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authorH. Peter Anvin <hpa@linux.intel.com>2013-01-27 10:43:28 -0800
committerH. Peter Anvin <hpa@linux.intel.com>2013-01-27 15:56:37 -0800
commit09c205afde70c15f20ca76ba0a57409dad175fd0 (patch)
tree77924ea22cf915e80ffbc5af58851c49e4820f5a /arch/x86/boot/header.S
parent65315d4889d403ea025081d8ca85ddf7b9c10f39 (diff)
x86, boot: Define the 2.12 bzImage boot protocol
Define the 2.12 bzImage boot protocol: add xloadflags and additional fields to allow the command line, initramfs and struct boot_params to live above the 4 GiB mark. The xloadflags now communicates if this is a 64-bit kernel with the legacy 64-bit entry point and which of the EFI handover entry points are supported. Avoid adding new read flags to loadflags because of claimed bootloaders testing the whole byte for == 1 to determine bzImageness at least until the issue can be researched further. This is based on patches by Yinghai Lu and David Woodhouse. Originally-by: Yinghai Lu <yinghai@kernel.org> Originally-by: David Woodhouse <dwmw2@infradead.org> Acked-by: Yinghai Lu <yinghai@kernel.org> Acked-by: David Woodhouse <dwmw2@infradead.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org Cc: Rob Landley <rob@landley.net> Cc: Gokul Caushik <caushik1@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joe Millenbach <jmillenbach@gmail.com>
Diffstat (limited to 'arch/x86/boot/header.S')
-rw-r--r--arch/x86/boot/header.S39
1 files changed, 29 insertions, 10 deletions
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 8c132a625b94..944ce595f767 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -21,6 +21,7 @@
#include <asm/e820.h>
#include <asm/page_types.h>
#include <asm/setup.h>
+#include <asm/bootparam.h>
#include "boot.h"
#include "voffset.h"
#include "zoffset.h"
@@ -255,6 +256,9 @@ section_table:
# header, from the old boot sector.
.section ".header", "a"
+ .globl sentinel
+sentinel: .byte 0xff, 0xff /* Used to detect broken loaders */
+
.globl hdr
hdr:
setup_sects: .byte 0 /* Filled in by build.c */
@@ -279,7 +283,7 @@ _start:
# Part 2 of the header, from the old setup.S
.ascii "HdrS" # header signature
- .word 0x020b # header version number (>= 0x0105)
+ .word 0x020c # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
@@ -297,13 +301,7 @@ type_of_loader: .byte 0 # 0 means ancient bootloader, newer
# flags, unused bits must be zero (RFU) bit within loadflags
loadflags:
-LOADED_HIGH = 1 # If set, the kernel is loaded high
-CAN_USE_HEAP = 0x80 # If set, the loader also has set
- # heap_end_ptr to tell how much
- # space behind setup.S can be used for
- # heap purposes.
- # Only the loader knows what is free
- .byte LOADED_HIGH
+ .byte LOADED_HIGH # The kernel is to be loaded high
setup_move_size: .word 0x8000 # size to move, when setup is not
# loaded at 0x90000. We will move setup
@@ -369,7 +367,23 @@ relocatable_kernel: .byte 1
relocatable_kernel: .byte 0
#endif
min_alignment: .byte MIN_KERNEL_ALIGN_LG2 # minimum alignment
-pad3: .word 0
+
+xloadflags:
+#ifdef CONFIG_X86_64
+# define XLF0 XLF_KERNEL_64 /* 64-bit kernel */
+#else
+# define XLF0 0
+#endif
+#ifdef CONFIG_EFI_STUB
+# ifdef CONFIG_X86_64
+# define XLF23 XLF_EFI_HANDOVER_64 /* 64-bit EFI handover ok */
+# else
+# define XLF23 XLF_EFI_HANDOVER_32 /* 32-bit EFI handover ok */
+# endif
+#else
+# define XLF23 0
+#endif
+ .word XLF0 | XLF23
cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
#added with boot protocol
@@ -397,8 +411,13 @@ 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
+handover_offset:
+#ifdef CONFIG_EFI_STUB
+ .long 0x30 # offset to the handover
# protocol entry point
+#else
+ .long 0
+#endif
# End of setup header #####################################################