sparc64 system bootstrapping procedures
When powered on, after a panic, or if the system is rebooted via
PROM will proceed to its initialization, and will boot an operating system if
autoboot is enabled.
The sparc64 boot process is split into two parts: a small first-stage bootblock
that is written into the superblock area of a partition (and hence is limited
in size to SBSIZE - DEV_BSIZE bytes), and a second-stage boot program that
resides in the filesystem proper. The first-stage bootblock is loaded into
memory by the PROM. After it receives control, it loads the second-stage boot
from the filesystem. The
second-stage boot program uses the device driver interface to the PROM and the
stand-alone filesystem code in libsa.a
and load the kernel. The first-stage bootblock and second-stage boot program
can be found in /usr/mdec/bootblk
respectively. The second-stage
boot program commonly resides in the root directory as
System boot blocks are installed using
which prepares an FFS filesystem partition for boot-strapping from the PROM.
The boot program attempts to load the kernel from the selected boot device,
which must currently be an SCSI (sd
) or IDE
) disk drive, or a CD-ROM
), or an SCSI tape drive
The UltraSPARC Open Firmware will normally look for a bootloader on the device
specified by the boot-device
bootloader will then look for a kernel named
by default, unless the
variable is set, or a different
filename has been specified in the boot command. To reset this variable to its
default, empty, value, type the following:
To boot from a
by default, boot-device
must be set to a disk
device hosting a chunk of the softraid volume:
must contain the
) device name of the softraid volume and
optionally a partition letter and/or kernel:
Autoboot is enabled by setting the auto-boot?
variable to “true”, and is the factory default.
The following options are recognized:
- Prompt for the root filesystem and swap devices after the
devices have been configured.
- Enter the “User Kernel Configuration” mode
upon startup (see
- Enter the debugger,
ddb(4), as soon as
the kernel console has been initialized.
- Boot the system single-user. The system will be booted
multi-user unless this option is specified.
If the sysctl(8)
is enabled, at any time
you can break back to the ROM by pressing the ‘L1’ (also known
as the “stop key”) and ‘a’ keys at the same time
(if the console is a serial port the same is achieved by sending a
“break”), and entering machine prom
at the prompt. If you do this accidentally you can continue whatever was in
progress by typing go
at the PROM prompt, and
to return to the system.
- default system kernel
- standalone installation kernel, suitable for disaster
- primary bootstrap for “ffs” file system
- secondary bootstrap (usually also installed as
- network bootstrap
- floppy disk bootstrap