Trying to get Plop to boot Linux from USB somehow - tried lots of things

[gerv]

Hi,

I am trying to use Plop or plopKExec (written to CD-ROM) to boot Linux from USB on some old machines which do not have USB-HDD boot support in the BIOS (they only have USB-FDD, USB-ZIP/LS and USB-CDROM). The Linux concerned is Ubuntu 13.04. I have various configs of Linux - I am trying to get any of them to work!

I don't have continuous access to the machines on which I want this to work, so I have been testing by using Plop to boot the Linux USB keys on my wife's Lenovo B570 laptop. This laptop does support USB boot, and the USB Linux configurations I am testing with all boot fine when booted directly.

I cannot get Plop to boot anything at all, either by selecting the correct partition from the list or by selecting the "USB" option. When selecting the partition, FAT32 systems (i.e. Ubuntu LiveUSB) give a "Boot error" message. EXT3 systems tell me the MBR is valid but then give a "No valid boot sector signature - Continue?" message. (How can this be, if the keys boot fine when booted directly?) When selecting the USB option, the scan finds two devices and then says it can't find anything bootable. I believe it finds 2 devices whether or not the Linux USB key is plugged in, suggesting it's not finding it at all.

Plop will happily boot the Linux EXT3 system on the hard disk of the machine, so it's not that my Plop doesn't like EXT3.

Following another tip on these forums, I tried the USB 1.1 boot (using Shift-U) and the step-by-step boot (using Alt-U). It makes no difference.

I can get plopKExec to boot the keys when the filesystem is FAT (i.e. it's a LiveUSB system) but not when it's Ext3. So plopKExec with a liveUSB system is my only success so far.

(I also tried using Ext4 systems before finally reading in a forum somewhere that Plop does not support this. Perhaps that could be documented somewhere?)

Some of my configurations have multiple partitions (system/swap/FAT32 for data exchange). Is this a problem? Is it required that the system be on the first partition? Is it required to have only one partition?

The USB keys I am using are USB 3.0, although the _ports_ are all USB 2.0. I have discovered that Plop does not support USB 3.0 ports (again, can this please be documented?) But I am told USB is backwardly-compatible as far as the keys are concerned so the fact that I am using USB 3.0 keys in a USB 2.0 port shouldn't make a difference. Is that correct?

The keys I am using are 8GB. Is there a USB key size limit of any sort in Plop?

It could be that some of this stuff will work better on the target machines, when I get a chance to try it. I don't know. But any enlightenment on the above, and some idea of what types of Linux partition configuration and filesystem Plop _will_ boot from USB, would be much appreciated.

Thanks :-)

Gerv

[Elmar]

hello,

I am trying to use Plop or plopKExec ....

i assume you mean with "Plop" my plop boot manager. "Plop" is the name of my sole trader business

I cannot get Plop to boot anything at all, either by selecting the correct partition from the list or by selecting the "USB" option. When selecting the partition, FAT32 systems (i.e. Ubuntu LiveUSB) give a "Boot error" message. EXT3 systems tell me the MBR is valid but then give a "No valid boot sector signature - Continue?" message. (How can this be, if the keys boot fine when booted directly?) When selecting the USB option, the scan finds two devices and then says it can't find anything bootable. I believe it finds 2 devices whether or not the Linux USB key is plugged in, suggesting it's not finding it at all.

the plop boot manager is not a linux loader. when you want to start linux directly from a partition, then you have to install lilo or grub to the partition. then you are able to boot directly from the partition.

I can get plopKExec to boot the keys when the filesystem is FAT (i.e. it's a LiveUSB system) but not when it's Ext3. So plopKExec with a liveUSB system is my only success so far.

plopkexec has fat and ext2 support and ext3 should be mounted as ext2. when you want to have native ext3, ext4 or other file systems, then you have to build your custom version.

(I also tried using Ext4 systems before finally reading in a forum somewhere that Plop does not support this. Perhaps that could be documented somewhere?)

i would say, at first read the docs. when you read the plopkexec introduction then you find "The distros can be on FAT, EXT2/3 formatted USB drives and on USB CD/DVD's." ext3 should be mounted as ext2. but why should i write that ext4 is not supported. ntfs and many other file systems are also not supported.

Some of my configurations have multiple partitions (system/swap/FAT32 for data exchange). Is this a problem? Is it required that the system be on the first partition? Is it required to have only one partition?

no problem.
no need that the system is on the first partition.
its not required to have only one partition.

The USB keys I am using are USB 3.0, although the _ports_ are all USB 2.0. I have discovered that Plop does not support USB 3.0 ports (again, can this please be documented?)

read the docs and you will find what is supported. assume that all that is not said is not supported.
"USB boot without BIOS support (UHCI, OHCI and EHCI)"
ok, not everybody knows that uhci and ohci are using the usb 1.1 protocol and ehci is using the 2.0 protocol.
when the docu was written, usb 3.0 was not available for users.

But I am told USB is backwardly-compatible as far as the keys are concerned so the fact that I am using USB 3.0 keys in a USB 2.0 port shouldn't make a difference. Is that correct?

some of my usb 3.0 drives does not work with the usb 2.0 port. till now i didn't read the usb 3.0 specs. i dont know if they have to work as usb 2.0 device.

The keys I am using are 8GB. Is there a USB key size limit of any sort in Plop?

no


regards
elmar

[gerv]

i assume you mean with "Plop" my plop boot manager. "Plop" is the name of my sole trader business

Yes, thank you :-)

the plop boot manager is not a linux loader. when you want to start linux directly from a partition, then you have to install lilo or grub to the partition. then you are able to boot directly from the partition.

But these keys boot directly (on a machine which does support USB boot), so they must have Grub on them, mustn't they?

I can certainly get a Grub menu when I boot them directly.

plopkexec has fat and ext2 support and ext3 should be mounted as ext2.

What steps to I have to take to make sure it's mounted as ext2? Or will plopkexec do that automatically when it sees an ext3 partition?

when you want to have native ext3, ext4 or other file systems, then you have to build your custom version.

OK... do you have any plans to support them out of the box?

i would say, at first read the docs. when you read the plopkexec introduction then you find "The distros can be on FAT, EXT2/3 formatted USB drives and on USB CD/DVD's."

Yes, it's documented for plopkexec, but not for Plop Boot Manager.

ext3 should be mounted as ext2. but why should i write that ext4 is not supported. ntfs and many other file systems are also not supported.

Because now that ext4 is the default for new Linux distributions, a lot of people are going to be using ext4?

read the docs and you will find what is supported. assume that all that is not said is not supported.
"USB boot without BIOS support (UHCI, OHCI and EHCI)"
ok, not everybody knows that uhci and ohci are using the usb 1.1 protocol and ehci is using the 2.0 protocol.
when the docu was written, usb 3.0 was not available for users.

Yes, I was not aware that this statement meant "no USB 3.0". Perhaps you could have mercy, and make it a little more obvious :-)

Thank you for your replies and your help :-) I have managed to get both Plop Boot Manager and plopkexec to boot a FAT32 live USB key on the target machines, so I'm going to go with that solution. plopkexec also booted the ext3 version, but not as reliably (although it may have been a dodgy USB key).

Gerv

[Elmar]

But these keys boot directly (on a machine which does support USB boot), so they must have Grub on them, mustn't they?

I can certainly get a Grub menu when I boot them directly.

either grub or syslinux is installed

What steps to I have to take to make sure it's mounted as ext2? Or will plopkexec do that automatically when it sees an ext3 partition?

it should work automatically

when you want to have native ext3, ext4 or other file systems, then you have to build your custom version.

OK... do you have any plans to support them out of the box?

its not included because plopkexec would became too big to fit on a 1.44 floppy. plopkexec is open source. everybody can modify it for his needs.

however, the latest linux kernel module of ext4 is able to mount ext2/3. if there comes a new plopkexec version, then ext4 will be also supported in the standard version.

i would say, at first read the docs. when you read the plopkexec introduction then you find "The distros can be on FAT, EXT2/3 formatted USB drives and on USB CD/DVD's."

Yes, it's documented for plopkexec, but not for Plop Boot Manager.

there is no file system is documented for the plop boot manager, because the plop boot manager does not support any file system. it only loads the boot sector of a partition. the program in the boot sector has to handle the rest.

ext3 should be mounted as ext2. but why should i write that ext4 is not supported. ntfs and many other file systems are also not supported.

Because now that ext4 is the default for new Linux distributions, a lot of people are going to be using ext4?

it makes no sense to write what not is supported. when you dont read ext4 in a docu then assume its not supported regardless whats currently default for others.




elmar