Add ELF loader.

diff --git a/elfload/elf.h b/elfload/elf.h
new file mode 100644 (file)
index 0000000..7240b69
--- /dev/null
+++ b/elfload/elf.h
@@ -0,0 +1,288 @@
+/* This file defines standard ELF types, structures, and macros.
+   Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ian Lance Taylor <ian@cygnus.com>.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef _ELF_H
+#define        _ELF_H 1
+
+#include <stdint.h>
+
+/* Standard ELF types.  */
+
+/* Type for a 16-bit quantity.  */
+typedef uint16_t Elf32_Half;
+typedef uint16_t Elf64_Half;
+
+/* Types for signed and unsigned 32-bit quantities.  */
+typedef uint32_t Elf32_Word;
+typedef        int32_t  Elf32_Sword;
+typedef uint32_t Elf64_Word;
+typedef        int32_t  Elf64_Sword;
+
+/* Types for signed and unsigned 64-bit quantities.  */
+typedef uint64_t Elf32_Xword;
+typedef        int64_t  Elf32_Sxword;
+typedef uint64_t Elf64_Xword;
+typedef        int64_t  Elf64_Sxword;
+
+/* Type of addresses.  */
+typedef uint32_t Elf32_Addr;
+typedef uint64_t Elf64_Addr;
+
+/* Type of file offsets.  */
+typedef uint32_t Elf32_Off;
+typedef uint64_t Elf64_Off;
+
+/* Type for section indices, which are 16-bit quantities.  */
+typedef uint16_t Elf32_Section;
+typedef uint16_t Elf64_Section;
+
+/* Type of symbol indices.  */
+typedef uint32_t Elf32_Symndx;
+typedef uint64_t Elf64_Symndx;
+
+
+/* The ELF file header.  This appears at the start of every ELF file.  */
+
+#define EI_NIDENT (16)
+
+typedef struct
+{
+  unsigned char        e_ident[EI_NIDENT];     /** Magic number and other info */
+  Elf32_Half   e_type;                 /** Object file type */
+  Elf32_Half   e_machine;              /** Architecture */
+  Elf32_Word   e_version;              /** Object file version */
+  Elf32_Addr   e_entry;                /** Entry point virtual address */
+  Elf32_Off    e_phoff;                /** Program header table file offset */
+  Elf32_Off    e_shoff;                /** Section header table file offset */
+  Elf32_Word   e_flags;                /** Processor-specific flags */
+  Elf32_Half   e_ehsize;               /** ELF header size in bytes */
+  Elf32_Half   e_phentsize;            /** Program header table entry size */
+  Elf32_Half   e_phnum;                /** Program header table entry count */
+  Elf32_Half   e_shentsize;            /** Section header table entry size */
+  Elf32_Half   e_shnum;                /** Section header table entry count */
+  Elf32_Half   e_shstrndx;             /** Section header string table index */
+} Elf32_Ehdr;
+
+/* Fields in the e_ident array.  The EI_* macros are indices into the
+   array.  The macros under each EI_* macro are the values the byte
+   may have.  */
+
+#define EI_MAG0                0               /* File identification byte 0 index */
+#define ELFMAG0                0x7f            /* Magic number byte 0 */
+
+#define EI_MAG1                1               /* File identification byte 1 index */
+#define ELFMAG1                'E'             /* Magic number byte 1 */
+
+#define EI_MAG2                2               /* File identification byte 2 index */
+#define ELFMAG2                'L'             /* Magic number byte 2 */
+
+#define EI_MAG3                3               /* File identification byte 3 index */
+#define ELFMAG3                'F'             /* Magic number byte 3 */
+
+/* Conglomeration of the identification bytes, for easy testing as a word.  */
+#define        ELFMAG          "\177ELF"
+#define        SELFMAG         4
+
+#define EI_CLASS       4               /* File class byte index */
+#define ELFCLASSNONE   0               /* Invalid class */
+#define ELFCLASS32     1               /* 32-bit objects */
+#define ELFCLASS64     2               /* 64-bit objects */
+#define ELFCLASSNUM    3
+
+#define EI_DATA                5               /* Data encoding byte index */
+#define ELFDATANONE    0               /* Invalid data encoding */
+#define ELFDATA2LSB    1               /* 2's complement, little endian */
+#define ELFDATA2MSB    2               /* 2's complement, big endian */
+#define ELFDATANUM     3
+
+#define EI_VERSION     6               /* File version byte index */
+                                       /* Value must be EV_CURRENT */
+
+#define EI_OSABI       7               /* OS ABI identification */
+#define ELFOSABI_SYSV          0       /* UNIX System V ABI */
+#define ELFOSABI_HPUX          1       /* HP-UX */
+#define ELFOSABI_FREEBSD        9       /* Free BSD */
+#define ELFOSABI_ARM           97      /* ARM */
+#define ELFOSABI_STANDALONE    255     /* Standalone (embedded) application */
+
+#define EI_ABIVERSION  8               /* ABI version */
+
+#define EI_PAD         9               /* Byte index of padding bytes */
+
+/* Legal values for e_type (object file type).  */
+
+#define ET_NONE                0               /* No file type */
+#define ET_REL         1               /* Relocatable file */
+#define ET_EXEC                2               /* Executable file */
+#define ET_DYN         3               /* Shared object file */
+#define ET_CORE                4               /* Core file */
+#define        ET_NUM          5               /* Number of defined types */
+#define ET_LOPROC      0xff00          /* Processor-specific */
+#define ET_HIPROC      0xffff          /* Processor-specific */
+
+/* Legal values for e_machine (architecture).  */
+
+#define EM_NONE                 0              /* No machine */
+#define EM_M32          1              /* AT&T WE 32100 */
+#define EM_SPARC        2              /* SUN SPARC */
+#define EM_386          3              /* Intel 80386 */
+#define EM_68K          4              /* Motorola m68k family */
+#define EM_88K          5              /* Motorola m88k family */
+#define EM_486          6              /* Intel 80486 */
+#define EM_860          7              /* Intel 80860 */
+#define EM_MIPS                 8              /* MIPS R3000 big-endian */
+#define EM_S370                 9              /* Amdahl */
+#define EM_MIPS_RS4_BE 10              /* MIPS R4000 big-endian */
+#define EM_RS6000      11              /* RS6000 */
+
+#define EM_PARISC      15              /* HPPA */
+#define EM_nCUBE       16              /* nCUBE */
+#define EM_VPP500      17              /* Fujitsu VPP500 */
+#define EM_SPARC32PLUS 18              /* Sun's "v8plus" */
+#define EM_960         19              /* Intel 80960 */
+#define EM_PPC         20              /* PowerPC */
+
+#define EM_V800                36              /* NEC V800 series */
+#define EM_FR20                37              /* Fujitsu FR20 */
+#define EM_RH32                38              /* TRW RH32 */
+#define EM_MMA         39              /* Fujitsu MMA */
+#define EM_ARM         40              /* ARM */
+#define EM_FAKE_ALPHA  41              /* Digital Alpha */
+#define EM_SH          42              /* Hitachi SH */
+#define EM_SPARCV9     43              /* SPARC v9 64-bit */
+#define EM_TRICORE     44              /* Siemens Tricore */
+#define EM_ARC         45              /* Argonaut RISC Core */
+#define EM_H8_300      46              /* Hitachi H8/300 */
+#define EM_H8_300H     47              /* Hitachi H8/300H */
+#define EM_H8S         48              /* Hitachi H8S */
+#define EM_H8_500      49              /* Hitachi H8/500 */
+#define EM_IA_64       50              /* Intel Merced */
+#define EM_MIPS_X      51              /* Stanford MIPS-X */
+#define EM_COLDFIRE    52              /* Motorola Coldfire */
+#define EM_68HC12      53              /* Motorola M68HC12 */
+#define EM_NUM         54
+
+/* If it is necessary to assign new unofficial EM_* values, please
+   pick large random numbers (0x8523, 0xa7f2, etc.) to minimize the
+   chances of collision with official or non-GNU unofficial values.  */
+
+#define EM_ALPHA       0x9026
+
+/* Legal values for e_version (version).  */
+
+#define EV_NONE                0               /* Invalid ELF version */
+#define EV_CURRENT     1               /* Current version */
+#define EV_NUM         2
+
+/* Section header.  */
+
+typedef struct
+{
+  Elf32_Word   sh_name;                /** Section name (string tbl index) */
+  Elf32_Word   sh_type;                /** Section type */
+  Elf32_Word   sh_flags;               /** Section flags */
+  Elf32_Addr   sh_addr;                /** Section virtual addr at execution */
+  Elf32_Off    sh_offset;              /** Section file offset */
+  Elf32_Word   sh_size;                /** Section size in bytes */
+  Elf32_Word   sh_link;                /** Link to another section */
+  Elf32_Word   sh_info;                /** Additional section information */
+  Elf32_Word   sh_addralign;           /** Section alignment */
+  Elf32_Word   sh_entsize;             /** Entry size if section holds table */
+} Elf32_Shdr;
+
+/* Special section indices.  */
+
+#define SHN_UNDEF      0               /* Undefined section */
+#define SHN_LORESERVE  0xff00          /* Start of reserved indices */
+#define SHN_LOPROC     0xff00          /* Start of processor-specific */
+#define SHN_HIPROC     0xff1f          /* End of processor-specific */
+#define SHN_ABS                0xfff1          /* Associated symbol is absolute */
+#define SHN_COMMON     0xfff2          /* Associated symbol is common */
+#define SHN_HIRESERVE  0xffff          /* End of reserved indices */
+
+/* Legal values for sh_type (section type).  */
+
+#define SHT_NULL        0              /* Section header table entry unused */
+#define SHT_PROGBITS    1              /* Program data */
+#define SHT_SYMTAB      2              /* Symbol table */
+#define SHT_STRTAB      3              /* String table */
+#define SHT_RELA        4              /* Relocation entries with addends */
+#define SHT_HASH        5              /* Symbol hash table */
+#define SHT_DYNAMIC     6              /* Dynamic linking information */
+#define SHT_NOTE        7              /* Notes */
+#define SHT_NOBITS      8              /* Program space with no data (bss) */
+#define SHT_REL                 9              /* Relocation entries, no addends */
+#define SHT_SHLIB       10             /* Reserved */
+#define SHT_DYNSYM      11             /* Dynamic linker symbol table */
+#define        SHT_NUM          12             /* Number of defined types.  */
+#define SHT_LOOS        0x60000000     /* Start OS-specific */
+#define SHT_LOSUNW      0x6ffffffb     /* Sun-specific low bound.  */
+#define SHT_SUNW_COMDAT  0x6ffffffb
+#define SHT_SUNW_syminfo 0x6ffffffc
+#define SHT_GNU_verdef  0x6ffffffd     /* Version definition section.  */
+#define SHT_GNU_verneed         0x6ffffffe     /* Version needs section.  */
+#define SHT_GNU_versym  0x6fffffff     /* Version symbol table.  */
+#define SHT_HISUNW      0x6fffffff     /* Sun-specific high bound.  */
+#define SHT_HIOS        0x6fffffff     /* End OS-specific type */
+#define SHT_LOPROC      0x70000000     /* Start of processor-specific */
+#define SHT_HIPROC      0x7fffffff     /* End of processor-specific */
+#define SHT_LOUSER      0x80000000     /* Start of application-specific */
+#define SHT_HIUSER      0x8fffffff     /* End of application-specific */
+
+/* Legal values for sh_flags (section flags).  */
+
+#define SHF_WRITE      (1 << 0)        /* Writable */
+#define SHF_ALLOC      (1 << 1)        /* Occupies memory during execution */
+#define SHF_EXECINSTR  (1 << 2)        /* Executable */
+#define SHF_MASKPROC   0xf0000000      /* Processor-specific */
+
+/* --- Simplified ELF header --- */
+typedef struct simple_elf {
+  const char *  e_fname;       /* filename of binary */
+  unsigned long e_entry;       /* entry point virtual address */
+  unsigned long e_txtoff;      /* offset of text segment in file */
+  unsigned long e_txtlen;      /* length of text segment in bytes */
+  unsigned long e_txtstart;    /* start of text segment virtual address */
+  unsigned long e_datoff;      /* offset of data segment in file */
+  unsigned long e_datlen;      /* length of data segment in bytes */
+  unsigned long e_datstart;    /* start of data segment in virtual memory */
+  unsigned long e_rodatoff;    /* offset of rodata segment in file */
+  unsigned long e_rodatlen;    /* length of rodata segment in bytes */
+  unsigned long e_rodatstart;  /* start of rodata segment in virtual memory*/
+  unsigned long e_bsslen;      /* length of bss  segment in bytes */
+} simple_elf_t;
+
+ /* --- Defines --- */
+#define NMAGIC 0410 /* 0x108 */
+#define N_MAGIC(exec) ((exec).a_midmag & 0xffff)
+#define N_BADMAG(x) (N_MAGIC(x) != NMAGIC) 
+
+#define ELF_NOTELF  -1
+#define ELF_SUCCESS  0
+#define NOT_PRESENT  -2
+
+/*
+ * elf function prototypes
+ */
+extern int getbytes( const char *filename, int offset, int size, char *buf);
+extern int elf_load_helper( simple_elf_t *se_hdr, const char *fname );
+extern int elf_check_header( const char *fname );
+
+#endif /* elf.h */

diff --git a/elfload/loader.c b/elfload/loader.c
new file mode 100644 (file)
index 0000000..f5be3a4
--- /dev/null
+++ b/elfload/loader.c
@@ -0,0 +1,104 @@
+#include <string.h>
+#include <stdio.h>
+#include "elf.h"
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <termios.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+
+#define FATAL do { fprintf(stderr, "Error at %s:%d (%d) [%s]\n", \
+  __FILE__, __LINE__, errno, strerror(errno)); exit(1); } while(0)
+
+#define MAP_SIZE 131072
+#define MAP_MASK (4096 - 1)
+
+char * snarf_file(char * fname) {
+
+       int fd = open(fname, O_RDONLY);
+       if (fd < 0) FATAL;
+
+       struct stat st;
+       if (fstat(fd, &st) < 0) FATAL;
+
+       char * buf = malloc(st.st_size);
+       if (!buf) FATAL;
+       if (read(fd, buf, st.st_size) != st.st_size) FATAL;
+
+       printf("Loaded %d bytes.\n", st.st_size);
+       return buf;
+}
+
+void dump_to_ram (void * src, int target, int size) {
+
+       printf("Copying %d bytes to 0x%08x...\n", size, target);
+
+       int fd = open("/dev/mem", O_RDWR | O_SYNC);
+        if (fd < 0) FATAL;
+
+        void * map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE,
+                               MAP_SHARED, fd, target & ~MAP_MASK);
+
+        if (map_base == (void *) -1) FATAL;
+
+        void * virt_addr = map_base + (target & MAP_MASK);
+        memcpy(virt_addr, src, size);
+
+}
+
+static const unsigned char elf_ident[4] = { 0x7F, 'E', 'L', 'F' }; 
+
+int load_elf (char * buf) {
+
+       Elf32_Ehdr * elf_hdr = (Elf32_Ehdr *) buf;
+       Elf32_Shdr * elf_sec_hdrs = (Elf32_Shdr *) (buf + elf_hdr->e_shoff);
+
+       if (memcmp(elf_hdr->e_ident, elf_ident, sizeof(elf_ident))) FATAL;
+       if (elf_hdr->e_type != ET_EXEC) FATAL;
+       if (elf_hdr->e_machine != EM_386) FATAL;
+       if (elf_hdr->e_version != EV_CURRENT) FATAL;
+
+       char * string_table = buf + elf_sec_hdrs[elf_hdr->e_shstrndx].sh_offset;
+
+       int i;
+       for (i = 0; i < elf_hdr->e_shnum; i++) {
+               if (elf_sec_hdrs[i].sh_name == SHN_UNDEF) {
+                       continue;
+               }
+
+               char * section_name = string_table + elf_sec_hdrs[i].sh_name;
+
+               if (!(elf_sec_hdrs[i].sh_flags & SHF_ALLOC)) {
+                       printf("Skipping %s...\n", section_name);
+                       continue;
+               }
+
+               printf("Loading %s...\n", section_name);
+
+               dump_to_ram(buf + elf_sec_hdrs[i].sh_offset,
+                           elf_sec_hdrs[i].sh_addr,
+                           elf_sec_hdrs[i].sh_size);
+       }
+
+       return 0;
+}
+
+int main(int argc, char **argv) {
+       if (argc != 2) {
+               printf("Usage: %s elffile\n", argv[0]);
+               return 1;
+       }
+
+       printf("Loading file...\n");
+
+       char * buf = snarf_file(argv[1]);
+       load_elf(buf);
+
+       return 0;
+}
+