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authorMatt Fleming <matt.fleming@intel.com>2012-07-19 10:23:48 +0100
committerH. Peter Anvin <hpa@zytor.com>2012-07-20 16:18:58 -0700
commit9ca8f72a9297f2052d806bd1111e176533aa69bd (patch)
tree520e3a306588bd49ae618a7e1930028e4e38ea01 /arch/x86/boot/header.S
parentbacef661acdb634170a8faddbc1cf28e8f8b9eee (diff)
downloadlinux-linaro-stable-9ca8f72a9297f2052d806bd1111e176533aa69bd.tar.gz
x86, efi: Handover Protocol
As things currently stand, traditional EFI boot loaders and the EFI boot stub are carrying essentially the same initialisation code required to setup an EFI machine for booting a kernel. There's really no need to have this code in two places and the hope is that, with this new protocol, initialisation and booting of the kernel can be left solely to the kernel's EFI boot stub. The responsibilities of the boot loader then become, o Loading the kernel image from boot media File system code still needs to be carried by boot loaders for the scenario where the kernel and initrd files reside on a file system that the EFI firmware doesn't natively understand, such as ext4, etc. o Providing a user interface Boot loaders still need to display any menus/interfaces, for example to allow the user to select from a list of kernels. Bump the boot protocol number because we added the 'handover_offset' field to indicate the location of the handover protocol entry point. Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Jones <pjones@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Acked-and-Tested-by: Matthew Garrett <mjg@redhat.com> Link: http://lkml.kernel.org/r/1342689828-16815-1-git-send-email-matt@console-pimps.org Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/boot/header.S')
-rw-r--r--arch/x86/boot/header.S4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 8bbea6aa40d9..097f4760faea 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -263,7 +263,7 @@ _start:
# Part 2 of the header, from the old setup.S
.ascii "HdrS" # header signature
- .word 0x020a # header version number (>= 0x0105)
+ .word 0x020b # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
@@ -381,6 +381,8 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr
#define INIT_SIZE VO_INIT_SIZE
#endif
init_size: .long INIT_SIZE # kernel initialization size
+handover_offset: .long 0x30 # offset to the handover
+ # protocol entry point
# End of setup header #####################################################