Hi Ahmad,

On Thu, 25 Sept 2025 at 01:43, Ahmad Fatoum [off-list ref] wrote:

Hello Simon,

Thanks for looking into this!

On 9/23/25 12:48 AM, Simon Glass wrote:

quoted

+def build_ramdisk(args, tmpdir):
+    """Build a cpio ramdisk containing kernel modules
+
+    Similar to mkinitramfs, this creates a compressed cpio-archive containing
+    the kernel modules for the current kernel version.
+
+    Args:
+        args (Namespace): Program arguments
+        tmpdir (str): Temporary directory to use for modules installation
+
+    Returns:
+        tuple:
+            bytes: Compressed cpio data containing modules
+            int: total uncompressed size
+    """
+    suppress = None if args.verbose else subprocess.DEVNULL
+    # Use provided tmpdir or custom install path
+    if args.path:
+        mod_path = args.path
+    else:
+        mod_path = os.path.join(tmpdir, 'modules_install')
+        os.makedirs(mod_path, exist_ok=True)
+
+    if args.verbose:
+        print(f'Installing modules to {mod_path}')
+
+    cmd = ['make', '-s', '-j']

Executing `make image.fit FIT_MODULES=1` in a fresh build will result in
a python stack trace, because image.fit only has dependencies for the
kernel image and the device trees, but none for the modules.

Even with that added, I don't think it's a good idea to have make call a
script only for it to call make again.

Yes I don't like that either.

Instead, there should probably be a modules.cpio.gz make target or
similar in its own right and image.fit should depend on it if
FIT_MODULES is set.

That seems better. I'll give it a try.

Thanks,
Ahmad

quoted

+
+    # It seems that the only way to prevent a 'jobserver unavailable' warning
+    # is to remove it from the makeflags
+    env = os.environ.copy()
+    makeflags = env.get('MAKEFLAGS', '')
+    env['MAKEFLAGS'] = ' '.join(f for f in makeflags.split()
+                                if not f.startswith('--jobserver-auth'))
+
+    if args.build_dir:
+        cmd.append(f'O={args.build_dir}')
+    cmd.extend(['INSTALL_MOD_PATH=' + mod_path, 'modules_install'])
+    subprocess.check_call(cmd, cwd=os.getcwd(), stdout=suppress, env=env)
+
+    # Find the modules directory that was created (e.g. due to dirty tree)
+    base_dir = os.path.join(mod_path, 'lib', 'modules')
+    if not os.path.exists(base_dir):
+        raise ValueError(f'Modules base directory {base_dir} not found')
+    dirs = [d for d in os.listdir(base_dir)
+            if os.path.isdir(os.path.join(base_dir, d))]
+    if not dirs:
+        raise ValueError(f'No module directories found in {base_dir}')
+    if len(dirs) > 1:
+        raise ValueError(f'Must have only one module directory in {base_dir}')
+
+    # Create initramfs-style directory structure (usr/lib/modules instead of
+    # lib/modules) and move modules into it
+    outdir = os.path.join(tmpdir, 'initramfs')
+    new_dir = os.path.join(outdir, 'usr', 'lib', 'modules')
+    os.makedirs(new_dir, exist_ok=True)
+    shutil.move(os.path.join(base_dir, dirs[0]), os.path.join(new_dir, dirs[0]))
+
+    if args.verbose:
+        print(f'Creating cpio archive from {outdir}')
+
+    with tempfile.NamedTemporaryFile() as cpio_file:
+        # Change to initramfs directory and create cpio archive
+        with subprocess.Popen(['find', '.', '-print0'], cwd=outdir,
+                              stdout=subprocess.PIPE) as find:
+            with subprocess.Popen(['cpio', '-o', '-0', '-H', 'newc'],
+                                  stdin=find.stdout, stdout=cpio_file,
+                                  stderr=suppress, cwd=outdir) as cpio:
+                find.stdout.close()
+                cpio.wait()
+                find.wait()
+
+                if cpio.returncode != 0:
+                    raise RuntimeError('Failed to create cpio archive')
+
+        cpio_file.seek(0)  # Reset to beginning for reading
+        return compress_data(cpio_file, args.compress), cpio_file.tell()
+
+
 def process_dtb(fname, args):
     """Process an input DTB, decomposing it if requested and is possible

@@ -318,11 +414,12 @@ def _process_dtbs(args, fsw, entries, fdts):
     return seq, size


-def build_fit(args):
+def build_fit(args, tmpdir):
     """Build the FIT from the provided files and arguments

     Args:
         args (Namespace): Program arguments
+        tmpdir (str): Temporary directory for any temporary files

     Returns:
         tuple:

@@ -344,20 +441,29 @@ def build_fit(args):

     # Handle the ramdisk if provided. Compression is not supported as it is
     # already compressed.
+    ramdisk_data = None
     if args.ramdisk:
         with open(args.ramdisk, 'rb') as inf:
-            data = inf.read()
-        size += len(data)
-        write_ramdisk(fsw, data, args)
+            ramdisk_data = inf.read()
+        size += len(ramdisk_data)
+    elif args.modules_ramdisk:
+        if args.verbose:
+            print('Building modules ramdisk...')
+        ramdisk_data, uncomp_size = build_ramdisk(args, tmpdir)
+        size += uncomp_size
+
+    if ramdisk_data:
+        write_ramdisk(fsw, ramdisk_data, args)

     count, fdt_size = _process_dtbs(args, fsw, entries, fdts)
     size += fdt_size

-    finish_fit(fsw, entries, bool(args.ramdisk))
+    finish_fit(fsw, entries, has_ramdisk=bool(ramdisk_data))

-    # Include the kernel itself in the returned file count
     fdt = fsw.as_fdt()
     fdt.pack()
+
+    # Count FDT files, kernel, plus ramdisk if present
     return fdt.as_bytearray(), count + 1 + bool(args.ramdisk), size

@@ -365,7 +471,12 @@ def run_make_fit():
     """Run the tool's main logic"""
     args = parse_args()

-    out_data, count, size = build_fit(args)
+    tmpdir = tempfile.mkdtemp(prefix='make_fit_')
+    try:
+        out_data, count, size = build_fit(args, tmpdir)
+    finally:
+        shutil.rmtree(tmpdir)
+
     with open(args.output, 'wb') as outf:
         outf.write(out_data)

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Regards,
Simon