uefi: T3880: support both VGA and serial consolex

(cherry picked from commit 479d2482f3cf08ab9863721784981de282b18f7b)

data/live-build-config/bootloaders/grub-pc/grub.cfg

@@ -1,59 +1,36 @@
 set default=0
 set timeout=10
 
-loadfont $prefix/dejavu-bold-16.pf2
-loadfont $prefix/dejavu-bold-14.pf2
-loadfont $prefix/unicode.pf2
-set gfxmode=auto
-insmod all_video
-insmod gfxterm
+insmod serial
+serial --unit=0 --speed=115200
+
+insmod part_msdos
+insmod ext2
+insmod efi_gop
+insmod efi_uga
 insmod png
 
+loadfont /boot/grub/dejavu-bold-16.pf2
+loadfont /boot/grub/dejavu-bold-14.pf2
+loadfont /boot/grub/unicode.pf2
+
+set gfxmode="640x480x16"
+set gfxpayload="640x480x16"
+terminal_output gfxterm
+
+set splash_img="/isolinux/splash.png"
+if [ -e ${splash_img} ]; then
+    background_image ${splash_img}
+fi
+
+terminal_output --append serial
+terminal_input serial console
+
 set color_normal=light-gray/black
 set color_highlight=white/black
 
-if [ -e /isolinux/splash.png ]; then
-    # binary_syslinux modifies the theme file to point to the correct
-    # background picture
-    set theme=/boot/grub/live-theme/theme.txt
-elif [ -e /boot/grub/splash.png ]; then
-    set theme=/boot/grub/live-theme/theme.txt
-else
-    set menu_color_normal=cyan/blue
-    set menu_color_highlight=white/blue
-fi
-
-terminal_output gfxterm
-
-insmod play
-play 960 440 1 0 4 440 1
-
 # Live boot
 LINUX_LIVE
 
-# You can add more entries like this
-# menuentry "Alternate live boot" {
-# linux KERNEL_LIVE APPEND_LIVE custom options here
-# initrd INITRD_LIVE
-# }
-# menuentry "Alternate graphical installer" {
-# linux KERNEL_GI APPEND_GI custom options here
-# initrd INITRD_GI
-# }
-# menuentry "Alternate textual installer" {
-# linux KERNEL_DI APPEND_DI custom options here
-# initrd INITRD_DI
-# }
-
 # Installer (if any)
 LINUX_INSTALL
-
-submenu 'Advanced options...' {
-
-# More installer entries (if any)
-LINUX_ADVANCED_INSTALL
-
-# Memtest (if any)
-MEMTEST
-
-}