default baud rates to 115200 across to installer

serial.patch

diff --git a/nixos/modules/installer/cd-dvd/iso-image.nix b/nixos/modules/installer/cd-dvd/iso-image.nix
index 74fce0d1721..e69a20156c9 100644
--- a/nixos/modules/installer/cd-dvd/iso-image.nix
+++ b/nixos/modules/installer/cd-dvd/iso-image.nix
@@ -88,7 +88,7 @@ let
   #     result in incorrect boot entries.

   baseIsolinuxCfg = ''
-    SERIAL 0 38400
+    SERIAL 0 115200
     TIMEOUT ${builtins.toString syslinuxTimeout}
     UI vesamenu.c32
     MENU TITLE NixOS
@@ -496,6 +496,8 @@ in
     boot.kernelParams =
       [ "root=LABEL=${config.isoImage.volumeID}"
         "boot.shell_on_fail"
+        "console=tty0"
+        "console=ttyS0,115200n8"
       ];

     fileSystems."/" =