--- a/arch/mips/bcm47xx/sprom.c
+++ b/arch/mips/bcm47xx/sprom.c
@@ -165,6 +165,8 @@ static void bcm47xx_fill_sprom_r1234589(
 					const char *prefix)
 {
 	nvram_read_u16(prefix, NULL, "boardrev", &sprom->board_rev, 0);
+	if (!sprom->board_rev)
+		nvram_read_u16(NULL, NULL, "boardrev", &sprom->board_rev, 0);
 	nvram_read_u16(prefix, NULL, "boardnum", &sprom->board_num, 0);
 	nvram_read_u8(prefix, NULL, "ledbh0", &sprom->gpio0, 0xff);
 	nvram_read_u8(prefix, NULL, "ledbh1", &sprom->gpio1, 0xff);