cmd/elf.c - platform/external/u-boot - Gitiles

 /*
  * Copyright (c) 2001 William L. Pitts
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms are freely
  * permitted provided that the above copyright notice and this
  * paragraph and the following disclaimer are duplicated in all
  * such forms.
  *
  * This software is provided "AS IS" and without any express or
  * implied warranties, including, without limitation, the implied
  * warranties of merchantability and fitness for a particular
  * purpose.
  */

 #include <common.h>
 #include <command.h>
 #include <elf.h>
 #include <env.h>
 #include <environment.h>
 #include <net.h>
 #include <vxworks.h>
 #ifdef CONFIG_X86
 #include <vbe.h>
 #include <asm/e820.h>
 #include <linux/linkage.h>
 #endif

 /*
  * A very simple ELF64 loader, assumes the image is valid, returns the
  * entry point address.
  *
  * Note if U-Boot is 32-bit, the loader assumes the to segment's
  * physical address and size is within the lower 32-bit address space.
  */
 static unsigned long load_elf64_image_phdr(unsigned long addr)
 {
 	Elf64_Ehdr *ehdr; /* Elf header structure pointer */
 	Elf64_Phdr *phdr; /* Program header structure pointer */
 	int i;

 	ehdr = (Elf64_Ehdr *)addr;
 	phdr = (Elf64_Phdr *)(addr + (ulong)ehdr->e_phoff);

 	/* Load each program header */
 	for (i = 0; i < ehdr->e_phnum; ++i) {
 		void *dst = (void *)(ulong)phdr->p_paddr;
 		void *src = (void *)addr + phdr->p_offset;

 		debug("Loading phdr %i to 0x%p (%lu bytes)\n",
 		      i, dst, (ulong)phdr->p_filesz);
 		if (phdr->p_filesz)
 			memcpy(dst, src, phdr->p_filesz);
 		if (phdr->p_filesz != phdr->p_memsz)
 			memset(dst + phdr->p_filesz, 0x00,
 			       phdr->p_memsz - phdr->p_filesz);
 		flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
 			    roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
 		++phdr;
 	}

 	if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
 					    EF_PPC64_ELFV1_ABI)) {
 		/*
 		 * For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
 		 * descriptor pointer with the first double word being the
 		 * address of the entry point of the function.
 		 */
 		uintptr_t addr = ehdr->e_entry;

 		return *(Elf64_Addr *)addr;
 	}

 	return ehdr->e_entry;
 }

 static unsigned long load_elf64_image_shdr(unsigned long addr)
 {
 	Elf64_Ehdr *ehdr; /* Elf header structure pointer */
 	Elf64_Shdr *shdr; /* Section header structure pointer */
 	unsigned char *strtab = 0; /* String table pointer */
 	unsigned char *image; /* Binary image pointer */
 	int i; /* Loop counter */

 	ehdr = (Elf64_Ehdr *)addr;

 	/* Find the section header string table for output info */
 	shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
 			     (ehdr->e_shstrndx * sizeof(Elf64_Shdr)));

 	if (shdr->sh_type == SHT_STRTAB)
 		strtab = (unsigned char *)(addr + (ulong)shdr->sh_offset);

 	/* Load each appropriate section */
 	for (i = 0; i < ehdr->e_shnum; ++i) {
 		shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
 				     (i * sizeof(Elf64_Shdr)));

 		if (!(shdr->sh_flags & SHF_ALLOC) ||
 		    shdr->sh_addr == 0 || shdr->sh_size == 0) {
 			continue;
 		}

 		if (strtab) {
 			debug("%sing %s @ 0x%08lx (%ld bytes)\n",
 			      (shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
 			       &strtab[shdr->sh_name],
 			       (unsigned long)shdr->sh_addr,
 			       (long)shdr->sh_size);
 		}

 		if (shdr->sh_type == SHT_NOBITS) {
 			memset((void *)(uintptr_t)shdr->sh_addr, 0,
 			       shdr->sh_size);
 		} else {
 			image = (unsigned char *)addr + (ulong)shdr->sh_offset;
 			memcpy((void *)(uintptr_t)shdr->sh_addr,
 			       (const void *)image, shdr->sh_size);
 		}
 		flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
 			    roundup((shdr->sh_addr + shdr->sh_size),
 				     ARCH_DMA_MINALIGN) -
 			            rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
 	}

 	if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
 					    EF_PPC64_ELFV1_ABI)) {
 		/*
 		 * For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
 		 * descriptor pointer with the first double word being the
 		 * address of the entry point of the function.
 		 */
 		uintptr_t addr = ehdr->e_entry;

 		return *(Elf64_Addr *)addr;
 	}

 	return ehdr->e_entry;
 }

 /*
  * A very simple ELF loader, assumes the image is valid, returns the
  * entry point address.
  *
  * The loader firstly reads the EFI class to see if it's a 64-bit image.
  * If yes, call the ELF64 loader. Otherwise continue with the ELF32 loader.
  */
 static unsigned long load_elf_image_phdr(unsigned long addr)
 {
 	Elf32_Ehdr *ehdr; /* Elf header structure pointer */
 	Elf32_Phdr *phdr; /* Program header structure pointer */
 	int i;

 	ehdr = (Elf32_Ehdr *)addr;
 	if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
 		return load_elf64_image_phdr(addr);

 	phdr = (Elf32_Phdr *)(addr + ehdr->e_phoff);

 	/* Load each program header */
 	for (i = 0; i < ehdr->e_phnum; ++i) {
 		void *dst = (void *)(uintptr_t)phdr->p_paddr;
 		void *src = (void *)addr + phdr->p_offset;

 		debug("Loading phdr %i to 0x%p (%i bytes)\n",
 		      i, dst, phdr->p_filesz);
 		if (phdr->p_filesz)
 			memcpy(dst, src, phdr->p_filesz);
 		if (phdr->p_filesz != phdr->p_memsz)
 			memset(dst + phdr->p_filesz, 0x00,
 			       phdr->p_memsz - phdr->p_filesz);
 		flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
 			    roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
 		++phdr;
 	}

 	return ehdr->e_entry;
 }

 static unsigned long load_elf_image_shdr(unsigned long addr)
 {
 	Elf32_Ehdr *ehdr; /* Elf header structure pointer */
 	Elf32_Shdr *shdr; /* Section header structure pointer */
 	unsigned char *strtab = 0; /* String table pointer */
 	unsigned char *image; /* Binary image pointer */
 	int i; /* Loop counter */

 	ehdr = (Elf32_Ehdr *)addr;
 	if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
 		return load_elf64_image_shdr(addr);

 	/* Find the section header string table for output info */
 	shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
 			     (ehdr->e_shstrndx * sizeof(Elf32_Shdr)));

 	if (shdr->sh_type == SHT_STRTAB)
 		strtab = (unsigned char *)(addr + shdr->sh_offset);

 	/* Load each appropriate section */
 	for (i = 0; i < ehdr->e_shnum; ++i) {
 		shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
 				     (i * sizeof(Elf32_Shdr)));

 		if (!(shdr->sh_flags & SHF_ALLOC) ||
 		    shdr->sh_addr == 0 || shdr->sh_size == 0) {
 			continue;
 		}

 		if (strtab) {
 			debug("%sing %s @ 0x%08lx (%ld bytes)\n",
 			      (shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
 			       &strtab[shdr->sh_name],
 			       (unsigned long)shdr->sh_addr,
 			       (long)shdr->sh_size);
 		}

 		if (shdr->sh_type == SHT_NOBITS) {
 			memset((void *)(uintptr_t)shdr->sh_addr, 0,
 			       shdr->sh_size);
 		} else {
 			image = (unsigned char *)addr + shdr->sh_offset;
 			memcpy((void *)(uintptr_t)shdr->sh_addr,
 			       (const void *)image, shdr->sh_size);
 		}
 		flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
 			    roundup((shdr->sh_addr + shdr->sh_size),
 				    ARCH_DMA_MINALIGN) -
 			    rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
 	}

 	return ehdr->e_entry;
 }

 /* Allow ports to override the default behavior */
 static unsigned long do_bootelf_exec(ulong (*entry)(int, char * const[]),
 				     int argc, char * const argv[])
 {
 	unsigned long ret;

 	/*
 	 * pass address parameter as argv[0] (aka command name),
 	 * and all remaining args
 	 */
 	ret = entry(argc, argv);

 	return ret;
 }

 /*
  * Determine if a valid ELF image exists at the given memory location.
  * First look at the ELF header magic field, then make sure that it is
  * executable.
  */
 int valid_elf_image(unsigned long addr)
 {
 	Elf32_Ehdr *ehdr; /* Elf header structure pointer */

 	ehdr = (Elf32_Ehdr *)addr;

 	if (!IS_ELF(*ehdr)) {
 		printf("## No elf image at address 0x%08lx\n", addr);
 		return 0;
 	}

 	if (ehdr->e_type != ET_EXEC) {
 		printf("## Not a 32-bit elf image at address 0x%08lx\n", addr);
 		return 0;
 	}

 	return 1;
 }

 /* Interpreter command to boot an arbitrary ELF image from memory */
 int do_bootelf(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	unsigned long addr; /* Address of the ELF image */
 	unsigned long rc; /* Return value from user code */
 	char *sload = NULL;
 	const char *ep = env_get("autostart");
 	int rcode = 0;

 	/* Consume 'bootelf' */
 	argc--; argv++;

 	/* Check for flag. */
 	if (argc >= 1 && (argv[0][0] == '-' && \
 				(argv[0][1] == 'p' || argv[0][1] == 's'))) {
 		sload = argv[0];
 		/* Consume flag. */
 		argc--; argv++;
 	}
 	/* Check for address. */
 	if (argc >= 1 && strict_strtoul(argv[0], 16, &addr) != -EINVAL) {
 		/* Consume address */
 		argc--; argv++;
 	} else
 		addr = load_addr;

 	if (!valid_elf_image(addr))
 		return 1;

 	if (sload && sload[1] == 'p')
 		addr = load_elf_image_phdr(addr);
 	else
 		addr = load_elf_image_shdr(addr);

 	if (ep && !strcmp(ep, "no"))
 		return rcode;

 	printf("## Starting application at 0x%08lx ...\n", addr);

 	/*
 	 * pass address parameter as argv[0] (aka command name),
 	 * and all remaining args
 	 */
 	rc = do_bootelf_exec((void *)addr, argc, argv);
 	if (rc != 0)
 		rcode = 1;

 	printf("## Application terminated, rc = 0x%lx\n", rc);

 	return rcode;
 }

 /*
  * Interpreter command to boot VxWorks from a memory image.  The image can
  * be either an ELF image or a raw binary.  Will attempt to setup the
  * bootline and other parameters correctly.
  */
 int do_bootvx(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	unsigned long addr; /* Address of image */
 	unsigned long bootaddr = 0; /* Address to put the bootline */
 	char *bootline; /* Text of the bootline */
 	char *tmp; /* Temporary char pointer */
 	char build_buf[128]; /* Buffer for building the bootline */
 	int ptr = 0;
 #ifdef CONFIG_X86
 	ulong base;
 	struct e820_info *info;
 	struct e820_entry *data;
 	struct efi_gop_info *gop;
 	struct vesa_mode_info *vesa = &mode_info.vesa;
 #endif

 	/*
 	 * Check the loadaddr variable.
 	 * If we don't know where the image is then we're done.
 	 */
 	if (argc < 2)
 		addr = load_addr;
 	else
 		addr = simple_strtoul(argv[1], NULL, 16);

 #if defined(CONFIG_CMD_NET)
 	/*
 	 * Check to see if we need to tftp the image ourselves
 	 * before starting
 	 */
 	if ((argc == 2) && (strcmp(argv[1], "tftp") == 0)) {
 		if (net_loop(TFTPGET) <= 0)
 			return 1;
 		printf("Automatic boot of VxWorks image at address 0x%08lx ...\n",
 			addr);
 	}
 #endif

 	/*
 	 * This should equate to
 	 * NV_RAM_ADRS + NV_BOOT_OFFSET + NV_ENET_OFFSET
 	 * from the VxWorks BSP header files.
 	 * This will vary from board to board
 	 */
 #if defined(CONFIG_SYS_VXWORKS_MAC_PTR)
 	tmp = (char *)CONFIG_SYS_VXWORKS_MAC_PTR;
 	eth_env_get_enetaddr("ethaddr", (uchar *)build_buf);
 	memcpy(tmp, build_buf, 6);
 #else
 	puts("## Ethernet MAC address not copied to NV RAM\n");
 #endif

 #ifdef CONFIG_X86
 	/*
 	 * Get VxWorks's physical memory base address from environment,
 	 * if we don't specify it in the environment, use a default one.
 	 */
 	base = env_get_hex("vx_phys_mem_base", VXWORKS_PHYS_MEM_BASE);
 	data = (struct e820_entry *)(base + E820_DATA_OFFSET);
 	info = (struct e820_info *)(base + E820_INFO_OFFSET);

 	memset(info, 0, sizeof(struct e820_info));
 	info->sign = E820_SIGNATURE;
 	info->entries = install_e820_map(E820MAX, data);
 	info->addr = (info->entries - 1) * sizeof(struct e820_entry) +
 		     E820_DATA_OFFSET;

 	/*
 	 * Explicitly clear the bootloader image size otherwise if memory
 	 * at this offset happens to contain some garbage data, the final
 	 * available memory size for the kernel is insane.
 	 */
 	*(u32 *)(base + BOOT_IMAGE_SIZE_OFFSET) = 0;

 	/*
 	 * Prepare compatible framebuffer information block.
 	 * The VESA mode has to be 32-bit RGBA.
 	 */
 	if (vesa->x_resolution && vesa->y_resolution) {
 		gop = (struct efi_gop_info *)(base + EFI_GOP_INFO_OFFSET);
 		gop->magic = EFI_GOP_INFO_MAGIC;
 		gop->info.version = 0;
 		gop->info.width = vesa->x_resolution;
 		gop->info.height = vesa->y_resolution;
 		gop->info.pixel_format = EFI_GOT_RGBA8;
 		gop->info.pixels_per_scanline = vesa->bytes_per_scanline / 4;
 		gop->fb_base = vesa->phys_base_ptr;
 		gop->fb_size = vesa->bytes_per_scanline * vesa->y_resolution;
 	}
 #endif

 	/*
 	 * Use bootaddr to find the location in memory that VxWorks
 	 * will look for the bootline string. The default value is
 	 * (LOCAL_MEM_LOCAL_ADRS + BOOT_LINE_OFFSET) as defined by
 	 * VxWorks BSP. For example, on PowerPC it defaults to 0x4200.
 	 */
 	tmp = env_get("bootaddr");
 	if (!tmp) {
 #ifdef CONFIG_X86
 		bootaddr = base + X86_BOOT_LINE_OFFSET;
 #else
 		printf("## VxWorks bootline address not specified\n");
 		return 1;
 #endif
 	}

 	if (!bootaddr)
 		bootaddr = simple_strtoul(tmp, NULL, 16);

 	/*
 	 * Check to see if the bootline is defined in the 'bootargs' parameter.
 	 * If it is not defined, we may be able to construct the info.
 	 */
 	bootline = env_get("bootargs");
 	if (!bootline) {
 		tmp = env_get("bootdev");
 		if (tmp) {
 			strcpy(build_buf, tmp);
 			ptr = strlen(tmp);
 		} else {
 			printf("## VxWorks boot device not specified\n");
 		}

 		tmp = env_get("bootfile");
 		if (tmp)
 			ptr += sprintf(build_buf + ptr, "host:%s ", tmp);
 		else
 			ptr += sprintf(build_buf + ptr, "host:vxWorks ");

 		/*
 		 * The following parameters are only needed if 'bootdev'
 		 * is an ethernet device, otherwise they are optional.
 		 */
 		tmp = env_get("ipaddr");
 		if (tmp) {
 			ptr += sprintf(build_buf + ptr, "e=%s", tmp);
 			tmp = env_get("netmask");
 			if (tmp) {
 				u32 mask = env_get_ip("netmask").s_addr;
 				ptr += sprintf(build_buf + ptr,
 					       ":%08x ", ntohl(mask));
 			} else {
 				ptr += sprintf(build_buf + ptr, " ");
 			}
 		}

 		tmp = env_get("serverip");
 		if (tmp)
 			ptr += sprintf(build_buf + ptr, "h=%s ", tmp);

 		tmp = env_get("gatewayip");
 		if (tmp)
 			ptr += sprintf(build_buf + ptr, "g=%s ", tmp);

 		tmp = env_get("hostname");
 		if (tmp)
 			ptr += sprintf(build_buf + ptr, "tn=%s ", tmp);

 		tmp = env_get("othbootargs");
 		if (tmp) {
 			strcpy(build_buf + ptr, tmp);
 			ptr += strlen(tmp);
 		}

 		bootline = build_buf;
 	}

 	memcpy((void *)bootaddr, bootline, max(strlen(bootline), (size_t)255));
 	flush_cache(bootaddr, max(strlen(bootline), (size_t)255));
 	printf("## Using bootline (@ 0x%lx): %s\n", bootaddr, (char *)bootaddr);

 	/*
 	 * If the data at the load address is an elf image, then
 	 * treat it like an elf image. Otherwise, assume that it is a
 	 * binary image.
 	 */
 	if (valid_elf_image(addr))
 		addr = load_elf_image_phdr(addr);
 	else
 		puts("## Not an ELF image, assuming binary\n");

 	printf("## Starting vxWorks at 0x%08lx ...\n", addr);

 	dcache_disable();
 #if defined(CONFIG_ARM64) && defined(CONFIG_ARMV8_PSCI)
 	armv8_setup_psci();
 	smp_kick_all_cpus();
 #endif

 #ifdef CONFIG_X86
 	/* VxWorks on x86 uses stack to pass parameters */
 	((asmlinkage void (*)(int))addr)(0);
 #else
 	((void (*)(int))addr)(0);
 #endif

 	puts("## vxWorks terminated\n");

 	return 1;
 }

 U_BOOT_CMD(
 	bootelf, CONFIG_SYS_MAXARGS, 0, do_bootelf,
 	"Boot from an ELF image in memory",
 	"[-p|-s] [address]\n"
 	"\t- load ELF image at [address] via program headers (-p)\n"
 	"\t  or via section headers (-s)"
 );

 U_BOOT_CMD(
 	bootvx, 2, 0, do_bootvx,
 	"Boot vxWorks from an ELF image",
 	" [address] - load address of vxWorks ELF image."
 );
	/*
	* Copyright (c) 2001 William L. Pitts
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms are freely
	* permitted provided that the above copyright notice and this
	* paragraph and the following disclaimer are duplicated in all
	* such forms.
	*
	* This software is provided "AS IS" and without any express or
	* implied warranties, including, without limitation, the implied
	* warranties of merchantability and fitness for a particular
	* purpose.
	*/

	#include <common.h>
	#include <command.h>
	#include <elf.h>
	#include <env.h>
	#include <environment.h>
	#include <net.h>
	#include <vxworks.h>
	#ifdef CONFIG_X86
	#include <vbe.h>
	#include <asm/e820.h>
	#include <linux/linkage.h>
	#endif

	/*
	* A very simple ELF64 loader, assumes the image is valid, returns the
	* entry point address.
	*
	* Note if U-Boot is 32-bit, the loader assumes the to segment's
	* physical address and size is within the lower 32-bit address space.
	*/
	static unsigned long load_elf64_image_phdr(unsigned long addr)
	{
	Elf64_Ehdr ehdr; / Elf header structure pointer */
	Elf64_Phdr phdr; / Program header structure pointer */
	int i;

	ehdr = (Elf64_Ehdr *)addr;
	phdr = (Elf64_Phdr *)(addr + (ulong)ehdr->e_phoff);

	/* Load each program header */
	for (i = 0; i < ehdr->e_phnum; ++i) {
	void dst = (void )(ulong)phdr->p_paddr;
	void src = (void )addr + phdr->p_offset;

	debug("Loading phdr %i to 0x%p (%lu bytes)\n",
	i, dst, (ulong)phdr->p_filesz);
	if (phdr->p_filesz)
	memcpy(dst, src, phdr->p_filesz);
	if (phdr->p_filesz != phdr->p_memsz)
	memset(dst + phdr->p_filesz, 0x00,
	phdr->p_memsz - phdr->p_filesz);
	flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
	roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
	++phdr;
	}

	if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
	EF_PPC64_ELFV1_ABI)) {
	/*
	* For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
	* descriptor pointer with the first double word being the
	* address of the entry point of the function.
	*/
	uintptr_t addr = ehdr->e_entry;

	return (Elf64_Addr )addr;
	}

	return ehdr->e_entry;
	}

	static unsigned long load_elf64_image_shdr(unsigned long addr)
	{
	Elf64_Ehdr ehdr; / Elf header structure pointer */
	Elf64_Shdr shdr; / Section header structure pointer */
	unsigned char strtab = 0; / String table pointer */
	unsigned char image; / Binary image pointer */
	int i; /* Loop counter */

	ehdr = (Elf64_Ehdr *)addr;

	/* Find the section header string table for output info */
	shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
	(ehdr->e_shstrndx * sizeof(Elf64_Shdr)));

	if (shdr->sh_type == SHT_STRTAB)
	strtab = (unsigned char *)(addr + (ulong)shdr->sh_offset);

	/* Load each appropriate section */
	for (i = 0; i < ehdr->e_shnum; ++i) {
	shdr = (Elf64_Shdr *)(addr + (ulong)ehdr->e_shoff +
	(i * sizeof(Elf64_Shdr)));

	if (!(shdr->sh_flags & SHF_ALLOC) \|\|
	shdr->sh_addr == 0 \|\| shdr->sh_size == 0) {
	continue;
	}

	if (strtab) {
	debug("%sing %s @ 0x%08lx (%ld bytes)\n",
	(shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
	&strtab[shdr->sh_name],
	(unsigned long)shdr->sh_addr,
	(long)shdr->sh_size);
	}

	if (shdr->sh_type == SHT_NOBITS) {
	memset((void *)(uintptr_t)shdr->sh_addr, 0,
	shdr->sh_size);
	} else {
	image = (unsigned char *)addr + (ulong)shdr->sh_offset;
	memcpy((void *)(uintptr_t)shdr->sh_addr,
	(const void *)image, shdr->sh_size);
	}
	flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
	roundup((shdr->sh_addr + shdr->sh_size),
	ARCH_DMA_MINALIGN) -
	rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
	}

	if (ehdr->e_machine == EM_PPC64 && (ehdr->e_flags &
	EF_PPC64_ELFV1_ABI)) {
	/*
	* For the 64-bit PowerPC ELF V1 ABI, e_entry is a function
	* descriptor pointer with the first double word being the
	* address of the entry point of the function.
	*/
	uintptr_t addr = ehdr->e_entry;

	return (Elf64_Addr )addr;
	}

	return ehdr->e_entry;
	}

	/*
	* A very simple ELF loader, assumes the image is valid, returns the
	* entry point address.
	*
	* The loader firstly reads the EFI class to see if it's a 64-bit image.
	* If yes, call the ELF64 loader. Otherwise continue with the ELF32 loader.
	*/
	static unsigned long load_elf_image_phdr(unsigned long addr)
	{
	Elf32_Ehdr ehdr; / Elf header structure pointer */
	Elf32_Phdr phdr; / Program header structure pointer */
	int i;

	ehdr = (Elf32_Ehdr *)addr;
	if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
	return load_elf64_image_phdr(addr);

	phdr = (Elf32_Phdr *)(addr + ehdr->e_phoff);

	/* Load each program header */
	for (i = 0; i < ehdr->e_phnum; ++i) {
	void dst = (void )(uintptr_t)phdr->p_paddr;
	void src = (void )addr + phdr->p_offset;

	debug("Loading phdr %i to 0x%p (%i bytes)\n",
	i, dst, phdr->p_filesz);
	if (phdr->p_filesz)
	memcpy(dst, src, phdr->p_filesz);
	if (phdr->p_filesz != phdr->p_memsz)
	memset(dst + phdr->p_filesz, 0x00,
	phdr->p_memsz - phdr->p_filesz);
	flush_cache(rounddown((unsigned long)dst, ARCH_DMA_MINALIGN),
	roundup(phdr->p_memsz, ARCH_DMA_MINALIGN));
	++phdr;
	}

	return ehdr->e_entry;
	}

	static unsigned long load_elf_image_shdr(unsigned long addr)
	{
	Elf32_Ehdr ehdr; / Elf header structure pointer */
	Elf32_Shdr shdr; / Section header structure pointer */
	unsigned char strtab = 0; / String table pointer */
	unsigned char image; / Binary image pointer */
	int i; /* Loop counter */

	ehdr = (Elf32_Ehdr *)addr;
	if (ehdr->e_ident[EI_CLASS] == ELFCLASS64)
	return load_elf64_image_shdr(addr);

	/* Find the section header string table for output info */
	shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
	(ehdr->e_shstrndx * sizeof(Elf32_Shdr)));

	if (shdr->sh_type == SHT_STRTAB)
	strtab = (unsigned char *)(addr + shdr->sh_offset);

	/* Load each appropriate section */
	for (i = 0; i < ehdr->e_shnum; ++i) {
	shdr = (Elf32_Shdr *)(addr + ehdr->e_shoff +
	(i * sizeof(Elf32_Shdr)));

	if (!(shdr->sh_flags & SHF_ALLOC) \|\|
	shdr->sh_addr == 0 \|\| shdr->sh_size == 0) {
	continue;
	}

	if (strtab) {
	debug("%sing %s @ 0x%08lx (%ld bytes)\n",
	(shdr->sh_type == SHT_NOBITS) ? "Clear" : "Load",
	&strtab[shdr->sh_name],
	(unsigned long)shdr->sh_addr,
	(long)shdr->sh_size);
	}

	if (shdr->sh_type == SHT_NOBITS) {
	memset((void *)(uintptr_t)shdr->sh_addr, 0,
	shdr->sh_size);
	} else {
	image = (unsigned char *)addr + shdr->sh_offset;
	memcpy((void *)(uintptr_t)shdr->sh_addr,
	(const void *)image, shdr->sh_size);
	}
	flush_cache(rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN),
	roundup((shdr->sh_addr + shdr->sh_size),
	ARCH_DMA_MINALIGN) -
	rounddown(shdr->sh_addr, ARCH_DMA_MINALIGN));
	}

	return ehdr->e_entry;
	}

	/* Allow ports to override the default behavior */
	static unsigned long do_bootelf_exec(ulong (entry)(int, char const[]),
	int argc, char * const argv[])
	{
	unsigned long ret;

	/*
	* pass address parameter as argv[0] (aka command name),
	* and all remaining args
	*/
	ret = entry(argc, argv);

	return ret;
	}

	/*
	* Determine if a valid ELF image exists at the given memory location.
	* First look at the ELF header magic field, then make sure that it is
	* executable.
	*/
	int valid_elf_image(unsigned long addr)
	{
	Elf32_Ehdr ehdr; / Elf header structure pointer */

	ehdr = (Elf32_Ehdr *)addr;

	if (!IS_ELF(*ehdr)) {
	printf("## No elf image at address 0x%08lx\n", addr);
	return 0;
	}

	if (ehdr->e_type != ET_EXEC) {
	printf("## Not a 32-bit elf image at address 0x%08lx\n", addr);
	return 0;
	}

	return 1;
	}

	/* Interpreter command to boot an arbitrary ELF image from memory */
	int do_bootelf(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	unsigned long addr; /* Address of the ELF image */
	unsigned long rc; /* Return value from user code */
	char *sload = NULL;
	const char *ep = env_get("autostart");
	int rcode = 0;

	/* Consume 'bootelf' */
	argc--; argv++;

	/* Check for flag. */
	if (argc >= 1 && (argv[0][0] == '-' && \
	(argv[0][1] == 'p' \|\| argv[0][1] == 's'))) {
	sload = argv[0];
	/* Consume flag. */
	argc--; argv++;
	}
	/* Check for address. */
	if (argc >= 1 && strict_strtoul(argv[0], 16, &addr) != -EINVAL) {
	/* Consume address */
	argc--; argv++;
	} else
	addr = load_addr;

	if (!valid_elf_image(addr))
	return 1;

	if (sload && sload[1] == 'p')
	addr = load_elf_image_phdr(addr);
	else
	addr = load_elf_image_shdr(addr);

	if (ep && !strcmp(ep, "no"))
	return rcode;

	printf("## Starting application at 0x%08lx ...\n", addr);

	/*
	* pass address parameter as argv[0] (aka command name),
	* and all remaining args
	*/
	rc = do_bootelf_exec((void *)addr, argc, argv);
	if (rc != 0)
	rcode = 1;

	printf("## Application terminated, rc = 0x%lx\n", rc);

	return rcode;
	}

	/*
	* Interpreter command to boot VxWorks from a memory image. The image can
	* be either an ELF image or a raw binary. Will attempt to setup the
	* bootline and other parameters correctly.
	*/
	int do_bootvx(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	unsigned long addr; /* Address of image */
	unsigned long bootaddr = 0; /* Address to put the bootline */
	char bootline; / Text of the bootline */
	char tmp; / Temporary char pointer */
	char build_buf[128]; /* Buffer for building the bootline */
	int ptr = 0;
	#ifdef CONFIG_X86
	ulong base;
	struct e820_info *info;
	struct e820_entry *data;
	struct efi_gop_info *gop;
	struct vesa_mode_info *vesa = &mode_info.vesa;
	#endif

	/*
	* Check the loadaddr variable.
	* If we don't know where the image is then we're done.
	*/
	if (argc < 2)
	addr = load_addr;
	else
	addr = simple_strtoul(argv[1], NULL, 16);

	#if defined(CONFIG_CMD_NET)
	/*
	* Check to see if we need to tftp the image ourselves
	* before starting
	*/
	if ((argc == 2) && (strcmp(argv[1], "tftp") == 0)) {
	if (net_loop(TFTPGET) <= 0)
	return 1;
	printf("Automatic boot of VxWorks image at address 0x%08lx ...\n",
	addr);
	}
	#endif

	/*
	* This should equate to
	* NV_RAM_ADRS + NV_BOOT_OFFSET + NV_ENET_OFFSET
	* from the VxWorks BSP header files.
	* This will vary from board to board
	*/
	#if defined(CONFIG_SYS_VXWORKS_MAC_PTR)
	tmp = (char *)CONFIG_SYS_VXWORKS_MAC_PTR;
	eth_env_get_enetaddr("ethaddr", (uchar *)build_buf);
	memcpy(tmp, build_buf, 6);
	#else
	puts("## Ethernet MAC address not copied to NV RAM\n");
	#endif

	#ifdef CONFIG_X86
	/*
	* Get VxWorks's physical memory base address from environment,
	* if we don't specify it in the environment, use a default one.
	*/
	base = env_get_hex("vx_phys_mem_base", VXWORKS_PHYS_MEM_BASE);
	data = (struct e820_entry *)(base + E820_DATA_OFFSET);
	info = (struct e820_info *)(base + E820_INFO_OFFSET);

	memset(info, 0, sizeof(struct e820_info));
	info->sign = E820_SIGNATURE;
	info->entries = install_e820_map(E820MAX, data);
	info->addr = (info->entries - 1) * sizeof(struct e820_entry) +
	E820_DATA_OFFSET;

	/*
	* Explicitly clear the bootloader image size otherwise if memory
	* at this offset happens to contain some garbage data, the final
	* available memory size for the kernel is insane.
	*/
	(u32 )(base + BOOT_IMAGE_SIZE_OFFSET) = 0;

	/*
	* Prepare compatible framebuffer information block.
	* The VESA mode has to be 32-bit RGBA.
	*/
	if (vesa->x_resolution && vesa->y_resolution) {
	gop = (struct efi_gop_info *)(base + EFI_GOP_INFO_OFFSET);
	gop->magic = EFI_GOP_INFO_MAGIC;
	gop->info.version = 0;
	gop->info.width = vesa->x_resolution;
	gop->info.height = vesa->y_resolution;
	gop->info.pixel_format = EFI_GOT_RGBA8;
	gop->info.pixels_per_scanline = vesa->bytes_per_scanline / 4;
	gop->fb_base = vesa->phys_base_ptr;
	gop->fb_size = vesa->bytes_per_scanline * vesa->y_resolution;
	}
	#endif

	/*
	* Use bootaddr to find the location in memory that VxWorks
	* will look for the bootline string. The default value is
	* (LOCAL_MEM_LOCAL_ADRS + BOOT_LINE_OFFSET) as defined by
	* VxWorks BSP. For example, on PowerPC it defaults to 0x4200.
	*/
	tmp = env_get("bootaddr");
	if (!tmp) {
	#ifdef CONFIG_X86
	bootaddr = base + X86_BOOT_LINE_OFFSET;
	#else
	printf("## VxWorks bootline address not specified\n");
	return 1;
	#endif
	}

	if (!bootaddr)
	bootaddr = simple_strtoul(tmp, NULL, 16);

	/*
	* Check to see if the bootline is defined in the 'bootargs' parameter.
	* If it is not defined, we may be able to construct the info.
	*/
	bootline = env_get("bootargs");
	if (!bootline) {
	tmp = env_get("bootdev");
	if (tmp) {
	strcpy(build_buf, tmp);
	ptr = strlen(tmp);
	} else {
	printf("## VxWorks boot device not specified\n");
	}

	tmp = env_get("bootfile");
	if (tmp)
	ptr += sprintf(build_buf + ptr, "host:%s ", tmp);
	else
	ptr += sprintf(build_buf + ptr, "host:vxWorks ");

	/*
	* The following parameters are only needed if 'bootdev'
	* is an ethernet device, otherwise they are optional.
	*/
	tmp = env_get("ipaddr");
	if (tmp) {
	ptr += sprintf(build_buf + ptr, "e=%s", tmp);
	tmp = env_get("netmask");
	if (tmp) {
	u32 mask = env_get_ip("netmask").s_addr;
	ptr += sprintf(build_buf + ptr,
	":%08x ", ntohl(mask));
	} else {
	ptr += sprintf(build_buf + ptr, " ");
	}
	}

	tmp = env_get("serverip");
	if (tmp)
	ptr += sprintf(build_buf + ptr, "h=%s ", tmp);

	tmp = env_get("gatewayip");
	if (tmp)
	ptr += sprintf(build_buf + ptr, "g=%s ", tmp);

	tmp = env_get("hostname");
	if (tmp)
	ptr += sprintf(build_buf + ptr, "tn=%s ", tmp);

	tmp = env_get("othbootargs");
	if (tmp) {
	strcpy(build_buf + ptr, tmp);
	ptr += strlen(tmp);
	}

	bootline = build_buf;
	}

	memcpy((void *)bootaddr, bootline, max(strlen(bootline), (size_t)255));
	flush_cache(bootaddr, max(strlen(bootline), (size_t)255));
	printf("## Using bootline (@ 0x%lx): %s\n", bootaddr, (char *)bootaddr);

	/*
	* If the data at the load address is an elf image, then
	* treat it like an elf image. Otherwise, assume that it is a
	* binary image.
	*/
	if (valid_elf_image(addr))
	addr = load_elf_image_phdr(addr);
	else
	puts("## Not an ELF image, assuming binary\n");

	printf("## Starting vxWorks at 0x%08lx ...\n", addr);

	dcache_disable();
	#if defined(CONFIG_ARM64) && defined(CONFIG_ARMV8_PSCI)
	armv8_setup_psci();
	smp_kick_all_cpus();
	#endif

	#ifdef CONFIG_X86
	/* VxWorks on x86 uses stack to pass parameters */
	((asmlinkage void (*)(int))addr)(0);
	#else
	((void (*)(int))addr)(0);
	#endif

	puts("## vxWorks terminated\n");

	return 1;
	}

	U_BOOT_CMD(
	bootelf, CONFIG_SYS_MAXARGS, 0, do_bootelf,
	"Boot from an ELF image in memory",
	"[-p\|-s] [address]\n"
	"\t- load ELF image at [address] via program headers (-p)\n"
	"\t or via section headers (-s)"
	);

	U_BOOT_CMD(
	bootvx, 2, 0, do_bootvx,
	"Boot vxWorks from an ELF image",
	" [address] - load address of vxWorks ELF image."
	);