usr/src/uts/i86pc/dboot/dboot_elfload.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27
  28 #include <sys/types.h>
  29 #include <sys/inttypes.h>
  30 #include <sys/systm.h>
  31 #include <sys/elf.h>
  32 #include <sys/elf_notes.h>
  33
  34 #include <util/memcpy.h>
  35
  36 #include "dboot_xboot.h"
  37 #include "dboot_elfload.h"
  38 #include "dboot_printf.h"
  39
  40 static caddr_t elf_file = 0;
  41
  42 #define PGETBYTES(offset)       ((void *)(elf_file + (offset)))
  43
  44 static void *
  45 getehdr(void)
  46 {
  47         uchar_t *ident;
  48         void *hdr = NULL;
  49
  50         ident = PGETBYTES(0);
  51         if (ident == NULL)
  52                 dboot_panic("Cannot read kernel ELF header");
  53
  54         if (ident[EI_MAG0] != ELFMAG0 || ident[EI_MAG1] != ELFMAG1 ||
  55             ident[EI_MAG2] != ELFMAG2 || ident[EI_MAG3] != ELFMAG3)
  56                 dboot_panic("not an ELF file!");
  57
  58         if (ident[EI_CLASS] == ELFCLASS32)
  59                 hdr = PGETBYTES(0);
  60         else if (ident[EI_CLASS] == ELFCLASS64)
  61                 hdr = PGETBYTES(0);
  62         else
  63                 dboot_panic("Unknown ELF class");
  64
  65         return (hdr);
  66 }
  67
  68
  69 /*
  70  * parse the elf file for program information
  71  */
  72 int
  73 dboot_elfload64(uintptr_t file_image)
  74 {
  75         Elf64_Ehdr *eh;
  76         Elf64_Phdr *phdr;
  77         Elf64_Shdr *shdr;
  78         caddr_t allphdrs, sechdrs;
  79         int i;
  80         paddr_t src;
  81         paddr_t dst;
  82         paddr_t next_addr;
  83
  84         elf_file = (caddr_t)file_image;
  85
  86         allphdrs = NULL;
  87
  88         eh = getehdr();
  89         if (eh == NULL)
  90                 dboot_panic("getehdr() failed");
  91
  92         if (eh->e_type != ET_EXEC)
  93                 dboot_panic("not ET_EXEC, e_type = 0x%x", eh->e_type);
  94
  95         if (eh->e_phnum == 0 || eh->e_phoff == 0)
  96                 dboot_panic("no program headers");
  97
  98         /*
  99          * Get the program headers.
 100          */
 101         allphdrs = PGETBYTES(eh->e_phoff);
 102         if (allphdrs == NULL)
 103                 dboot_panic("Failed to get program headers e_phnum = %d",
 104                     eh->e_phnum);
 105
 106         /*
 107          * Get the section headers.
 108          */
 109         sechdrs = PGETBYTES(eh->e_shoff);
 110         if (sechdrs == NULL)
 111                 dboot_panic("Failed to get section headers e_shnum = %d",
 112                     eh->e_shnum);
 113
 114         /*
 115          * Next look for interesting program headers.
 116          */
 117         for (i = 0; i < eh->e_phnum; i++) {
 118                 /*LINTED [ELF program header alignment]*/
 119                 phdr = (Elf64_Phdr *)(allphdrs + eh->e_phentsize * i);
 120
 121                 /*
 122                  * Dynamically-linked executable.
 123                  * Complain.
 124                  */
 125                 if (phdr->p_type == PT_INTERP) {
 126                         dboot_printf("warning: PT_INTERP section\n");
 127                         continue;
 128                 }
 129
 130                 /*
 131                  * at this point we only care about PT_LOAD segments
 132                  */
 133                 if (phdr->p_type != PT_LOAD)
 134                         continue;
 135
 136                 if (phdr->p_flags == (PF_R | PF_W) && phdr->p_vaddr == 0) {
 137                         dboot_printf("warning: krtld reloc info?\n");
 138                         continue;
 139                 }
 140
 141                 /*
 142                  * If memory size is zero just ignore this header.
 143                  */
 144                 if (phdr->p_memsz == 0)
 145                         continue;
 146
 147                 /*
 148                  * If load address 1:1 then ignore this header.
 149                  */
 150                 if (phdr->p_paddr == phdr->p_vaddr) {
 151                         if (prom_debug)
 152                                 dboot_printf("Skipping PT_LOAD segment for "
 153                                     "paddr = 0x%lx\n", (ulong_t)phdr->p_paddr);
 154                         continue;
 155                 }
 156
 157                 /*
 158                  * copy the data to kernel area
 159                  */
 160                 if (phdr->p_paddr != FOUR_MEG && phdr->p_paddr != 2 * FOUR_MEG)
 161                         dboot_panic("Bad paddr for kernel nucleus segment");
 162                 src = (uintptr_t)PGETBYTES(phdr->p_offset);
 163                 dst = ktext_phys + phdr->p_paddr - FOUR_MEG;
 164                 if (prom_debug)
 165                         dboot_printf("copying %ld bytes from ELF offset 0x%lx "
 166                             "to physaddr 0x%lx (va=0x%lx)\n",
 167                             (ulong_t)phdr->p_filesz, (ulong_t)phdr->p_offset,
 168                             (ulong_t)dst, (ulong_t)phdr->p_vaddr);
 169                 (void) memcpy((void *)(uintptr_t)dst,
 170                     (void *)(uintptr_t)src, (size_t)phdr->p_filesz);
 171
 172                 next_addr = dst + phdr->p_filesz;
 173         }
 174
 175
 176         /*
 177          * Next look for bss
 178          */
 179         for (i = 0; i < eh->e_shnum; i++) {
 180                 shdr = (Elf64_Shdr *)(sechdrs + eh->e_shentsize * i);
 181
 182                 /* zero out bss */
 183                 if (shdr->sh_type == SHT_NOBITS) {
 184                         if (prom_debug)
 185                                 dboot_printf("zeroing BSS %ld bytes from "
 186                                     "physaddr 0x%llx (end=0x%llx)\n",
 187                                     (ulong_t)shdr->sh_size,
 188                                     (long long unsigned)next_addr,
 189                                     next_addr + shdr->sh_size);
 190                         (void) memset((void *)(uintptr_t)next_addr, 0,
 191                             shdr->sh_size);
 192                         break;
 193                 }
 194         }
 195
 196         /*
 197          * Ignore the intepreter (or should we die if there is one??)
 198          */
 199         return (0);
 200 }