src/arch/i386/core/elf.c

   1 #include "etherboot.h"
   2 #include "elf.h"
   3 #include "memsizes.h"
   4
   5
   6 #define NAME "Etherboot"
   7
   8 #if defined(PCBIOS)
   9 #define FIRMWARE "PCBIOS"
  10 #endif
  11 #if defined(LINUXBIOS)
  12 #define FIRMWARE "LinuxBIOS"
  13 #endif
  14 #if !defined(FIRMWARE)
  15 #error "No BIOS selected"
  16 #endif
  17
  18 #define SZ(X) ((sizeof(X)+3) & ~3)
  19 #define CP(D,S) (memcpy(&(D), &(S), sizeof(S)))
  20
  21 struct elf_notes {
  22         /* The note header */
  23         struct Elf_Bhdr hdr;
  24
  25         /* First the Fixed sized entries that must be well aligned */
  26
  27         /* Pointer to bootp data */
  28         Elf_Nhdr nf1;
  29         char     nf1_name[SZ(EB_PARAM_NOTE)];
  30         uint32_t nf1_bootp_data;
  31
  32         /* Pointer to ELF header */
  33         Elf_Nhdr nf2;
  34         char     nf2_name[SZ(EB_PARAM_NOTE)];
  35         uint32_t nf2_header;
  36
  37         /* A copy of the i386 memory map */
  38         Elf_Nhdr nf3;
  39         char     nf3_name[SZ(EB_PARAM_NOTE)];
  40         struct meminfo nf3_meminfo;
  41
  42         /* Then the variable sized data string data where alignment does not matter */
  43
  44         /* The bootloader name */
  45         Elf_Nhdr nv1;
  46         char     nv1_desc[SZ(NAME)];
  47         /* The bootloader version */
  48         Elf_Nhdr nv2;
  49         char     nv2_desc[SZ(VERSION)];
  50         /* The firmware type */
  51         Elf_Nhdr nv3;
  52         char     nv3_desc[SZ(FIRMWARE)];
  53         /* Name of the loaded image */
  54         Elf_Nhdr nv4;
  55         char     nv4_loaded_image[128];
  56         /* An empty command line */
  57         Elf_Nhdr nv5;
  58         char     nv5_cmdline[SZ("")];
  59 };
  60
  61 #define ELF_NOTE_COUNT  (3 + 5)
  62
  63 static struct elf_notes notes;
  64 struct Elf_Bhdr *prepare_boot_params(void *header)
  65 {
  66         memset(&notes, 0, sizeof(notes));
  67         notes.hdr.b_signature = ELF_BHDR_MAGIC;
  68         notes.hdr.b_size      = sizeof(notes);
  69         notes.hdr.b_checksum  = 0;
  70         notes.hdr.b_records   = ELF_NOTE_COUNT;
  71
  72         /* Initialize the fixed length entries. */
  73         notes.nf1.n_namesz = sizeof(EB_PARAM_NOTE);
  74         notes.nf1.n_descsz = sizeof(notes.nf1_bootp_data);
  75         notes.nf1.n_type   = EB_BOOTP_DATA;
  76         CP(notes.nf1_name,   EB_PARAM_NOTE);
  77         notes.nf1_bootp_data = virt_to_phys(&bootp_data);
  78
  79         notes.nf2.n_namesz = sizeof(EB_PARAM_NOTE);
  80         notes.nf2.n_descsz = sizeof(notes.nf2_header);
  81         notes.nf2.n_type   = EB_HEADER;
  82         CP(notes.nf2_name,   EB_PARAM_NOTE);
  83         notes.nf2_header   = virt_to_phys(header);
  84
  85         notes.nf3.n_namesz = sizeof(EB_PARAM_NOTE);
  86         notes.nf3.n_descsz = sizeof(notes.nf3_meminfo);
  87         notes.nf3.n_type   = EB_I386_MEMMAP;
  88         CP(notes.nf3_name,   EB_PARAM_NOTE);
  89         memcpy(&notes.nf3_meminfo, &meminfo, sizeof(meminfo));
  90
  91         /* Initialize the variable length entries */
  92         notes.nv1.n_namesz = 0;
  93         notes.nv1.n_descsz = sizeof(NAME);
  94         notes.nv1.n_type   = EBN_BOOTLOADER_NAME;
  95         CP(notes.nv1_desc,   NAME);
  96
  97         notes.nv2.n_namesz = 0;
  98         notes.nv2.n_descsz = sizeof(VERSION);
  99         notes.nv2.n_type   = EBN_BOOTLOADER_VERSION;
 100         CP(notes.nv2_desc,   VERSION);
 101
 102         notes.nv3.n_namesz = 0;
 103         notes.nv3.n_descsz = sizeof(FIRMWARE);
 104         notes.nv3.n_type   = EBN_FIRMWARE_TYPE;
 105         CP(notes.nv3_desc,   FIRMWARE);
 106
 107         /* Attempt to pass the name of the loaded image */
 108         notes.nv4.n_namesz = 0;
 109         notes.nv4.n_descsz = sizeof(notes.nv4_loaded_image);
 110         notes.nv4.n_type   = EBN_LOADED_IMAGE;
 111         memcpy(&notes.nv4_loaded_image, KERNEL_BUF, sizeof(notes.nv4_loaded_image));
 112
 113         /* Pass an empty command line for now */
 114         notes.nv5.n_namesz = 0;
 115         notes.nv5.n_descsz = sizeof("");
 116         notes.nv5.n_type   = EBN_COMMAND_LINE;
 117         CP(notes.nv5_cmdline,   "");
 118
 119
 120         notes.hdr.b_checksum = ipchksum(&notes, sizeof(notes));
 121         /* Like UDP invert a 0 checksum to show that a checksum is present */
 122         if (notes.hdr.b_checksum == 0) {
 123                 notes.hdr.b_checksum = 0xffff;
 124         }
 125         return &notes.hdr;
 126 }
 127
 128 int elf_start(unsigned long machine __unused_i386, unsigned long entry, unsigned long params)
 129 {
 130 #if defined(CONFIG_X86_64)
 131         if (machine == EM_X86_64) {
 132                 return xstart_lm(entry, params);
 133         }
 134 #endif
 135         return xstart32(entry, params);
 136 }