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Commit 456a29dd authored by Dave Young's avatar Dave Young Committed by Matt Fleming
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x86: Add xloadflags bit for EFI runtime support on kexec 



Old kexec-tools can not load new kernels. The reason is kexec-tools does
not fill efi_info in x86 setup header previously, thus EFI failed to
initialize.  In new kexec-tools it will by default to fill efi_info and
pass other EFI required infomation to 2nd kernel so kexec kernel EFI
initialization can succeed finally.

To prevent from breaking userspace, add a new xloadflags bit so
kexec-tools can check the flag and switch to old logic.

Signed-off-by: default avatarDave Young <dyoung@redhat.com>
Acked-by: default avatarBorislav Petkov <bp@suse.de>
Tested-by: default avatarToshi Kani <toshi.kani@hp.com>
Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
parent 1fec0533

Documentation/x86/boot.txt

+3 −0
Original line number Original line Diff line number Diff line
@@ -608,6 +608,9 @@ Protocol: 2.12+ 
	- If 1, the kernel supports the 64-bit EFI handoff entry point

	- If 1, the kernel supports the 64-bit EFI handoff entry point

          given at handover_offset + 0x200.

          given at handover_offset + 0x200.





  Bit 4 (read): XLF_EFI_KEXEC

	- If 1, the kernel supports kexec EFI boot with EFI runtime support.



Field name:	cmdline_size

Field name:	cmdline_size

Type:		read

Type:		read

Offset/size:	0x238/4

Offset/size:	0x238/4

arch/x86/boot/header.S

+8 −1
Original line number Original line Diff line number Diff line
@@ -391,7 +391,14 @@ xloadflags: 
#else

#else

# define XLF23 0

# define XLF23 0

#endif

#endif

			.word XLF0 | XLF1 | XLF23



#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC)

# define XLF4 XLF_EFI_KEXEC

#else

# define XLF4 0

#endif



			.word XLF0 | XLF1 | XLF23 | XLF4





cmdline_size:   .long   COMMAND_LINE_SIZE-1     #length of the command line,

cmdline_size:   .long   COMMAND_LINE_SIZE-1     #length of the command line,

                                                #added with boot protocol

                                                #added with boot protocol

arch/x86/include/uapi/asm/bootparam.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -24,6 +24,7 @@ 
#define XLF_CAN_BE_LOADED_ABOVE_4G	(1<<1)

#define XLF_CAN_BE_LOADED_ABOVE_4G	(1<<1)

#define XLF_EFI_HANDOVER_32		(1<<2)

#define XLF_EFI_HANDOVER_32		(1<<2)

#define XLF_EFI_HANDOVER_64		(1<<3)

#define XLF_EFI_HANDOVER_64		(1<<3)

#define XLF_EFI_KEXEC			(1<<4)





#ifndef __ASSEMBLY__

#ifndef __ASSEMBLY__