3 replies to this topic

[osmethod]

Hello,

It's been years since I coded assembly but I have some free time and would like to get into it again.
In the past using Smart Boot Manager I managed to install 18 OSes in a box with 2 IDE drives and 4 SCSI drives. Each of the oses installed on primary partitions. This is why I feel this boot manager has proven itself to me. Typically, each of the oses installs its own boot loader into its own partition which SBM is able to scan and create a menu item respectively, which in turn can then be set Active. It also is able to boot atapi cdroms even if not supported by the bios.

What it can't do is scan USB devices. The source code for SBM is released under GPL so I would to try to add USB device scanning for boot loaders, add them to the menu and set active to boot accordingly whether the USB device contains Windows, Linux, BSD or whatever... e.g. vmware's ESX3i is bootable from a USB stick and is a linux based boot. I've seen where windows can be booted also from a USB stick.

I'd like to just scan the USB bus, locate the device, see if its bootable.....

Can someone provide me with links or references for same and maybe some clarifications?

Are there int13 extensions provided in newer bioses to locate USB devices?
If not, does one need to provide a USB stack and can this be provided without device drivers?

I'd prefer not to have to use specific device drivers to try and find the USB device...

I appreciate any comments or help.

Thank you,

osmethod

[was_jaclaz]

First thing, welcome to the board.

Are there int13 extensions provided in newer bioses to locate USB devices?
If not, does one need to provide a USB stack and can this be provided without device drivers?

Yes/No.

I mean, BIOS implementations differ a lot, as far as I know there are three main "categories":
1) Do NOT support USB (booting) properly
2) Only provide the "extension" or "internal" stack if BIOS settings are set to boot from USB
3) Also allow the above "on the fly" by pressing F10, F11 or F12
The setting that is sometimes referred as "Legacy USB support" appears to affect the behaviour of BIOS, somehow.
Some BIOS have options to boot:
1) Generic USB boot
2) ONLY "Floppy"
3) Choose between "Floppy" or "HD like"
4) Choose between "Floppy" or "Zip Drive" or "HD like"
Some BIOSes, moreover limit the "Floppy" type to "real" floppies, i.e. 1,44 or 2,88, whilst other also accept "Superfloppies"

All in all it is a mess, and to be more precise, an UNDOCUMENTED mess .

Since you have assembly/low level experience, you could be the contributor to the "missing steps".

Do read these, AND links therein:
http://www.911cd.net...o...c=16847&hl=
http://www.911cd.net...o...c=17633&hl=
http://www.911cd.net...o...c=18650&hl=
http://www.911cd.net...o...c=20310&hl=
http://www.911cd.net...o...c=20450&hl=
http://www.boot-land...?...=2246&st=15


And maybe these:
http://www.911cd.net...o...c=15776&hl=
http://www.911cd.net...o...c=19731&hl=

I know it's a lot, expecially all together , so you'd better
START WORKING!





jaclaz

[liquid98]

Hi Jaclaz and osmethod,


@Jaclaz: How was the plop bootloader in booting usb devices?

-- http://www.plop.at/d...mngrusblog.html

I see there is yet some work to do, but it looks promising.

@osmethod:

I think he is trying to accomplish the same thing as you want,
maybe Elmar can help you...

liquid98

[was_jaclaz]

@Jaclaz: How was the plop bootloader in booting usb devices?

-- http://www.plop.at/d...mngrusblog.html

I see there is yet some work to do, but it looks promising.

I haven't tested it, mainly because the only way to know if it works as expected is to try it on "real" hardware that has no USB support, which I do not have handy.

ktp did a couple of tests in QEMU:
http://www.boot-land...port-t3226.html

but nothing definite, as you can see.

However plop's Author appears to be working hard in solving problems, he is already onto RC5:
http://www.plop.at/e...mngrusblog.html


jaclaz