Add a version of the FreeBSD bootloader which can run in userland, packaged

as a shared library. This is intended to be used by BHyVe to load FreeBSD
kernels into new virtual machines.

5 files changed, 890 insertions, 3 deletions

diff --git a/sys/boot/common/Makefile.inc b/sys/boot/common/Makefile.inc
index be6c3301..ad9535c 100644
--- a/sys/boot/common/Makefile.inc
+++ b/sys/boot/common/Makefile.inc
@@ -1,6 +1,6 @@
 # $FreeBSD$
 
-SRCS+=	boot.c commands.c console.c devopen.c interp.c 
+SRCS+=	boot.c commands.c console.c devopen.c disk.c interp.c 
 SRCS+=	interp_backslash.c interp_parse.c ls.c misc.c 
 SRCS+=	module.c panic.c
 
diff --git a/sys/boot/common/disk.c b/sys/boot/common/disk.c
new file mode 100644
index 0000000..40dbc8a
--- /dev/null
+++ b/sys/boot/common/disk.c
@@ -0,0 +1,788 @@
+/*-
+ * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * MBR/GPT partitioned disk device handling.
+ *
+ * Ideas and algorithms from:
+ *
+ * - NetBSD libi386/biosdisk.c
+ * - FreeBSD biosboot/disk.c
+ *
+ */
+
+#include <stand.h>
+
+#include <sys/diskmbr.h>
+#include <sys/disklabel.h>
+#include <sys/gpt.h>
+
+#include <stdarg.h>
+#include <uuid.h>
+
+#include <bootstrap.h>
+
+#include "disk.h"
+
+#ifdef DISK_DEBUG
+# define DEBUG(fmt, args...)	printf("%s: " fmt "\n" , __func__ , ## args)
+#else
+# define DEBUG(fmt, args...)
+#endif
+
+/*
+ * Search for a slice with the following preferences:
+ *
+ * 1: Active FreeBSD slice
+ * 2: Non-active FreeBSD slice
+ * 3: Active Linux slice
+ * 4: non-active Linux slice
+ * 5: Active FAT/FAT32 slice
+ * 6: non-active FAT/FAT32 slice
+ */
+#define PREF_RAWDISK	0
+#define PREF_FBSD_ACT	1
+#define PREF_FBSD	2
+#define PREF_LINUX_ACT	3
+#define PREF_LINUX	4
+#define PREF_DOS_ACT	5
+#define PREF_DOS	6
+#define PREF_NONE	7
+
+#ifdef LOADER_GPT_SUPPORT
+
+struct gpt_part {
+	int		gp_index;
+	uuid_t		gp_type;
+	uint64_t	gp_start;
+	uint64_t	gp_end;
+};
+
+static uuid_t efi = GPT_ENT_TYPE_EFI;
+static uuid_t freebsd_boot = GPT_ENT_TYPE_FREEBSD_BOOT;
+static uuid_t freebsd_ufs = GPT_ENT_TYPE_FREEBSD_UFS;
+static uuid_t freebsd_swap = GPT_ENT_TYPE_FREEBSD_SWAP;
+static uuid_t freebsd_zfs = GPT_ENT_TYPE_FREEBSD_ZFS;
+static uuid_t ms_basic_data = GPT_ENT_TYPE_MS_BASIC_DATA;
+
+#endif
+
+/* Given a size in 512 byte sectors, convert it to a human-readable number. */
+static char *
+display_size(uint64_t size)
+{
+	static char buf[80];
+	char unit;
+
+	size /= 2;
+	unit = 'K';
+	if (size >= 10485760000LL) {
+		size /= 1073741824;
+		unit = 'T';
+	} else if (size >= 10240000) {
+		size /= 1048576;
+		unit = 'G';
+	} else if (size >= 10000) {
+		size /= 1024;
+		unit = 'M';
+	}
+	sprintf(buf, "%.6ld%cB", (long)size, unit);
+	return (buf);
+}
+
+static void
+disk_checkextended(struct disk_devdesc *dev,
+    struct dos_partition *slicetab, int slicenum, int *nslicesp)
+{
+	uint8_t			buf[DISK_SECSIZE];
+	struct dos_partition	*dp;
+	uint32_t		base;
+	int			rc, i, start, end;
+
+	dp = &slicetab[slicenum];
+	start = *nslicesp;
+
+	if (dp->dp_size == 0)
+		goto done;
+	if (dp->dp_typ != DOSPTYP_EXT)
+		goto done;
+	rc = dev->d_dev->dv_strategy(dev, F_READ, dp->dp_start, DISK_SECSIZE,
+		(char *) buf, NULL);
+	if (rc)
+		goto done;
+	if (buf[0x1fe] != 0x55 || buf[0x1ff] != 0xaa) {
+		DEBUG("no magic in extended table");
+		goto done;
+	}
+	base = dp->dp_start;
+	dp = (struct dos_partition *) &buf[DOSPARTOFF];
+	for (i = 0; i < NDOSPART; i++, dp++) {
+		if (dp->dp_size == 0)
+			continue;
+		if (*nslicesp == NEXTDOSPART)
+			goto done;
+		dp->dp_start += base;
+		bcopy(dp, &slicetab[*nslicesp], sizeof(*dp));
+		(*nslicesp)++;
+	}
+	end = *nslicesp;
+
+	/*
+	 * now, recursively check the slices we just added
+	 */
+	for (i = start; i < end; i++)
+		disk_checkextended(dev, slicetab, i, nslicesp);
+done:
+	return;
+}
+
+static int
+disk_readslicetab(struct disk_devdesc *dev,
+    struct dos_partition **slicetabp, int *nslicesp)
+{
+	struct dos_partition	*slicetab = NULL;
+	int			nslices, i;
+	int			rc;
+	uint8_t			buf[DISK_SECSIZE];
+
+	/*
+	 * Find the slice in the DOS slice table.
+	 */
+	rc = dev->d_dev->dv_strategy(dev, F_READ, 0, DISK_SECSIZE,
+		(char *) buf, NULL);
+	if (rc) {
+		DEBUG("error reading MBR");
+		return (rc);
+	}
+
+	/*
+	 * Check the slice table magic.
+	 */
+	if (buf[0x1fe] != 0x55 || buf[0x1ff] != 0xaa) {
+		DEBUG("no slice table/MBR (no magic)");
+		return (rc);
+	}
+
+	/*
+	 * copy the partition table, then pick up any extended partitions.
+	 */
+	slicetab = malloc(NEXTDOSPART * sizeof(struct dos_partition));
+	bcopy(buf + DOSPARTOFF, slicetab,
+		sizeof(struct dos_partition) * NDOSPART);
+	nslices = NDOSPART;		/* extended slices start here */
+	for (i = 0; i < NDOSPART; i++)
+		disk_checkextended(dev, slicetab, i, &nslices);
+
+	*slicetabp = slicetab;
+	*nslicesp = nslices;
+	return (0);
+}
+
+/*
+ * Search for the best MBR slice (typically the first FreeBSD slice).
+ */
+static int
+disk_bestslice(struct dos_partition *slicetab, int nslices)
+{
+	struct dos_partition *dp;
+	int pref, preflevel;
+	int i, prefslice;
+
+	prefslice = 0;
+	preflevel = PREF_NONE;
+
+	dp = &slicetab[0];
+	for (i = 0; i < nslices; i++, dp++) {
+		switch (dp->dp_typ) {
+		case DOSPTYP_386BSD:		/* FreeBSD */
+			pref = dp->dp_flag & 0x80 ? PREF_FBSD_ACT : PREF_FBSD;
+			break;
+
+		case DOSPTYP_LINUX:
+			pref = dp->dp_flag & 0x80 ? PREF_LINUX_ACT : PREF_LINUX;
+			break;
+
+		case 0x01:		/* DOS/Windows */
+		case 0x04:
+		case 0x06:
+		case 0x0b:
+		case 0x0c:
+		case 0x0e:
+			pref = dp->dp_flag & 0x80 ? PREF_DOS_ACT : PREF_DOS;
+			break;
+
+		default:
+		        pref = PREF_NONE;
+		}
+		if (pref < preflevel) {
+			preflevel = pref;
+			prefslice = i + 1;
+		}
+	}
+	return (prefslice);
+}
+
+static int
+disk_openmbr(struct disk_devdesc *dev)
+{
+	struct dos_partition	*slicetab = NULL, *dptr;
+	int			nslices, sector, slice;
+	int			rc;
+	uint8_t			buf[DISK_SECSIZE];
+	struct disklabel	*lp;
+
+	/*
+	 * Following calculations attempt to determine the correct value
+	 * for dev->d_offset by looking for the slice and partition specified,
+	 * or searching for reasonable defaults.
+	 */
+	rc = disk_readslicetab(dev, &slicetab, &nslices);
+	if (rc)
+		return (rc);
+
+	/*
+	 * if a slice number was supplied but not found, this is an error.
+	 */
+	if (dev->d_slice > 0) {
+		slice = dev->d_slice - 1;
+		if (slice >= nslices) {
+			DEBUG("slice %d not found", slice);
+			rc = EPART;
+			goto out;
+		}
+	}
+
+	/*
+	 * Check for the historically bogus MBR found on true dedicated disks
+	 */
+	if (slicetab[3].dp_typ == DOSPTYP_386BSD &&
+	    slicetab[3].dp_start == 0 && slicetab[3].dp_size == 50000) {
+		sector = 0;
+		goto unsliced;
+	}
+
+	/*
+	 * Try to auto-detect the best slice; this should always give
+	 * a slice number
+	 */
+	if (dev->d_slice == 0) {
+		slice = disk_bestslice(slicetab, nslices);
+		if (slice == -1) {
+			rc = ENOENT;
+			goto out;
+		}
+		dev->d_slice = slice;
+	}
+
+	/*
+	 * Accept the supplied slice number unequivocally (we may be looking
+	 * at a DOS partition).
+	 * Note: we number 1-4, offsets are 0-3
+	 */
+	dptr = &slicetab[dev->d_slice - 1];
+	sector = dptr->dp_start;
+	DEBUG("slice entry %d at %d, %d sectors",
+		dev->d_slice - 1, sector, dptr->dp_size);
+
+unsliced:
+	/*
+	 * Now we have the slice offset, look for the partition in the
+	 * disklabel if we have a partition to start with.
+	 *
+	 * XXX we might want to check the label checksum.
+	 */
+	if (dev->d_partition < 0) {
+		/* no partition, must be after the slice */
+		DEBUG("opening raw slice");
+		dev->d_offset = sector;
+		rc = 0;
+		goto out;
+	}
+
+	rc = dev->d_dev->dv_strategy(dev, F_READ, sector + LABELSECTOR,
+            DISK_SECSIZE, (char *) buf, NULL);
+	if (rc) {
+		DEBUG("error reading disklabel");
+		goto out;
+	}
+
+	lp = (struct disklabel *) buf;
+
+	if (lp->d_magic != DISKMAGIC) {
+		DEBUG("no disklabel");
+		rc = ENOENT;
+		goto out;
+	}
+	if (dev->d_partition >= lp->d_npartitions) {
+		DEBUG("partition '%c' exceeds partitions in table (a-'%c')",
+		  'a' + dev->d_partition,
+		  'a' + lp->d_npartitions);
+		rc = EPART;
+		goto out;
+	}
+
+	dev->d_offset =
+		lp->d_partitions[dev->d_partition].p_offset -
+		lp->d_partitions[RAW_PART].p_offset +
+		sector;
+	rc = 0;
+
+out:
+	if (slicetab)
+		free(slicetab);
+	return (rc);
+}
+
+/*
+ * Print out each valid partition in the disklabel of a FreeBSD slice.
+ * For size calculations, we assume a 512 byte sector size.
+ */
+static void
+disk_printbsdslice(struct disk_devdesc *dev, daddr_t offset,
+    char *prefix, int verbose)
+{
+	char			line[80];
+	char			buf[DISK_SECSIZE];
+	struct disklabel	*lp;
+	int			i, rc, fstype;
+
+	/* read disklabel */
+	rc = dev->d_dev->dv_strategy(dev, F_READ, offset + LABELSECTOR,
+		DISK_SECSIZE, (char *) buf, NULL);
+	if (rc)
+		return;
+	lp =(struct disklabel *)(&buf[0]);
+	if (lp->d_magic != DISKMAGIC) {
+		sprintf(line, "%s: FFS  bad disklabel\n", prefix);
+		pager_output(line);
+		return;
+	}
+
+	/* Print partitions */
+	for (i = 0; i < lp->d_npartitions; i++) {
+		/*
+		 * For each partition, make sure we know what type of fs it
+		 * is.  If not, then skip it.
+		 */
+		fstype = lp->d_partitions[i].p_fstype;
+		if (fstype != FS_BSDFFS &&
+		    fstype != FS_SWAP &&
+		    fstype != FS_VINUM)
+			continue;
+
+		/* Only print out statistics in verbose mode */
+		if (verbose)
+			sprintf(line, "  %s%c: %s %s (%d - %d)\n",
+				prefix, 'a' + i,
+			    (fstype == FS_SWAP) ? "swap " :
+			    (fstype == FS_VINUM) ? "vinum" :
+			    "FFS  ",
+			    display_size(lp->d_partitions[i].p_size),
+			    lp->d_partitions[i].p_offset,
+			    (lp->d_partitions[i].p_offset
+			     + lp->d_partitions[i].p_size));
+		else
+			sprintf(line, "  %s%c: %s\n", prefix, 'a' + i,
+			    (fstype == FS_SWAP) ? "swap" :
+			    (fstype == FS_VINUM) ? "vinum" :
+			    "FFS");
+		pager_output(line);
+	}
+}
+
+static void
+disk_printslice(struct disk_devdesc *dev, int slice,
+    struct dos_partition *dp, char *prefix, int verbose)
+{
+	char stats[80];
+	char line[80];
+
+	if (verbose)
+		sprintf(stats, " %s (%d - %d)", display_size(dp->dp_size),
+		    dp->dp_start, dp->dp_start + dp->dp_size);
+	else
+		stats[0] = '\0';
+
+	switch (dp->dp_typ) {
+	case DOSPTYP_386BSD:
+		disk_printbsdslice(dev, (daddr_t)dp->dp_start,
+		     prefix, verbose);
+		return;
+	case DOSPTYP_LINSWP:
+		sprintf(line, "%s: Linux swap%s\n", prefix, stats);
+		break;
+	case DOSPTYP_LINUX:
+		/*
+		 * XXX
+		 * read the superblock to confirm this is an ext2fs partition?
+		 */
+		sprintf(line, "%s: ext2fs%s\n", prefix, stats);
+		break;
+	case 0x00:				/* unused partition */
+	case DOSPTYP_EXT:
+		return;
+	case 0x01:
+		sprintf(line, "%s: FAT-12%s\n", prefix, stats);
+		break;
+	case 0x04:
+	case 0x06:
+	case 0x0e:
+		sprintf(line, "%s: FAT-16%s\n", prefix, stats);
+		break;
+	case 0x07:
+		sprintf(line, "%s: NTFS/HPFS%s\n", prefix, stats);
+		break;
+	case 0x0b:
+	case 0x0c:
+		sprintf(line, "%s: FAT-32%s\n", prefix, stats);
+		break;
+	default:
+		sprintf(line, "%s: Unknown fs: 0x%x %s\n", prefix, dp->dp_typ,
+		    stats);
+	}
+	pager_output(line);
+}
+
+int
+disk_printmbr(struct disk_devdesc *dev, char *prefix, int verbose)
+{
+	struct dos_partition	*slicetab;
+	int			nslices, i;
+	int			rc;
+	char			line[80];
+
+	rc = disk_readslicetab(dev, &slicetab, &nslices);
+	if (rc)
+		return (rc);
+	for (i = 0; i < nslices; i++) {
+		sprintf(line, "%ss%d", prefix, i + 1);
+		disk_printslice(dev, i, &slicetab[i], line, verbose);
+	}
+	free(slicetab);
+	return (0);
+}
+
+#ifdef LOADER_GPT_SUPPORT
+
+static int
+disk_readgpt(struct disk_devdesc *dev, struct gpt_part **gptp, int *ngptp)
+{
+	struct dos_partition	*dp;
+	struct gpt_hdr		*hdr;
+	struct gpt_ent		*ent;
+	struct gpt_part		*gptab = NULL;
+	int			entries_per_sec, rc, i, part;
+	daddr_t			lba, elba;
+	uint8_t			gpt[DISK_SECSIZE], tbl[DISK_SECSIZE];
+
+	/*
+	 * Following calculations attempt to determine the correct value
+	 * for dev->d_offset by looking for the slice and partition specified,
+	 * or searching for reasonable defaults.
+	 */
+	rc = 0;
+
+	/* First, read the MBR and see if we have a PMBR. */
+	rc = dev->d_dev->dv_strategy(dev, F_READ, 0, DISK_SECSIZE,
+		(char *) tbl, NULL);
+	if (rc) {
+		DEBUG("error reading MBR");
+		return (EIO);
+	}
+
+	/* Check the slice table magic. */
+	if (tbl[0x1fe] != 0x55 || tbl[0x1ff] != 0xaa)
+		return (ENXIO);
+
+	/* Check for GPT slice. */
+	part = 0;
+	dp = (struct dos_partition *)(tbl + DOSPARTOFF);
+	for (i = 0; i < NDOSPART; i++) {
+		if (dp[i].dp_typ == 0xee)
+			part++;
+		else if ((part != 1) && (dp[i].dp_typ != 0x00))
+			return (EINVAL);
+	}
+	if (part != 1)
+		return (EINVAL);
+
+	/* Read primary GPT table header. */
+	rc = dev->d_dev->dv_strategy(dev, F_READ, 1, DISK_SECSIZE,
+		(char *) gpt, NULL);
+	if (rc) {
+		DEBUG("error reading GPT header");
+		return (EIO);
+	}
+	hdr = (struct gpt_hdr *)gpt;
+	if (bcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)) != 0 ||
+	    hdr->hdr_lba_self != 1 || hdr->hdr_revision < 0x00010000 ||
+	    hdr->hdr_entsz < sizeof(*ent) ||
+	    DISK_SECSIZE % hdr->hdr_entsz != 0) {
+		DEBUG("Invalid GPT header\n");
+		return (EINVAL);
+	}
+
+	/* Walk the partition table to count valid partitions. */
+	part = 0;
+	entries_per_sec = DISK_SECSIZE / hdr->hdr_entsz;
+	elba = hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec;
+	for (lba = hdr->hdr_lba_table; lba < elba; lba++) {
+		rc = dev->d_dev->dv_strategy(dev, F_READ, lba, DISK_SECSIZE,
+			(char *) tbl, NULL);
+		if (rc) {
+			DEBUG("error reading GPT table");
+			return (EIO);
+		}
+		for (i = 0; i < entries_per_sec; i++) {
+			ent = (struct gpt_ent *)(tbl + i * hdr->hdr_entsz);
+			if (uuid_is_nil(&ent->ent_type, NULL) ||
+			    ent->ent_lba_start == 0 ||
+			    ent->ent_lba_end < ent->ent_lba_start)
+				continue;
+			part++;
+		}
+	}
+
+	/* Save the important information about all the valid partitions. */
+	if (part != 0) {
+		gptab = malloc(part * sizeof(struct gpt_part));
+		part = 0;
+		for (lba = hdr->hdr_lba_table; lba < elba; lba++) {
+			rc = dev->d_dev->dv_strategy(dev, F_READ, lba, DISK_SECSIZE,
+				(char *) tbl, NULL);
+			if (rc) {
+				DEBUG("error reading GPT table");
+				free(gptab);
+				return (EIO);
+			}
+			for (i = 0; i < entries_per_sec; i++) {
+				ent = (struct gpt_ent *)(tbl + i * hdr->hdr_entsz);
+				if (uuid_is_nil(&ent->ent_type, NULL) ||
+				    ent->ent_lba_start == 0 ||
+				    ent->ent_lba_end < ent->ent_lba_start)
+					continue;
+				gptab[part].gp_index = (lba - hdr->hdr_lba_table) *
+					entries_per_sec + i + 1;
+				gptab[part].gp_type = ent->ent_type;
+				gptab[part].gp_start = ent->ent_lba_start;
+				gptab[part].gp_end = ent->ent_lba_end;
+				part++;
+			}
+		}
+	}
+
+	*gptp = gptab;
+	*ngptp = part;
+	return (0);
+}
+
+static struct gpt_part *
+disk_bestgpt(struct gpt_part *gpt, int ngpt)
+{
+	struct gpt_part *gp, *prefpart;
+	int i, pref, preflevel;
+
+	prefpart = NULL;
+	preflevel = PREF_NONE;
+
+	gp = gpt;
+	for (i = 0; i < ngpt; i++, gp++) {
+		/* Windows. XXX: Also Linux. */
+		if (uuid_equal(&gp->gp_type, &ms_basic_data, NULL))
+			pref = PREF_DOS;
+		/* FreeBSD */
+		else if (uuid_equal(&gp->gp_type, &freebsd_ufs, NULL) ||
+		         uuid_equal(&gp->gp_type, &freebsd_zfs, NULL))
+			pref = PREF_FBSD;
+		else
+			pref = PREF_NONE;
+		if (pref < preflevel) {
+			preflevel = pref;
+			prefpart = gp;
+		}
+	}
+	return (prefpart);
+}
+
+int
+disk_opengpt(struct disk_devdesc *dev)
+{
+	struct gpt_part		*gpt = NULL, *gp;
+	int			rc, ngpt, i;
+
+	rc = disk_readgpt(dev, &gpt, &ngpt);
+	if (rc)
+		return (rc);
+
+	/* Is this a request for the whole disk? */
+	if (dev->d_slice < 0) {
+		dev->d_offset = 0;
+		rc = 0;
+		goto out;
+	}
+
+	/*
+	 * If a partition number was supplied, then the user is trying to use
+	 * an MBR address rather than a GPT address, so fail.
+	 */
+	if (dev->d_partition != 0xff) {
+		rc = ENOENT;
+		goto out;
+	}
+
+	/* If a slice number was supplied but not found, this is an error. */
+	gp = NULL;
+	if (dev->d_slice > 0) {
+		for (i = 0; i < ngpt; i++) {
+			if (gpt[i].gp_index == dev->d_slice) {
+				gp = &gpt[i];
+				break;
+			}
+		}
+		if (gp == NULL) {
+			DEBUG("partition %d not found", dev->d_slice);
+			rc = ENOENT;
+			goto out;
+		}
+	}
+
+	/* Try to auto-detect the best partition. */
+	if (dev->d_slice == 0) {
+		gp = disk_bestgpt(gpt, ngpt);
+		if (gp == NULL) {
+			rc = ENOENT;
+			goto out;
+		}
+		dev->d_slice = gp->gp_index;
+	}
+
+	dev->d_offset = gp->gp_start;
+	rc = 0;
+
+out:
+	if (gpt)
+		free(gpt);
+	return (rc);
+}
+
+static void
+disk_printgptpart(struct disk_devdesc *dev, struct gpt_part *gp,
+    char *prefix, int verbose)
+{
+	char stats[80];
+	char line[96];
+
+	if (verbose)
+		sprintf(stats, " %s",
+			display_size(gp->gp_end + 1 - gp->gp_start));
+	else
+		stats[0] = '\0';
+
+	if (uuid_equal(&gp->gp_type, &efi, NULL))
+		sprintf(line, "%s: EFI         %s\n", prefix, stats);
+	else if (uuid_equal(&gp->gp_type, &ms_basic_data, NULL))
+		sprintf(line, "%s: FAT/NTFS    %s\n", prefix, stats);
+	else if (uuid_equal(&gp->gp_type, &freebsd_boot, NULL))
+		sprintf(line, "%s: FreeBSD boot%s\n", prefix, stats);
+	else if (uuid_equal(&gp->gp_type, &freebsd_ufs, NULL))
+		sprintf(line, "%s: FreeBSD UFS %s\n", prefix, stats);
+	else if (uuid_equal(&gp->gp_type, &freebsd_zfs, NULL))
+		sprintf(line, "%s: FreeBSD ZFS %s\n", prefix, stats);
+	else if (uuid_equal(&gp->gp_type, &freebsd_swap, NULL))
+		sprintf(line, "%s: FreeBSD swap%s\n", prefix, stats);
+	else
+		sprintf(line,
+		    "%s: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x%s\n",
+		    prefix,
+		    gp->gp_type.time_low, gp->gp_type.time_mid,
+		    gp->gp_type.time_hi_and_version,
+		    gp->gp_type.clock_seq_hi_and_reserved,
+		    gp->gp_type.clock_seq_low,
+		    gp->gp_type.node[0],
+		    gp->gp_type.node[1],
+		    gp->gp_type.node[2],
+		    gp->gp_type.node[3],
+		    gp->gp_type.node[4],
+		    gp->gp_type.node[5],
+		    stats);
+	pager_output(line);
+}
+
+static int
+disk_printgpt(struct disk_devdesc *dev, char *prefix, int verbose)
+{
+	struct gpt_part		*gpt = NULL;
+	int			rc, ngpt, i;
+	char			line[80];
+
+	rc = disk_readgpt(dev, &gpt, &ngpt);
+	if (rc)
+		return (rc);
+	for (i = 0; i < ngpt; i++) {
+		sprintf(line, "%sp%d", prefix, i + 1);
+		disk_printgptpart(dev, &gpt[i], line, verbose);
+	}
+	free(gpt);
+	return (0);
+}
+
+#endif
+
+int
+disk_open(struct disk_devdesc *dev)
+{
+	int rc;
+
+	/*
+	 * While we are reading disk metadata, make sure we do it relative
+	 * to the start of the disk
+	 */
+	dev->d_offset = 0;
+
+#ifdef LOADER_GPT_SUPPORT
+	rc = disk_opengpt(dev);
+	if (rc)
+#endif
+		rc = disk_openmbr(dev);
+
+	return (rc);
+}
+
+void
+disk_print(struct disk_devdesc *dev, char *prefix, int verbose)
+{
+	int			rc;
+
+#ifdef LOADER_GPT_SUPPORT
+	rc = disk_printgpt(dev, prefix, verbose);
+	if (rc == 0)
+		return;
+#endif
+	disk_printmbr(dev, prefix, verbose);
+}
diff --git a/sys/boot/common/disk.h b/sys/boot/common/disk.h
new file mode 100644
index 0000000..0fc7e91
--- /dev/null
+++ b/sys/boot/common/disk.h
@@ -0,0 +1,99 @@
+/*-
+ * Copyright (c) 2011 Google, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Device descriptor for partitioned disks. We assume that all disk addresses
+ * are 512 byte block offsets from the start of the disk. To use, set the
+ * d_slice and d_partition variables as follows:
+ *
+ * Whole disk access:
+ *
+ * 	d_slice = -1
+ * 	d_partition = -1
+ *
+ * Whole MBR slice:
+ *
+ * 	d_slice = MBR slice number (typically 1..4)
+ * 	d_partition = -1
+ *
+ * BSD disklabel partition within an MBR slice:
+ *
+ * 	d_slice = MBR slice number (typically 1..4)
+ * 	d_partition = disklabel partition (typically 0..7)
+ *
+ * GPT partition:
+ *
+ * 	d_slice = GPT partition number (typically 1..N)
+ * 	d_partition = 255
+ *
+ * For both MBR and GPT, to automatically find the 'best' slice or partition,
+ * set d_slice to zero. This uses the partition type to decide which partition
+ * to use according to the following list of preferences:
+ *
+ * 	FreeBSD (active)
+ * 	FreeBSD (inactive)
+ * 	Linux (active)
+ * 	Linux (inactive)
+ * 	DOS/Windows (active)
+ * 	DOS/Windows (inactive)
+ *
+ * Active MBR slices (marked as bootable) are preferred over inactive. GPT
+ * doesn't have the concept of active/inactive partitions. In both MBR and GPT,
+ * if there are multiple slices/partitions of a given type, the first one
+ * is chosen.
+ *
+ * The low-level disk device will typically call slice_open() from its open
+ * method to interpret the disk partition tables according to the rules above.
+ * This will initialize d_offset to the block offset of the start of the
+ * selected partition - this offset should be added to the offset passed to
+ * the device's strategy method.
+ */
+
+#define DISK_SECSIZE	512
+
+struct disk_devdesc
+{
+	struct devsw	*d_dev;
+	int		d_type;
+	int		d_unit;
+	void		*d_opendata;
+	int		d_slice;
+	int		d_partition;
+	int		d_offset;
+};
+
+/*
+ * Parse disk metadata and initialise dev->d_offset.
+ */
+extern int disk_open(struct disk_devdesc * dev);
+
+/*
+ * Print information about slices on a disk.  For the size calculations we
+ * assume a 512 byte sector.
+ */
+extern void disk_print(struct disk_devdesc *dev, char *prefix, int verbose);
diff --git a/sys/boot/common/load_elf.c b/sys/boot/common/load_elf.c
index ee6389f..bf095bb 100644
--- a/sys/boot/common/load_elf.c
+++ b/sys/boot/common/load_elf.c
@@ -260,7 +260,7 @@ __elfN(loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off)
     firstaddr = lastaddr = 0;
     ehdr = ef->ehdr;
     if (ef->kernel) {
-#ifdef __i386__
+#if defined(__i386__) || defined(__amd64__)
 #if __ELF_WORD_SIZE == 64
 	off = - (off & 0xffffffffff000000ull);/* x86_64 relocates after locore */
 #else
diff --git a/sys/boot/common/reloc_elf.c b/sys/boot/common/reloc_elf.c
index 43b7cbf..b614091 100644
--- a/sys/boot/common/reloc_elf.c
+++ b/sys/boot/common/reloc_elf.c
@@ -78,7 +78,7 @@ __elfN(reloc)(struct elf_file *ef, symaddr_fn *symaddr, const void *reldata,
 	}
 
 	return (0);
-#elif defined(__i386__) && __ELF_WORD_SIZE == 64
+#elif (defined(__i386__) || defined(__amd64__)) && __ELF_WORD_SIZE == 64
 	Elf64_Addr *where, val;
 	Elf_Addr addend, addr;
 	Elf_Size rtype, symidx;