Commit 45839d09 authored by Thomas Weißschuh's avatar Thomas Weißschuh
Browse files

selftests/nolibc: don't embed initramfs into kernel image 



When the initramfs is embedded into the kernel each rebuild of it will
trigger a full kernel relink and all the expensive postprocessing steps.

Currently nolibc-test and therefore the initramfs are always rebuild,
even without source changes, leading to lots of slow kernel relinks.

Instead of linking the initramfs into the kernel assemble it manually
and pass it explicitly to qemu.
This avoids all of the kernel relinks.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Reviewed-by: default avatarNicolas Schier <nicolas@fjasle.eu>
Link: https://lore.kernel.org/r/20230917-nolibc-initramfs-v2-1-f0f293a8b198@weissschuh.net
parent 4ed03f63

tools/testing/selftests/nolibc/.gitignore

+1 −0
Original line number Diff line number Diff line 
/initramfs/

/initramfs.cpio

/libc-test

/nolibc-test

/run.out

tools/testing/selftests/nolibc/Makefile

+26 −16
Original line number Diff line number Diff line
@@ -137,9 +137,11 @@ help: 
	@echo "  nolibc-test       build the executable (uses \$$CC and \$$CROSS_COMPILE)"

	@echo "  libc-test         build an executable using the compiler's default libc instead"

	@echo "  run-user          runs the executable under QEMU (uses \$$XARCH, \$$TEST)"

	@echo "  initramfs    prepare the initramfs with nolibc-test"

	@echo "  initramfs.cpio    prepare the initramfs archive with nolibc-test"

	@echo "  initramfs         prepare the initramfs tree with nolibc-test"

	@echo "  defconfig         create a fresh new default config (uses \$$XARCH)"

	@echo "  kernel       (re)build the kernel with the initramfs (uses \$$XARCH)"

	@echo "  kernel            (re)build the kernel (uses \$$XARCH)"

	@echo "  kernel-standalone (re)build the kernel with the initramfs (uses \$$XARCH)"

	@echo "  run               runs the kernel in QEMU after building it (uses \$$XARCH, \$$TEST)"

	@echo "  rerun             runs a previously prebuilt kernel in QEMU (uses \$$XARCH, \$$TEST)"

	@echo "  clean             clean the sysroot, initramfs, build and output files"
@@ -195,6 +197,9 @@ run-user: nolibc-test 
	$(Q)qemu-$(QEMU_ARCH) ./nolibc-test > "$(CURDIR)/run.out" || :

	$(Q)$(REPORT) $(CURDIR)/run.out



initramfs.cpio: kernel nolibc-test

	$(QUIET_GEN)echo 'file /init nolibc-test 755 0 0' | $(srctree)/usr/gen_init_cpio - > initramfs.cpio



initramfs: nolibc-test

	$(QUIET_MKDIR)mkdir -p initramfs

	$(call QUIET_INSTALL, initramfs/init)
@@ -203,17 +208,20 @@ initramfs: nolibc-test 
defconfig:

	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) mrproper $(DEFCONFIG) prepare



kernel: initramfs

kernel:

	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME)



kernel-standalone: initramfs

	$(Q)$(MAKE) -C $(srctree) ARCH=$(ARCH) CC=$(CC) CROSS_COMPILE=$(CROSS_COMPILE) $(IMAGE_NAME) CONFIG_INITRAMFS_SOURCE=$(CURDIR)/initramfs



# run the tests after building the kernel

run: kernel

	$(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(srctree)/$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(CURDIR)/run.out"

run: kernel initramfs.cpio

	$(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(srctree)/$(IMAGE)" -initrd initramfs.cpio -serial stdio $(QEMU_ARGS) > "$(CURDIR)/run.out"

	$(Q)$(REPORT) $(CURDIR)/run.out



# re-run the tests from an existing kernel

rerun:

	$(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(srctree)/$(IMAGE)" -serial stdio $(QEMU_ARGS) > "$(CURDIR)/run.out"

	$(Q)qemu-system-$(QEMU_ARCH) -display none -no-reboot -kernel "$(srctree)/$(IMAGE)" -initrd initramfs.cpio -serial stdio $(QEMU_ARGS) > "$(CURDIR)/run.out"

	$(Q)$(REPORT) $(CURDIR)/run.out



# report with existing test log
@@ -227,6 +235,8 @@ clean: 
	$(Q)rm -f nolibc-test

	$(call QUIET_CLEAN, libc-test)

	$(Q)rm -f libc-test

	$(call QUIET_CLEAN, initramfs.cpio)

	$(Q)rm -rf initramfs.cpio

	$(call QUIET_CLEAN, initramfs)

	$(Q)rm -rf initramfs

	$(call QUIET_CLEAN, run.out)