diff --git a/compatibility_matrices/build/vintf_compatibility_matrix.go b/compatibility_matrices/build/vintf_compatibility_matrix.go
index c72cbde..4f342b2 100644
--- a/compatibility_matrices/build/vintf_compatibility_matrix.go
+++ b/compatibility_matrices/build/vintf_compatibility_matrix.go
@@ -35,10 +35,10 @@
 	pctx = android.NewPackageContext("android/vintf")
 
 	assembleVintfRule = pctx.AndroidStaticRule("assemble_vintf", blueprint.RuleParams{
-		Command:     `${assembleVintfCmd} -i ${inputs} -o ${out}`,
+		Command:     `${assembleVintfCmd} -i ${inputs} -o ${out} ${extraParams}`,
 		CommandDeps: []string{"${assembleVintfCmd}"},
 		Description: "assemble_vintf -i ${inputs}",
-	}, "inputs")
+	}, "inputs", "extraParams")
 
 	xmllintXsd = pctx.AndroidStaticRule("xmllint-xsd", blueprint.RuleParams{
 		Command:     `$XmlLintCmd --quiet --schema $xsd $in > /dev/null && touch -a $out`,
@@ -64,6 +64,13 @@
 
 	// list of kernel_config modules to be combined to final output
 	Kernel_configs []string
+
+	// Default is "default" for compatibility matrices on /vendor
+	// and /odm, and "disallow" for compatibility matrices on /system,
+	// /product, and /system_ext.
+	// If value is "only", only android.* HALs are allowed. If value
+	// is "disallow", none of android.* HALs are allowed.
+	Core_hals *string
 }
 
 type vintfCompatibilityMatrixRule struct {
@@ -166,7 +173,8 @@
 		Implicits:   inputPaths,
 		Output:      g.genFile,
 		Args: map[string]string{
-			"inputs": strings.Join(inputPaths.Strings(), ":"),
+			"inputs":      strings.Join(inputPaths.Strings(), ":"),
+			"extraParams": strings.Join(g.getExtraParams(), " "),
 		},
 	})
 	g.generateValidateBuildAction(ctx, g.genFile, schema.Path())
@@ -191,3 +199,23 @@
 		},
 	}
 }
+
+// Return extra parameters to assemble_vintf.
+func (g *vintfCompatibilityMatrixRule) getExtraParams() []string {
+	var extraParams []string
+
+	coreHalsStrategy := proptools.StringDefault(
+		g.properties.Core_hals,
+		g.defaultCoreHalsStrategy(),
+	)
+	extraParams = append(extraParams, "--core-hals", proptools.ShellEscape(coreHalsStrategy))
+	return extraParams
+}
+
+func (g *vintfCompatibilityMatrixRule) defaultCoreHalsStrategy() string {
+	// TODO(b/290408770): default to "disallow" for FCMs
+
+	// For Device (vendor, odm) compatibility matrix, default is
+	// to not check anything.
+	return "default"
+}