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  * Copyright 2020 Joyent, Inc.
  29  */
  30 
  31 #include <sys/types.h>
  32 #include <sys/inttypes.h>
  33 #include <sys/systm.h>
  34 #include <sys/elf.h>
  35 #include <sys/elf_notes.h>
  36 
  37 #include <util/memcpy.h>
  38 
  39 #include "dboot_xboot.h"
  40 #include "dboot_elfload.h"
  41 #include "dboot_printf.h"
  42 
  43 static caddr_t elf_file = 0;
  44 
  45 #define PGETBYTES(offset)       ((void *)(elf_file + (offset)))
  46 
  47 static void *
  48 getehdr(void)
  49 {
  50         uchar_t *ident;
  51         void *hdr = NULL;
  52 
  53         ident = PGETBYTES(0);
  54         if (ident == NULL)
  55                 dboot_panic("Cannot read kernel ELF header");
  56 
  57         if (ident[EI_MAG0] != ELFMAG0 || ident[EI_MAG1] != ELFMAG1 ||
  58             ident[EI_MAG2] != ELFMAG2 || ident[EI_MAG3] != ELFMAG3)
  59                 dboot_panic("not an ELF file!");
  60 
  61         if (ident[EI_CLASS] == ELFCLASS32)
  62                 hdr = PGETBYTES(0);
  63         else if (ident[EI_CLASS] == ELFCLASS64)
  64                 hdr = PGETBYTES(0);
  65         else
  66                 dboot_panic("Unknown ELF class");
  67 
  68         return (hdr);
  69 }
  70 
  71 
  72 /*
  73  * parse the elf file for program information
  74  */
  75 int
  76 dboot_elfload64(uintptr_t file_image)
  77 {
  78         Elf64_Ehdr *eh;
  79         Elf64_Phdr *phdr;
  80         Elf64_Shdr *shdr;
  81         caddr_t allphdrs, sechdrs;
  82         int i;
  83         paddr_t src;
  84         paddr_t dst;
  85         paddr_t next_addr;
  86 
  87         elf_file = (caddr_t)file_image;
  88 
  89         allphdrs = NULL;
  90 
  91         eh = getehdr();
  92         if (eh == NULL)
  93                 dboot_panic("getehdr() failed");
  94 
  95         if (eh->e_type != ET_EXEC)
  96                 dboot_panic("not ET_EXEC, e_type = 0x%x", eh->e_type);
  97 
  98         if (eh->e_phnum == 0 || eh->e_phoff == 0)
  99                 dboot_panic("no program headers");
 100 
 101         /*
 102          * Get the program headers.
 103          */
 104         allphdrs = PGETBYTES(eh->e_phoff);
 105         if (allphdrs == NULL)
 106                 dboot_panic("Failed to get program headers e_phnum = %d",
 107                     eh->e_phnum);
 108 
 109         /*
 110          * Get the section headers.
 111          */
 112         sechdrs = PGETBYTES(eh->e_shoff);
 113         if (sechdrs == NULL)
 114                 dboot_panic("Failed to get section headers e_shnum = %d",
 115                     eh->e_shnum);
 116 
 117         /*
 118          * Next look for interesting program headers.
 119          */
 120         for (i = 0; i < eh->e_phnum; i++) {
 121                 /*LINTED [ELF program header alignment]*/
 122                 phdr = (Elf64_Phdr *)(allphdrs + eh->e_phentsize * i);
 123 
 124                 /*
 125                  * Dynamically-linked executable.
 126                  * Complain.
 127                  */
 128                 if (phdr->p_type == PT_INTERP) {
 129                         dboot_printf("warning: PT_INTERP section\n");
 130                         continue;
 131                 }
 132 
 133                 /*
 134                  * at this point we only care about PT_LOAD segments
 135                  */
 136                 if (phdr->p_type != PT_LOAD)
 137                         continue;
 138 
 139                 if (phdr->p_flags == (PF_R | PF_W) && phdr->p_vaddr == 0) {
 140                         dboot_printf("warning: krtld reloc info?\n");
 141                         continue;
 142                 }
 143 
 144                 /*
 145                  * If memory size is zero just ignore this header.
 146                  */
 147                 if (phdr->p_memsz == 0)
 148                         continue;
 149 
 150                 /*
 151                  * If load address 1:1 then ignore this header.
 152                  */
 153                 if (phdr->p_paddr == phdr->p_vaddr) {
 154                         if (prom_debug)
 155                                 dboot_printf("Skipping PT_LOAD segment for "
 156                                     "paddr = 0x%lx\n", (ulong_t)phdr->p_paddr);
 157                         continue;
 158                 }
 159 
 160                 /*
 161                  * copy the data to kernel area
 162                  */
 163                 if (phdr->p_paddr != FOUR_MEG && phdr->p_paddr != 2 * FOUR_MEG)
 164                         dboot_panic("Bad paddr for kernel nucleus segment");
 165                 src = (uintptr_t)PGETBYTES(phdr->p_offset);
 166                 dst = ktext_phys + phdr->p_paddr - FOUR_MEG;
 167                 if (prom_debug)
 168                         dboot_printf("copying %ld bytes from ELF offset 0x%lx "
 169                             "to physaddr 0x%lx (va=0x%lx)\n",
 170                             (ulong_t)phdr->p_filesz, (ulong_t)phdr->p_offset,
 171                             (ulong_t)dst, (ulong_t)phdr->p_vaddr);
 172                 (void) memcpy((void *)(uintptr_t)dst,
 173                     (void *)(uintptr_t)src, (size_t)phdr->p_filesz);
 174 
 175                 next_addr = dst + phdr->p_filesz;
 176         }
 177 
 178 
 179         /*
 180          * Next look for bss
 181          */
 182         for (i = 0; i < eh->e_shnum; i++) {
 183                 shdr = (Elf64_Shdr *)(sechdrs + eh->e_shentsize * i);
 184 
 185                 /* zero out bss */
 186                 if (shdr->sh_type == SHT_NOBITS) {
 187                         if (prom_debug)
 188                                 dboot_printf("zeroing BSS %lu bytes from "
 189                                     "physaddr 0x%" PRIx64
 190                                     " (end=0x%" PRIx64 ")\n",
 191                                     (ulong_t)shdr->sh_size,
 192                                     next_addr,
 193                                     next_addr + shdr->sh_size);
 194                         (void) memset((void *)(uintptr_t)next_addr, 0,
 195                             shdr->sh_size);
 196                         break;
 197                 }
 198         }
 199 
 200         /*
 201          * Ignore the intepreter (or should we die if there is one??)
 202          */
 203         return (0);
 204 }