[PATCH v2 13/13] selftests/nolibc: riscv: customize makefile for rv32

[Zhangjin Wu]

Willy, Arnd and Thomas

Based on your suggestions, in the comming v3, I plan to split the whole rv32
support to something like this:

1. Generic part1

   (The old feedbacks are applied with the new Suggested-by lines, welcome your
    additional feedbacks if there are ;-))

    selftests/nolibc: syscall_args: use generic __NR_statx
    tools/nolibc: add missing nanoseconds support for __NR_statx
    selftests/nolibc: allow specify extra arguments for qemu
    selftests/nolibc: fix up compile warning with glibc on x86_64
    selftests/nolibc: not include limits.h for nolibc
    selftests/nolibc: use INT_MAX instead of __INT_MAX__
    tools/nolibc: arm: add missing my_syscall6
    tools/nolibc: open: fix up compile warning for arm
    selftests/nolibc: support two errnos with EXPECT_SYSER2()
    selftests/nolibc: remove gettimeofday_bad1/2 completely
    selftests/nolibc: add new gettimeofday test cases

2. Add Compile support for rv32

   (Convert all of the unsupported syscalls to a return of -ENOSYS, this
    allows us to fix up the test failures one by one not that urgently later)

    tools/nolibc: fix up #error compile failures with -ENOSYS
    tools/nolibc: fix up undeclared syscall macros with #ifdef and -ENOSYS
    selftests/nolibc: riscv: customize makefile for rv32

   (The first two are new but clear enough, based on the idea of suggestion from Arnd [1])

3. Fix up the left test failures one by one

   (Plan to add everyone as a standalone patchset, which will easier the review
    and merge progress)

   wait4 -> waitid
   lseek -> llseek
   gettimeofday -> clock_gettime/clock_gettime64
   select -> pselect6/pselect6_time64
   ppoll -> ppoll_time64

4. Clean up some old test cases one by one

   Like statx ...

Best regards,
Zhangjin

[1]: https://lore.kernel.org/linux-riscv/5e7d2adf-e96f-41ca-a4c6-5c87a25d4c9c@app.fastmail.com/

> Both riscv64 and riscv32 have:
> 
> * the same ARCH value, it is riscv
> * the same arch/riscv source code tree
> 
> 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, there is no
> need to add it as a whole new architecture but just need a flag to
> record and reflect the difference.
> 
> The 32bit mips and loongarch may be able to use the same method, so,
> let's use a meaningful flag: CONFIG_32BIT. If required in the future,
> this flag can also be automatically loaded from
> include/config/auto.conf.
> 
> With this patch, it is able to run nolibc test for rv32 like this:
> 
>     $ make run ARCH=riscv32 CROSS_COMPILE=riscv64-linux-gnu- ...
> 
> Signed-off-by: Zhangjin Wu <falcon at tinylab.org>
> ---
>  tools/testing/selftests/nolibc/Makefile | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
> index 44088535682e..ea434a0acdc1 100644
> --- a/tools/testing/selftests/nolibc/Makefile
> +++ b/tools/testing/selftests/nolibc/Makefile
> @@ -14,6 +14,12 @@ include $(srctree)/scripts/subarch.include
>  ARCH = $(SUBARCH)
>  endif
>  
> +# Allow pass ARCH=riscv|riscv32|riscv64, riscv implies riscv64
> +ifneq ($(findstring xriscv,x$(ARCH)),)
> +  CONFIG_32BIT := $(if $(findstring 32x,$(ARCH)x),1)
> +  override ARCH := riscv
> +endif
> +
>  # kernel image names by architecture
>  IMAGE_i386       = arch/x86/boot/bzImage
>  IMAGE_x86_64     = arch/x86/boot/bzImage
> @@ -34,7 +40,7 @@ DEFCONFIG_x86        = defconfig
>  DEFCONFIG_arm64      = defconfig
>  DEFCONFIG_arm        = multi_v7_defconfig
>  DEFCONFIG_mips       = malta_defconfig
> -DEFCONFIG_riscv      = defconfig
> +DEFCONFIG_riscv      = $(if $(CONFIG_32BIT),rv32_defconfig,defconfig)
>  DEFCONFIG_s390       = defconfig
>  DEFCONFIG_loongarch  = defconfig
>  DEFCONFIG            = $(DEFCONFIG_$(ARCH))
> @@ -49,7 +55,7 @@ QEMU_ARCH_x86        = x86_64
>  QEMU_ARCH_arm64      = aarch64
>  QEMU_ARCH_arm        = arm
>  QEMU_ARCH_mips       = mipsel  # works with malta_defconfig
> -QEMU_ARCH_riscv      = riscv64
> +QEMU_ARCH_riscv      = $(if $(CONFIG_32BIT),riscv32,riscv64)
>  QEMU_ARCH_s390       = s390x
>  QEMU_ARCH_loongarch  = loongarch64
>  QEMU_ARCH            = $(QEMU_ARCH_$(ARCH))
> @@ -76,6 +82,7 @@ else
>  Q=@
>  endif
>  
> +CFLAGS_riscv = $(if $(CONFIG_32BIT),-march=rv32i -mabi=ilp32)
>  CFLAGS_s390 = -m64
>  CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all))
>  CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 \
> -- 
> 2.25.1