[PATCH v2 4/7] selftests/nolibc: add XARCH and ARCH mapping support

From: Zhangjin Wu
Date: Wed Jul 26 2023 - 10:54:52 EST


Most of the CPU architectures have different variants, but kernel
usually only accept parts of them via the ARCH variable, the others
should be customized via kernel config file.

To simplify testing, the external ARCH variable is extended to accept
more CPU variants from user's input, a new internal XARCH variable is
added to save users' ARCH input and used to customize variant specific
variables, at last convert XARCH to the internal ARCH variable
acceptable by kernel:

e.g. make run-user ARCH=<variants>
|
v
external ARCH from cmdline -> internal XARCH -> internal ARCH for kernel
|
`--> variant specific variables

XARCH and ARCH are carefully mapped to allow users to pass architecture
variants via external ARCH (or XARCH) from cmdline:

- From developers' perspective

- XARCH records the architecture variant from user's ARCH input, after
'override ARCH', ARCH is overridden by the one supported by kernel

- Map from XARCH to the kernel supported ARCH: 'ARCH_<XARCH> = <ARCH>'

- Configure a default variant for kernel supported ARCH: 'XARCH_<ARCH> = <XARCH>'

- From users' perspective

- ARCH (or XARCH) are architecture variants of a target architecture

- the variants are XARCH names from the "ARCH_<XARCH> = <ARCH>" mapping list

Suggested-by: Willy Tarreau <w@xxxxxx>
Link: https://lore.kernel.org/lkml/20230702171715.GD16233@xxxxxx/
Reviewed-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Signed-off-by: Zhangjin Wu <falcon@xxxxxxxxxxx>
---
tools/testing/selftests/nolibc/Makefile | 27 ++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 9576f1a0a98d..f04ec1cc132b 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -14,6 +14,14 @@ include $(srctree)/scripts/subarch.include
ARCH = $(SUBARCH)
endif

+# XARCH is used to save user-input ARCH variant
+# allow configure default variant for target ARCH
+XARCH := $(or $(XARCH_$(ARCH)),$(ARCH))
+
+# ARCH is supported by kernel
+# map from user-input variant to kernel-supported
+override ARCH := $(or $(ARCH_$(XARCH)),$(XARCH))
+
# kernel image names by architecture
IMAGE_i386 = arch/x86/boot/bzImage
IMAGE_x86_64 = arch/x86/boot/bzImage
@@ -24,7 +32,7 @@ IMAGE_mips = vmlinuz
IMAGE_riscv = arch/riscv/boot/Image
IMAGE_s390 = arch/s390/boot/bzImage
IMAGE_loongarch = arch/loongarch/boot/vmlinuz.efi
-IMAGE = $(IMAGE_$(ARCH))
+IMAGE = $(IMAGE_$(XARCH))
IMAGE_NAME = $(notdir $(IMAGE))

# default kernel configurations that appear to be usable
@@ -37,10 +45,10 @@ DEFCONFIG_mips = malta_defconfig
DEFCONFIG_riscv = defconfig
DEFCONFIG_s390 = defconfig
DEFCONFIG_loongarch = defconfig
-DEFCONFIG = $(DEFCONFIG_$(ARCH))
+DEFCONFIG = $(DEFCONFIG_$(XARCH))

# extra kernel config files under configs/, include common + architecture specific
-EXTCONFIG = common.config $(ARCH).config
+EXTCONFIG = common.config $(XARCH).config

# optional tests to run (default = all)
TEST =
@@ -55,7 +63,7 @@ QEMU_ARCH_mips = mipsel # works with malta_defconfig
QEMU_ARCH_riscv = riscv64
QEMU_ARCH_s390 = s390x
QEMU_ARCH_loongarch = loongarch64
-QEMU_ARCH = $(QEMU_ARCH_$(ARCH))
+QEMU_ARCH = $(QEMU_ARCH_$(XARCH))

# QEMU_ARGS : some arch-specific args to pass to qemu
QEMU_ARGS_i386 = -M pc -append "console=ttyS0,9600 i8042.noaux panic=-1 $(TEST:%=NOLIBC_TEST=%)"
@@ -67,7 +75,7 @@ QEMU_ARGS_mips = -M malta -append "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=%)"
-QEMU_ARGS = $(QEMU_ARGS_$(ARCH)) $(QEMU_ARGS_EXTRA)
+QEMU_ARGS = $(QEMU_ARGS_$(XARCH)) $(QEMU_ARGS_EXTRA)

# OUTPUT is only set when run from the main makefile, otherwise
# it defaults to this nolibc directory.
@@ -84,7 +92,7 @@ CFLAGS_mips = -EL
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 \
$(call cc-option,-fno-stack-protector) \
- $(CFLAGS_$(ARCH)) $(CFLAGS_STACKPROTECTOR)
+ $(CFLAGS_$(XARCH)) $(CFLAGS_STACKPROTECTOR)
LDFLAGS := -s

REPORT ?= awk '/\[OK\][\r]*$$/{p++} /\[FAIL\][\r]*$$/{if (!f) printf("\n"); f++; print;} /\[SKIPPED\][\r]*$$/{s++} \
@@ -102,7 +110,7 @@ help:
@echo " run-user runs the executable under QEMU (uses \$$ARCH, \$$TEST)"
@echo " initramfs prepare the initramfs with nolibc-test"
@echo " defconfig create a fresh new default config (uses \$$ARCH)"
- @echo " kernel (re)build the kernel with the initramfs (uses \$$ARCH)"
+ @echo " kernel (re)build the kernel with the initramfs (uses $$ARCH)"
@echo " run runs the kernel in QEMU after building it (uses \$$ARCH, \$$TEST)"
@echo " rerun runs a previously prebuilt kernel in QEMU (uses \$$ARCH, \$$TEST)"
@echo " clean clean the sysroot, initramfs, build and output files"
@@ -111,12 +119,13 @@ help:
@echo ""
@echo "Currently using the following variables:"
@echo " ARCH = $(ARCH)"
+ @echo " XARCH = $(XARCH)"
@echo " CROSS_COMPILE = $(CROSS_COMPILE)"
@echo " CC = $(CC)"
@echo " OUTPUT = $(OUTPUT)"
@echo " TEST = $(TEST)"
- @echo " QEMU_ARCH = $(if $(QEMU_ARCH),$(QEMU_ARCH),UNKNOWN_ARCH) [determined from \$$ARCH]"
- @echo " IMAGE_NAME = $(if $(IMAGE_NAME),$(IMAGE_NAME),UNKNOWN_ARCH) [determined from \$$ARCH]"
+ @echo " QEMU_ARCH = $(if $(QEMU_ARCH),$(QEMU_ARCH),UNKNOWN_ARCH) [determined from \$$XARCH]"
+ @echo " IMAGE_NAME = $(if $(IMAGE_NAME),$(IMAGE_NAME),UNKNOWN_ARCH) [determined from \$$XARCH]"
@echo ""

all: run
--
2.25.1