path: root/sys/sys/gpt.h
diff options
authorJohn Baldwin <jhb@FreeBSD.org>2007-10-24 21:33:00 +0000
committerJohn Baldwin <jhb@FreeBSD.org>2007-10-24 21:33:00 +0000
commitf352a0d45f6b081b5b551de6b9734f513a358fae (patch)
tree2e0ad7e3920a2c896b216cf32db1db922c1f0e29 /sys/sys/gpt.h
parente0f5da6d08207c2148e3fc47e301db60dd3e93a5 (diff)
First cut at support for booting a GPT labeled disk via the BIOS bootstrap
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)
Notes: svn path=/head/; revision=172940
Diffstat (limited to 'sys/sys/gpt.h')
1 files changed, 3 insertions, 1 deletions
diff --git a/sys/sys/gpt.h b/sys/sys/gpt.h
index 0c5fb061c79a..2afd4f2f3196 100644
--- a/sys/sys/gpt.h
+++ b/sys/sys/gpt.h
@@ -84,6 +84,8 @@ struct gpt_ent {
+ {0x83bd6b9d,0x7f41,0x11dc,0xbe,0x0b,{0x00,0x15,0x60,0xb8,0x4f,0x0f}}
* The following are unused but documented here to avoid reuse.
@@ -95,7 +97,7 @@ struct gpt_ent {
* Foreign partition types that we're likely to encounter. Note that Linux
* apparently choose to share data partitions with MS. I don't what the
- * advantage might be. I can see how sharing swap partitions is advantaous
+ * advantage might be. I can see how sharing swap partitions is advantageous
* though.