On Tue, Jun 6, 2023, at 13:12, Zhangjin Wu wrote:
On Sat, Jun 3, 2023, at 11:05, Zhangjin Wu wrote: would seem more consistent with how x86 is handled, and would probably be more easily extensible if we want to also make this work with other sub-targets like mipseb, armv5 or ppc32 in the future.
As Arnd and Thomas suggested to align with x86, I just tried to find a solution to avoid mixing the use of _ARCH and ARCH in this Makefile.
Since both riscv32 and riscv64 share the same SRCARCH=riscv (arch/riscv), and the kernel side doesn't accept riscv32 or riscv64 currently, we need to manually convert them to _ARCH=riscv and pass them to the kernel makefile like this: ARCH=$(_ARCH), it mixes the use of _ARCH and ARCH, this is why I used the '$(if' method currently.
The solution is adding something like x86 in the kernel Makefile:
diff --git a/Makefile b/Makefile index 9d765ebcccf1..a442c893d795 100644 --- a/Makefile +++ b/Makefile @@ -415,6 +415,14 @@ ifeq ($(ARCH),parisc64) SRCARCH := parisc endif +# Additional ARCH settings for riscv +ifeq ($(ARCH),riscv32) + SRCARCH := riscv +endif +ifeq ($(ARCH),riscv64) + SRCARCH := riscv +endif + export cross_compiling := ifneq ($(SRCARCH),$(SUBARCH)) cross_compiling := 1I've never been a big fan of the top-level $(ARCH) setting in the kernel, is there a reason this has to be the same as the variable in tools/include/nolibc? If not, I'd just leave the Linux Makefile unchanged.
For userspace we have a lot more target names than arch/*/ directories in the kernel, and I don't think I'd want to enumerate all the possibilities in the build system globally.
Ok, agree very much, it is the root cause why we used the old method before, because I don't want to touch the top-level Makefile, here explains the details again just as did for Thomas and Willy [1] ;-)
Without the top-level makefile change, we must add something in selftests/nolibc/Makefile like this, because the kernel makefile doesn't accept something like ARCH=riscv32 and ARCH=riscv64 currently, it only accepts ARCH=riscv (will paste the code later).
ifneq ($(findstring riscv,$(ARCH)),) _ARCH = riscv else _ARCH = $(ARCH) endif
...
sysroot/$(ARCH)/include: $(Q)rm -rf sysroot/$(ARCH) sysroot/sysroot $(QUIET_MKDIR)mkdir -p sysroot $(Q)$(MAKE) -C ../../../include/nolibc ARCH=$(_ARCH) OUTPUT=$(CURDIR)/sysroot/ headers_standalone $(Q)mv sysroot/sysroot sysroot/$(ARCH)
defconfig: $(Q)$(MAKE) -C $(srctree) ARCH=$(_ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare
kernel: initramfs $(Q)$(MAKE) -C $(srctree) ARCH=$(_ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME) CONFIG_INITRAMFS_SOURCE=$(CURDIR)/initramfs
The above change really works, but it looks not that good, this is the mixing use of _ARCH and ARCH I mentioned in last reply.
Otherwise, we will get such error:
$ make run ARCH=riscv64 CROSS_COMPILE=riscv64-linux-gnu- MKDIR sysroot/riscv64/include make[1]: Entering directory '/labs/linux-lab/src/linux-stable/tools/include/nolibc' make[2]: Entering directory '/labs/linux-lab/src/linux-stable' Makefile:763: arch/riscv64/Makefile: No such file or directory make[2]: *** No rule to make target 'arch/riscv64/Makefile'. Stop. make[2]: Leaving directory '/labs/linux-lab/src/linux-stable' make[1]: *** [Makefile:87: headers_standalone] Error 2 make[1]: Leaving directory '/labs/linux-lab/src/linux-stable/tools/include/nolibc' make: *** [Makefile:129: sysroot/riscv64/include] Error 2 $ make run ARCH=riscv32 CROSS_COMPILE=riscv64-linux-gnu- MKDIR sysroot/riscv32/include make[1]: Entering directory '/labs/linux-lab/src/linux-stable/tools/include/nolibc' make[2]: Entering directory '/labs/linux-lab/src/linux-stable' Makefile:763: arch/riscv32/Makefile: No such file or directory make[2]: *** No rule to make target 'arch/riscv32/Makefile'. Stop. make[2]: Leaving directory '/labs/linux-lab/src/linux-stable' make[1]: *** [Makefile:87: headers_standalone] Error 2 make[1]: Leaving directory '/labs/linux-lab/src/linux-stable/tools/include/nolibc' make: *** [Makefile:129: sysroot/riscv32/include] Error 2
That's because in top-level Makefile, it doesn't accept ARCH=riscv32 and ARCH=riscv64, but x86 and sparc and even parisc support such variants, this allows the ARCH variants share the same arch/<SRCARCH>/ source code tree, otherwise, they will directly find the arch/<ARCH>/ source code, then fails.
top-level Makefile:
... ARCH ?= $(SUBARCH)
# Architecture as present in compile.h UTS_MACHINE := $(ARCH) SRCARCH := $(ARCH) ---> SRCARCH is assigned as ARCH by default
# Additional ARCH settings for x86 ifeq ($(ARCH),i386) SRCARCH := x86 endif ifeq ($(ARCH),x86_64) SRCARCH := x86 endif
# Additional ARCH settings for sparc ifeq ($(ARCH),sparc32) SRCARCH := sparc endif ifeq ($(ARCH),sparc64) SRCARCH := sparc endif
# Additional ARCH settings for parisc ifeq ($(ARCH),parisc64) SRCARCH := parisc endif
So, to really align with x86, we should let the top-level makefile be able to get the right SRCARCH for riscv32 and riscv64 too ;-)
I even tried to pass SRCARCH=riscv to the top-level Makefile, but it failed:
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile index 1b2247a6365d..04067776b569 100644 --- a/tools/testing/selftests/nolibc/Makefile +++ b/tools/testing/selftests/nolibc/Makefile @@ -14,6 +14,10 @@ include $(srctree)/scripts/subarch.include ARCH = $(SUBARCH) endif
+ifneq ($(findstring riscv,$(ARCH)),) +SRCARCH := SRCARCH=riscv +endif + # kernel image names by architecture IMAGE_i386 = arch/x86/boot/bzImage IMAGE_x86_64 = arch/x86/boot/bzImage @@ -126,7 +130,7 @@ sysroot: sysroot/$(ARCH)/include sysroot/$(ARCH)/include: $(Q)rm -rf sysroot/$(ARCH) sysroot/sysroot $(QUIET_MKDIR)mkdir -p sysroot - $(Q)$(MAKE) -C ../../../include/nolibc ARCH=$(ARCH) OUTPUT=$(CURDIR)/sysroot/ headers_standalone + $(Q)$(MAKE) -C ../../../include/nolibc ARCH=$(ARCH) $(SRCARCH) OUTPUT=$(CURDIR)/sysroot/ headers_standalone $(Q)mv sysroot/sysroot sysroot/$(ARCH)
nolibc-test: nolibc-test.c sysroot/$(ARCH)/include @@ -150,10 +154,10 @@ initramfs: nolibc-test $(Q)cp nolibc-test initramfs/init
defconfig: - $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare + $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) $(SRCARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare
kernel: initramfs - $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME) CONFIG_INITRAMFS_SOURCE=$(CURDIR)/initramfs + $(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) $(SRCARCH )CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME) CONFIG_INITRAMFS_SOURCE=$(CURDIR)/initramfs
# run the tests after building the kernel run: kernel
$ make run ARCH=riscv32 CROSS_COMPILE=riscv64-linux-gnu- QEMU_ARGS_EXTRA="-bios /labs/linux-lab/opensbi-riscv32-generic-fw_dynamic.bin" MKDIR sysroot/riscv32/include make[1]: Entering directory '/labs/linux-lab/src/linux-stable/tools/include/nolibc' make[2]: Entering directory '/labs/linux-lab/src/linux-stable' Makefile:397: srcarch: riscv make[2]: Leaving directory '/labs/linux-lab/src/linux-stable' make[2]: Entering directory '/labs/linux-lab/src/linux-stable' Makefile:397: srcarch: riscv INSTALL /labs/linux-lab/src/linux-stable/tools/testing/selftests/nolibc/sysroot/sysroot/include make[2]: Leaving directory '/labs/linux-lab/src/linux-stable' make[1]: Leaving directory '/labs/linux-lab/src/linux-stable/tools/include/nolibc' CC nolibc-test MKDIR initramfs INSTALL initramfs/init make[1]: Entering directory '/labs/linux-lab/src/linux-stable' Makefile:397: srcarch: riscv32 SYNC include/config/auto.conf.cmd Makefile:397: srcarch: riscv32 Makefile:687: arch/riscv32/Makefile: No such file or directory make[2]: *** No rule to make target 'arch/riscv32/Makefile'. Stop. make[1]: *** [Makefile:795: include/config/auto.conf.cmd] Error 2 make[1]: Leaving directory '/labs/linux-lab/src/linux-stable'
So, to keep consistent eventually, perhaps we do need to touch the top-level Makefile.
Best regards, Zhangjin
[1]: https://lore.kernel.org/linux-riscv/20230526092029.149351-1-falcon@tinylab.o...
Arnd