[utils] Add rv64 ELF support to extract_sw_logs.py

The upstream script assumes a 32-bit struct layout (5×uint32, 20 B, LONG
header). Mocha's rv64 log_fields_t uses 8-byte const char * pointer
fields, giving a 32-byte struct and an 8-byte QUAD section-address
header.

Add a patch that detects the ELF class at runtime and selects the
correct header format, entry size, and unpack string accordingly.

Wire the script into build_sw_collateral_for_sim.py so each
CMake install step produces the .logs.txt and .rodata.txt files
that sw_logger_if needs at simulation start.

Signed-off-by: martin-velay <mvelay@lowrisc.org>

Author: martin-velay

hw/vendor/lowrisc_ip.vendor.hjson

@@ -16,7 +16,7 @@
     // Utilities.
     {from: "util/basegen",         to: "util/basegen"}, // Dependency of top generator.
     {from: "util/design",          to: "util/design"}, // Dependency of IP generator.
-    {from: "util/device_sw_utils", to: "util/device_sw_utils"},
+    {from: "util/device_sw_utils", to: "util/device_sw_utils", patch_dir: "util_device_sw_utils"},
     {from: "util/ipgen.py",        to: "util/ipgen.py"}, // IP generator.
     {from: "util/ipgen",           to: "util/ipgen"},
     {from: "util/raclgen",         to: "util/raclgen"}, // Dependency of top generator.

hw/vendor/lowrisc_ip/util/device_sw_utils/extract_sw_logs.py

@@ -222,17 +222,30 @@ def extract_sw_logs(elf_file, logs_fields_section):
                 logs_fields_section, elf_file))
             sys.exit(1)
 
-        header_size = 4
-        logs_offset, = struct.unpack('I', logs_data[0:header_size])
+        # rv64 ELF: struct layout is 32 bytes with 8-byte pointer fields and a
+        # QUAD section-address header.  rv32 ELF: 20 bytes, all uint32, LONG header.
+        is_64bit = elf.elfclass == 64
+        if is_64bit:
+            header_size = 8
+            entry_size  = 32
+            header_fmt  = '<Q'
+            entry_fmt   = '<I4xQIIQ'
+        else:
+            header_size = 4
+            entry_size  = LOGS_FIELDS_SIZE   # 20
+            header_fmt  = '<I'
+            entry_fmt   = '<IIIII'
+
+        logs_offset, = struct.unpack(header_fmt, logs_data[0:header_size])
 
         # Dump the logs with fields.
         result = ""
-        num_logs = (logs_size - header_size) // LOGS_FIELDS_SIZE
+        num_logs = (logs_size - header_size) // entry_size
         for i in range(num_logs):
-            start = header_size + i * LOGS_FIELDS_SIZE
-            end = start + LOGS_FIELDS_SIZE
+            start = header_size + i * entry_size
+            end = start + entry_size
             severity, file_addr, line, nargs, format_addr = struct.unpack(
-                'IIIII', logs_data[start:end])
+                entry_fmt, logs_data[start:end])
             result += "addr: {}\n".format(hex(logs_offset + start)[2:])
             result += "severity: {}\n".format(severity)
             result += "file: {}\n".format(

hw/vendor/patches/lowrisc_ip/util_device_sw_utils/0001-rv64-elf-support.patch

@@ -0,0 +1,40 @@
+diff --git a/extract_sw_logs.py b/extract_sw_logs.py
+--- a/extract_sw_logs.py
++++ b/extract_sw_logs.py
+@@ -222,17 +222,30 @@ def extract_sw_logs(elf_file, logs_fields_section):
+                 logs_fields_section, elf_file))
+             sys.exit(1)
+
+-        header_size = 4
+-        logs_offset, = struct.unpack('I', logs_data[0:header_size])
++        # rv64 ELF: struct layout is 32 bytes with 8-byte pointer fields and a
++        # QUAD section-address header.  rv32 ELF: 20 bytes, all uint32, LONG header.
++        is_64bit = elf.elfclass == 64
++        if is_64bit:
++            header_size = 8
++            entry_size  = 32
++            header_fmt  = '<Q'
++            entry_fmt   = '<I4xQIIQ'
++        else:
++            header_size = 4
++            entry_size  = LOGS_FIELDS_SIZE   # 20
++            header_fmt  = '<I'
++            entry_fmt   = '<IIIII'
++
++        logs_offset, = struct.unpack(header_fmt, logs_data[0:header_size])
+
+         # Dump the logs with fields.
+         result = ""
+-        num_logs = (logs_size - header_size) // LOGS_FIELDS_SIZE
++        num_logs = (logs_size - header_size) // entry_size
+         for i in range(num_logs):
+-            start = header_size + i * LOGS_FIELDS_SIZE
+-            end = start + LOGS_FIELDS_SIZE
++            start = header_size + i * entry_size
++            end = start + entry_size
+             severity, file_addr, line, nargs, format_addr = struct.unpack(
+-                'IIIII', logs_data[start:end])
++                entry_fmt, logs_data[start:end])
+             result += "addr: {}\n".format(hex(logs_offset + start)[2:])
+             result += "severity: {}\n".format(severity)
+             result += "file: {}\n".format(

util/build_sw_collateral_for_sim.py

@@ -5,8 +5,46 @@
 
 import argparse
 import subprocess
+import sys
 from pathlib import Path
 
+# Path to the OpenTitan-derived script that generates the .logs.txt and
+# .rodata.txt database files consumed by the DV sw_logger_if monitor.
+_EXTRACT_SW_LOGS = (
+    Path(__file__).parent.parent /
+    "hw" / "vendor" / "lowrisc_ip" / "util" / "device_sw_utils" /
+    "extract_sw_logs.py"
+)
+
+
+def _extract_logs(elf_file: Path, out_dir: Path) -> None:
+    """Run extract_sw_logs.py to generate the DV logger database files.
+
+    Generates <target>.logs.txt and <target>.rodata.txt in out_dir.
+    The sw_logger_if monitor reads these at simulation start to decode
+    printf-style log messages written by firmware to SW_DV_LOG_ADDR.
+
+    A missing .logs.fields ELF section is non-fatal: it means the SW image
+    was built without logging support, so we emit a warning and continue.
+    """
+    if not _EXTRACT_SW_LOGS.exists():
+        print(f"Warning: extract_sw_logs.py not found at {_EXTRACT_SW_LOGS}, "
+              "skipping DV log database generation.")
+        return
+
+    name = elf_file.stem if elf_file.suffix else elf_file.name
+    cmd = [
+        sys.executable, str(_EXTRACT_SW_LOGS),
+        "--elf-file", str(elf_file),
+        "--name", name,
+        "--outdir", str(out_dir),
+    ]
+    result = subprocess.run(cmd, capture_output=True)
+    if result.returncode != 0:
+        stderr = result.stderr.decode(errors="replace").strip()
+        print(f"Warning: DV log extraction skipped for '{name}' "
+              f"(no .logs.fields section or parse error): {stderr}")
+
 
 def generate(args) -> None:
     """Build with cmake"""
@@ -26,6 +64,12 @@ def generate(args) -> None:
         cmd = [*install_cmd, target]
         subprocess.run(cmd, capture_output=False, check=True)
 
+        # Generate .logs.txt / .rodata.txt for the sw_logger_if DV monitor.
+        # The ELF is installed without an extension (CMake default).
+        elf_file = out_dir / target
+        if elf_file.exists():
+            _extract_logs(elf_file, out_dir)
+
     print("Finished")