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authorBrian Mak <makb@juniper.net>2025-08-05 14:15:27 -0700
committerAndrew Morton <akpm@linux-foundation.org>2025-09-13 17:32:43 -0700
commitf367474b5884edbc42661e7fecf784cb131dd25d (patch)
treec741ae41f49be0f846fca4c44c610cc8cd4c9908 /include/linux
parent1440648c0feed03cfd51c7dba92a77feb34bf27b (diff)
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 <makb@juniper.net> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Young <dyoung@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Rob Herring <robh@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/kexec.h5
1 files changed, 4 insertions, 1 deletions
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;