For 32bit UEFI secure boot, the package name is grub-efi-ia32-signed

avoids spitting out warning
> [2020-06-07 22:30:32] lb binary_grub-efi
> P: Begin preparing Grub based EFI support...
> Reading package lists...
> Building dependency tree...
> Reading state information...
> Package grub-efi-amd64-signed is not available, but is referred to by another package.
> This may mean that the package is missing, has been obsoleted, or
> is only available from another source
>
> E: Package 'grub-efi-amd64-signed' has no installation candidate
> W: UEFI Secure Boot disabled due to missing signed Grub/Shim.

1 files changed, 6 insertions, 1 deletions

diff --git a/scripts/build/binary_grub-efi b/scripts/build/binary_grub-efi
index 9cb105370..b12dd0efe 100755
--- a/scripts/build/binary_grub-efi
+++ b/scripts/build/binary_grub-efi
@@ -67,11 +67,16 @@ Check_package chroot /sbin/mkfs.msdos dosfstools
 # By default (auto) do a best-effort build: if the signed binaries are available use
 # them, but don't fail if they are not, just print a warning.
 case "${LB_ARCHITECTURE}" in
-	amd64|i386)
+	amd64)
 		_SB_EFI_PLATFORM="x86_64"
 		_SB_EFI_NAME="x64"
 		_SB_EFI_DEB="amd64"
 		;;
+	i386)
+		_SB_EFI_PLATFORM="i386"
+		_SB_EFI_NAME="ia32"
+		_SB_EFI_DEB="ia32"
+		;;
 	arm64)
 		_SB_EFI_PLATFORM="arm64"
 		_SB_EFI_NAME="aa64"