From f367474b5884edbc42661e7fecf784cb131dd25d Mon Sep 17 00:00:00 2001 From: Brian Mak Date: Tue, 5 Aug 2025 14:15:27 -0700 Subject: x86/kexec: carry forward the boot DTB on kexec Currently, the kexec_file_load syscall on x86 does not support passing a device tree blob to the new kernel. Some embedded x86 systems use device trees. On these systems, failing to pass a device tree to the new kernel causes a boot failure. To add support for this, we copy the behavior of ARM64 and PowerPC and copy the current boot's device tree blob for use in the new kernel. We do this on x86 by passing the device tree blob as a setup_data entry in accordance with the x86 boot protocol. This behavior is gated behind the KEXEC_FILE_FORCE_DTB flag. Link: https://lkml.kernel.org/r/20250805211527.122367-3-makb@juniper.net Signed-off-by: Brian Mak Cc: Alexander Graf Cc: Baoquan He Cc: Borislav Betkov Cc: Dave Young Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Rob Herring Cc: Saravana Kannan Cc: Thomas Gleinxer Signed-off-by: Andrew Morton --- include/linux/kexec.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 39fe3e6cd282..ff7e231b0485 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -395,6 +395,9 @@ struct kimage { /* Information for loading purgatory */ struct purgatory_info purgatory_info; + + /* Force carrying over the DTB from the current boot */ + bool force_dtb; #endif #ifdef CONFIG_CRASH_HOTPLUG @@ -461,7 +464,7 @@ bool kexec_load_permitted(int kexec_image_type); /* List of defined/legal kexec file flags */ #define KEXEC_FILE_FLAGS (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \ KEXEC_FILE_NO_INITRAMFS | KEXEC_FILE_DEBUG | \ - KEXEC_FILE_NO_CMA) + KEXEC_FILE_NO_CMA | KEXEC_FILE_FORCE_DTB) /* flag to track if kexec reboot is in progress */ extern bool kexec_in_progress; -- cgit v1.2.3