diff --git a/stand/efi/loader/main.c b/stand/efi/loader/main.c
--- a/stand/efi/loader/main.c
+++ b/stand/efi/loader/main.c
@@ -909,6 +909,7 @@
 	char buf[24];
 	int revision;
 
+	loader_features |= FEATURE_EARLY_ACPI;
 	if ((rsdp = efi_get_table(&acpi20)) == NULL)
 		if ((rsdp = efi_get_table(&acpi)) == NULL)
 			return;
diff --git a/stand/liblua/lutils.c b/stand/liblua/lutils.c
--- a/stand/liblua/lutils.c
+++ b/stand/liblua/lutils.c
@@ -580,6 +580,40 @@
 };
 #undef REG_SIMPLE
 
+static void
+lua_add_feature(void *cookie, const char *name, const char *desc, bool enabled)
+{
+	lua_State *L = cookie;
+
+	/*
+	 * We don't currently make features not enabled available to the
+	 * interpreter, but there's no reason we couldn't make it so.
+	 */
+	if (!enabled)
+		return;
+
+	/*
+	 * The feature table consists solely of features that are enabled, and
+	 * their associated descriptions for debugging purposes.
+	 */
+	lua_pushstring(L, desc);
+	lua_setfield(L, -2, name);
+}
+
+static void
+lua_add_features(lua_State *L)
+{
+
+	lua_newtable(L);
+	loader_iter_features(&lua_add_feature, L);
+
+	/*
+	 * We should still have just the table on the stack after we're done
+	 * iterating.
+	 */
+	lua_setfield(L, -2, "features");
+}
+
 int
 luaopen_loader(lua_State *L)
 {
@@ -593,6 +627,7 @@
 	lua_setfield(L, -2, "lua_path");
 	lua_pushinteger(L, bootprog_rev);
 	lua_setfield(L, -2, "version");
+	lua_add_features(L);
 	/* Set global printc to loader.printc */
 	lua_register(L, "printc", lua_printc);
 	return 1;
diff --git a/stand/libsa/Makefile b/stand/libsa/Makefile
--- a/stand/libsa/Makefile
+++ b/stand/libsa/Makefile
@@ -13,7 +13,7 @@
 
 # standalone components and stuff we have modified locally
 SRCS+=	gzguts.h zutil.h __main.c abort.c assert.c bcd.c environment.c \
-	getopt.c gets.c globals.c \
+	features.c getopt.c gets.c globals.c \
 	hexdump.c nvstore.c pager.c panic.c printf.c strdup.c strerror.c \
 	random.c sbrk.c tslog.c twiddle.c zalloc.c zalloc_malloc.c
 
diff --git a/stand/libsa/features.c b/stand/libsa/features.c
new file mode 100644
--- /dev/null
+++ b/stand/libsa/features.c
@@ -0,0 +1,54 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 Kyle Evans <kevans@FreeBSD.org>
+ *
+ * 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/param.h>
+
+#include "stand.h"
+
+uint32_t loader_features;
+
+#define	FEATURE_ENTRY(name, desc)	{ FEATURE_##name, #name, desc }
+static const struct loader_feature_entry {
+	uint32_t	value;
+	const char	*name;
+	const char	*desc;
+} loader_feature_map[] = {
+	FEATURE_ENTRY(EARLY_ACPI,  "Loader probes ACPI in early startup"),
+};
+
+void
+loader_iter_features(loader_iter_feature_fn *iter_fn, void *cookie)
+{
+	const struct loader_feature_entry *entry;
+
+	for (size_t i = 0; i < nitems(loader_feature_map); i++) {
+		entry = &loader_feature_map[i];
+
+		(*iter_fn)(cookie, entry->name, entry->desc,
+		    (loader_features & entry->value) != 0);
+	}
+}
diff --git a/stand/libsa/stand.h b/stand/libsa/stand.h
--- a/stand/libsa/stand.h
+++ b/stand/libsa/stand.h
@@ -498,6 +498,20 @@
  */
 caddr_t ptov(uintptr_t);
 
+/* features.c */
+typedef void (loader_iter_feature_fn)(void *, const char *, const char *, bool);
+
+extern void loader_iter_features(loader_iter_feature_fn *, void *);
+extern uint32_t loader_features;
+
+/*
+ * Note that these should also be added to the mapping table in features.c,
+ * which the interpreter may query to provide details from.  The name with
+ * FEATURE_ removed is assumed to be the name we'll provide in the loader
+ * features table, just to simplify reasoning about these.
+ */
+#define	FEATURE_EARLY_ACPI	0x0001
+
 /* hexdump.c */
 void	hexdump(caddr_t region, size_t len);
 
diff --git a/stand/lua/core.lua b/stand/lua/core.lua
--- a/stand/lua/core.lua
+++ b/stand/lua/core.lua
@@ -382,6 +382,16 @@
 	loader.perform(composeLoaderCmd("boot", argstr))
 end
 
+-- XXX TODO: Document in manpage
+function core.hasFeature(name)
+	if not loader.features then
+		-- Loader too old, no feature support
+		return false
+	end
+
+	return loader.features[name]
+end
+
 function core.isSingleUserBoot()
 	local single_user = loader.getenv("boot_single")
 	return single_user ~= nil and single_user:lower() == "yes"