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-rw-r--r--Documentation/kernel-parameters.txt3
-rw-r--r--Documentation/x86/boot.txt65
-rw-r--r--Documentation/x86/zero-page.txt4
-rw-r--r--arch/mips/cavium-octeon/dma-octeon.c3
-rw-r--r--arch/sparc/mm/init_64.c24
-rw-r--r--arch/x86/boot/boot.h18
-rw-r--r--arch/x86/boot/cmdline.c12
-rw-r--r--arch/x86/boot/compressed/cmdline.c12
-rw-r--r--arch/x86/boot/compressed/head_64.S48
-rw-r--r--arch/x86/boot/compressed/misc.c2
-rw-r--r--arch/x86/boot/compressed/misc.h1
-rw-r--r--arch/x86/boot/header.S47
-rw-r--r--arch/x86/boot/setup.ld2
-rw-r--r--arch/x86/include/asm/bootparam_utils.h38
-rw-r--r--arch/x86/include/asm/init.h28
-rw-r--r--arch/x86/include/asm/kexec.h6
-rw-r--r--arch/x86/include/asm/numa.h2
-rw-r--r--arch/x86/include/asm/numa_64.h6
-rw-r--r--arch/x86/include/asm/page.h4
-rw-r--r--arch/x86/include/asm/page_types.h2
-rw-r--r--arch/x86/include/asm/pgtable.h2
-rw-r--r--arch/x86/include/asm/pgtable_64_types.h4
-rw-r--r--arch/x86/include/asm/pgtable_types.h1
-rw-r--r--arch/x86/include/asm/processor.h1
-rw-r--r--arch/x86/include/asm/realmode.h3
-rw-r--r--arch/x86/include/asm/x86_init.h12
-rw-r--r--arch/x86/include/uapi/asm/bootparam.h63
-rw-r--r--arch/x86/kernel/acpi/boot.c1
-rw-r--r--arch/x86/kernel/amd_gart_64.c5
-rw-r--r--arch/x86/kernel/cpu/amd.c9
-rw-r--r--arch/x86/kernel/cpu/intel.c1
-rw-r--r--arch/x86/kernel/e820.c16
-rw-r--r--arch/x86/kernel/head32.c21
-rw-r--r--arch/x86/kernel/head64.c133
-rw-r--r--arch/x86/kernel/head_64.S210
-rw-r--r--arch/x86/kernel/machine_kexec_64.c171
-rw-r--r--arch/x86/kernel/setup.c231
-rw-r--r--arch/x86/kernel/traps.c9
-rw-r--r--arch/x86/kernel/x86_init.c4
-rw-r--r--arch/x86/mm/init.c459
-rw-r--r--arch/x86/mm/init_32.c106
-rw-r--r--arch/x86/mm/init_64.c237
-rw-r--r--arch/x86/mm/mm_internal.h19
-rw-r--r--arch/x86/mm/numa_64.c13
-rw-r--r--arch/x86/mm/pageattr.c16
-rw-r--r--arch/x86/platform/efi/efi.c7
-rw-r--r--arch/x86/power/hibernate_64.c66
-rw-r--r--arch/x86/realmode/init.c45
-rw-r--r--arch/x86/tools/relocs.c6
-rw-r--r--arch/x86/xen/mmu.c28
-rw-r--r--drivers/xen/swiotlb-xen.c4
-rw-r--r--include/linux/bootmem.h5
-rw-r--r--include/linux/kexec.h3
-rw-r--r--include/linux/memblock.h1
-rw-r--r--include/linux/mm.h1
-rw-r--r--include/linux/swiotlb.h2
-rw-r--r--kernel/kexec.c34
-rw-r--r--lib/swiotlb.c47
-rw-r--r--mm/bootmem.c8
-rw-r--r--mm/memblock.c17
-rw-r--r--mm/nobootmem.c23
61 files changed, 1429 insertions, 942 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 363e348bff9b..da0e0773ca96 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -594,6 +594,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
is selected automatically. Check
Documentation/kdump/kdump.txt for further details.
+ crashkernel_low=size[KMG]
+ [KNL, x86] parts under 4G.
+
crashkernel=range1:size1[,range2:size2,...][@offset]
[KNL] Same as above, but depends on the memory
in the running system. The syntax of range is
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 406d82d5d2bb..0e383169839a 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -57,6 +57,10 @@ Protocol 2.10: (Kernel 2.6.31) Added a protocol for relaxed alignment
Protocol 2.11: (Kernel 3.6) Added a field for offset of EFI handover
protocol entry point.
+Protocol 2.12: (Kernel 3.9) Added the xloadflags field and extension fields
+ to struct boot_params for for loading bzImage and ramdisk
+ above 4G in 64bit.
+
**** MEMORY LAYOUT
The traditional memory map for the kernel loader, used for Image or
@@ -182,7 +186,7 @@ Offset Proto Name Meaning
0230/4 2.05+ kernel_alignment Physical addr alignment required for kernel
0234/1 2.05+ relocatable_kernel Whether kernel is relocatable or not
0235/1 2.10+ min_alignment Minimum alignment, as a power of two
-0236/2 N/A pad3 Unused
+0236/2 2.12+ xloadflags Boot protocol option flags
0238/4 2.06+ cmdline_size Maximum size of the kernel command line
023C/4 2.07+ hardware_subarch Hardware subarchitecture
0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data
@@ -582,6 +586,27 @@ Protocol: 2.10+
misaligned kernel. Therefore, a loader should typically try each
power-of-two alignment from kernel_alignment down to this alignment.
+Field name: xloadflags
+Type: read
+Offset/size: 0x236/2
+Protocol: 2.12+
+
+ This field is a bitmask.
+
+ Bit 0 (read): XLF_KERNEL_64
+ - If 1, this kernel has the legacy 64-bit entry point at 0x200.
+
+ Bit 1 (read): XLF_CAN_BE_LOADED_ABOVE_4G
+ - If 1, kernel/boot_params/cmdline/ramdisk can be above 4G.
+
+ Bit 2 (read): XLF_EFI_HANDOVER_32
+ - If 1, the kernel supports the 32-bit EFI handoff entry point
+ given at handover_offset.
+
+ Bit 3 (read): XLF_EFI_HANDOVER_64
+ - If 1, the kernel supports the 64-bit EFI handoff entry point
+ given at handover_offset + 0x200.
+
Field name: cmdline_size
Type: read
Offset/size: 0x238/4
@@ -1029,6 +1054,44 @@ must have read/write permission; CS must be __BOOT_CS and DS, ES, SS
must be __BOOT_DS; interrupt must be disabled; %esi must hold the base
address of the struct boot_params; %ebp, %edi and %ebx must be zero.
+**** 64-bit BOOT PROTOCOL
+
+For machine with 64bit cpus and 64bit kernel, we could use 64bit bootloader
+and we need a 64-bit boot protocol.
+
+In 64-bit boot protocol, the first step in loading a Linux kernel
+should be to setup the boot parameters (struct boot_params,
+traditionally known as "zero page"). The memory for struct boot_params
+could be allocated anywhere (even above 4G) and initialized to all zero.
+Then, the setup header at offset 0x01f1 of kernel image on should be
+loaded into struct boot_params and examined. The end of setup header
+can be calculated as follows:
+
+ 0x0202 + byte value at offset 0x0201
+
+In addition to read/modify/write the setup header of the struct
+boot_params as that of 16-bit boot protocol, the boot loader should
+also fill the additional fields of the struct boot_params as described
+in zero-page.txt.
+
+After setting up the struct boot_params, the boot loader can load
+64-bit kernel in the same way as that of 16-bit boot protocol, but
+kernel could be loaded above 4G.
+
+In 64-bit boot protocol, the kernel is started by jumping to the
+64-bit kernel entry point, which is the start address of loaded
+64-bit kernel plus 0x200.
+
+At entry, the CPU must be in 64-bit mode with paging enabled.
+The range with setup_header.init_size from start address of loaded
+kernel and zero page and command line buffer get ident mapping;
+a GDT must be loaded with the descriptors for selectors
+__BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat
+segment; __BOOT_CS must have execute/read permission, and __BOOT_DS
+must have read/write permission; CS must be __BOOT_CS and DS, ES, SS
+must be __BOOT_DS; interrupt must be disabled; %rsi must hold the base
+address of the struct boot_params.
+
**** EFI HANDOVER PROTOCOL
This protocol allows boot loaders to defer initialisation to the EFI
diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
index cf5437deda81..199f453cb4de 100644
--- a/Documentation/x86/zero-page.txt
+++ b/Documentation/x86/zero-page.txt
@@ -19,6 +19,9 @@ Offset Proto Name Meaning
090/010 ALL hd1_info hd1 disk parameter, OBSOLETE!!
0A0/010 ALL sys_desc_table System description table (struct sys_desc_table)
0B0/010 ALL olpc_ofw_header OLPC's OpenFirmware CIF and friends
+0C0/004 ALL ext_ramdisk_image ramdisk_image high 32bits
+0C4/004 ALL ext_ramdisk_size ramdisk_size high 32bits
+0C8/004 ALL ext_cmd_line_ptr cmd_line_ptr high 32bits
140/080 ALL edid_info Video mode setup (struct edid_info)
1C0/020 ALL efi_info EFI 32 information (struct efi_info)
1E0/004 ALL alk_mem_k Alternative mem check, in KB
@@ -27,6 +30,7 @@ Offset Proto Name Meaning
1E9/001 ALL eddbuf_entries Number of entries in eddbuf (below)
1EA/001 ALL edd_mbr_sig_buf_entries Number of entries in edd_mbr_sig_buffer
(below)
+1EF/001 ALL sentinel Used to detect broken bootloaders
290/040 ALL edd_mbr_sig_buffer EDD MBR signatures
2D0/A00 ALL e820_map E820 memory map table
(array of struct e820entry)
diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
index 41dd00884975..02f244475207 100644
--- a/arch/mips/cavium-octeon/dma-octeon.c
+++ b/arch/mips/cavium-octeon/dma-octeon.c
@@ -317,7 +317,8 @@ void __init plat_swiotlb_setup(void)
octeon_swiotlb = alloc_bootmem_low_pages(swiotlbsize);
- swiotlb_init_with_tbl(octeon_swiotlb, swiotlb_nslabs, 1);
+ if (swiotlb_init_with_tbl(octeon_swiotlb, swiotlb_nslabs, 1) == -ENOMEM)
+ panic("Cannot allocate SWIOTLB buffer");
mips_dma_map_ops = &octeon_linear_dma_map_ops.dma_map_ops;
}
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index c3b72423c846..fc5a7c4bd9e8 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -2021,6 +2021,16 @@ static void __init patch_tlb_miss_handler_bitmap(void)
flushi(&valid_addr_bitmap_insn[0]);
}
+static void __init register_page_bootmem_info(void)
+{
+#ifdef CONFIG_NEED_MULTIPLE_NODES
+ int i;
+
+ for_each_online_node(i)
+ if (NODE_DATA(i)->node_spanned_pages)
+ register_page_bootmem_info_node(NODE_DATA(i));
+#endif
+}
void __init mem_init(void)
{
unsigned long codepages, datapages, initpages;
@@ -2038,20 +2048,8 @@ void __init mem_init(void)
high_memory = __va(last_valid_pfn << PAGE_SHIFT);
-#ifdef CONFIG_NEED_MULTIPLE_NODES
- {
- int i;
- for_each_online_node(i) {
- if (NODE_DATA(i)->node_spanned_pages != 0) {
- totalram_pages +=
- free_all_bootmem_node(NODE_DATA(i));
- }
- }
- totalram_pages += free_low_memory_core_early(MAX_NUMNODES);
- }
-#else
+ register_page_bootmem_info();
totalram_pages = free_all_bootmem();
-#endif
/* We subtract one to account for the mem_map_zero page
* allocated below.
diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index 18997e5a1053..5b7531966b84 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -285,16 +285,26 @@ struct biosregs {
void intcall(u8 int_no, const struct biosregs *ireg, struct biosregs *oreg);
/* cmdline.c */
-int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int bufsize);
-int __cmdline_find_option_bool(u32 cmdline_ptr, const char *option);
+int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize);
+int __cmdline_find_option_bool(unsigned long cmdline_ptr, const char *option);
static inline int cmdline_find_option(const char *option, char *buffer, int bufsize)
{
- return __cmdline_find_option(boot_params.hdr.cmd_line_ptr, option, buffer, bufsize);
+ unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
+
+ if (cmd_line_ptr >= 0x100000)
+ return -1; /* inaccessible */
+
+ return __cmdline_find_option(cmd_line_ptr, option, buffer, bufsize);
}
static inline int cmdline_find_option_bool(const char *option)
{
- return __cmdline_find_option_bool(boot_params.hdr.cmd_line_ptr, option);
+ unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
+
+ if (cmd_line_ptr >= 0x100000)
+ return -1; /* inaccessible */
+
+ return __cmdline_find_option_bool(cmd_line_ptr, option);
}
diff --git a/arch/x86/boot/cmdline.c b/arch/x86/boot/cmdline.c
index 6b3b6f708c04..625d21b0cd3f 100644
--- a/arch/x86/boot/cmdline.c
+++ b/arch/x86/boot/cmdline.c
@@ -27,7 +27,7 @@ static inline int myisspace(u8 c)
* Returns the length of the argument (regardless of if it was
* truncated to fit in the buffer), or -1 on not found.
*/
-int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int bufsize)
+int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize)
{
addr_t cptr;
char c;
@@ -41,8 +41,8 @@ int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int
st_bufcpy /* Copying this to buffer */
} state = st_wordstart;
- if (!cmdline_ptr || cmdline_ptr >= 0x100000)
- return -1; /* No command line, or inaccessible */
+ if (!cmdline_ptr)
+ return -1; /* No command line */
cptr = cmdline_ptr & 0xf;
set_fs(cmdline_ptr >> 4);
@@ -99,7 +99,7 @@ int __cmdline_find_option(u32 cmdline_ptr, const char *option, char *buffer, int
* Returns the position of that option (starts counting with 1)
* or 0 on not found
*/
-int __cmdline_find_option_bool(u32 cmdline_ptr, const char *option)
+int __cmdline_find_option_bool(unsigned long cmdline_ptr, const char *option)
{
addr_t cptr;
char c;
@@ -111,8 +111,8 @@ int __cmdline_find_option_bool(u32 cmdline_ptr, const char *option)
st_wordskip, /* Miscompare, skip */
} state = st_wordstart;
- if (!cmdline_ptr || cmdline_ptr >= 0x100000)
- return -1; /* No command line, or inaccessible */
+ if (!cmdline_ptr)
+ return -1; /* No command line */
cptr = cmdline_ptr & 0xf;
set_fs(cmdline_ptr >> 4);
diff --git a/arch/x86/boot/compressed/cmdline.c b/arch/x86/boot/compressed/cmdline.c
index 10f6b1178c68..bffd73b45b1f 100644
--- a/arch/x86/boot/compressed/cmdline.c
+++ b/arch/x86/boot/compressed/cmdline.c
@@ -13,13 +13,21 @@ static inline char rdfs8(addr_t addr)
return *((char *)(fs + addr));
}
#include "../cmdline.c"
+static unsigned long get_cmd_line_ptr(void)
+{
+ unsigned long cmd_line_ptr = real_mode->hdr.cmd_line_ptr;
+
+ cmd_line_ptr |= (u64)real_mode->ext_cmd_line_ptr << 32;
+
+ return cmd_line_ptr;
+}
int cmdline_find_option(const char *option, char *buffer, int bufsize)
{
- return __cmdline_find_option(real_mode->hdr.cmd_line_ptr, option, buffer, bufsize);
+ return __cmdline_find_option(get_cmd_line_ptr(), option, buffer, bufsize);
}
int cmdline_find_option_bool(const char *option)
{
- return __cmdline_find_option_bool(real_mode->hdr.cmd_line_ptr, option);
+ return __cmdline_find_option_bool(get_cmd_line_ptr(), option);
}
#endif
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 2c4b171eec33..d9ae9a4ffcb9 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -37,6 +37,12 @@
__HEAD
.code32
ENTRY(startup_32)
+ /*
+ * 32bit entry is 0 and it is ABI so immutable!
+ * If we come here directly from a bootloader,
+ * kernel(text+data+bss+brk) ramdisk, zero_page, command line
+ * all need to be under the 4G limit.
+ */
cld
/*
* Test KEEP_SEGMENTS flag to see if the bootloader is asking
@@ -154,6 +160,12 @@ ENTRY(startup_32)
btsl $_EFER_LME, %eax
wrmsr
+ /* After gdt is loaded */
+ xorl %eax, %eax
+ lldt %ax
+ movl $0x20, %eax
+ ltr %ax
+
/*
* Setup for the jump to 64bit mode
*
@@ -176,28 +188,18 @@ ENTRY(startup_32)
lret
ENDPROC(startup_32)
-no_longmode:
- /* This isn't an x86-64 CPU so hang */
-1:
- hlt
- jmp 1b
-
-#include "../../kernel/verify_cpu.S"
-
- /*
- * Be careful here startup_64 needs to be at a predictable
- * address so I can export it in an ELF header. Bootloaders
- * should look at the ELF header to find this address, as
- * it may change in the future.
- */
.code64
.org 0x200
ENTRY(startup_64)
/*
+ * 64bit entry is 0x200 and it is ABI so immutable!
* We come here either from startup_32 or directly from a
- * 64bit bootloader. If we come here from a bootloader we depend on
- * an identity mapped page table being provied that maps our
- * entire text+data+bss and hopefully all of memory.
+ * 64bit bootloader.
+ * If we come here from a bootloader, kernel(text+data+bss+brk),
+ * ramdisk, zero_page, command line could be above 4G.
+ * We depend on an identity mapped page table being provided
+ * that maps our entire kernel(text+data+bss+brk), zero page
+ * and command line.
*/
#ifdef CONFIG_EFI_STUB
/*
@@ -247,9 +249,6 @@ preferred_addr:
movl %eax, %ss
movl %eax, %fs
movl %eax, %gs
- lldt %ax
- movl $0x20, %eax
- ltr %ax
/*
* Compute the decompressed kernel start address. It is where
@@ -349,6 +348,15 @@ relocated:
*/
jmp *%rbp
+ .code32
+no_longmode:
+ /* This isn't an x86-64 CPU so hang */
+1:
+ hlt
+ jmp 1b
+
+#include "../../kernel/verify_cpu.S"
+
.data
gdt:
.word gdt_end - gdt
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 88f7ff6da404..7cb56c6ca351 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -325,6 +325,8 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
{
real_mode = rmode;
+ sanitize_boot_params(real_mode);
+
if (real_mode->screen_info.orig_video_mode == 7) {
vidmem = (char *) 0xb0000;
vidport = 0x3b4;
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 0e6dc0ee0eea..674019d8e235 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -18,6 +18,7 @@
#include <asm/page.h>
#include <asm/boot.h>
#include <asm/bootparam.h>
+#include <asm/bootparam_utils.h>
#define BOOT_BOOT_H
#include "../ctype.h"
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 8c132a625b94..9ec06a1f6d61 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 +367,31 @@ 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
+
+#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64)
+ /* kernel/boot_param/ramdisk could be loaded above 4g */
+# define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G
+#else
+# define XLF1 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 | XLF1 | XLF23
cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line,
#added with boot protocol
@@ -397,8 +419,13 @@ 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 #####################################################
diff --git a/arch/x86/boot/setup.ld b/arch/x86/boot/setup.ld
index 03c0683636b6..96a6c7563538 100644
--- a/arch/x86/boot/setup.ld
+++ b/arch/x86/boot/setup.ld
@@ -13,7 +13,7 @@ SECTIONS
.bstext : { *(.bstext) }
.bsdata : { *(.bsdata) }
- . = 497;
+ . = 495;
.header : { *(.header) }
.entrytext : { *(.entrytext) }
.inittext : { *(.inittext) }
diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h
new file mode 100644
index 000000000000..5b5e9cb774b5
--- /dev/null
+++ b/arch/x86/include/asm/bootparam_utils.h
@@ -0,0 +1,38 @@
+#ifndef _ASM_X86_BOOTPARAM_UTILS_H
+#define _ASM_X86_BOOTPARAM_UTILS_H
+
+#include <asm/bootparam.h>
+
+/*
+ * This file is included from multiple environments. Do not
+ * add completing #includes to make it standalone.
+ */
+
+/*
+ * Deal with bootloaders which fail to initialize unknown fields in
+ * boot_params to zero. The list fields in this list are taken from
+ * analysis of kexec-tools; if other broken bootloaders initialize a
+ * different set of fields we will need to figure out how to disambiguate.
+ *
+ */
+static void sanitize_boot_params(struct boot_params *boot_params)
+{