x86, boot: add linked list of struct setup_data

This patch adds a field of 64-bit physical pointer to NULL terminated
single linked list of struct setup_data to real-mode kernel
header. This is used as a more extensible boot parameters passing
mechanism.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 6d2df8d61c54..af86e431acfa 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -120,7 +120,7 @@ _start:
         # Part 2 of the header, from the old setup.S
 
                 .ascii  "HdrS"          # header signature
-                .word   0x0208          # header version number (>= 0x0105)
+                .word   0x0209          # header version number (>= 0x0105)
                                         # or else old loadlin-1.5 will fail)
                 .globl realmode_swtch
 realmode_swtch: .word   0, 0            # default_switch, SETUPSEG
@@ -227,6 +227,10 @@ hardware_subarch_data:	.quad 0
 payload_offset:         .long input_data
 payload_length:         .long input_data_end-input_data
 
+setup_data:             .quad 0                 # 64-bit physical pointer to
+                                                # single linked list of
+                                                # struct setup_data
+
 # End of setup header #####################################################
 
         .section ".inittext", "ax"