Hi Bin
Bin Meng bmeng.cn@gmail.com 於 2019年5月22日 週三 下午5:25寫道：
Hi Eric,
On Wed, May 22, 2019 at 4:23 PM tesheng@andestech.com wrote:
Hi Bin,
-----Original Message----- From: Bin Meng [mailto:bmeng.cn@gmail.com] Sent: Tuesday, May 21, 2019 3:56 PM To: Eric Te-Sheng Lin(林德晟) Cc: U-Boot Mailing List; Lukas Auer; Anup Patel; Rick Jian-Zhi Chen(陳建志); Greentime Ying-Han Hu(胡英漢); dslin1010@gmail.com Subject: Re: [PATCH] riscv: add Kconfig entries for the F and D ISA extensions support
Hi Eric,
On Tue, May 21, 2019 at 3:18 PM Eric Lin tesheng@andestech.com wrote:
This patch add Kconfig entries for the F (Single-Precision)
adds
OK I'll correct it as adds
and D (Double-Precision) floating point instruction-set extensions.
Could you please provide reason that why U-Boot has to be compiled using F/D extension?
Cause on AE350 platform, we have two different kinds of toolchain v5d (support I/M/A/C/F/D ISA) and v5 (support I/M/A/C ISA). If we use the v5d toolchain to build U-Boot it will build fail, so we would like to add F/D extension on U-Boot.
I don't understand. What difference do these two toochains have? Isn't the v5d toolchain's default -march string be pre-configured to imafd? But even if the toolchain is pre-configured to generate fd instruction, I think it can be override by the compiler flags. Can you please share the details of the toolchain you used? I suspect you have to fix your toolchain, not U-Boot.
It's seems the ABI issue. Because our toolchain don't support multilib, the v5d toolchain libraries ABI is ilp64d. If I use the v5d toolchain to build U-Boot with -mabi=lp64, it will get link error as below: ... riscv64-linux-ld.bfd: /nds64le-linux-glibc-v5d/bin/../lib/gcc/riscv64-linux/7.3.0/libgcc.a(save-restore.o): can't link double-float modules with soft-float modules riscv64-linux-ld.bfd: failed to merge target specific data of file /nds64le-linux-glibc-v5d/bin/../lib/gcc/riscv64-linux/7.3.0/libgcc.a(save-restore.o) examples/standalone/Makefile:62: recipe for target 'examples/standalone/hello_world' failed ...
so we would like to override the compiler flag mabi to lp64d.
Signed-off-by: Eric Lin tesheng@andestech.com
arch/riscv/Kconfig | 8 ++++++++ arch/riscv/Makefile | 12 ++++++++---- 2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 362f3cdc65..a8031fa230 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -91,6 +91,14 @@ config RISCV_ISA_C when building U-Boot, which results in compressed instructions
in the
U-Boot binary.+config RISCV_ISA_F
bool "Emit Floating-point instructions"default nthis can be dropped as default is n
OK, I'll drop it
helpAdds "F" to the ISA subsets that the toolchain is allowed to emitwhen building U-Boot, which results in Single and- Double-precision instructions
This does not match what the config name says. The config name is for F and it cannot indicate both F and D here.
OK, I'll correct it as follows to cover F and D: 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.
in the U-Boot binary.config RISCV_ISA_A def_bool y
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 0b80eb8d86..87ec0ea4b5 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -5,15 +5,19 @@
ifeq ($(CONFIG_ARCH_RV64I),y) ARCH_BASE = rv64im
ABI = lp64
ABI := lp64endif ifeq ($(CONFIG_ARCH_RV32I),y) ARCH_BASE = rv32im
ABI = ilp32
ABI := ilp32endif ifeq ($(CONFIG_RISCV_ISA_A),y) ARCH_A = a endif +ifeq ($(CONFIG_RISCV_ISA_F),y)
ARCH_F = fdifeq ($(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)$(ARCH_F)$(ARCH_C)
ARCH_FLAGS = -march=$(ARCH_BASE)$(ARCH_A)$(ARCH_FD)$(ARCH_C)
-mabi=$(ABI) \
-mcmodel=$(CMODEL)PLATFORM_CPPFLAGS += $(ARCH_FLAGS) CFLAGS_EFI += $(ARCH_FLAGS)
Regards, Bin
Thanks for your review Eric