not have VTOC information about the partitions, it will be created.
This is because the VTOC information is used for the partition type
and FreeBSD's sunlabel(8) does not create nor use VTOC information.
For this purpose, new tags have been added to support FreeBSD's
partition types.
partition table is empty, check to see if we have something that
looks sufficiently like a BPB. On non-i386 machines, the boot
sector typically doesn't contain boot code; the end of the boot
sector is all zeroes. This is also where the partition table is
for MBRs.
We only check the sector size and cluster size, as that seems to
be the most reliable across implementations, BPB versions and
platforms.
only because there's a partition table where the boot sector has
boot code. Boot sectors without boot code look like a MBR for all
practical purposes. This change adds a check for the partition table
and fails the probe when it's obvously invalid. The assumption being
that the sector contains a boot sector and not a MBR.
More checks are needed to distinguish a boot secto without boot code
from a (empty) MBR.
o BSD disklabels have relative offsets. Even for the BSD in MBR slice
setup, except when the mbroffset ioctl is supported. Since we don't
support that ioctl, bsdlabel(8) expects relative offsets. So, when
reading an existing disklabel, correct for disklabels that mistakenly
have the mbroffset offsets.
o Don't take the geometry seriously, because it's untrustworthy. We do
expect the numbers to be within range. This means that the secperunit
field will not be computed from secpercyl and ncyls, but simply is
the mediasize in sectors.
o Don't enforce partitions to be aligned to track boundaries. The
default label, constructed by bsdlabel(8), puts partition a at offset
BBSIZE bytes, which commonly means sector 16.
o Disklabels can have between 8 and 20 partitions (inclusive).
o No device special file is created for the raw partition.
o Switch ia64 to use this backend.
o No support for boot code yet.
on i386 and amd64 machines. The overall process is that /boot/pmbr lives
in the PMBR (similar to /boot/mbr for MBR disks) and is responsible for
locating and loading /boot/gptboot. /boot/gptboot is similar to /boot/boot
except that it groks GPT rather than MBR + bsdlabel. Unlike /boot/boot,
/boot/gptboot lives in its own dedicated GPT partition with a new
"FreeBSD boot" type. This partition does not have a fixed size in that
/boot/pmbr will load the entire partition into the lower 640k. However,
it is limited in that it can only be 545k. That's still a lot better than
the current 7.5k limit for boot2 on MBR. gptboot mostly acts just like
boot2 in that it reads /boot.config and loads up /boot/loader. Some more
details:
- Include uuid_equal() and uuid_is_nil() in libstand.
- Add a new 'boot' command to gpt(8) which makes a GPT disk bootable using
/boot/pmbr and /boot/gptboot. Note that the disk must have some free
space for the boot partition.
- This required exposing the backend of the 'add' function as a
gpt_add_part() function to the rest of gpt(8). 'boot' uses this to
create a boot partition if needed.
- Don't cripple cgbase() in the UFS boot code for /boot/gptboot so that
it can handle a filesystem > 1.5 TB.
- /boot/gptboot has a simple loader (gptldr) that doesn't do any I/O
unlike boot1 since /boot/pmbr loads all of gptboot up front. The
C portion of gptboot (gptboot.c) has been repocopied from boot2.c.
The primary changes are to parse the GPT to find a root filesystem
and to use 64-bit disk addresses. Currently gptboot assumes that the
first UFS partition on the disk is the / filesystem, but this algorithm
will likely be improved in the future.
- Teach the biosdisk driver in /boot/loader to understand GPT tables.
GPT partitions are identified as 'disk0pX:' (e.g. disk0p2:) which is
similar to the /dev names the kernel uses (e.g. /dev/ad0p2).
- Add a new "freebsd-boot" alias to g_part() for the new boot UUID.
MFC after: 1 month
Discussed with: marcel (some things might still change, but am committing
what I have so far)
don't have it. Some partitioning schemes, as well as file systems,
operate on the geometry and without it such schemes (e.g. MBR)
and file systems (e.g. FAT) can't be created. This is useful for
memory disks.
exists and contains the 'C' flag.
o The partition label can be the empty string. It's how labels are
cleared.
o When an action fails, lower permissions when they were raised
in order to allow the action. A failed action will not result
in any uncommitted changes.
o Allow the flags paremeter to be present but empty. It's the
equivalent of not being present.
119373: o Remove the query verb, along with the request and response
parameters.
o Add the version and output parameters.
119390: [APM,GPT] Properly clear deleted entries.
119394: o Make the alias the standard and use the '!' to prefix
literal partition types.
o Treat schemes and partition types as case insensitive.
119462: [GPT] Fix a page fault caused when modifying a partition entry
without a new partition type.
partitioning class that supports multiple schemes. Current
schemes supported are APM (Apple Partition Map) and GPT.
Change all GEOM_APPLE anf GEOM_GPT options into GEOM_PART_APM
and GEOM_PART_GPT (resp).
The ctlreq interface supports verbs to create and destroy
partitioning schemes on a disk; to add, delete and modify
partitions; and to commit or undo changes made.
