6. Additional

6.1 Boot manager bypass

In case the XOSL fails to boot, or crashes at a certain point, it is possible to bypass the entire boot manager. That is, the entire boot manager is loaded, but no initialization is preformed.

XOSL is bypassed by depressing both the left and the right Alt and Ctrl keys while the boot manager is loaded.

If loading or initialization of XOSL fails, the boot manager is automatically bypassed.

NOTE: Boot manager bypass is not yet password protected.

6.2 Booting Linux

Because XOSL cannot yet boot Linux directly, you need to have Lilo installed in either the boot record of a (Linux) partition, or in the master boot record of an HD other than the first.

6.2.1 Booting single-kernel Linux systems

As you will notice, when Linux is booted, the Lilo-prompt is still shown. The simplest way to bypass this prompt, and make XOSL boot Linux directly, is to edit the /etc/lilo.conf file, and comment or remove the æprompt' line. Now the Lilo prompt will not be shown anymore, and the first item will be booted directly.

6.2.2 Booting multi-kernel Linux systems

By default, Lilo will drain the keyboard buffer on start-up. This way it will not be possible to let XOSL control Lilo through the Additional Keys feature. To make XOSL control Lilo, you have to re-compile Lilo, with NODRAIN defined. This can be done as following:

Edit the Makefile and find the CONFIG line. This line will look something like:
CONFIG=-DIGNORECASE -DVARSETUP -DREWRITE_TABLE
Add -DNODRAIN to the CONFIG line.
Execute æmake'
Replace the existing boot.b (most likely located in /boot/) with the new one.
Execute ælilo'

If, for instance, you have two options defined in /etc/lilo.conf: LinuxNew and LinuxOld, you can now make XOSL boot these options by defining as additional keys: L.i.n.u.x.N.e.w.ret and L.i.n.u.x.O.l.d.ret respectively.

NOTE: make sure æprompt' is present in /etc/lilo.conf, or else the first item will be automatically booted.

NOTE: this solution of course also works for a single-kernel system.

6.2.3 Multiple Linux distributions

When you have more than one distribution of Linux installed, one of the following two approaches can be used to boot Linux:

An installation of Lilo per partition/distribution (refer to single-kernel Linux systems)
One installation of Lilo, controlling all distributions (refer to multi-kernel Linux systems)

6.3 Booting MS-DOS/Windows 9x off the second hard disk

Normally you can only boot a Microsoft OS if it is install on the first HD. This XOSL it is possible to boot MS-DOS or Windows 9x off a HD other than the first.

6.3.1 Background and solution

In the boot record (first sector of the partition) of a FAT file system, an entry exists which holds the drive number. By default the Microsoft format utility sets this to 0x80 (128 decimal). Even if this partition is on the second HD, it is still 0x80 (instead of 0x81 or 129). This prevents booting a Microsoft OS off the second HD.

XOSL solves this problem by fixing the drive number. So if the partition is on the second drive, the drive number entry is set to 0x81. XOSL does not update the boot record on the disk. Instead, after loading the boot record, and before executing it (booting), the drive number is set to the correct value, and MS-DOS/Windows 9x is booted correctly.

6.3.2 Implementation the solution

To boot MS-DOS or Windows 9x installed on the second HD, the following actions need to be performed after adding the boot item

Check the Fix FAT drive number check box at Setup/Misc (checked automatically)
Hide all FAT partitions on the first HD. It is mandatory you do this, or else booting will still fail.

NOTE: if you have installed Windows NT on a FAT partition on the second drive, it should be possible to boot it with XOSL, after performing the above actions. However, this is an assumption. It is not actually tested. Note that you will also have to hide all NTFS partitions on your first drive.

6.4 Installing XOSL together with other boot managers

XOSL provides the unique ability to coexist with virtually any other boot manager. Two approaches exist to have XOSL installed together with some other boot manager.

6.4.1 XOSL as primary boot loader

When you install XOSL 1.1.2, it will backup the original Master Boot Record (MBR). In addition, XOSL provides the ability to boot this original MBR. It is shown as Original MBR, the first entry of any partition list. The original MBR is either a default loader (as after fdisk /mbr), or some boot loader that was installed before XOSL got installed.

XOSL does not backup the original MBR on the first (unused) track of your hard disk (as does XOSL 1.1.0), because that might overwrite some other boot manager that got installed there. Instead, it is copied to a file (ORIG_MBR.XCF).

Finally, XOSL will restore the partition table (as found in the MBR) for this original MBR, thus the original loader will always find the correct partition data.

6.4.2 XOSL as secondary boot loader

If you install XOSL on a dedicated partition, you can also boot this partition, which will start XOSL. This way you can use XOSL as secondary boot loader instead: use some other boot manager to boot the XOSL partition.

6.4.3 Additional notes

Some boot managers completely hide partitions, instead of just changing the file system Id. If you use such a boot manager as secondary boot loader, XOSL will still run, even if its partition is completely hidden. If a partition of a boot item is completely hidden from XOSL, it will be disabled automatically. However, if it is restore again (by the other boot loader), you have to enable the boot item manually.

6.5 Unconfirmed hints [new]

This section provides several hints of untested features or hints of users, all of which I either could not get or do not have a confirmation.

6.5.1 XOSL and GoBack

GoBack is a Windows utility which provides the ability to completely undo any changes. For instance, completely uninstall an application, restore documents, etc. The first part of GoBack resides in the Master Boot Record, which means it does not allow you to have a boot manager installed (at least the current version does not). XOSL however provides the ability to coexist with virtually any other boot manager. This should also include GoBack. Refer to section 6.4.1 for details.

GoBack: http://www.goback.com

6.5.2 Booting BeOS

It seems that XOSL cannot directly boot BeOS. However, if you have first installed the BeOS Bootman, XOSL can boot it (even though Bootman is overwritten). The reason seems to be that both Bootman and XOSL require that zbeos is installed on the BeOS partition. When you install Bootman, zbeos is automatically installed and can be executed by booting the boot record of the BeOS partition. So if you first install the BeOS Bootman, and then XOSL, XOSL will be able to boot the BeOS partition directly.

The above assumption is made on to the fact that according to some online FAQ, Lilo also has to execute zbeos in order to get BeOS booted.

6.5.3 Install and the Japanese MS-DOS

In order to successfully use the XOSL Install Utility from the Japanese MS-DOS, first execute æus' and then æinstall'.