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PLoP showextended

Posted: 30 Jan 2016, 17:57
by dinosaur
I added the APPEND line to the PLoP entry in porteus.cfg as it seemed convenient to be be convenient to be able to boot into Debian on sda5 from a Porteus usb stick.

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LABEL plop
MENU LABEL PLoP BootManager
KERNEL plpbt
APPEND showextended=yes
TEXT HELP
    Run the plop boot manager.
    This utility provides handy
    boot-USB options for machines
    with vintage/defective BIOS
ENDTEXT
I see that thei feature was added on 7th Feb 2012. https://www.plop.at/en/bootmngrusblog.html

I'm just wondering if the version included in Porteus is the latest version.

Should I just get a later version of plpbt or ask PLoP for help?

Thanks.

Re: PLoP show

Posted: 30 Jan 2016, 18:00
by dinosaur
The title should be PLoP showextended

(mod action complete)

Re: PLoP show

Posted: 30 Jan 2016, 18:03
by dinosaur
Forgot to say that Porteus version is Desktop 3.1.

Re: PLoP show

Posted: 30 Jan 2016, 18:22
by Bogomips
Welcome to Porteus! Someone should be along shortly to give you the heads up :)

Re: PLoP show

Posted: 30 Jan 2016, 22:55
by donald
To find out which version:

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hexdump -C plpbt | tail
Example:

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guest@localhost:/mnt/sda1/boot/syslinux$ hexdump -C plpbt | tail
.........
0000a910  0b 68 69 64 64 65 6e 63  64 72 6f 6d 09 69 6e 74  |.hiddencdrom.int|
0000a920  31 39 68 3d 6f 6e 32 30  20 73 65 63 6f 6e 64 73  |19h=on20 seconds|
0000a930  00 75 73 65 20 63 75 72  73 6f 72 20 75 70 2f 64  |.use cursor up/d|
0000a940  6f 77 6e 00 20 50 6c 6f  70 20 42 6f 6f 74 20 4d  |own. Plop Boot M|
0000a950  61 6e 61 67 65 72 20 76  35 2e 30 2e 31 31 20 32  |anager v5.0.11 2|
0000a960  30 31 30 31 30 31 38 00  77 72 69 74 74 65 6e 20  |0101018.written |
0000a970  62 79 20 45 6c 6d 61 72  20 48 61 6e 6c 68 6f 66  |by Elmar Hanlhof|
0000a980  65 72 00 68 74 74 70 3a  2f 2f 77 77 77 2e 70 6c  |er.http://www.pl|
0000a990  6f 70 2e 61 74 00 70 6c  70 62 74 63 68 6b        |op.at.plpbtchk|
Note: i'm using v 2.0 , v 3.1 may have a different version...

Re: PLoP show

Posted: 30 Jan 2016, 23:26
by dinosaur
As to versions, I tried downloading the latest version, but it didn't help. The original version is suffixed .old

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guest@porteus:~$ cd /mnt/sdb1/Porteus/boot/syslinux
guest@porteus:/mnt/sdb1/Porteus/boot/syslinux$ ls
boot.cat       isolinux.bin   lilo.conf    porteus.cfg.old  vmlinuz
chain.c32      isolinux.boot  plpbt        porteus.png
extlinux.conf  isolinux.cfg   plpbt.old    syslinux.cfg
initrd.xz      ldlinux.sys    porteus.cfg  vesamenu.c32
guest@porteus:/mnt/sdb1/Porteus/boot/syslinux$ hexdump -C plpbt | tail
0000a9b0  68 6f 77 65 78 74 65 6e  64 65 64 3d 79 65 73 01  |howextended=yes.|
0000a9c0  32 30 20 73 65 63 6f 6e  64 73 00 75 73 65 20 63  |20 seconds.use c|
0000a9d0  75 72 73 6f 72 20 75 70  2f 64 6f 77 6e 00 20 50  |ursor up/down. P|
0000a9e0  6c 6f 70 20 42 6f 6f 74  20 4d 61 6e 61 67 65 72  |lop Boot Manager|
0000a9f0  20 35 2e 30 2e 31 35 20  32 30 31 33 30 34 31 35  | 5.0.15 20130415|
0000aa00  00 77 72 69 74 74 65 6e  20 62 79 20 45 6c 6d 61  |.written by Elma|
0000aa10  72 20 48 61 6e 6c 68 6f  66 65 72 00 68 74 74 70  |r Hanlhofer.http|
0000aa20  3a 2f 2f 77 77 77 2e 70  6c 6f 70 2e 61 74 00 70  |://www.plop.at.p|
0000aa30  6c 70 62 74 63 68 6b                              |lpbtchk|
0000aa37
guest@porteus:/mnt/sdb1/Porteus/boot/syslinux$ hexdump -C plpbt.old | tail
0000a9b0  68 6f 77 65 78 74 65 6e  64 65 64 3d 79 65 73 01  |howextended=yes.|
0000a9c0  32 30 20 73 65 63 6f 6e  64 73 00 75 73 65 20 63  |20 seconds.use c|
0000a9d0  75 72 73 6f 72 20 75 70  2f 64 6f 77 6e 00 20 50  |ursor up/down. P|
0000a9e0  6c 6f 70 20 42 6f 6f 74  20 4d 61 6e 61 67 65 72  |lop Boot Manager|
0000a9f0  20 35 2e 30 2e 31 34 20  32 30 31 32 30 32 31 31  | 5.0.14 20120211|
0000aa00  00 77 72 69 74 74 65 6e  20 62 79 20 45 6c 6d 61  |.written by Elma|
0000aa10  72 20 48 61 6e 6c 68 6f  66 65 72 00 68 74 74 70  |r Hanlhofer.http|
0000aa20  3a 2f 2f 77 77 77 2e 70  6c 6f 70 2e 61 74 00 70  |://www.plop.at.p|
0000aa30  6c 70 62 74 63 68 6b                              |lpbtchk|
0000aa37
guest@porteus:/mnt/sdb1/Porteus/boot/syslinux$ - 
So it looks like I've gone from 5.0.14 to 5.0.15.

Both look as if they should support showextended=yes.

I think this means I need to contact PLoP - unless someone has any good ideas.

The ability to boot into any installed OS when the bootloader goes walkabout - well, that's enough to make Porteus on a usb stick my recovery tool of choice.

Re: PLoP show

Posted: 31 Jan 2016, 00:01
by donald

Re: PLoP showextended

Posted: 31 Jan 2016, 15:27
by dinosaur
Thanks, Donald.

In boot/syslinux as root with the config program in the same directory. the command

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./plpcfgbt plpbt
listed the options as set and

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./plpcfgbt showextended=yes plpbt
changed the option

However, the result was not as I expected. It just listed the extended partition, not the contained logical partitions.

Suspecting a nested menu, I selected sda4 and it tried to boot the extended partition!

So, to me this looks like a PLoP bug, not a feature.

My problem now, is that I have not been able to create an account on forum.plop.at - It calls me a spam! I've tried emailing the admin, but no response as yet.

Re: PLoP showextended

Posted: 31 Jan 2016, 17:40
by donald
I have read a little further on the "plop" website.As I understand it, the "showextended"
option actually only show the extended partition itself, not the contained logical ones.
Logical Partitions should be shown by default as L1..L4.
If you have more than 4 logical partitions they are not shown because you will
have an extended partition containing another extended partition with the (more than 4) logical partitions.
https://forum.plop.at/index.php?topic=197.0
Do you see any logical partition in the menu?

Re: PLoP showextended

Posted: 02 Feb 2016, 01:18
by dinosaur
My disk was created from a smaller one with dd.

I then grew the extended partition.

Current position is

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GNU Parted 3.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print free                                                       
Model: ATA WDC WD10J31X-00U (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos
Disk Flags: 

Number  Start   End     Size    Type      File system  Flags
        32.3kB  1049kB  1016kB            Free Space
 1      1049kB  517MB   516MB   primary   ext4
 2      517MB   73.7GB  73.1GB  primary   ntfs
 3      73.7GB  247GB   173GB   primary   ntfs
        247GB   247GB   1048kB            Free Space
 4      247GB   1000GB  754GB   extended
 5      247GB   315GB   68.7GB  logical   ext4
 6      315GB   530GB   215GB   logical   ext4
 7      530GB   1000GB  470GB   logical   ext4
        1000GB  1000GB  745kB             Free Space
I did have a couple of others, including a linux swap, but I deleted them to get the numbers down. I kept the linux root and home and an empty one.

(btw, this megabyte alignment is rather wasteful).

There is a conflict between the usage of extended partition tables between the PLoP forum thread @Donald referenced and Wikipedia Extended boot record.

Whereas the PLoP author was saying that all 4 entries can be used,Wikipedia says only 2 - the first pointing to the next following partition and the 2nd, if used, to a nested extended partition etc - forming a linked list.

So I downloaded active@ disk editor and had a look.

Well, the first one at least used the 1 entry + nested logical method (I used gparted for partitioning) - so it looks like I'm not going to get booting from logical partitions working.

I might be able to get the first one going, but is it worth the effort.

So, now I'm looking for a way to boot from within Porteus.

Re: PLoP showextended

Posted: 02 Feb 2016, 02:09
by dinosaur
Irriot| :oops:

I can just use tab to edit the last entry on the default boot menu. :Yahoo!:

Re: PLoP showextended

Posted: 02 Feb 2016, 07:10
by donald
--> the conflict <--
I think they mean the same thing but use a different wording.

About extended partitions:
the first 512 bytes of the partition contain another partition table, which describes how the extended partition itself is layed out.

There are two "standards" around:
first one (used by DOS, works on Linux too)
is to use the first entry of that table for a real, "data" partition
and the second entry (if needed) for another nested extended partition that
will describe the remaining partitions in the same way.
So you get a chain of extended partitions, when each one describes the next one
and also a "data" (ext2, DOS or whatever you like) partition.

second one (accepted by Linux at least)
allows using as many entries as you want in an extended partition, with the
limit that is contains at most another extended partition.

At the end, you got it working, don't you? :D