DEFAULT_APPEND / FAILSAFE_APPEND / XEN_KERNEL_APPEND
Kernel parameters (other than vga) that are automatically appended to the default,
failsafe and XEN boot entries in the bootloader conguration le.
CYCLE_DETECTION / CYCLE_NEXT_ENTRY
Congure whether to use boot cycle detection and if so, which alternative boot
entry from to boot in case of a reboot cycle (e.g. Failsafe). See /usr/share/
doc/packages/bootcycle/README for detailed information.
10.2.5 Mapping between BIOS drives and
Linux devices
In GRUB Legacy, the device.map conguration le was used to derive Linux device
names from BIOS drive numbers. The map between BIOS drives and Linux devices
cannot always be guessed correctly: for example, GRUB will get the order wrong if
you exchange the boot sequence between IDE and SCSI in your BIOS.
GRUB2 avoids this problem by using device ID strings (UUIDs) or le system labels
when generating grub.cfg. GRUB2 utilities create a temporary device map on the
y, which is usually sufcient, particularly in the case of single-disk systems.
However, if you need to override the GRUB2's automatic device mapping mechanism,
create your custom mapping le /boot/grub2/device.map similarly as in GRUB
Legacy (see Section 9.1.2, “The File device.map” (page 162) for more details). Please
note that GRUB2 partition number start at 1 and not at 0 as in GRUB Legacy.
10.2.6 Editing Menu Entries during the Boot
Procedure
Editing menu entries facilitates the repair of a defective system that can no longer be
booted, because the faulty conguration le of the boot loader can be circumvented by
manually entering parameters. Manually entering parameters during the boot procedure
is also useful for testing new settings without impairing the native system.
In the graphical boot menu, select the operating system to boot with the arrow keys. If
you select a Linux system, you can enter additional boot parameters at the boot prompt.
184 Reference
