efi_selftest: allow to select a single test for execution

Environment variable efi_selftest is passed as load options
to the selftest application. It is used to select a single
test to be executed.

The load options are an UTF8 string. Yet I decided to keep
the name propertiy of the tests as char[] to reduce code
size.

Special value 'list' displays a list of all available tests.

Tests get an on_request property. If this property is set
the tests are only executed if explicitly requested.

The invocation of efi_selftest is changed to reflect that
bootefi selftest with efi_selftest = 'list' will call the
Exit bootservice.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_selftest/efi_selftest_console.c b/lib/efi_selftest/efi_selftest_console.c
index 840e229..6a7fd20 100644
--- a/lib/efi_selftest/efi_selftest_console.c
+++ b/lib/efi_selftest/efi_selftest_console.c
@@ -142,6 +142,7 @@
 	const char *c;
 	u16 *pos = buf;
 	const char *s;
+	const u16 *u;
 
 	va_start(args, fmt);
 
@@ -179,9 +180,18 @@
 			case 'p':
 				++c;
 				switch (*c) {
+				/* MAC address */
 				case 'm':
 					mac(va_arg(args, void*), &pos);
 					break;
+
+				/* u16 string */
+				case 's':
+					u = va_arg(args, u16*);
+					/* Ensure string fits into buffer */
+					for (; *u && pos < buf + 120; ++u)
+						*pos++ = *u;
+					break;
 				default:
 					--c;
 					pointer(va_arg(args, void*), &pos);