[U-Boot] [PATCH v2] riscv: add Kconfig entries for the F and D ISA extensions support

[Eric Lin]

This patch adds Kconfig entries for the F (Single-Precision)
and D (Double-Precision) floating point instruction-set extensions.

Signed-off-by: Eric Lin <tesheng at andestech.com>
---
Changes for v2:
	- Grammatical correction in commit message "adds"
	- Fixed the config name to indicate both F and D 

 arch/riscv/Kconfig  |  7 +++++++
 arch/riscv/Makefile | 12 ++++++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 362f3cdc65..e7a76c67cc 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -91,6 +91,13 @@ config RISCV_ISA_C
 	  when building U-Boot, which results in compressed instructions in the
 	  U-Boot binary.
 
+config RISCV_ISA_FD
+	bool "Emit Floating-point instructions"
+	help
+	  Adds "F" and "D" to the ISA subsets that the toolchain is allowed to emit
+	  when building U-Boot, which results in Single and Double-precision instructions
+	  in the U-Boot binary.
+
 config RISCV_ISA_A
 	def_bool y
 
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 0b80eb8d86..5a5c8e75f0 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -5,15 +5,19 @@
 
 ifeq ($(CONFIG_ARCH_RV64I),y)
 	ARCH_BASE = rv64im
-	ABI = lp64
+	ABI := lp64
 endif
 ifeq ($(CONFIG_ARCH_RV32I),y)
 	ARCH_BASE = rv32im
-	ABI = ilp32
+	ABI := ilp32
 endif
 ifeq ($(CONFIG_RISCV_ISA_A),y)
 	ARCH_A = a
 endif
+ifeq ($(CONFIG_RISCV_ISA_FD),y)
+	ARCH_FD = fd
+	ABI := $(ABI)d
+endif
 ifeq ($(CONFIG_RISCV_ISA_C),y)
 	ARCH_C = c
 endif
@@ -24,8 +28,8 @@ ifeq ($(CONFIG_CMODEL_MEDANY),y)
 	CMODEL = medany
 endif
 
-ARCH_FLAGS = -march=$(ARCH_BASE)$(ARCH_A)$(ARCH_C) -mabi=$(ABI) \
-	     -mcmodel=$(CMODEL)
+ARCH_FLAGS = -march=$(ARCH_BASE)$(ARCH_A)$(ARCH_FD)$(ARCH_C) -mabi=$(ABI) \
+			         -mcmodel=$(CMODEL)
 
 PLATFORM_CPPFLAGS	+= $(ARCH_FLAGS)
 CFLAGS_EFI		+= $(ARCH_FLAGS)
-- 
2.17.0