Gentoo Archives: gentoo-mips

From: Mike Martin <mikemartin@×××××.ca>
To: gentoo-mips@l.g.o
Subject: Re: [gentoo-mips] Question - Kumba LiveCD RC6
Date: Tue, 23 Jan 2007 16:14:57
Message-Id: 855e88d00701230624q2c525093gdc0ed5c2826739cf@mail.gmail.com
In Reply to: Re: [gentoo-mips] Question - Kumba LiveCD RC6 by Kumba
1 Thanks for your help. I will try another burn. I'm using cdrecord and am
2 using (I believe) good media. What command parameters for cdrecord would you
3 recommend?
4
5 For fun I tried booting with a different external CD-ROM drive ... with
6 identical results.
7
8 I will also try the disk out on a R4600 Indy.
9
10 Thanks for your hard work.
11 MikeMartin
12
13 On 1/22/07, Kumba <kumba@g.o> wrote:
14 >
15 > Mike Martin wrote:
16 > > I recently downloaded and attempted to boot an Octane with this disk. It
17 > > died mounting the root partition:
18 > >
19 > > mount: Mounting /newroot/dev/loop0 on /newroot/mnt/livecd failed:
20 > > Invalid argument
21 > >
22 > > Not sure what happened. I assume I burnt the disk correctly else it
23 > > wouldn't have made it that far. Any suggestions?
24 > >
25 > > MikeM
26 >
27 >
28 > It's really hard to say. I tested it on all of my systems before
29 > uploading, and
30 > with the Octane, this means an external drive (funny enough, an O2 CD
31 > drive
32 > jammed into a Sun 411 case). And that booted fine on both my Octane and
33 > Indy.
34 >
35 > "Invalid Argument" from mount could mean a wide array of things (yay for
36 > Unix's
37 > legacy of non-descriptive, ambiguous errors). The process that occurs on
38 > an SGI
39 > bootcd for us is a rather complex one:
40 >
41 > 1. arcload boots from the DVh partition of the CD
42 > (yes, these CDs have partitions)
43 > 2. arcload finds and boots a kernel
44 > 3. kernel loads, and executes /init in an embedded initramfs file linked
45 > into the kernel
46 > 4. /init does some prep work, and launches `getdvhoff` to scan the CD
47 > for the offset of the next partition (where / lives), and passes a
48 > number representing this offset back to `losetup`.
49 > 5. losetup uses this number to "point" /dev/loop0 at this offset, which
50 > effectively makes /dev/loop0 a block device with data on it.
51 > 6. mount tries to mount /dev/loop0 and pivot_root into the real Gentoo
52 > filesystem.
53 >
54 >
55 > Quite likely, step #5 might've failed somewheres along the line. The
56 > offset has
57 > to be exact to the bit, so maybe something got whacked in the burn and the
58 > detected offset is invalid. Hard to say without more information. Thus,
59 > when
60 > it got to step #6, boom.
61 >
62 > I'd try re-burning the disk at a slower speed, use only CD-R's of decent
63 > quality
64 > (TDK, Memorex, Sony, Ricoh/Ritek, etc,.. brands), and use cdrecord (or
65 > whatever
66 > license-unencumbered version is out there. stupid license wars). A few
67 > people
68 > reported getting it to work with a windows burn tool, but we have little
69 > data on
70 > that, thus why cdrecord is the suggested tool.
71 >
72 > Mostly, you were able to read the kernel into memory, which is ~8MB. It's
73 > possible the disc you burned was good enough to get those 8MB off to boot
74 > the
75 > kernel, but when it went looking for the meat, it got denied and pwned.
76 >
77 >
78 >
79 > --Kumba
80 >
81 > --
82 > Gentoo/MIPS Team Lead
83 >
84 > "Such is oft the course of deeds that move the wheels of the world: small
85 > hands
86 > do them because they must, while the eyes of the great are
87 > elsewhere." --Elrond
88 > --
89 > gentoo-mips@g.o mailing list
90 >
91 >

Replies

Subject Author
Re: [gentoo-mips] Question - Kumba LiveCD RC6 Kumba <kumba@g.o>