SquashFS: modifying rootsquash file

psychic_teabag

Nah, you don't need to patch the kernel to build and run squashfs utils. Well, I'd be *very* surprised - it's just a user-mode program that manipulates a big file.

Are you sure the patches aren't just to allow you to *use* the resultant squashfs ?

psychic_teabag

esuhl wrote: »

I've downloaded the source and have been trying to wrap my head round creating a PKGBUILD file (for Arch's package manager).

You probably don't need to bother - you can build and run programs without having to package them. Just copy binary to /usr/local/bin or ~/bin, or whereever suits you.

Just cd into the squashfs-utils dir and invoke make. Hmm, well, that ought to work, but trying it here, I get a compilation error (and lots of warnings). I guess gcc has got stricter since it was originally written.

lines 432 and 489 in mksquashfs.c - either split into two assignments, or add brackets to the second assignment, so the cast is outside - and then a link error because read_from_file wasn't exported - just remove the inline directive from around line 696

debitcardmayhem

Lightbulb moment .....
try this

cd to the unsquashed squashfs-root
then enter

 sudo sbin/mksquashfs . ../rootsquash  -b 32768 -noappend -le

put that new rootsquash back on the ISO and VOILA


e.g.

cd squashfs-root

sudo sbin/mksquashfs . ../rootsquash  -b 32768 -noappend -le
[sudo] password for rob: 
Creating little endian filesystem on ../rootsquash, block size 32768.

Little endian filesystem, data block size 32768, compressed data, compressed metadata
Filesystem size 114350.62 Kbytes (111.67 Mbytes)
    39.65% of uncompressed filesystem size (288364.65 Kbytes)
Inode table size 163887 bytes (160.05 Kbytes)
    58.68% of uncompressed inode table size (279295 bytes)
Directory table size 135820 bytes (132.64 Kbytes)
    50.74% of uncompressed directory table size (267669 bytes)
Number of duplicate files found 864
Number of inodes 19083
Number of files 11526
Number of symbolic links  815
Number of device nodes 4969
Number of fifo nodes 3
Number of socket nodes 0
Number of directories 1770
Number of uids 2
    root (0)
    unknown (1001)
Number of gids 10
    unknown (43)
    unknown (2000)
    gdm (42)
    tty (5)
    dip (40)
    ftp (50)
    disk (6)
    unknown (44)
    man (15)
    adm (4)

and below (using my normal unsquashfs

sudo unsquashfs -s ../rootsquash
Found a valid little endian SQUASHFS 1:0 superblock on ../rootsquash.
Creation or last append time Wed Aug 29 13:33:21 2018
Filesystem size 114350.62 Kbytes (111.67 Mbytes)
Block size 32768
Filesystem is not exportable via NFS
Inodes are compressed
Data is compressed
Check data is not present in the filesystem
Duplicates are removed
Number of inodes 19083
Number of uids 2
Number of gids 10

esuhl

debitcardmayhem wrote: »

Lightbulb moment .....
try this

cd to the unsquashed squashfs-root
then enter

 sudo sbin/mksquashfs . ../rootsquash  -b 32768 -noappend -le

put that new rootsquash back on the ISO and VOILA

Aha! Very clever!

My first attempt booted further than previously, but froze before booting into X/GXMAME.

So I tried only adding the new files without the -noappend option, and... IT WORKED!!!

:j :T :beer: :money: :j

Thank you both so much! Yay!

debitcardmayhem

esuhl wrote: »

Aha! Very clever!

My first attempt booted further than previously, but froze before booting into X/GXMAME.

So I tried only adding the new files without the -noappend option, and... IT WORKED!!!

:j :T :beer: :money: :j

Thank you both so much! Yay!

Glad to have helped, now for the next question.....:cool: