arch: Introduce LoongArch64

Introduce LoongArch64 at architecture level.

Config.in.loongarch is prepared for possible loongarch32
enablement in future, thus BR2_ARCH_IS_64 is being depended
by some 64bit only options.

Internal toolchain is supported, as our minimal binutils
version is already beyond LoongArch minimal version and
GCC option is limited by BR2_ARCH_NEEDS_GCC_AT_LEAST_12.

BR2_ARCH_HAS_NO_TOOLCHAIN_BUILDROOT is selected temporary
and it's going to be rmoved after we gain libc support.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
[Julien: fix typo in Kconfig BR2_LOONGARCH_ABI_LP64S prompt
  replace "lp64d" by "lp64s"]
Signed-off-by: Julien Olivain <ju.o@free.fr>

DEVELOPERS

@@ -1642,6 +1642,9 @@ F:	package/libuhttpd/
 F:	package/libuwsc/
 F:	package/rtty/
 
+N:	Jiaxun Yang <jiaxun.yang@flygoat.com>
+F:	arch/Config.in.loongarch
+
 N:	Joachim Wiberg <troglobit@gmail.com>
 F:	configs/globalscale_espressobin_defconfig
 F:	board/globalscale/espressobin/

arch/Config.in

@@ -80,6 +80,17 @@ config BR2_i386
 	  Intel i386 architecture compatible microprocessor
 	  http://en.wikipedia.org/wiki/I386
 
+config BR2_loongarch64
+	bool "LoongArch64"
+	select BR2_USE_MMU
+	select BR2_ARCH_IS_64
+	select BR2_ARCH_NEEDS_GCC_AT_LEAST_12
+	select BR2_ARCH_HAS_NO_TOOLCHAIN_BUILDROOT
+	help
+	  LoongArch64 is 64-bit architecture developed by Loongson.
+	  http://www.loongson.cn/
+	  https://en.wikipedia.org/wiki/Loongson
+
 config BR2_m68k
 	bool "m68k"
 	# MMU support is set by the subarchitecture file, arch/Config.in.m68k
@@ -383,6 +394,10 @@ if BR2_arm || BR2_armeb || BR2_aarch64 || BR2_aarch64_be
 source "arch/Config.in.arm"
 endif
 
+if BR2_loongarch64
+source "arch/Config.in.loongarch"
+endif
+
 if BR2_m68k
 source "arch/Config.in.m68k"
 endif

arch/Config.in.loongarch

@@ -0,0 +1,128 @@
+# LoongArch CPU
+
+choice
+	prompt "Target Architecture Variant"
+	default BR2_loongarch64_generic if BR2_ARCH_IS_64
+
+config BR2_loongarch64_generic
+	bool "Generic LoongArch 64-bit"
+	depends on BR2_ARCH_IS_64
+	help
+	  Generic LoongArch 64-bit processor.
+
+config BR2_loongarch64_v1_0
+	bool "LoongArch64 ISA version 1.0"
+	depends on BR2_ARCH_IS_64
+	select BR2_ARCH_NEEDS_GCC_AT_LEAST_13
+	help
+	  LoongArch64 ISA version 1.0 processor.
+
+config BR2_loongarch64_v1_1
+	bool "LoongArch64 ISA version 1.1"
+	depends on BR2_ARCH_IS_64
+	select BR2_ARCH_NEEDS_GCC_AT_LEAST_13
+	help
+	  LoongArch64 ISA version 1.1 processor.
+
+endchoice
+
+choice
+	prompt "FPU Type"
+	default BR2_LOONGARCH_FPU_64
+
+config BR2_LOONGARCH_FPU_64
+	bool "64"
+	help
+	  Allow the use of hardware floating-point instructions for
+	  32-bit and 64-bit operations.
+
+config BR2_LOONGARCH_FPU_32
+	bool "32"
+	help
+	  Allow the use of hardware floating-point instructions for
+	  32-bit operations only.
+
+config BR2_LOONGARCH_FPU_NONE
+	bool "none"
+	help
+	  Prevent the use of hardware floating-point instructions.
+endchoice
+
+choice
+	prompt "SIMD Type"
+	default BR2_LOONGARCH_SIMD_NONE
+
+config BR2_LOONGARCH_SIMD_NONE
+	bool "none"
+	help
+	  Prevent the use of hardware SIMD instructions.
+
+config BR2_LOONGARCH_SIMD_LSX
+	bool "LSX"
+	help
+	  Enable generating instructions from the 128-bit LoongArch SIMD
+	  Extension (LSX).
+
+config BR2_LOONGARCH_SIMD_LASX
+	bool "LASX"
+	help
+	  Enable generating instructions from the 256-bit LoongArch
+	  Advanced SIMD Extension (LASX) and the 128-bit LoongArch
+	  SIMD Extension (LSX).
+endchoice
+
+choice
+	prompt "Target ABI"
+	default BR2_LOONGARCH_ABI_LP64D if BR2_ARCH_IS_64 && BR2_LOONGARCH_FPU_64
+	default BR2_LOONGARCH_ABI_LP64F if BR2_ARCH_IS_64 && BR2_LOONGARCH_FPU_32
+	default BR2_LOONGARCH_ABI_LP64S if BR2_ARCH_IS_64 && BR2_LOONGARCH_SIMD_NONE
+
+config BR2_LOONGARCH_ABI_LP64D
+	bool "lp64d"
+	depends on BR2_ARCH_IS_64
+	depends on BR2_LOONGARCH_FPU_64
+
+config BR2_LOONGARCH_ABI_LP64F
+	bool "lp64f"
+	depends on BR2_ARCH_IS_64
+	depends on BR2_LOONGARCH_FPU_64 || BR2_LOONGARCH_FPU_32
+
+config BR2_LOONGARCH_ABI_LP64S
+	bool "lp64s"
+	depends on BR2_ARCH_IS_64
+endchoice
+
+config BR2_ARCH
+	default "loongarch64" if BR2_ARCH_IS_64
+
+config BR2_NORMALIZED_ARCH
+	default "loongarch"
+
+config BR2_ENDIAN
+	default "LITTLE"
+
+config BR2_GCC_TARGET_ARCH
+	default "loongarch64" if BR2_loongarch64_generic
+	default "la64v1.0" if BR2_loongarch64_v1_0
+	default "la64v1.1" if BR2_loongarch64_v1_1
+
+config BR2_GCC_TARGET_FPU
+	default "64" if BR2_LOONGARCH_FPU_64
+	default "32" if BR2_LOONGARCH_FPU_32
+	default "none" if BR2_LOONGARCH_FPU_NONE
+
+config BR2_GCC_TARGET_SIMD
+	default "lasx" if BR2_LOONGARCH_SIMD_LASX
+	default "lsx" if BR2_LOONGARCH_SIMD_LSX
+	default "none" if BR2_LOONGARCH_FPU_NONE
+
+config BR2_GCC_TARGET_ABI
+	default "lp64d" if BR2_LOONGARCH_ABI_LP64D
+	default "lp64f" if BR2_LOONGARCH_ABI_LP64F
+	default "lp64s" if BR2_LOONGARCH_ABI_LP64S
+
+config BR2_READELF_ARCH_NAME
+	default "LoongArch"
+
+# vim: ft=kconfig
+# -*- mode:kconfig; -*-