[PATCH v5 5/5] selftests/nolibc: riscv: customize makefile for rv32

[Zhangjin Wu]

Both riscv64 and riscv32 have:

* the same arch/riscv source code tree
* the same tools/include/nolibc/arch-riscv.h
* the same ARCH=riscv value passed to top-level kernel Makefile

The only differences are:

* riscv64 uses defconfig, riscv32 uses rv32_defconfig
* riscv64 uses qemu-system-riscv64, riscv32 uses qemu-system-riscv32
* riscv32 has different compiler options (-march= and -mabi=)

So, riscv32 can share most of the settings with riscv64, add riscv32
support like the original ARCH=riscv support.

To align with x86, the default riscv is reserved for riscv64 and a new
riscv64 is also added to allow users pass ARCH=riscv64 directly.

Since top-level kernel Makefile only accept ARCH=riscv, to make kernel
happy, let's set kernel specific KARCH as riscv for both riscv32 and
riscv64.

And since they share the same arch-riscv.h, let's set nolibc specific
NARCH as riscv too.

Usage:

    $ make defconfig ARCH=riscv32 CROSS_COMPILE=riscv64-linux-gnu- ...
    $ make run ARCH=riscv32 CROSS_COMPILE=riscv64-linux-gnu- ...

Suggested-by: Thomas Weißschuh <linux at weissschuh.net>
Link: https://lore.kernel.org/linux-riscv/4a3b1cdf-91d5-4668-925e-21f8f5c64a92@t-8ch.de/
Suggested-by: Arnd Bergmann <arnd at arndb.de>
Link: https://lore.kernel.org/linux-riscv/d1c83340-af4c-4780-a101-b9d22b47379c@app.fastmail.com/
Suggested-by: Willy Tarreau <w at 1wt.eu>
Link: https://lore.kernel.org/lkml/ZIAywHvr6UB1J4of@1wt.eu/
Signed-off-by: Zhangjin Wu <falcon at tinylab.org>
---
 tools/include/nolibc/Makefile           |  4 ++++
 tools/testing/selftests/nolibc/Makefile | 11 +++++++++++
 2 files changed, 15 insertions(+)

diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile
index 14a6416fa57f..875e13e3c851 100644
--- a/tools/include/nolibc/Makefile
+++ b/tools/include/nolibc/Makefile
@@ -24,9 +24,13 @@ Q=@
 endif
 
 # kernel supported ARCH names by architecture
+KARCH_riscv32    = riscv
+KARCH_riscv64    = riscv
 KARCH            = $(or $(KARCH_$(ARCH)),$(ARCH))
 
 # nolibc supported ARCH names by architecture
+NARCH_riscv32    = riscv
+NARCH_riscv64    = riscv
 NARCH_arm64      = aarch64
 NARCH            = $(or $(NARCH_$(ARCH)),$(ARCH))
 
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index ebecb8cfd947..848884204a84 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -15,6 +15,8 @@ ARCH = $(SUBARCH)
 endif
 
 # kernel supported ARCH names by architecture
+KARCH_riscv32    = riscv
+KARCH_riscv64    = riscv
 KARCH            = $(or $(KARCH_$(ARCH)),$(ARCH))
 
 # kernel image names by architecture
@@ -24,6 +26,8 @@ IMAGE_x86        = arch/x86/boot/bzImage
 IMAGE_arm64      = arch/arm64/boot/Image
 IMAGE_arm        = arch/arm/boot/zImage
 IMAGE_mips       = vmlinuz
+IMAGE_riscv32    = arch/riscv/boot/Image
+IMAGE_riscv64    = arch/riscv/boot/Image
 IMAGE_riscv      = arch/riscv/boot/Image
 IMAGE_s390       = arch/s390/boot/bzImage
 IMAGE_loongarch  = arch/loongarch/boot/vmlinuz.efi
@@ -37,6 +41,8 @@ DEFCONFIG_x86        = defconfig
 DEFCONFIG_arm64      = defconfig
 DEFCONFIG_arm        = multi_v7_defconfig
 DEFCONFIG_mips       = malta_defconfig
+DEFCONFIG_riscv32    = rv32_defconfig
+DEFCONFIG_riscv64    = defconfig
 DEFCONFIG_riscv      = defconfig
 DEFCONFIG_s390       = defconfig
 DEFCONFIG_loongarch  = defconfig
@@ -52,6 +58,8 @@ QEMU_ARCH_x86        = x86_64
 QEMU_ARCH_arm64      = aarch64
 QEMU_ARCH_arm        = arm
 QEMU_ARCH_mips       = mipsel  # works with malta_defconfig
+QEMU_ARCH_riscv32    = riscv32
+QEMU_ARCH_riscv64    = riscv64
 QEMU_ARCH_riscv      = riscv64
 QEMU_ARCH_s390       = s390x
 QEMU_ARCH_loongarch  = loongarch64
@@ -64,6 +72,8 @@ QEMU_ARGS_x86        = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(
 QEMU_ARGS_arm64      = -M virt -cpu cortex-a53 -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_arm        = -M virt -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_mips       = -M malta -append "panic=-1 $(TEST:%=NOLIBC_TEST=%)"
+QEMU_ARGS_riscv32    = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
+QEMU_ARGS_riscv64    = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_riscv      = -M virt -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_s390       = -M s390-ccw-virtio -m 1G -append "console=ttyS0 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
 QEMU_ARGS_loongarch  = -M virt -append "console=ttyS0,115200 panic=-1 $(TEST:%=NOLIBC_TEST=%)"
@@ -79,6 +89,7 @@ else
 Q=@
 endif
 
+CFLAGS_riscv32 = -march=rv32im -mabi=ilp32
 CFLAGS_s390 = -m64
 CFLAGS_mips = -EL
 CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all))
-- 
2.25.1