Disk Image Inspector (disk-inspect)

What is it?

disk-inspect is a planned interactive browser for Impossible OS disk images and drives: the GPT partition table, the IXFS superblock, inodes and their extents, the directory tree, the block bitmap and raw sectors, in the spirit of fdisk -l plus debugfs. None of its five sections has been built. The partition-table half already exists in the boot-artifact inspector, and the IXFS half would reuse the SDK's IXFS parser once that parser is back in step with the kernel's format.

How does it work?

What exists today.

python3 tools/bootimg/bootimg.py inspect <image> (tools/bootimg/bootimg.py) reads raw, VHD, VHDX, VDI and ISO images and prints every GPT partition with its name, type GUID, detected filesystem, label, size and LBA range, plus signature and manifest status. --json gives the same data for scripts. It covers the roadmap's section 1 already.
tools/make-system-disk.c writes the GPT and records the byte offset of each partition in build/system-disk.img.info, which scripts read rather than hard-coding offsets.
The SDK's IXFS parser in sdk/src/ixfs-mount/ reads the superblock, inodes, extents and directories. Its inode layout is out of date (see IXFS Mount), so it cannot yet be the base for inode inspection.

Planned design.

GPT table: header, entries, type GUIDs named (EFI System, Basic Data, IXFS), sizes and filesystems.
IXFS metadata: superblock fields, used and free inodes, inode N with type, size, extents, timestamps and permissions, and a size-against-extents consistency check.
Directory browsing: ls, tree, cat and stat by path.
Raw views: hexdump of file data, sector LBA count, block N and a visual block bitmap.
Shell: a disk-inspect> prompt with tab completion, history and help.

flowchart LR
    I[disk image or device] --> G[GPT table]
    G --> X[IXFS superblock and inodes]
    X --> D[directories: ls, tree, cat, stat]
    G --> H[raw sectors and blocks]
    D & H --> S[interactive shell]

What are its interfaces?

Interface	Status
`bootimg.py inspect <image> [--json]`	Shipped, lists partitions
`build/system-disk.img.info` partition offsets	Shipped
`ixfs_open`, `ixfs_read_inode`, `ixfs_readdir` in the SDK parser	Shipped, but reads the wrong inode size
`disk-inspect <image>` and its commands	Planned in sections 1 to 5

How do I use it?

For the partition table, use the boot-artifact inspector. On the image built on 2026-09-30:

$ python3 tools/bootimg/bootimg.py inspect build/system-disk.img
Partitions:
  [1] EFI System ... fs=fat32 label='NO NAME' size=64 MiB lba=[2048..133119]
  [2] BlackBox ... fs=fat32 label='BLACKBOX' size=128 MiB lba=[133120..395263]
  [3] Impossible OS A ... fs=ixfs label='Impossible OS' size=269 MiB lba=[397312..948223]
  [4] Impossible OS B ... fs=ixfs label='Impossible OS' size=270 MiB lba=[948224..1501183]
  [5] Impossible OS ABMeta ... fs=unknown label='' size=1 MiB lba=[395264..397311]
  [6] Impossible OS Recovery ... fs=fat32 label='RECOVERY' size=34 MiB lba=[1501184..1572829]

Type GUIDs are elided here. The build makes the A/B layout, so IXFS is partitions 3 and 4, not 3 alone as the roadmap's example shows. For the FAT32 partitions, mdir and mcopy from mtools read the volume at its offset (mdir -i build/system-disk.img@@<offset> ::/). Raw sectors can be read with xxd -s <offset> -l 512 build/system-disk.img.

What is not implemented yet?

GPT Partition Table Parser, largely covered by bootimg.py inspect; the section should reuse it rather than write a second GPT reader
IXFS Superblock + Inode Inspector
Directory Listing
Hex Dump and Raw Sector Read
Interactive Shell

Sections 2 and 3 depend on the shared IXFS parser being resynchronised with the kernel's on-disk format, filed in the IXFS mount roadmap. The roadmap's example shows an inline file (hello.txt ... inline): the kernel stores up to 48 bytes of a small file in the inode itself (IXFS_INLINE_MAX in include/kernel/fs/ixfs.h), and the inspector's inode and hexdump views need to show that case rather than an empty extent list.

How does it compare with Windows 11 and Linux?

On Linux, fdisk -l or sgdisk -p show the partition table and debugfs browses ext4 metadata interactively; Windows offers diskpart and fsutil for volumes but no NTFS metadata browser. For Impossible OS the partition view already exists in the artifact inspector; the planned tool adds the debugfs-style IXFS view that neither host OS can give for this filesystem.