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Booting Ubuntu with BKO

Locating from where does the nfsboot is getting called

Mistory of do_nfsmount

do_nfsmount is defined at two places, why?

  1. /scripts/casper +198
  2. /scripts/nfs +8

My guess is that file /scripts/nfs is not used, it is just present there from older versions and has not been removed.

do_nfsmount function is getting called from /scripts/casper +188 which is from inside of


and depend on variable


The do_netmount() is getting called from mountroot() which is inside /scripts/casper +581 and the call depends on variable presense of variable ${NETBOOT} which is the boot parameter value of parameter netboot

qemu + ubuntu 9.04 Desktop i386 booting problem

ubuntu-9.04-desktop-i386.iso is refusing to boot over qemu. I am using command line

qemu -cdrom /var/www/ubuntu-9.04-desktop-i386.iso -net nic -net user

It gives error gives error :

[  3.284007]  ..MP-BIOS bug: 8254 timer not connected to IO-APIC

and freezes.
I am using following version of qemu

$ qemu
QEMU PC emulator version 0.10.0, Copyright (c) 2003-2008 Fabrice Bellard

The BIOS number was found and BIOS version used by qemu is as follows

QEMU BIOS - build: 08/15/08
$Revision: 1.209 $date: 2008/06/02 20:08:10$

I had to update my qemu to version 0.10.5 then it started working

$ qemu
QEMU PC emulator version 0.10.5, Copyright (c) 2003-2008 Fabrice Bellard


I am getting following errors in the process of booting. My guess is, most of these errors are related to failure of httpfs in providing requested logical block, but I need to confirm this.

Buffer I/O error on device loop0, logical block 272374
SQUASHFS error: sb_bread is failed reading block 0x845d5
SQUASHFS error: unable to read fragment cache block [211696cb]
SQUASHFS error: unable to read page, block 211696cb, size c115

I have seen this error before, but if I retry the booting then it works. But now, I have failed two consecutive time on local webserver, which is quite alarming.

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