libopenbios/elf_info.c

   1 /* Support for ELF Boot Proposal as a boot image */
   2 #include "config.h"
   3 #include "arch/common/elf_boot.h"
   4 #include "libopenbios/sys_info.h"
   5 #include "asm/io.h"
   6 #include "libopenbios/ipchecksum.h"
   7 #include "openbios-version.h"
   8 #define printf printk
   9 #define debug  printk
  10
  11 /* ELF image notes provide information to the loader who boots us */
  12
  13 /* This compiles and generates correct PT_NOTE segment for me.
  14  * If it doesn't, use assembly version below. */
  15
  16 struct elf_image_note {
  17     Elf_Nhdr hdr0;
  18     char name0[sizeof(ELF_NOTE_BOOT)];
  19     char prog_name[sizeof(PROGRAM_NAME)];
  20
  21     Elf_Nhdr hdr1;
  22     char name1[sizeof(ELF_NOTE_BOOT)];
  23     char version[sizeof(OPENBIOS_VERSION_STR)];
  24
  25     Elf_Nhdr hdr2;
  26     char name2[sizeof(ELF_NOTE_BOOT)];
  27     unsigned short checksum;
  28 };
  29
  30 const struct elf_image_note elf_image_notes
  31         __attribute__ ((section (".note.ELFBoot"))) =
  32 {
  33     .hdr0 = {
  34         .n_namesz = sizeof(ELF_NOTE_BOOT),
  35         .n_descsz = sizeof(PROGRAM_NAME),
  36         .n_type = EIN_PROGRAM_NAME,
  37     },
  38     .name0 = ELF_NOTE_BOOT,
  39     .prog_name = PROGRAM_NAME,
  40
  41     .hdr1 = {
  42         .n_namesz = sizeof(ELF_NOTE_BOOT),
  43         .n_descsz = sizeof(OPENBIOS_VERSION_STR),
  44         .n_type = EIN_PROGRAM_VERSION,
  45     },
  46     .name1 = ELF_NOTE_BOOT,
  47     .version = OPENBIOS_VERSION_STR,
  48
  49     .hdr2 = {
  50         .n_namesz = sizeof(ELF_NOTE_BOOT),
  51         .n_descsz = sizeof(unsigned short),
  52         .n_type = EIN_PROGRAM_CHECKSUM,
  53     },
  54     .name2 = ELF_NOTE_BOOT,
  55     .checksum = 0, /* to be computed by external tool */
  56 };
  57
  58 /* This is refered by other files */
  59 const char *program_name = elf_image_notes.prog_name;
  60 const char *program_version = elf_image_notes.version;
  61
  62 #if 0
  63
  64         /* This tells the linker to make a PT_NOTE segment.
  65          * If the section is named just ".note", it will be
  66          * mixed up with useless .version notes generated by GCC.
  67          */
  68         .section ".note.ELFBoot", "a"
  69
  70         .align 4
  71         .int 2f - 1f
  72         .int 4f - 3f
  73         .int EIN_PROGRAM_NAME
  74 1:      .asciz "ELFBoot"
  75 2:      .align 4
  76 3:      .asciz PROGRAM_NAME
  77 4:
  78
  79         .align 4
  80         .int 2f - 1f
  81         .int 4f - 3f
  82         .int EIN_PROGRAM_VERSION
  83 1:      .asciz "ELFBoot"
  84 2:      .align 4
  85 3:      .asciz OPENBIOS_VERSION_STR
  86 4:
  87
  88         .align 4
  89         .int 2f - 1f
  90         .int 4f - 3f
  91         .int EIN_PROGRAM_CHECKSUM
  92 1:      .asciz "ELFBoot"
  93 2:      .align 4
  94 3:      .short 0
  95 4:
  96 #endif
  97
  98 /* Collect information from the ELF bootloader
  99  * Note that we have to copy them to our own memory,
 100  * otherwise they might be overwritten afterward. */
 101 void collect_elfboot_info(struct sys_info *info)
 102 {
 103     Elf_Bhdr *hdr = NULL;
 104     char *addr, *end;
 105     Elf_Nhdr *nhdr;
 106     char *desc;
 107
 108     if (info->boot_type == ELF_BHDR_MAGIC)
 109         hdr = phys_to_virt(info->boot_data);
 110     else
 111         hdr = phys_to_virt(info->boot_arg);
 112
 113     if (hdr->b_signature != ELF_BHDR_MAGIC)
 114         return;
 115
 116     if (ipchksum(hdr, hdr->b_size) != 0) {
 117         printf("Broken ELF boot notes\n");
 118         return;
 119     }
 120
 121     addr = (char *) (hdr + 1);
 122     end = addr + hdr->b_size;
 123     while (addr <  end) {
 124         nhdr = (Elf_Nhdr *) addr;
 125         addr += sizeof(Elf_Nhdr);
 126         addr += (nhdr->n_namesz + 3) & ~3;
 127         desc = addr;
 128         addr += (nhdr->n_descsz + 3) & ~3;
 129
 130         if (nhdr->n_namesz == 0) {
 131             /* Standard notes */
 132             switch (nhdr->n_type) {
 133             case EBN_FIRMWARE_TYPE:
 134                 info->firmware = strdup(desc);
 135                 break;
 136             case EBN_BOOTLOADER_NAME:
 137                 debug("Bootloader: %s\n", desc);
 138                 break;
 139             case EBN_BOOTLOADER_VERSION:
 140                 debug("Version: %s\n", desc);
 141                 break;
 142             case EBN_COMMAND_LINE:
 143                 info->command_line = strdup(desc);
 144                 break;
 145             case EBN_LOADED_IMAGE:
 146                 debug("Image name: %s\n", desc);
 147                 break;
 148             }
 149         }
 150     }
 151 }