arch/x86/kernel/kexec-bzimage64.c - kernel/common - Git at Google

 /*
  * Kexec bzImage loader
  *
  * Copyright (C) 2014 Red Hat Inc.
  * Authors:
  *      Vivek Goyal <[email protected]>
  *
  * This source code is licensed under the GNU General Public License,
  * Version 2.  See the file COPYING for more details.
  */

 #define pr_fmt(fmt)	"kexec-bzImage64: " fmt

 #include <linux/string.h>
 #include <linux/printk.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/kexec.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/efi.h>
 #include <linux/verification.h>

 #include <asm/bootparam.h>
 #include <asm/setup.h>
 #include <asm/crash.h>
 #include <asm/efi.h>
 #include <asm/e820/api.h>
 #include <asm/kexec-bzimage64.h>

 #define MAX_ELFCOREHDR_STR_LEN	30	/* elfcorehdr=0x<64bit-value> */

 /*
  * Defines lowest physical address for various segments. Not sure where
  * exactly these limits came from. Current bzimage64 loader in kexec-tools
  * uses these so I am retaining it. It can be changed over time as we gain
  * more insight.
  */
 #define MIN_PURGATORY_ADDR	0x3000
 #define MIN_BOOTPARAM_ADDR	0x3000
 #define MIN_KERNEL_LOAD_ADDR	0x100000
 #define MIN_INITRD_LOAD_ADDR	0x1000000

 /*
  * This is a place holder for all boot loader specific data structure which
  * gets allocated in one call but gets freed much later during cleanup
  * time. Right now there is only one field but it can grow as need be.
  */
 struct bzimage64_data {
 	/*
 	 * Temporary buffer to hold bootparams buffer. This should be
 	 * freed once the bootparam segment has been loaded.
 	 */
 	void *bootparams_buf;
 };

 static int setup_initrd(struct boot_params *params,
 		unsigned long initrd_load_addr, unsigned long initrd_len)
 {
 	params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL;
 	params->hdr.ramdisk_size = initrd_len & 0xffffffffUL;

 	params->ext_ramdisk_image = initrd_load_addr >> 32;
 	params->ext_ramdisk_size = initrd_len >> 32;

 	return 0;
 }

 static int setup_cmdline(struct kimage *image, struct boot_params *params,
 			 unsigned long bootparams_load_addr,
 			 unsigned long cmdline_offset, char *cmdline,
 			 unsigned long cmdline_len)
 {
 	char *cmdline_ptr = ((char *)params) + cmdline_offset;
 	unsigned long cmdline_ptr_phys, len = 0;
 	uint32_t cmdline_low_32, cmdline_ext_32;

 	if (image->type == KEXEC_TYPE_CRASH) {
 		len = sprintf(cmdline_ptr,
 			"elfcorehdr=0x%lx ", image->arch.elf_load_addr);
 	}
 	memcpy(cmdline_ptr + len, cmdline, cmdline_len);
 	cmdline_len += len;

 	cmdline_ptr[cmdline_len - 1] = '\0';

 	pr_debug("Final command line is: %s\n", cmdline_ptr);
 	cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
 	cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
 	cmdline_ext_32 = cmdline_ptr_phys >> 32;

 	params->hdr.cmd_line_ptr = cmdline_low_32;
 	if (cmdline_ext_32)
 		params->ext_cmd_line_ptr = cmdline_ext_32;

 	return 0;
 }

 static int setup_e820_entries(struct boot_params *params)
 {
 	unsigned int nr_e820_entries;

 	nr_e820_entries = e820_table_kexec->nr_entries;

 	/* TODO: Pass entries more than E820_MAX_ENTRIES_ZEROPAGE in bootparams setup data */
 	if (nr_e820_entries > E820_MAX_ENTRIES_ZEROPAGE)
 		nr_e820_entries = E820_MAX_ENTRIES_ZEROPAGE;

 	params->e820_entries = nr_e820_entries;
 	memcpy(&params->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry));

 	return 0;
 }

 #ifdef CONFIG_EFI
 static int setup_efi_info_memmap(struct boot_params *params,
 				  unsigned long params_load_addr,
 				  unsigned int efi_map_offset,
 				  unsigned int efi_map_sz)
 {
 	void *efi_map = (void *)params + efi_map_offset;
 	unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
 	struct efi_info *ei = &params->efi_info;

 	if (!efi_map_sz)
 		return 0;

 	efi_runtime_map_copy(efi_map, efi_map_sz);

 	ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
 	ei->efi_memmap_hi = efi_map_phys_addr >> 32;
 	ei->efi_memmap_size = efi_map_sz;

 	return 0;
 }

 static int
 prepare_add_efi_setup_data(struct boot_params *params,
 		       unsigned long params_load_addr,
 		       unsigned int efi_setup_data_offset)
 {
 	unsigned long setup_data_phys;
 	struct setup_data *sd = (void *)params + efi_setup_data_offset;
 	struct efi_setup_data *esd = (void *)sd + sizeof(struct setup_data);

 	esd->fw_vendor = efi.fw_vendor;
 	esd->runtime = efi.runtime;
 	esd->tables = efi.config_table;
 	esd->smbios = efi.smbios;

 	sd->type = SETUP_EFI;
 	sd->len = sizeof(struct efi_setup_data);

 	/* Add setup data */
 	setup_data_phys = params_load_addr + efi_setup_data_offset;
 	sd->next = params->hdr.setup_data;
 	params->hdr.setup_data = setup_data_phys;

 	return 0;
 }

 static int
 setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
 		unsigned int efi_map_offset, unsigned int efi_map_sz,
 		unsigned int efi_setup_data_offset)
 {
 	struct efi_info *current_ei = &boot_params.efi_info;
 	struct efi_info *ei = &params->efi_info;

 	if (!current_ei->efi_memmap_size)
 		return 0;

 	/*
 	 * If 1:1 mapping is not enabled, second kernel can not setup EFI
 	 * and use EFI run time services. User space will have to pass
 	 * acpi_rsdp=<addr> on kernel command line to make second kernel boot
 	 * without efi.
 	 */
 	if (efi_enabled(EFI_OLD_MEMMAP))
 		return 0;

 	ei->efi_loader_signature = current_ei->efi_loader_signature;
 	ei->efi_systab = current_ei->efi_systab;
 	ei->efi_systab_hi = current_ei->efi_systab_hi;

 	ei->efi_memdesc_version = current_ei->efi_memdesc_version;
 	ei->efi_memdesc_size = efi_get_runtime_map_desc_size();

 	setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
 			      efi_map_sz);
 	prepare_add_efi_setup_data(params, params_load_addr,
 				   efi_setup_data_offset);
 	return 0;
 }
 #endif /* CONFIG_EFI */

 static int
 setup_boot_parameters(struct kimage *image, struct boot_params *params,
 		      unsigned long params_load_addr,
 		      unsigned int efi_map_offset, unsigned int efi_map_sz,
 		      unsigned int efi_setup_data_offset)
 {
 	unsigned int nr_e820_entries;
 	unsigned long long mem_k, start, end;
 	int i, ret = 0;

 	/* Get subarch from existing bootparams */
 	params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;

 	/* Copying screen_info will do? */
 	memcpy(&params->screen_info, &boot_params.screen_info,
 				sizeof(struct screen_info));

 	/* Fill in memsize later */
 	params->screen_info.ext_mem_k = 0;
 	params->alt_mem_k = 0;

 	/* Default APM info */
 	memset(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));

 	/* Default drive info */
 	memset(&params->hd0_info, 0, sizeof(params->hd0_info));
 	memset(&params->hd1_info, 0, sizeof(params->hd1_info));

 	if (image->type == KEXEC_TYPE_CRASH) {
 		ret = crash_setup_memmap_entries(image, params);
 		if (ret)
 			return ret;
 	} else
 		setup_e820_entries(params);

 	nr_e820_entries = params->e820_entries;

 	for (i = 0; i < nr_e820_entries; i++) {
 		if (params->e820_table[i].type != E820_TYPE_RAM)
 			continue;
 		start = params->e820_table[i].addr;
 		end = params->e820_table[i].addr + params->e820_table[i].size - 1;

 		if ((start <= 0x100000) && end > 0x100000) {
 			mem_k = (end >> 10) - (0x100000 >> 10);
 			params->screen_info.ext_mem_k = mem_k;
 			params->alt_mem_k = mem_k;
 			if (mem_k > 0xfc00)
 				params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
 			if (mem_k > 0xffffffff)
 				params->alt_mem_k = 0xffffffff;
 		}
 	}

 #ifdef CONFIG_EFI
 	/* Setup EFI state */
 	setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
 			efi_setup_data_offset);
 #endif

 	/* Setup EDD info */
 	memcpy(params->eddbuf, boot_params.eddbuf,
 				EDDMAXNR * sizeof(struct edd_info));
 	params->eddbuf_entries = boot_params.eddbuf_entries;

 	memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
 	       EDD_MBR_SIG_MAX * sizeof(unsigned int));

 	return ret;
 }

 static int bzImage64_probe(const char *buf, unsigned long len)
 {
 	int ret = -ENOEXEC;
 	struct setup_header *header;

 	/* kernel should be at least two sectors long */
 	if (len < 2 * 512) {
 		pr_err("File is too short to be a bzImage\n");
 		return ret;
 	}

 	header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
 	if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
 		pr_err("Not a bzImage\n");
 		return ret;
 	}

 	if (header->boot_flag != 0xAA55) {
 		pr_err("No x86 boot sector present\n");
 		return ret;
 	}

 	if (header->version < 0x020C) {
 		pr_err("Must be at least protocol version 2.12\n");
 		return ret;
 	}

 	if (!(header->loadflags & LOADED_HIGH)) {
 		pr_err("zImage not a bzImage\n");
 		return ret;
 	}

 	if (!(header->xloadflags & XLF_KERNEL_64)) {
 		pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
 		return ret;
 	}

 	if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
 		pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
 		return ret;
 	}

 	/*
 	 * Can't handle 32bit EFI as it does not allow loading kernel
 	 * above 4G. This should be handled by 32bit bzImage loader
 	 */
 	if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
 		pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
 		return ret;
 	}

 	/* I've got a bzImage */
 	pr_debug("It's a relocatable bzImage64\n");
 	ret = 0;

 	return ret;
 }

 static void *bzImage64_load(struct kimage *image, char *kernel,
 			    unsigned long kernel_len, char *initrd,
 			    unsigned long initrd_len, char *cmdline,
 			    unsigned long cmdline_len)
 {

 	struct setup_header *header;
 	int setup_sects, kern16_size, ret = 0;
 	unsigned long setup_header_size, params_cmdline_sz;
 	struct boot_params *params;
 	unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
 	struct bzimage64_data *ldata;
 	struct kexec_entry64_regs regs64;
 	void *stack;
 	unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
 	unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
 	struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
 				  .top_down = true };
 	struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR,
 				  .buf_max = ULONG_MAX, .top_down = true };

 	header = (struct setup_header *)(kernel + setup_hdr_offset);
 	setup_sects = header->setup_sects;
 	if (setup_sects == 0)
 		setup_sects = 4;

 	kern16_size = (setup_sects + 1) * 512;
 	if (kernel_len < kern16_size) {
 		pr_err("bzImage truncated\n");
 		return ERR_PTR(-ENOEXEC);
 	}

 	if (cmdline_len > header->cmdline_size) {
 		pr_err("Kernel command line too long\n");
 		return ERR_PTR(-EINVAL);
 	}

 	/*
 	 * In case of crash dump, we will append elfcorehdr=<addr> to
 	 * command line. Make sure it does not overflow
 	 */
 	if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
 		pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
 		return ERR_PTR(-EINVAL);
 	}

 	/* Allocate and load backup region */
 	if (image->type == KEXEC_TYPE_CRASH) {
 		ret = crash_load_segments(image);
 		if (ret)
 			return ERR_PTR(ret);
 	}

 	/*
 	 * Load purgatory. For 64bit entry point, purgatory  code can be
 	 * anywhere.
 	 */
 	ret = kexec_load_purgatory(image, &pbuf);
 	if (ret) {
 		pr_err("Loading purgatory failed\n");
 		return ERR_PTR(ret);
 	}

 	pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem);


 	/*
 	 * Load Bootparams and cmdline and space for efi stuff.
 	 *
 	 * Allocate memory together for multiple data structures so
 	 * that they all can go in single area/segment and we don't
 	 * have to create separate segment for each. Keeps things
 	 * little bit simple
 	 */
 	efi_map_sz = efi_get_runtime_map_size();
 	params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
 				MAX_ELFCOREHDR_STR_LEN;
 	params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
 	kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
 				sizeof(struct setup_data) +
 				sizeof(struct efi_setup_data);

 	params = kzalloc(kbuf.bufsz, GFP_KERNEL);
 	if (!params)
 		return ERR_PTR(-ENOMEM);
 	efi_map_offset = params_cmdline_sz;
 	efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);

 	/* Copy setup header onto bootparams. Documentation/x86/boot.txt */
 	setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;

 	/* Is there a limit on setup header size? */
 	memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);

 	kbuf.buffer = params;
 	kbuf.memsz = kbuf.bufsz;
 	kbuf.buf_align = 16;
 	kbuf.buf_min = MIN_BOOTPARAM_ADDR;
 	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out_free_params;
 	bootparam_load_addr = kbuf.mem;
 	pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 		 bootparam_load_addr, kbuf.bufsz, kbuf.bufsz);

 	/* Load kernel */
 	kbuf.buffer = kernel + kern16_size;
 	kbuf.bufsz =  kernel_len - kern16_size;
 	kbuf.memsz = PAGE_ALIGN(header->init_size);
 	kbuf.buf_align = header->kernel_alignment;
 	kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
 	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out_free_params;
 	kernel_load_addr = kbuf.mem;

 	pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 		 kernel_load_addr, kbuf.bufsz, kbuf.memsz);

 	/* Load initrd high */
 	if (initrd) {
 		kbuf.buffer = initrd;
 		kbuf.bufsz = kbuf.memsz = initrd_len;
 		kbuf.buf_align = PAGE_SIZE;
 		kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
 		ret = kexec_add_buffer(&kbuf);
 		if (ret)
 			goto out_free_params;
 		initrd_load_addr = kbuf.mem;

 		pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 				initrd_load_addr, initrd_len, initrd_len);

 		setup_initrd(params, initrd_load_addr, initrd_len);
 	}

 	setup_cmdline(image, params, bootparam_load_addr,
 		      sizeof(struct boot_params), cmdline, cmdline_len);

 	/* bootloader info. Do we need a separate ID for kexec kernel loader? */
 	params->hdr.type_of_loader = 0x0D << 4;
 	params->hdr.loadflags = 0;

 	/* Setup purgatory regs for entry */
 	ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
 					     sizeof(regs64), 1);
 	if (ret)
 		goto out_free_params;

 	regs64.rbx = 0; /* Bootstrap Processor */
 	regs64.rsi = bootparam_load_addr;
 	regs64.rip = kernel_load_addr + 0x200;
 	stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
 	if (IS_ERR(stack)) {
 		pr_err("Could not find address of symbol stack_end\n");
 		ret = -EINVAL;
 		goto out_free_params;
 	}

 	regs64.rsp = (unsigned long)stack;
 	ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
 					     sizeof(regs64), 0);
 	if (ret)
 		goto out_free_params;

 	ret = setup_boot_parameters(image, params, bootparam_load_addr,
 				    efi_map_offset, efi_map_sz,
 				    efi_setup_data_offset);
 	if (ret)
 		goto out_free_params;

 	/* Allocate loader specific data */
 	ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
 	if (!ldata) {
 		ret = -ENOMEM;
 		goto out_free_params;
 	}

 	/*
 	 * Store pointer to params so that it could be freed after loading
 	 * params segment has been loaded and contents have been copied
 	 * somewhere else.
 	 */
 	ldata->bootparams_buf = params;
 	return ldata;

 out_free_params:
 	kfree(params);
 	return ERR_PTR(ret);
 }

 /* This cleanup function is called after various segments have been loaded */
 static int bzImage64_cleanup(void *loader_data)
 {
 	struct bzimage64_data *ldata = loader_data;

 	if (!ldata)
 		return 0;

 	kfree(ldata->bootparams_buf);
 	ldata->bootparams_buf = NULL;

 	return 0;
 }

 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
 static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
 {
 	return verify_pefile_signature(kernel, kernel_len,
 				       VERIFY_USE_SECONDARY_KEYRING,
 				       VERIFYING_KEXEC_PE_SIGNATURE);
 }
 #endif

 const struct kexec_file_ops kexec_bzImage64_ops = {
 	.probe = bzImage64_probe,
 	.load = bzImage64_load,
 	.cleanup = bzImage64_cleanup,
 #ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
 	.verify_sig = bzImage64_verify_sig,
 #endif
 };
	/*
	* Kexec bzImage loader
	*
	* Copyright (C) 2014 Red Hat Inc.
	* Authors:
	* Vivek Goyal <[email protected]>
	*
	* This source code is licensed under the GNU General Public License,
	* Version 2. See the file COPYING for more details.
	*/

	#define pr_fmt(fmt) "kexec-bzImage64: " fmt

	#include <linux/string.h>
	#include <linux/printk.h>
	#include <linux/errno.h>
	#include <linux/slab.h>
	#include <linux/kexec.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/efi.h>
	#include <linux/verification.h>

	#include <asm/bootparam.h>
	#include <asm/setup.h>
	#include <asm/crash.h>
	#include <asm/efi.h>
	#include <asm/e820/api.h>
	#include <asm/kexec-bzimage64.h>

	#define MAX_ELFCOREHDR_STR_LEN 30 /* elfcorehdr=0x<64bit-value> */

	/*
	* Defines lowest physical address for various segments. Not sure where
	* exactly these limits came from. Current bzimage64 loader in kexec-tools
	* uses these so I am retaining it. It can be changed over time as we gain
	* more insight.
	*/
	#define MIN_PURGATORY_ADDR 0x3000
	#define MIN_BOOTPARAM_ADDR 0x3000
	#define MIN_KERNEL_LOAD_ADDR 0x100000
	#define MIN_INITRD_LOAD_ADDR 0x1000000

	/*
	* This is a place holder for all boot loader specific data structure which
	* gets allocated in one call but gets freed much later during cleanup
	* time. Right now there is only one field but it can grow as need be.
	*/
	struct bzimage64_data {
	/*
	* Temporary buffer to hold bootparams buffer. This should be
	* freed once the bootparam segment has been loaded.
	*/
	void *bootparams_buf;
	};

	static int setup_initrd(struct boot_params *params,
	unsigned long initrd_load_addr, unsigned long initrd_len)
	{
	params->hdr.ramdisk_image = initrd_load_addr & 0xffffffffUL;
	params->hdr.ramdisk_size = initrd_len & 0xffffffffUL;

	params->ext_ramdisk_image = initrd_load_addr >> 32;
	params->ext_ramdisk_size = initrd_len >> 32;

	return 0;
	}

	static int setup_cmdline(struct kimage image, struct boot_params params,
	unsigned long bootparams_load_addr,
	unsigned long cmdline_offset, char *cmdline,
	unsigned long cmdline_len)
	{
	char cmdline_ptr = ((char )params) + cmdline_offset;
	unsigned long cmdline_ptr_phys, len = 0;
	uint32_t cmdline_low_32, cmdline_ext_32;

	if (image->type == KEXEC_TYPE_CRASH) {
	len = sprintf(cmdline_ptr,
	"elfcorehdr=0x%lx ", image->arch.elf_load_addr);
	}
	memcpy(cmdline_ptr + len, cmdline, cmdline_len);
	cmdline_len += len;

	cmdline_ptr[cmdline_len - 1] = '\0';

	pr_debug("Final command line is: %s\n", cmdline_ptr);
	cmdline_ptr_phys = bootparams_load_addr + cmdline_offset;
	cmdline_low_32 = cmdline_ptr_phys & 0xffffffffUL;
	cmdline_ext_32 = cmdline_ptr_phys >> 32;

	params->hdr.cmd_line_ptr = cmdline_low_32;
	if (cmdline_ext_32)
	params->ext_cmd_line_ptr = cmdline_ext_32;

	return 0;
	}

	static int setup_e820_entries(struct boot_params *params)
	{
	unsigned int nr_e820_entries;

	nr_e820_entries = e820_table_kexec->nr_entries;

	/* TODO: Pass entries more than E820_MAX_ENTRIES_ZEROPAGE in bootparams setup data */
	if (nr_e820_entries > E820_MAX_ENTRIES_ZEROPAGE)
	nr_e820_entries = E820_MAX_ENTRIES_ZEROPAGE;

	params->e820_entries = nr_e820_entries;
	memcpy(&params->e820_table, &e820_table_kexec->entries, nr_e820_entries*sizeof(struct e820_entry));

	return 0;
	}

	#ifdef CONFIG_EFI
	static int setup_efi_info_memmap(struct boot_params *params,
	unsigned long params_load_addr,
	unsigned int efi_map_offset,
	unsigned int efi_map_sz)
	{
	void efi_map = (void )params + efi_map_offset;
	unsigned long efi_map_phys_addr = params_load_addr + efi_map_offset;
	struct efi_info *ei = &params->efi_info;

	if (!efi_map_sz)
	return 0;

	efi_runtime_map_copy(efi_map, efi_map_sz);

	ei->efi_memmap = efi_map_phys_addr & 0xffffffff;
	ei->efi_memmap_hi = efi_map_phys_addr >> 32;
	ei->efi_memmap_size = efi_map_sz;

	return 0;
	}

	static int
	prepare_add_efi_setup_data(struct boot_params *params,
	unsigned long params_load_addr,
	unsigned int efi_setup_data_offset)
	{
	unsigned long setup_data_phys;
	struct setup_data sd = (void )params + efi_setup_data_offset;
	struct efi_setup_data esd = (void )sd + sizeof(struct setup_data);

	esd->fw_vendor = efi.fw_vendor;
	esd->runtime = efi.runtime;
	esd->tables = efi.config_table;
	esd->smbios = efi.smbios;

	sd->type = SETUP_EFI;
	sd->len = sizeof(struct efi_setup_data);

	/* Add setup data */
	setup_data_phys = params_load_addr + efi_setup_data_offset;
	sd->next = params->hdr.setup_data;
	params->hdr.setup_data = setup_data_phys;

	return 0;
	}

	static int
	setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
	unsigned int efi_map_offset, unsigned int efi_map_sz,
	unsigned int efi_setup_data_offset)
	{
	struct efi_info *current_ei = &boot_params.efi_info;
	struct efi_info *ei = &params->efi_info;

	if (!current_ei->efi_memmap_size)
	return 0;

	/*
	* If 1:1 mapping is not enabled, second kernel can not setup EFI
	* and use EFI run time services. User space will have to pass
	* acpi_rsdp=<addr> on kernel command line to make second kernel boot
	* without efi.
	*/
	if (efi_enabled(EFI_OLD_MEMMAP))
	return 0;

	ei->efi_loader_signature = current_ei->efi_loader_signature;
	ei->efi_systab = current_ei->efi_systab;
	ei->efi_systab_hi = current_ei->efi_systab_hi;

	ei->efi_memdesc_version = current_ei->efi_memdesc_version;
	ei->efi_memdesc_size = efi_get_runtime_map_desc_size();

	setup_efi_info_memmap(params, params_load_addr, efi_map_offset,
	efi_map_sz);
	prepare_add_efi_setup_data(params, params_load_addr,
	efi_setup_data_offset);
	return 0;
	}
	#endif /* CONFIG_EFI */

	static int
	setup_boot_parameters(struct kimage image, struct boot_params params,
	unsigned long params_load_addr,
	unsigned int efi_map_offset, unsigned int efi_map_sz,
	unsigned int efi_setup_data_offset)
	{
	unsigned int nr_e820_entries;
	unsigned long long mem_k, start, end;
	int i, ret = 0;

	/* Get subarch from existing bootparams */
	params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch;

	/* Copying screen_info will do? */
	memcpy(&params->screen_info, &boot_params.screen_info,
	sizeof(struct screen_info));

	/* Fill in memsize later */
	params->screen_info.ext_mem_k = 0;
	params->alt_mem_k = 0;

	/* Default APM info */
	memset(&params->apm_bios_info, 0, sizeof(params->apm_bios_info));

	/* Default drive info */
	memset(&params->hd0_info, 0, sizeof(params->hd0_info));
	memset(&params->hd1_info, 0, sizeof(params->hd1_info));

	if (image->type == KEXEC_TYPE_CRASH) {
	ret = crash_setup_memmap_entries(image, params);
	if (ret)
	return ret;
	} else
	setup_e820_entries(params);

	nr_e820_entries = params->e820_entries;

	for (i = 0; i < nr_e820_entries; i++) {
	if (params->e820_table[i].type != E820_TYPE_RAM)
	continue;
	start = params->e820_table[i].addr;
	end = params->e820_table[i].addr + params->e820_table[i].size - 1;

	if ((start <= 0x100000) && end > 0x100000) {
	mem_k = (end >> 10) - (0x100000 >> 10);
	params->screen_info.ext_mem_k = mem_k;
	params->alt_mem_k = mem_k;
	if (mem_k > 0xfc00)
	params->screen_info.ext_mem_k = 0xfc00; /* 64M*/
	if (mem_k > 0xffffffff)
	params->alt_mem_k = 0xffffffff;
	}
	}

	#ifdef CONFIG_EFI
	/* Setup EFI state */
	setup_efi_state(params, params_load_addr, efi_map_offset, efi_map_sz,
	efi_setup_data_offset);
	#endif

	/* Setup EDD info */
	memcpy(params->eddbuf, boot_params.eddbuf,
	EDDMAXNR * sizeof(struct edd_info));
	params->eddbuf_entries = boot_params.eddbuf_entries;

	memcpy(params->edd_mbr_sig_buffer, boot_params.edd_mbr_sig_buffer,
	EDD_MBR_SIG_MAX * sizeof(unsigned int));

	return ret;
	}

	static int bzImage64_probe(const char *buf, unsigned long len)
	{
	int ret = -ENOEXEC;
	struct setup_header *header;

	/* kernel should be at least two sectors long */
	if (len < 2 * 512) {
	pr_err("File is too short to be a bzImage\n");
	return ret;
	}

	header = (struct setup_header *)(buf + offsetof(struct boot_params, hdr));
	if (memcmp((char *)&header->header, "HdrS", 4) != 0) {
	pr_err("Not a bzImage\n");
	return ret;
	}

	if (header->boot_flag != 0xAA55) {
	pr_err("No x86 boot sector present\n");
	return ret;
	}

	if (header->version < 0x020C) {
	pr_err("Must be at least protocol version 2.12\n");
	return ret;
	}

	if (!(header->loadflags & LOADED_HIGH)) {
	pr_err("zImage not a bzImage\n");
	return ret;
	}

	if (!(header->xloadflags & XLF_KERNEL_64)) {
	pr_err("Not a bzImage64. XLF_KERNEL_64 is not set.\n");
	return ret;
	}

	if (!(header->xloadflags & XLF_CAN_BE_LOADED_ABOVE_4G)) {
	pr_err("XLF_CAN_BE_LOADED_ABOVE_4G is not set.\n");
	return ret;
	}

	/*
	* Can't handle 32bit EFI as it does not allow loading kernel
	* above 4G. This should be handled by 32bit bzImage loader
	*/
	if (efi_enabled(EFI_RUNTIME_SERVICES) && !efi_enabled(EFI_64BIT)) {
	pr_debug("EFI is 32 bit. Can't load kernel above 4G.\n");
	return ret;
	}

	/* I've got a bzImage */
	pr_debug("It's a relocatable bzImage64\n");
	ret = 0;

	return ret;
	}

	static void bzImage64_load(struct kimage image, char *kernel,
	unsigned long kernel_len, char *initrd,
	unsigned long initrd_len, char *cmdline,
	unsigned long cmdline_len)
	{

	struct setup_header *header;
	int setup_sects, kern16_size, ret = 0;
	unsigned long setup_header_size, params_cmdline_sz;
	struct boot_params *params;
	unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
	struct bzimage64_data *ldata;
	struct kexec_entry64_regs regs64;
	void *stack;
	unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
	unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
	struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
	.top_down = true };
	struct kexec_buf pbuf = { .image = image, .buf_min = MIN_PURGATORY_ADDR,
	.buf_max = ULONG_MAX, .top_down = true };

	header = (struct setup_header *)(kernel + setup_hdr_offset);
	setup_sects = header->setup_sects;
	if (setup_sects == 0)
	setup_sects = 4;

	kern16_size = (setup_sects + 1) * 512;
	if (kernel_len < kern16_size) {
	pr_err("bzImage truncated\n");
	return ERR_PTR(-ENOEXEC);
	}

	if (cmdline_len > header->cmdline_size) {
	pr_err("Kernel command line too long\n");
	return ERR_PTR(-EINVAL);
	}

	/*
	* In case of crash dump, we will append elfcorehdr=<addr> to
	* command line. Make sure it does not overflow
	*/
	if (cmdline_len + MAX_ELFCOREHDR_STR_LEN > header->cmdline_size) {
	pr_debug("Appending elfcorehdr=<addr> to command line exceeds maximum allowed length\n");
	return ERR_PTR(-EINVAL);
	}

	/* Allocate and load backup region */
	if (image->type == KEXEC_TYPE_CRASH) {
	ret = crash_load_segments(image);
	if (ret)
	return ERR_PTR(ret);
	}

	/*
	* Load purgatory. For 64bit entry point, purgatory code can be
	* anywhere.
	*/
	ret = kexec_load_purgatory(image, &pbuf);
	if (ret) {
	pr_err("Loading purgatory failed\n");
	return ERR_PTR(ret);
	}

	pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem);


	/*
	* Load Bootparams and cmdline and space for efi stuff.
	*
	* Allocate memory together for multiple data structures so
	* that they all can go in single area/segment and we don't
	* have to create separate segment for each. Keeps things
	* little bit simple
	*/
	efi_map_sz = efi_get_runtime_map_size();
	params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
	MAX_ELFCOREHDR_STR_LEN;
	params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
	kbuf.bufsz = params_cmdline_sz + ALIGN(efi_map_sz, 16) +
	sizeof(struct setup_data) +
	sizeof(struct efi_setup_data);

	params = kzalloc(kbuf.bufsz, GFP_KERNEL);
	if (!params)
	return ERR_PTR(-ENOMEM);
	efi_map_offset = params_cmdline_sz;
	efi_setup_data_offset = efi_map_offset + ALIGN(efi_map_sz, 16);

	/* Copy setup header onto bootparams. Documentation/x86/boot.txt */
	setup_header_size = 0x0202 + kernel[0x0201] - setup_hdr_offset;

	/* Is there a limit on setup header size? */
	memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);

	kbuf.buffer = params;
	kbuf.memsz = kbuf.bufsz;
	kbuf.buf_align = 16;
	kbuf.buf_min = MIN_BOOTPARAM_ADDR;
	ret = kexec_add_buffer(&kbuf);
	if (ret)
	goto out_free_params;
	bootparam_load_addr = kbuf.mem;
	pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
	bootparam_load_addr, kbuf.bufsz, kbuf.bufsz);

	/* Load kernel */
	kbuf.buffer = kernel + kern16_size;
	kbuf.bufsz = kernel_len - kern16_size;
	kbuf.memsz = PAGE_ALIGN(header->init_size);
	kbuf.buf_align = header->kernel_alignment;
	kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
	ret = kexec_add_buffer(&kbuf);
	if (ret)
	goto out_free_params;
	kernel_load_addr = kbuf.mem;

	pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
	kernel_load_addr, kbuf.bufsz, kbuf.memsz);

	/* Load initrd high */
	if (initrd) {
	kbuf.buffer = initrd;
	kbuf.bufsz = kbuf.memsz = initrd_len;
	kbuf.buf_align = PAGE_SIZE;
	kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
	ret = kexec_add_buffer(&kbuf);
	if (ret)
	goto out_free_params;
	initrd_load_addr = kbuf.mem;

	pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
	initrd_load_addr, initrd_len, initrd_len);

	setup_initrd(params, initrd_load_addr, initrd_len);
	}

	setup_cmdline(image, params, bootparam_load_addr,
	sizeof(struct boot_params), cmdline, cmdline_len);

	/* bootloader info. Do we need a separate ID for kexec kernel loader? */
	params->hdr.type_of_loader = 0x0D << 4;
	params->hdr.loadflags = 0;

	/* Setup purgatory regs for entry */
	ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
	sizeof(regs64), 1);
	if (ret)
	goto out_free_params;

	regs64.rbx = 0; /* Bootstrap Processor */
	regs64.rsi = bootparam_load_addr;
	regs64.rip = kernel_load_addr + 0x200;
	stack = kexec_purgatory_get_symbol_addr(image, "stack_end");
	if (IS_ERR(stack)) {
	pr_err("Could not find address of symbol stack_end\n");
	ret = -EINVAL;
	goto out_free_params;
	}

	regs64.rsp = (unsigned long)stack;
	ret = kexec_purgatory_get_set_symbol(image, "entry64_regs", &regs64,
	sizeof(regs64), 0);
	if (ret)
	goto out_free_params;

	ret = setup_boot_parameters(image, params, bootparam_load_addr,
	efi_map_offset, efi_map_sz,
	efi_setup_data_offset);
	if (ret)
	goto out_free_params;

	/* Allocate loader specific data */
	ldata = kzalloc(sizeof(struct bzimage64_data), GFP_KERNEL);
	if (!ldata) {
	ret = -ENOMEM;
	goto out_free_params;
	}

	/*
	* Store pointer to params so that it could be freed after loading
	* params segment has been loaded and contents have been copied
	* somewhere else.
	*/
	ldata->bootparams_buf = params;
	return ldata;

	out_free_params:
	kfree(params);
	return ERR_PTR(ret);
	}

	/* This cleanup function is called after various segments have been loaded */
	static int bzImage64_cleanup(void *loader_data)
	{
	struct bzimage64_data *ldata = loader_data;

	if (!ldata)
	return 0;

	kfree(ldata->bootparams_buf);
	ldata->bootparams_buf = NULL;

	return 0;
	}

	#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
	static int bzImage64_verify_sig(const char *kernel, unsigned long kernel_len)
	{
	return verify_pefile_signature(kernel, kernel_len,
	VERIFY_USE_SECONDARY_KEYRING,
	VERIFYING_KEXEC_PE_SIGNATURE);
	}
	#endif

	const struct kexec_file_ops kexec_bzImage64_ops = {
	.probe = bzImage64_probe,
	.load = bzImage64_load,
	.cleanup = bzImage64_cleanup,
	#ifdef CONFIG_KEXEC_BZIMAGE_VERIFY_SIG
	.verify_sig = bzImage64_verify_sig,
	#endif
	};