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How to use AOS on multi-boot machines?

If you have multiple operation systems installed on your computer, you will need a boot manager which allows you to select which OS should be started. Typically, you will need to add an entry for AOS to your boot manager to make AOS appear in the boot menu.

Bluebottle Boot Manager

My personal favorite boot manager is the Bluebottle Boot Manager (staubesv). In particular, it is not necessary to add entries for the different operating systems. Instead, the Bluebottle Boot Manager displays a list of all partitions and you just select the partition you want to boot. The boot manager will remember the last selection.
If this is the boot manager you use, there is nothing to do. Refer to the Bluebottle document BootManager.Text

Other boot managers and AOS

When a primary or logical partition is created and formatted to host an AOS file system - AosFS, it contains by construction, at the beginning, a bootloader in charge of locating and loading a kernel and further on the rest of the OS. The presence of the "magic value" 55aah at offset 1feh in the PBR signals that the partition is formatted. Hence, AOS can be started by accessing the PBR and passing control to it. That is precisely the technique used by the boot managers to start AOS when instructed as documented below. In Linux jargon, one speaks of chain loading.

Exceptionally, an AOS partition destined to serve exclusively as data repository may be formatted without kernel and programs. Such a partition is not bootable, in spite of the presence of a valid signature 55aah, just by lack of kernel. It can only be mounted/unmounted in AOS.

When any of the boot managers cited below is installed on the occasion of installing an OS, one can expect that Windows or Linux partitions will be recognized and that these OSes will be "automatically" included in a boot menu to be bootable. But none will take action in the presence of AOS and that justifies the details given below.

GRUB installed on the occasion of installing Ubuntu 7.10 or Google's gOS

  • Option to start AOS permanently recorded in the GRUB menu
In Ubuntu, navigate to Applications > Accessories > Terminal to open a terminal, then sign in as supervisor with:
sudo -s (at the prompt enter the supervisor password)
Note: In the Ubuntu-based gOS, navigate to Applications > System Tools > UXTerm.
Now enter the command:
vi /boot/grub/menu.lst
Place the cursor where to insert new text in the menu, enter 'i' to start inserting these lines in menu.lst:
# This is for booting AOS residing in hd0,2 = IDE0#3 for example
title AOS on hd0,2
chainloader (hd0,2)+1
Enter ':x' to save the updated menu and to quit editing.
  • On-the-fly command controlled start of AOS from a GRUB menu
When the GRUB menu appears at start up, enter 'c' for commands. Then enter the following commands in succession:
chainloader (hd0,2)+1
The boot command is required here but implied when the menu.lst is interpreted.

Hard drives are recognized by the BIOS at boot time and GRUB numbers them starting from 0.
Partitions numbers start from 0 too (note the difference in the example given).

MS Windows NT/2000/XP Boot Manager

The simplest way the add an entry for AOS to the MS Windows NT/2000/XP boot manager is to use the freeware tool bootpart (download at http://www.winimage.com/bootpart.htm). You will need an image of the boot loader (first sector of the partition where AOS is installed). The create this image, boot from the AOS CD, open the Partition Tool (found in Menu->Files->Partitions). In Partition Tool, select the AOS partition and use the opeartion Partitions->ToFile to store the first sector to a file. Start Windows NT/2000/XP, run the command line shell and type bootpart.exe /? to get information on how to proceed.

Note: Whenever you change to boot loader of the AOS partition (e.g. re-formatting it), you must create a new image of it.

MS Windows Vista Boot Manager

Give the preference to NeoSmart Technologies's http://neosmart.net software EasyBCD - current version 1.7.1. - free download. The tool is of easy use: add an entry, name it, specify in which partition AOS resides and save an adequately modified binary file BCD (Boot Configuration Data).

While in Windows XP and earlier versions it was simple enough to edit boot.ini to instruct the built-in boot manager to start another OS, Vista requires much more from a user to persuade its boot manager to cooperate with other OSes. boot.ini was replaced by the BCD binary file which, in Vista pure, must be edited using a console application named bcdedit.exe. This might reveal itself as a tedious task better performed with a tool such as EasyBCD. More such tools may be around of course.

GAG - Graphical boot manager

Start GAG from a GAG boot volume, or from a bootable GAG CD-ROM, and follow the GUI instructions:

  1. Press 's' to Set up GAG
  2. Press 'a' to add an AOS
  3. Press the letter associated with the target AOS among the listed OSes (using the GRUB example 'c' for AOS)
    or press a digit '1' .. '8' to address another volume where the AOS resides
  4. Type a description (up to 15 characters)
  5. Type a password or none
  6. Press the letter associated with the icon to represent AOS
  7. Press 'h' to save in hard disk
    or 'r' to return to main menu for testing this sequence.

Use Installer to install native A2 from WinAos

It is possible to install native A2 from WinAos. This can be useful if you want, for example, create a bootable USB drive containing A2.

Step 1 Create folder /WinAos/Test/ (the folder must be on same hierarchy level as the Work folder is)

Step 2 Include this folder in the WinAos search path by editing /WinAos/aos.ini (or myaos.ini if available)

[Configuration] Paths.Search = Work; [...] ;Test <-- add Test at the end of line (entries separated by semicolon)

Step 3 Now execute the following commands (also found in Build.Tool)

   # Compile all modules and generate ZIP files required by installer

   Release.Build -b --zip --xml --path=../Test/ A2 ~

   # Link boot image (boot from H.D.D.)

   Linker.Link \P../Test/ \.Obx ../Test/IDE.Bin 0100000H 1000H Kernel Traps
	ATADisks DiskVolumes DiskFS BootConsole ~

   # If you want to create a bootable USB drive, link the USB boot image...

   Linker.Link \P../Test/ \.Obx ../Test/USB.Bin 0100000H 1000H Kernel Traps
	UsbHubDriver UsbEhci UsbStorageBoot
	DiskVolumes DiskFS BootConsole ~

   # If you want to create a bootable USB drive, rename the USB boot image to the standard boot image IDE.Bin

   FSTools.CopyFiles -o ../Test/USB.Bin => ../Test/IDE.Bin ~

Step 4 Mount physical disk unter WinAos. Note: This requires WinAos to run with administrator privileges!

   WinDisks.Install "PhysicalDrive0" "RW" ~

   Note: Try PhysicalDrive0, PhysicalDrive1, PhysicalDrive2, ... until you have found the physical disk you want to install A2 onto.

Step 5 Start the Installer (Menu->System->Installer)

Step 6 Select the partition where you want to install A2 and proceed with installation

Step 7 Under WinAos, the device names are different. This makes it necessary to manually adapt the BootVol configuration string. Open the Partition Tool (Menu->Files->Partitions). Select the partition where you just have installed A2. Int the Partition Tool, go to Tab "A2" and click on "Config". Edit the BootVol configuration string.

When using the installer under WinAos, the BootVol string will look like:

BootVol1 = AOS AosFS PhysicalDrive0#1

The device names under A2 are IDE0, IDE1, ... for IDE H.D.D. and USB0, USB1, ... for USB mass storage devices. If A2 has been installed in the first partition of a USB device, the correct BootVol config string looks like:

BootVol1 = AOS AosFS USB0#1

Step 8 Make A2 partition bootable The Installer will neither install a MBR nor a boot manager. To be able to boot A2, you have to either install the A2 Boot Manager (Step 8.1) or a Master Boot Record (MBR, Step 8.2).

Step 8.1 A2 Boot Manager

IMPORTANT: The A2 boot manager will be installed in the MBR (sector 0) and therefore it will overwrite any other code there (other boot managers, MBR, ...).

Open the Partition Tool (Menu->Files->Partitions), select partition 0 from the device where A2 is installed (e.g. USB0#0). Go to the tab "A2" and press on Install BootManager (the files names in the popup window are right, just click on ok).

Step 8.2 Oberon MBR & Active Partition

To install the Master Boot Record (MBR), open the Partition Tool (Menu->Files->Partitions). Go to the tab "Partitions". Select the partition 0 of the disk device where you installed A2 and press on WriteMBR. The default settings of the dialog window are fine. The MBR contains some code that will be executed at boot up time. This code will locate the active partition on the respective drive, load its first sector (boot record, in our case the Oberon boot loader) and execute it. It is therefore necessary to set the active flag of the partition where A2 has been installed to. To set the active flag, selected the partition and press on "Activate".

Copyright © 2007 ETH Zürich
Page last modified on September 06, 2010, at 01:54 PM