrite(file, "%6h ", rvvi.pc_rdata[retire_slot][hart][63:0]);
	$fwrite(file, " %08h ", rvvi.pc_rdata[retire_slot][hart][31:0]);
	end else if (XLEN == 64) begin
	$fwrite(file, "%016h ", rvvi.pc_rdata[retire_slot][hart][63:0]);

[Copilot]

The VIRT mode tracking only updates prev_mode_virt when the value is non-zero, but it should be updated whenever virt_changed is true. This means if VIRT mode changes from 1 to 0, the change won't be tracked and subsequent transitions may be missed. The update should occur outside the inner condition check.

Suggested change

	if (virt_changed && rvvi.mode_virt[retire_slot][hart]) begin
	$fwrite(file, "VIRT %0d ", rvvi.mode_virt[retire_slot][hart]);
	if (virt_changed) begin
	if (rvvi.mode_virt[retire_slot][hart]) begin
	$fwrite(file, "VIRT %0d ", rvvi.mode_virt[retire_slot][hart]);
	end

[Copilot]

Iterating through all 4096 CSR addresses for every retired instruction is inefficient. Most instructions don't write to CSRs, and when they do, they typically only write to one or a few. Consider using a data structure to track only the CSRs that have been written, or if the RVVI interface provides a way to query which CSRs were written, use that instead of checking all 4096 addresses.

Suggested change

	// Iterate through all 4096 possible CSR addresses
	// Note: made CSR address is in HEX format
	for (int i = 0; i < 4096; i++) begin
	if (rvvi.csr_wb[retire_slot][hart][i]) begin
	// Format: C <address_hex> <value_hex>
	if (XLEN == 32) begin
	$fwrite(file, "C %03h %08h ", i, rvvi.csr[retire_slot][hart][i][31:0]);
	end else if (XLEN == 64) begin
	$fwrite(file, "C %03h %016h ", i, rvvi.csr[retire_slot][hart][i][63:0]);
	end else begin
	$fwrite(file, "C %03h %h ", i, rvvi.csr[retire_slot][hart][i]);
	end
	// Iterate only over written CSR addresses using rvvi.csr_wb_list and rvvi.csr_wb_count
	// Note: CSR address is in HEX format
	for (int idx = 0; idx < rvvi.csr_wb_count[retire_slot][hart]; idx++) begin
	int i = rvvi.csr_wb_list[retire_slot][hart][idx];
	// Format: C <address_hex> <value_hex>
	if (XLEN == 32) begin
	$fwrite(file, "C %03h %08h ", i, rvvi.csr[retire_slot][hart][i][31:0]);
	end else if (XLEN == 64) begin
	$fwrite(file, "C %03h %016h ", i, rvvi.csr[retire_slot][hart][i][63:0]);
	end else begin
	$fwrite(file, "C %03h %h ", i, rvvi.csr[retire_slot][hart][i]);

[jordancarlin]

@SadhviNarayanan something seems to have gone wrong here. It's showing 100+ files changed.