grub-2.12 debug

debug=acpi,affs,ahci,appleload,arcdisk,archelp,ata,atkeyb,badram,bsd,btrfs,cache,cbfs,chain,cros,cros_keyboard,crypt,cryptodisk,datetime,devalias,disk,diskfilter,dl,dns,drivemap,efi,efidisk,efiemu,ehci,elf,exfat,expand,fat,fdt,fdtbus,fixvideo,font,fs,geli,gpt,hostdisk,http,ieee1275,init,jpeg,keystatus,linux,loader,luks,luks2,memdisk,mmap,modules,multiboot_loader,nativedisk,net,ohci,partition,pata,plainmount,play,pmtimer,png,regions,reiserfs,reiserfs_blocktype,reiserfs_tree,relocator,scsi,sections,serial,smbios,syslinux,tftp,tga,tpm,ubootdisk,uhci,usb,usb_keyboard,usbms,verify,video,xen,xen_loader,xfs,xnu,zfs

grub-deps.py

#!/usr/bin/env python3
import argparse
import re
import subprocess
import tempfile
from pathlib import Path
from queue import Queue

not_all_video_mods = [
    "efi_gop",
    "efi_uga",
    "ieee1275_fb",
    "vbe",
    "vga",
    "video_bochs",
    "video_cirrus",
]


def get_deps(mod: str) -> dict[str, list[str]]:
    deps = {}
    q = Queue()
    q.put(mod)
    while not q.empty():
        mod = q.get()
        deps[mod] = []
        with tempfile.TemporaryDirectory() as tmpdir:
            sections = subprocess.check_output(
                ["objdump", "-h", f"/boot/grub/x86_64-efi/{mod}.mod"]
            ).splitlines()[5:]
            sections = b"\n".join(sections)
            if b".moddeps" not in sections:
                continue

            subprocess.run(
                [
                    "objcopy",
                    "--dump-section",
                    f".moddeps={tmpdir}/out",
                    f"/boot/grub/x86_64-efi/{mod}.mod",
                    "/dev/null",
                ]
            )
            with Path(tmpdir, "out").open() as f:
                lines = f.read().split("\0")
                lines = [line for line in lines if line]
                deps[mod] = lines
                for dep in deps[mod]:
                    if dep not in deps:
                        q.put(dep)
    return deps


insmod_pattern = r"insmod\s+([\w]+)"


def read_grub_cfg(path: str):
    mod_counter = {}
    with Path(path).open() as f:
        for line in f:
            line = line.strip()
            if "insmod" in line:
                match = re.search(insmod_pattern, line)
                mod = match.group(1)
                mod_counter[mod] = mod_counter.get(mod, 0) + 1
    for neg_mod in not_all_video_mods:
        if neg_mod in mod_counter:
            mod_counter[neg_mod] -= 1
            if mod_counter[neg_mod] == 0:
                del mod_counter[neg_mod]
    return list(mod_counter.keys())


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("-i", "--input", required=True, help="grub.cfg file")
    args = parser.parse_args()
    mods = read_grub_cfg(args.input)
    flatten = []
    for mod in mods:
        deps = get_deps(mod)
        for key, values in deps.items():
            if key not in flatten:
                flatten.append(key)
            for value in values:
                if value not in flatten:
                    flatten.append(value)
    flatten.sort()
    print(" ".join(flatten))


if __name__ == "__main__":
    main()

https://fourdollars.blogspot.com/2013/07/grub2.html