lib: elf: Move the generic elf loading/validating functions to lib
authorKeerthy <j-keerthy@ti.com>
Wed, 12 Feb 2020 08:25:03 +0000 (13:55 +0530)
committerLokesh Vutla <lokeshvutla@ti.com>
Tue, 3 Mar 2020 07:38:14 +0000 (13:08 +0530)
Move the generic elf loading/validating functions to lib/
so that they can be re-used and accessed by code existing
outside cmd.

While at it remove the duplicate static version of load_elf_image_phdr
under arch/arm/mach-imx/imx_bootaux.c.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Suggested-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
arch/arm/mach-imx/imx_bootaux.c
cmd/Kconfig
cmd/elf.c
include/elf.h
lib/Kconfig
lib/Makefile
lib/elf.c [new file with mode: 0644]

index 21e96f8c883c5cf86c9d0eff6e54188692110716..ec0da1164f3cb888f32a9c711683f4d8b6804a57 100644 (file)
 #include <linux/compiler.h>
 #include <cpu_func.h>
 
-#ifndef CONFIG_IMX8M
-const __weak struct rproc_att hostmap[] = { };
-
-static const struct rproc_att *get_host_mapping(unsigned long auxcore)
-{
-       const struct rproc_att *mmap = hostmap;
-
-       while (mmap && mmap->size) {
-               if (mmap->da <= auxcore &&
-                   mmap->da + mmap->size > auxcore)
-                       return mmap;
-               mmap++;
-       }
-
-       return NULL;
-}
-
-/*
- * A very simple elf loader, assumes the image is valid, returns the
- * entry point address.
- */
-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;
-       phdr = (Elf32_Phdr *)(addr + ehdr->e_phoff);
-
-       /* Load each program header */
-       for (i = 0; i < ehdr->e_phnum; ++i, ++phdr) {
-               const struct rproc_att *mmap = get_host_mapping(phdr->p_paddr);
-               void *dst, *src;
-
-               if (phdr->p_type != PT_LOAD)
-                       continue;
-
-               if (!mmap) {
-                       printf("Invalid aux core address: %08x",
-                              phdr->p_paddr);
-                       return 0;
-               }
-
-               dst = (void *)(phdr->p_paddr - mmap->da) + mmap->sa;
-               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((unsigned long)dst &
-                           ~(CONFIG_SYS_CACHELINE_SIZE - 1),
-                           ALIGN(phdr->p_filesz, CONFIG_SYS_CACHELINE_SIZE));
-       }
-
-       return ehdr->e_entry;
-}
-#endif
-
 int arch_auxiliary_core_up(u32 core_id, ulong addr)
 {
        ulong stack, pc;
index 6403bc45a5ef790726deff449330236f32c7e25f..faa133da650a05017235c8b34089c60de8ca3c39 100644 (file)
@@ -399,6 +399,7 @@ config CMD_ABOOTIMG
 config CMD_ELF
        bool "bootelf, bootvx"
        default y
+       select LIB_ELF
        help
          Boot an ELF/vxWorks image from the memory.
 
index 036be5f44381ae5ac0e24820d30854d7eb0b3c5e..10e8264d3c7d14e5e09ed5ed3511848b4e7458ee 100644 (file)
--- a/cmd/elf.c
+++ b/cmd/elf.c
 #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[])
@@ -238,30 +33,6 @@ static unsigned long do_bootelf_exec(ulong (*entry)(int, char * const[]),
        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[])
 {
index 81f40191d73bcaf7b7f5ae0649336002ead3641b..e7c51986df84d986e1b1ac4dd70cd29d4574b77d 100644 (file)
@@ -692,6 +692,10 @@ unsigned long elf_hash(const unsigned char *name);
 
 #ifndef __ASSEMBLER__
 int valid_elf_image(unsigned long addr);
+unsigned long load_elf64_image_phdr(unsigned long addr);
+unsigned long load_elf64_image_shdr(unsigned long addr);
+unsigned long load_elf_image_phdr(unsigned long addr);
+unsigned long load_elf_image_shdr(unsigned long addr);
 #endif
 
 #endif /* _ELF_H */
index ab6aff710dd6e430ab41e17f0a889275208415bc..452f390c8024845c6e7be9bda8ffa1c4bb206425 100644 (file)
@@ -602,4 +602,10 @@ config TEST_FDTDEC
 config LIB_DATE
        bool
 
+config LIB_ELF
+       bool
+       help
+         Supoort basic elf loading/validating functions.
+         This supports fir 32 bit and 64 bit versions.
+
 endmenu
index 15259d0473c4032b0c22c5af5a2cf013d018baba..32bf3f36931e50610ad9a7dd312ca0b9e132d4a9 100644 (file)
@@ -122,6 +122,7 @@ obj-y += vsprintf.o strto.o
 endif
 
 obj-y += date.o
+obj-$(CONFIG_LIB_ELF) += elf.o
 
 #
 # Build a fast OID lookup registry from include/linux/oid_registry.h
diff --git a/lib/elf.c b/lib/elf.c
new file mode 100644 (file)
index 0000000..d074e4e
--- /dev/null
+++ b/lib/elf.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+   Copyright (c) 2001 William L. Pitts
+*/
+
+#include <common.h>
+#include <command.h>
+#include <cpu_func.h>
+#include <elf.h>
+#include <env.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.
+ */
+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;
+}
+
+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.
+ */
+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;
+}
+
+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;
+}
+
+/*
+ * 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;
+}