boot/grub2: Introduce loongarch64-efi target

loongarch64-efi target presents in GRUB can be utilised
by any EFI compatible LoongArch64 machine to boot kernel.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Julien Olivain <ju.o@free.fr>

boot/grub2/Config.in

@@ -5,6 +5,7 @@ config BR2_TARGET_GRUB2_ARCH_SUPPORTS
 	default y if BR2_arm
 	default y if BR2_aarch64
 	default y if BR2_RISCV_64
+	default y if BR2_loongarch64
 	depends on BR2_USE_MMU
 
 menuconfig BR2_TARGET_GRUB2
@@ -112,6 +113,15 @@ config BR2_TARGET_GRUB2_RISCV64_EFI
 	  64bit RISC-V platform and you want to boot Grub 2 as an EFI
 	  application.
 
+config BR2_TARGET_GRUB2_LOONGARCH64_EFI
+	bool "loongarch64-efi"
+	depends on BR2_loongarch64
+	select BR2_TARGET_GRUB2_HAS_EFI_BOOT
+	help
+	  Select this option if the platform you're targetting is a
+	  64bit LoongArch platform and you want to boot Grub 2 as an EFI
+	  application.
+
 if BR2_TARGET_GRUB2_HAS_LEGACY_BOOT
 
 comment "Options for the x86 legacy BIOS or ARM U-Boot support"

boot/grub2/grub2.mk

@@ -102,6 +102,15 @@ GRUB2_BUILTIN_CONFIG_riscv64-efi = $(GRUB2_BUILTIN_CONFIG_EFI)
 GRUB2_BUILTIN_MODULES_riscv64-efi = $(GRUB2_BUILTIN_MODULES_EFI)
 GRUB2_TUPLES-$(BR2_TARGET_GRUB2_RISCV64_EFI) += riscv64-efi
 
+GRUB2_IMAGE_loongarch64-efi = $(BINARIES_DIR)/efi-part/EFI/BOOT/bootloongarch64.efi
+GRUB2_CFG_loongarch64-efi = $(BINARIES_DIR)/efi-part/EFI/BOOT/grub.cfg
+GRUB2_PREFIX_loongarch64-efi = /EFI/BOOT
+GRUB2_TARGET_loongarch64-efi = loongarch64
+GRUB2_PLATFORM_loongarch64-efi = efi
+GRUB2_BUILTIN_CONFIG_loongarch64-efi = $(GRUB2_BUILTIN_CONFIG_EFI)
+GRUB2_BUILTIN_MODULES_loongarch64-efi = $(GRUB2_BUILTIN_MODULES_EFI)
+GRUB2_TUPLES-$(BR2_TARGET_GRUB2_LOONGARCH64_EFI) += loongarch64-efi
+
 # Grub2 is kind of special: it considers CC, LD and so on to be the
 # tools to build the host programs and uses TARGET_CC, TARGET_CFLAGS,
 # TARGET_CPPFLAGS, TARGET_LDFLAGS to build the bootloader itself.