Add EFI ZFS boot support

This builds on the modular EFI loader support added r294060 adding a
module to provide ZFS boot support on EFI systems.

It should be noted that EFI uses a fixed size memory block for all
allocations performed by the loader so it may be necessary to tune this
size.

For example when building an image which uses mfs_root e.g. mfsbsd, adding
the following to /etc/make.conf would be needed to prevent EFI from running
out of memory when loading the mfs_root image.
EFI_STAGING_SIZE=128

Submitted by:	Eric McCorkle
MFC after:	2 weeks
X-MFC-With:	r293268
Sponsored by:	Multiplay

4 files changed, 122 insertions, 1 deletions

diff --git a/sys/boot/efi/loader/Makefile b/sys/boot/efi/loader/Makefile
index 59d32ff..d36e54b 100644
--- a/sys/boot/efi/loader/Makefile
+++ b/sys/boot/efi/loader/Makefile
@@ -21,6 +21,16 @@ SRCS=	autoload.c \
 	smbios.c \
 	vers.c
 
+.if ${MK_ZFS} != "no"
+SRCS+=		zfs.c
+.PATH:		${.CURDIR}/../../zfs
+
+# Disable warnings that are currently incompatible with the zfs boot code
+CWARNFLAGS.zfs.c+=	-Wno-sign-compare
+CWARNFLAGS.zfs.c+=	-Wno-array-bounds
+CWARNFLAGS.zfs.c+=	-Wno-missing-prototypes
+.endif
+
 .PATH: ${.CURDIR}/arch/${MACHINE}
 # For smbios.c
 .PATH: ${.CURDIR}/../../i386/libi386
@@ -33,6 +43,11 @@ CFLAGS+=	-I${.CURDIR}/../include/${MACHINE}
 CFLAGS+=	-I${.CURDIR}/../../../contrib/dev/acpica/include
 CFLAGS+=	-I${.CURDIR}/../../..
 CFLAGS+=	-I${.CURDIR}/../../i386/libi386
+.if ${MK_ZFS} != "no"
+CFLAGS+=	-I${.CURDIR}/../../zfs
+CFLAGS+=	-I${.CURDIR}/../../../cddl/boot/zfs
+CFLAGS+=	-DEFI_ZFS_BOOT
+.endif
 CFLAGS+=	-DNO_PCI -DEFI
 
 # make buildenv doesn't set DESTDIR, this means LIBSTAND
diff --git a/sys/boot/efi/loader/conf.c b/sys/boot/efi/loader/conf.c
index 8bb9d5f..ecbf8b0 100644
--- a/sys/boot/efi/loader/conf.c
+++ b/sys/boot/efi/loader/conf.c
@@ -31,14 +31,23 @@ __FBSDID("$FreeBSD$");
 #include <bootstrap.h>
 #include <efi.h>
 #include <efilib.h>
+#ifdef EFI_ZFS_BOOT
+#include <libzfs.h>
+#endif
 
 struct devsw *devsw[] = {
 	&efipart_dev,
 	&efinet_dev,
+#ifdef EFI_ZFS_BOOT
+	&zfs_dev,
+#endif
 	NULL
 };
 
 struct fs_ops *file_system[] = {
+#ifdef EFI_ZFS_BOOT
+	&zfs_fsops,
+#endif
 	&dosfs_fsops,
 	&ufs_fsops,
 	&cd9660_fsops,
diff --git a/sys/boot/efi/loader/devicename.c b/sys/boot/efi/loader/devicename.c
index c6591c8..8fc80eb 100644
--- a/sys/boot/efi/loader/devicename.c
+++ b/sys/boot/efi/loader/devicename.c
@@ -33,6 +33,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/disklabel.h>
 #include <sys/param.h>
 #include <bootstrap.h>
+#ifdef EFI_ZFS_BOOT
+#include <libzfs.h>
+#endif
 
 #include <efi.h>
 #include <efilib.h>
@@ -104,6 +107,23 @@ efi_parsedev(struct devdesc **dev, const char *devspec, const char **path)
 
 	np = devspec + strlen(dv->dv_name);
 
+#ifdef EFI_ZFS_BOOT
+	if (dv->dv_type == DEVT_ZFS) {
+		int err;
+
+		idev = malloc(sizeof(struct zfs_devdesc));
+		if (idev == NULL)
+			return (ENOMEM);
+
+		err = zfs_parsedev((struct zfs_devdesc*)idev, np, path);
+		if (err != 0) {
+			free(idev);
+			return (err);
+		}
+		*dev = idev;
+		cp = strchr(np + 1, ':');
+	} else
+#endif
 	{
 		idev = malloc(sizeof(struct devdesc));
 		if (idev == NULL)
@@ -143,6 +163,10 @@ efi_fmtdev(void *vdev)
 	static char buf[SPECNAMELEN + 1];
 
 	switch(dev->d_type) {
+#ifdef EFI_ZFS_BOOT
+	case DEVT_ZFS:
+		return (zfs_fmtdev(dev));
+#endif
 	case DEVT_NONE:
 		strcpy(buf, "(no device)");
 		break;
diff --git a/sys/boot/efi/loader/main.c b/sys/boot/efi/loader/main.c
index 43a015d..4ba42d9 100644
--- a/sys/boot/efi/loader/main.c
+++ b/sys/boot/efi/loader/main.c
@@ -39,6 +39,10 @@ __FBSDID("$FreeBSD$");
 #include <bootstrap.h>
 #include <smbios.h>
 
+#ifdef EFI_ZFS_BOOT
+#include <libzfs.h>
+#endif
+
 #include "loader_efi.h"
 
 extern char bootprog_name[];
@@ -61,6 +65,10 @@ EFI_GUID memtype = MEMORY_TYPE_INFORMATION_TABLE_GUID;
 EFI_GUID debugimg = DEBUG_IMAGE_INFO_TABLE_GUID;
 EFI_GUID fdtdtb = FDT_TABLE_GUID;
 
+#ifdef EFI_ZFS_BOOT
+static void efi_zfs_probe(void);
+#endif
+
 /*
  * Need this because EFI uses UTF-16 unicode string constants, but we
  * use UTF-8. We can't use printf due to the possiblity of \0 and we
@@ -83,6 +91,7 @@ main(int argc, CHAR16 *argv[])
 	EFI_GUID *guid;
 	int i, j, vargood, unit;
 	struct devsw *dev;
+	uint64_t pool_guid;
 	UINTN k;
 
 	archsw.arch_autoload = efi_autoload;
@@ -90,6 +99,10 @@ main(int argc, CHAR16 *argv[])
 	archsw.arch_copyin = efi_copyin;
 	archsw.arch_copyout = efi_copyout;
 	archsw.arch_readin = efi_readin;
+#ifdef EFI_ZFS_BOOT
+	/* Note this needs to be set before ZFS init. */
+	archsw.arch_zfs_probe = efi_zfs_probe;
+#endif
 
 	/*
 	 * XXX Chicken-and-egg problem; we want to have console output
@@ -168,10 +181,27 @@ main(int argc, CHAR16 *argv[])
 	 */
 	BS->SetWatchdogTimer(0, 0, 0, NULL);
 
-	if (efi_handle_lookup(img->DeviceHandle, &dev, &unit) != 0)
+	if (efi_handle_lookup(img->DeviceHandle, &dev, &unit, &pool_guid) != 0)
 		return (EFI_NOT_FOUND);
 
 	switch (dev->dv_type) {
+#ifdef EFI_ZFS_BOOT
+	case DEVT_ZFS: {
+		struct zfs_devdesc currdev;
+
+		currdev.d_dev = dev;
+		currdev.d_unit = unit;
+		currdev.d_type = currdev.d_dev->dv_type;
+		currdev.d_opendata = NULL;
+		currdev.pool_guid = pool_guid;
+		currdev.root_guid = 0;
+		env_setenv("currdev", EV_VOLATILE, efi_fmtdev(&currdev),
+			   efi_setcurrdev, env_nounset);
+		env_setenv("loaddev", EV_VOLATILE, efi_fmtdev(&currdev), env_noset,
+			   env_nounset);
+		break;
+	}
+#endif
 	default: {
 		struct devdesc currdev;
 
@@ -456,6 +486,29 @@ command_nvram(int argc, char *argv[])
 	return (CMD_OK);
 }
 
+#ifdef EFI_ZFS_BOOT
+COMMAND_SET(lszfs, "lszfs", "list child datasets of a zfs dataset",
+    command_lszfs);
+
+static int
+command_lszfs(int argc, char *argv[])
+{
+	int err;
+
+	if (argc != 2) {
+		command_errmsg = "wrong number of arguments";
+		return (CMD_ERROR);
+	}
+
+	err = zfs_list(argv[1]);
+	if (err != 0) {
+		command_errmsg = strerror(err);
+		return (CMD_ERROR);
+	}
+	return (CMD_OK);
+}
+#endif
+
 #ifdef LOADER_FDT_SUPPORT
 extern int command_fdt_internal(int argc, char *argv[]);
 
@@ -474,3 +527,23 @@ command_fdt(int argc, char *argv[])
 
 COMMAND_SET(fdt, "fdt", "flattened device tree handling", command_fdt);
 #endif
+
+#ifdef EFI_ZFS_BOOT
+static void
+efi_zfs_probe(void)
+{
+	EFI_HANDLE h;
+	u_int unit;
+	int i;
+	char dname[SPECNAMELEN + 1];
+	uint64_t guid;
+
+	unit = 0;
+	h = efi_find_handle(&efipart_dev, 0);
+	for (i = 0; h != NULL; h = efi_find_handle(&efipart_dev, ++i)) {
+		snprintf(dname, sizeof(dname), "%s%d:", efipart_dev.dv_name, i);
+		if (zfs_probe_dev(dname, &guid) == 0)
+			(void)efi_handle_update_dev(h, &zfs_dev, unit++, guid);
+	}
+}
+#endif