Bug 280520

Summary:	LiveCD (install-sparc64-minimal-20090803.iso) doesn't boot
Product:	Gentoo Release Media	Reporter:	Michel Wendrich <m.wendrich>
Component:	InstallCD	Assignee:	Gentoo Release Team <releng>
Status:	RESOLVED FIXED
Severity:	blocker
Priority:	High
Version:	unspecified
Hardware:	Sparc
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---

Description Michel Wendrich 2009-08-06 00:52:34 UTC

After booting the InstallCD on my Ultra 10, I get an error message that the SquashFS file can't be mounted. I've also tried the autobuild from 2009-07-06, which has the same result.

dmesg shows the following line at the end:
SQHASHFS: Mounting a different endian SQUASHFS filesystem on loop0


Reproducible: Always

Steps to Reproduce:
1. Download ISO from mirror
2. Burn ISO to CD
3. Boot from CD

Actual Results:  
>> Media found on /dev/hdc
>> Determining root device...
>> Determining looptype...
>> Mounting squashfs filesystem
mount: mounting /dev/loop0 on /newroot/mnt/livecd failed: Invalid argument
!! Failed to $1; failing back to the shell...


BusyBox v1.7.4 (2009-08-03 17:59:34 UTC) built-in shell (ash)
Enter 'help' for a list of built-in commands.

/bin/ash: can't access tty; job control turned off
#

Expected Results:  
A SquashFS filesystem that properly mounts.

Apparently I'm not the only one who seems to be having the same problem, see http://ekschi.com/technology/2009/07/29/experiencing-linux-on-sparc-ldomgentoo/ for reference.

Comment 1 Michel Wendrich 2009-08-15 02:02:23 UTC

Looks like I've found the problem.

Recently, squashfs-tools-4.0 was marked sparc (bug #273131), which requires a kernel >=2.6.29. However, the current stable version of gentoo-sources is stuck at 2.6.28-r5 for sparc, which only has support for SquashFS <=v3.

Until gentoo-sources >=2.6.29 has been stabled for sparc (and the build host generates a new InstallCD which includes that kernel), this problem will occur with any weekly InstallCD that is currently on the mirror.

However, there is a workaround that requires a helper system (in my case, an amd64 box) with a >=2.6.29 kernel and SquashFS/loop support built in. It took a while to figure this out (with a bit of help from the Catalyst sources), so I'll post the entire process here in case somebody has to deal with the same problem.

- Emerge squashfs-tools (emerge =sys-fs/squashfs-tools-3.3)
- Create a bunch of temporary directories (mkdir /mnt/sparc-old /mnt/sparc-new /mnt/squashfs)
- Mount the InstallCD ISO as a loop filesystem (mount /home/user/install-sparc64-minimal-20090803.iso /mnt/sparc-old -o loop)
- Copy the contents of that mount point to a different directory (cp -a /mnt/sparc-old /mnt/sparc-new)
- Unmount the old ISO file (umount /mnt/sparc-old)
- Mount the v4 image.squashfs (mount /mnt/sparc-new/image.squashfs /mnt/squashfs -t squashfs)
- Create a new SquashFS v3 file (mksquashfs /mnt/squashfs /mnt/image.squashfs)
- Unmount SquashFS v4 (umount /mnt/squashfs)
- Move the new SquashFS v3 file (mv /mnt/image.squashfs /mnt/sparc-new)
- Create a new ISO file (mkisofs -J -R -l -V "Gentoo Linux - SPARC 20090815" -o /home/user/install-sparc64-minimal-20090815.iso -G "/mnt/sparc-new/boot/isofs.b" -B ... /mnt/sparc-new
- Burn the ISO and see if it works
- Remove the directories (rm -rf /mnt/sparc-old /mnt/sparc-new /mnt/squashfs)

Voilà, a custom InstallCD that boots completely.

Comment 2 Andrew Gaffney (RETIRED) gentoo-dev

2009-08-15 02:23:19 UTC

I've already fixed this by downgrading squashfs-tools to 3.3 on bender, the sparc build machine