Document recently added GPT attributes (bootme, bootonce, bootfailed) and

list other schemes attributes.

Reviewed by:	simon, rpaulo
MFC after:	2 weeks
This commit is contained in:
Pawel Jakub Dawidek 2010-09-28 09:07:00 +00:00
parent bbb64c2143
commit 15d98d9738
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=213245

View File

@ -24,7 +24,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd Sep 24, 2010
.Dd September 28, 2010
.Dt GPART 8
.Os
.Sh NAME
@ -382,6 +382,9 @@ about its use.
.\" ==== SET ====
.It Cm set
Set the named attribute on the partition entry.
See the section entitled
.Sx "ATTRIBUTES"
below for a list of available attributes.
.Pp
Additional options include:
.Bl -tag -width 10n
@ -406,6 +409,9 @@ action and can be used to undo any changes that have not been committed.
.\" ==== UNSET ====
.It Cm unset
Clear the named attribute on the partition entry.
See the section entitled
.Sx "ATTRIBUTES"
below for a list of available attributes.
.Pp
Additional options include:
.Bl -tag -width 10n
@ -502,6 +508,103 @@ This type is known as
.Qq Li "!024dee41-33e7-11d3-9d69-0008c781f39f"
by GPT.
.El
.Sh ATTRIBUTES
The scheme-specific attributes for EBR:
.Bl -tag -width ".Ar active"
.It Ar active
.El
.Pp
The scheme-specific attributes for GPT:
.Bl -tag -width ".Ar bootfailed"
.It Ar bootme
When set, the
.Nm gptboot
stage 1 boot loader will try to boot the system from this partition.
Multiple partitions might be marked with the
.Ar bootme
attribute.
In such scenario the
.Nm gptboot
will try all
.Ar bootme
partitions one by one, until the next boot stage is successfully entered.
.It Ar bootonce
Setting this attribute automatically sets the
.Ar bootme
attribute.
When set, the
.Nm gptboot
stage 1 boot loader will try to boot the system from this partition only once.
Partitions with both
.Ar bootonce
and
.Ar bootme
attributes are tried before partitions with only the
.Ar bootme
attribute.
Before
.Ar bootonce
partition is tried, the
.Nm gptboot
removes the
.Ar bootme
attribute and tries to execute the next boot stage.
If it fails, the
.Ar bootonce
attribute that is now alone is replaced with the
.Ar bootfailed
attribute.
If the execution of the next boot stage succeeds, but the system is not fully
booted, the
.Nm gptboot
will look for
.Ar bootonce
attributes alone (without the
.Ar bootme
attribute) on the next system boot and will replace those with the
.Ar bootfailed
attribute.
If the system is fully booted, the
.Pa /etc/rc.d/gptboot
start-up script will look for partition with the
.Ar bootonce
attribute alone, will remove the attribute and log that the system was
successfully booted from this partition.
There should be at most one
.Ar bootonce
partition when system is successfully booted.
Multiple partitions might be marked with the
.Ar bootonce
and
.Ar bootme
attribute pairs.
.It Ar bootfailed
This attribute should not be manually managed.
It is managed by the
.Nm gptboot
stage 1 boot loader and the
.Pa /etc/rc.d/gptboot
start-up script.
This attribute is used to mark partitions that had the
.Ar bootonce
attribute set, but we failed to boot from them.
Once we successfully boot, the
.Pa /etc/rc.d/gptboot
script will log all the partitions we failed to boot from and will remove the
.Ar bootfailed
attributes.
.El
.Pp
The scheme-specific attributes for MBR:
.Bl -tag -width ".Ar active"
.It Ar active
.El
.Pp
The scheme-specific attributes for PC98:
.Bl -tag -width ".Ar bootable"
.It Ar active
.It Ar bootable
.El
.Sh OPERATIONAL FLAGS
Actions other than the
.Cm commit