diff --git a/stand/liblua/lutils.c b/stand/liblua/lutils.c
--- a/stand/liblua/lutils.c
+++ b/stand/liblua/lutils.c
@@ -75,6 +75,25 @@
 	return 1;
 }
 
+static int
+lua_has_feature(lua_State *L)
+{
+	const char	*feature;
+	char *msg;
+
+	feature = luaL_checkstring(L, 1);
+
+	if (feature_name_is_enabled(feature)) {
+		lua_pushboolean(L, 1);
+		return 1;
+	}
+
+	lua_pushnil(L);
+	lua_pushstring(L, "Feature not enabled");
+	return 2;
+}
+
+
 static int
 lua_perform(lua_State *L)
 {
@@ -552,6 +571,7 @@
 	REG_SIMPLE(parse),
 	REG_SIMPLE(getenv),
 	REG_SIMPLE(has_command),
+	REG_SIMPLE(has_feature),
 	REG_SIMPLE(perform),
 	REG_SIMPLE(printc),	/* Also registered as the global 'printc' */
 	REG_SIMPLE(setenv),
@@ -579,6 +599,33 @@
 };
 #undef REG_SIMPLE
 
+static void
+lua_add_feature(void *cookie, const char *name, const char *desc, bool enabled)
+{
+	lua_State *L = cookie;
+
+	/*
+	 * 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);
+	feature_iter(&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)
 {
@@ -592,6 +639,7 @@
 	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 +1,56 @@
+/*-
+ * Copyright (c) 2023 Kyle Evans <kevans@FreeBSD.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ */
+
+#include <sys/param.h>
+
+#include "stand.h"
+
+static uint32_t loader_features;
+
+#define	FEATURE_ENTRY(name, desc)	{ FEATURE_##name, #name, desc }
+static const struct feature_entry {
+	uint32_t	value;
+	const char	*name;
+	const char	*desc;
+} feature_map[] = {
+	FEATURE_ENTRY(EARLY_ACPI,  "Loader probes ACPI in early startup"),
+};
+
+void
+feature_enable(uint32_t mask)
+{
+
+	loader_features |= mask;
+}
+
+bool
+feature_name_is_enabled(const char *name)
+{
+	const struct feature_entry *entry;
+
+	for (size_t i = 0; i < nitems(feature_map); i++) {
+		entry = &feature_map[i];
+
+		if (strcmp(entry->name, name) == 0)
+			return ((loader_features & entry->value) != 0);
+	}
+
+	return (false);
+}
+
+void
+feature_iter(feature_iter_fn *iter_fn, void *cookie)
+{
+	const struct feature_entry *entry;
+
+	for (size_t i = 0; i < nitems(feature_map); i++) {
+		entry = &feature_map[i];
+
+		(*iter_fn)(cookie, entry->name, entry->desc,
+		    (loader_features & entry->value) != 0);
+	}
+}
diff --git a/stand/libsa/libsa.3 b/stand/libsa/libsa.3
--- a/stand/libsa/libsa.3
+++ b/stand/libsa/libsa.3
@@ -497,6 +497,66 @@
 .Fa fname .
 Returns -1 on error, 0 at EOF, or 1 if the user elects to quit while reading.
 .El
+.Sh FEATURE SUPPORT
+A set of functions are provided to communicate support of features from the
+loader binary to the interpreter.
+These are used to do something sensible if we are still operating with a loader
+binary that behaves differently than expected.
+.Bl -hang -width 10n
+.It Xo
+.Ft void
+.Fn feature_enable "uint32_t mask"
+.Xc
+.Pp
+Enable the referenced
+.Fa mask
+feature, which should be one of the
+.Li FEATURE_*
+macros defined in
+.In stand.h .
+.It Xo
+.Ft bool
+.Fn feature_name_is_enabled "const char *name"
+.Xc
+.Pp
+Check if the referenced
+.Fa name
+feature is enabled.
+The
+.Fa name
+is usually the same name as the
+.Li FEATURE_*
+macro, but with the FEATURE_ prefix stripped off.
+The authoritative source of feature names is the mapping table near the top in
+.Pa stand/libsa/features.c .
+.It Xo
+.Ft void
+.Fn "(feature_iter_fn)" "void *cookie" "const char *name" "const char *desc" "bool enabled"
+.Xc
+.Pp
+The
+.Fa cookie
+argument is passed as-is from the argument of the same name to
+.Fn feature_iter .
+The
+.Fa name
+and
+.Fa desc
+arguments are defined in the mapping table in
+.Pa stand/libsa/features.c .
+The
+.Fa enabled
+argument indicates the current status of the feature, though one could
+theoretically turn a feature off in later execution.
+As such, this should likely not be trusted if it is needed after the iteration
+has finished.
+.It Xo
+.Ft void
+.Fn "feature_iter" "feature_iter_fn *iter_fn" "void *cookie"
+.Xc
+.Pp
+Iterate over the current set of features.
+.El
 .Sh MISC
 .Bl -hang -width 10n
 .It Xo
diff --git a/stand/libsa/stand.h b/stand/libsa/stand.h
--- a/stand/libsa/stand.h
+++ b/stand/libsa/stand.h
@@ -496,6 +496,21 @@
  */
 caddr_t ptov(uintptr_t);
 
+/* features.c */
+typedef void (feature_iter_fn)(void *, const char *, const char *, bool);
+
+extern void feature_enable(uint32_t);
+extern bool feature_name_is_enabled(const char *);
+extern void feature_iter(feature_iter_fn *, void *);
+
+/*
+ * 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
@@ -378,6 +378,15 @@
 	loader.perform(composeLoaderCmd("boot", argstr))
 end
 
+function core.hasFeature(name)
+	if not loader.has_feature then
+		-- Loader too old, no feature support
+		return nil, "No feature support in loaded loader"
+	end
+
+	return loader.has_feature(name)
+end
+
 function core.isSingleUserBoot()
 	local single_user = loader.getenv("boot_single")
 	return single_user ~= nil and single_user:lower() == "yes"
diff --git a/stand/lua/core.lua.8 b/stand/lua/core.lua.8
--- a/stand/lua/core.lua.8
+++ b/stand/lua/core.lua.8
@@ -24,7 +24,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd November 20, 2023
+.Dd December 8, 2023
 .Dt CORE.LUA 8
 .Os
 .Sh NAME
@@ -142,6 +142,13 @@
 .Ic kernel
 or
 .Ic kernels .
+.It Fn core.hasFeature featureName
+Checks whether the named
+.Fa featureName
+is enabled in the current loader.
+This is specifically used for detecting capabilities of the loaded loader
+binary, so that one can reasonably implement backwards compatibility shims if
+needed.
 .It Fn core.kernelList
 Returns a table of kernels to display on the boot menu.
 This will combine