From: Christian Marangi <ansuelsmth@gmail.com>
Date: Mon, 16 Sep 2024 16:38:16 +0000 (+0200)
Subject: kernel: copy kernel build dir on Per-Device Initramfs compilation
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=d78dec3e19e3f2ab0f14ba6819357d50156b30b8;p=openwrt%2Fstaging%2Fthess.git

kernel: copy kernel build dir on Per-Device Initramfs compilation

To speedup compilation of Per-Device Initramfs, copy the kernel build
directory for each rootfs ID.

This permits concurrent execution of kernel build without conflicting
with each other at the expense of additional disk space usage.

To limit disk space usage, the copied kernel directory is deleted after
the Per-Device Initramfs image is generated and saved.

Link: https://github.com/openwrt/openwrt/pull/16404
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---

diff --git a/include/kernel-defaults.mk b/include/kernel-defaults.mk
index fc1262aad3..e9e36d72b6 100644
--- a/include/kernel-defaults.mk
+++ b/include/kernel-defaults.mk
@@ -153,13 +153,13 @@ endif
 # $1: image suffix
 # $2: Per Device Rootfs ID
 define Kernel/CopyImage
-	cmp -s $(LINUX_DIR)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).debug$(2) || { \
-		$(KERNEL_CROSS)objcopy -O binary $(OBJCOPY_STRIP) -S $(LINUX_DIR)/vmlinux $(LINUX_KERNEL)$(1)$(2); \
-		$(KERNEL_CROSS)objcopy $(OBJCOPY_STRIP) -S $(LINUX_DIR)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).elf$(2); \
-		$(CP) $(LINUX_DIR)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).debug$(2); \
+	cmp -s $(LINUX_DIR)$(2)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).debug$(2) || { \
+		$(KERNEL_CROSS)objcopy -O binary $(OBJCOPY_STRIP) -S $(LINUX_DIR)$(2)/vmlinux $(LINUX_KERNEL)$(1)$(2); \
+		$(KERNEL_CROSS)objcopy $(OBJCOPY_STRIP) -S $(LINUX_DIR)$(2)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).elf$(2); \
+		$(CP) $(LINUX_DIR)$(2)/vmlinux $(KERNEL_BUILD_DIR)/vmlinux$(1).debug$(2); \
 		$(foreach k, \
 			$(if $(KERNEL_IMAGES),$(KERNEL_IMAGES),$(filter-out vmlinux dtbs,$(KERNELNAME))), \
-			$(CP) $(LINUX_DIR)/arch/$(LINUX_KARCH)/boot/$(IMAGES_DIR)/$(k) $(KERNEL_BUILD_DIR)/$(k)$(1)$(2); \
+			$(CP) $(LINUX_DIR)$(2)/arch/$(LINUX_KARCH)/boot/$(IMAGES_DIR)/$(k) $(KERNEL_BUILD_DIR)/$(k)$(1)$(2); \
 		) \
 	}
 endef
@@ -173,7 +173,9 @@ endef
 define Kernel/PrepareConfigPerRootfs
 	{ \
 		[ ! -d "$(1)" ] || rm -rf $(1); \
-		mkdir $(1) && $(CP) $(LINUX_DIR)/.config $(1); \
+		mkdir $(1) && $(CP) -T $(LINUX_DIR) $(1); \
+		touch $(1)/.config; \
+		rm -rf $(1)/usr/initramfs_data.cpio*; \
 	}
 endef
 
@@ -209,10 +211,9 @@ define Kernel/CompileImage/Initramfs
 			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_ZSTD), \
 				$(STAGING_DIR_HOST)/bin/zstd -T0 -f -o $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio.zstd $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio;) \
 			$(if $(2),,$(KERNEL_MAKE) $(KERNEL_MAKEOPTS_IMAGE) $(if $(KERNELNAME),$(KERNELNAME),all);),\
-			$(call locked,$(if $(2),$(CP) $(LINUX_DIR)$(2)/.config* $(LINUX_DIR) && touch $(LINUX_DIR)/.config && ) \
-				rm -rf $(LINUX_DIR)/usr/initramfs_data.cpio* $(LINUX_DIR)/.config.prev && \
-				$(KERNEL_MAKE) $(KERNEL_MAKEOPTS_IMAGE) $(if $(KERNELNAME),$(KERNELNAME),all), compile-initramfs);) \
+			$(KERNEL_MAKE) $(if $(2),-C $(LINUX_DIR)$(2)) $(KERNEL_MAKEOPTS_IMAGE) $(if $(KERNELNAME),$(KERNELNAME),all);) \
 		$(call Kernel/CopyImage,-initramfs,$(2)); \
+		$(if $(2),rm -rf $(LINUX_DIR)$(2);) \
 	}, gen-initramfs$(if $(2),-$(2)));
 endef
 else