Kconfig: add option to use compressed instructions for RISCV

There is another commit in PPSI repo doing the same for PPSI. Signed-off-by: Adam Wujek <dev_public@wujek.eu>

Kconfig: add option to use compressed instructions for RISCV
There is another commit in PPSI repo doing the same for PPSI. Signed-off-by: Adam Wujek <dev_public@wujek.eu>
9e38118b · Adam Wujek · 42d8028c · 9e38118b · 9e38118b · 9e38118b
Commit 9e38118b authored Dec 21, 2021 by Adam Wujek
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Showing with 17 additions and 6 deletions

Kconfig Kconfig +7 -0

Makefile Makefile +8 -5

spec_riscv_defconfig configs/spec_riscv_defconfig +1 -0

Makefile sdb-lib/Makefile +1 -1

No files found.
--- a/Kconfig
+++ b/Kconfig
@@ -16,6 +16,13 @@ config ARCH_RISCV

 endchoice

+config RISCV_COMP_INSTR
+	bool "Use compressed instructions for RISCV"
+	depends on ARCH_RISCV
+	default n
+	help
+	  Use compressed instructions for RISCV. This changes the compiler flags at build time.
+
 choice
 	prompt "Target Platform"


--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,9 @@ CROSS_COMPILE_RISCV ?= riscv-elf-
 CROSS_COMPILE-$(CONFIG_ARCH_LM32) ?= $(CROSS_COMPILE_LM32)
 CROSS_COMPILE-$(CONFIG_ARCH_RISCV) ?= $(CROSS_COMPILE_RISCV)

+# use compressed instructions for RISCV
+USE-COMP-INSTR-$(CONFIG_RISCV_COMP_INSTR) = c
+
 # use a cross compiler for all architectures
 CROSS_COMPILE ?= $(CROSS_COMPILE-y)

@@ -94,12 +97,12 @@ obj-$(CONFIG_EMBEDDED_NODE) += \
 	lib/ppsi-wrappers.o

 cflags-$(CONFIG_ARCH_LM32) += -mmultiply-enabled -mbarrel-shift-enabled
-cflags-$(CONFIG_ARCH_RISCV) += -march=rv32im -mabi=ilp32
+cflags-$(CONFIG_ARCH_RISCV) += -march=rv32im$(USE-COMP-INSTR-y) -mabi=ilp32
 ldflags-$(CONFIG_ARCH_LM32) = -mmultiply-enabled -mbarrel-shift-enabled \
 	-nostdlib -T $(LDS-y)
-ldflags-$(CONFIG_ARCH_RISCV) = -march=rv32im -mabi=ilp32 \
+ldflags-$(CONFIG_ARCH_RISCV) = -march=rv32im$(USE-COMP-INSTR-y) -mabi=ilp32 \
 	-nostdlib -T $(LDS-y)
-asflags-$(CONFIG_ARCH_RISCV) += -march=rv32im -mabi=ilp32
+asflags-$(CONFIG_ARCH_RISCV) += -march=rv32im$(USE-COMP-INSTR-y) -mabi=ilp32
 arch-files-$(CONFIG_ARCH_LM32) = $(OUTPUT).bram $(OUTPUT).vhd $(OUTPUT).mif
 arch-files-$(CONFIG_ARCH_RISCV) = $(OUTPUT).bram $(OUTPUT).vhd $(OUTPUT).mif

@@ -178,10 +181,10 @@ $(obj-ppsi): gitmodules
 	$(MAKE) -C $(PPSI) ppsi.a WRPCSW_ROOT=.. \
 		CROSS_COMPILE=$(CROSS_COMPILE) CONFIG_NO_PRINTF=y \
 		USER_CFLAGS="$(PPSI_USER_CFLAGS)" \
-		CPU_ARCH=$(CPU_ARCH)
+		CPU_ARCH=$(CPU_ARCH) \

 sdb-lib/libsdbfs.a:
-	$(MAKE) -C sdb-lib CPU_ARCH=$(CPU_ARCH)
+	$(MAKE) -C sdb-lib CPU_ARCH=$(CPU_ARCH) USE-COMP-INSTR-y=$(USE-COMP-INSTR-y)

 $(OUTPUT).elf: $(LDS-y) $(AUTOCONF) gitmodules config.o $(OBJS)
 	$(CC) $(CFLAGS) -D__GIT_VER__="\"$(GIT_VER)\"" -D__GIT_USR__="\"$(GIT_USR)\"" -c revision.c

--- a/configs/spec_riscv_defconfig
+++ b/configs/spec_riscv_defconfig
@@ -4,6 +4,7 @@
 #
 # CONFIG_ARCH_LM32 is not set
 CONFIG_ARCH_RISCV=y
+# CONFIG_RISCV_COMP_INSTR is not set
 CONFIG_TARGET_GENERIC_PHY_8BIT=y
 # CONFIG_TARGET_GENERIC_PHY_16BIT is not set
 # CONFIG_TARGET_WR_SWITCH is not set

--- a/sdb-lib/Makefile
+++ b/sdb-lib/Makefile
@@ -20,7 +20,7 @@ OBJDUMP         = $(CROSS_COMPILE)objdump
 ENDIAN := $(shell ./check-endian $(CC))

 CFLAGS-CPU-LM32  = -mmultiply-enabled -mbarrel-shift-enabled
-CFLAGS-CPU-RISCV = -march=rv32im -mabi=ilp32
+CFLAGS-CPU-RISCV = -march=rv32im$(USE-COMP-INSTR-y) -mabi=ilp32

 CFLAGS = -Wall -ggdb -Os $(CFLAGS-CPU-$(CPU_ARCH))
 CFLAGS += -I../include/linux -I../include # for <sdb.h>