arch/ppc/boot/utils/mkprep.c

   1 /*
   2  * Makes a prep bootable image which can be dd'd onto
   3  * a disk device to make a bootdisk.  Will take
   4  * as input a elf executable, strip off the header
   5  * and write out a boot image as:
   6  * 1) default - strips elf header
   7  *      suitable as a network boot image
   8  * 2) -pbp - strips elf header and writes out prep boot partition image
   9  *      cat or dd onto disk for booting
  10  * 3) -asm - strips elf header and writes out as asm data
  11  *      useful for generating data for a compressed image
  12  *                  -- Cort
  13  *
  14  * Modified for x86 hosted builds by Matt Porter <porter@neta.com>
  15  * Modified for Sparc hosted builds by Peter Wahl <PeterWahl@web.de>
  16  */
  17
  18 #include <stdio.h>
  19 #include <string.h>
  20 #include <stdlib.h>
  21
  22 /* size of read buffer */
  23 #define SIZE 0x1000
  24
  25 /*
  26  * Partition table entry
  27  *  - from the PReP spec
  28  */
  29 typedef struct partition_entry {
  30         unsigned char boot_indicator;
  31         unsigned char starting_head;
  32         unsigned char starting_sector;
  33         unsigned char starting_cylinder;
  34
  35         unsigned char system_indicator;
  36         unsigned char ending_head;
  37         unsigned char ending_sector;
  38         unsigned char ending_cylinder;
  39
  40         unsigned char beginning_sector[4];
  41         unsigned char number_of_sectors[4];
  42 } partition_entry_t;
  43
  44 #define BootActive      0x80
  45 #define SystemPrep      0x41
  46
  47 void copy_image(FILE *, FILE *);
  48 void write_prep_partition(FILE *, FILE *);
  49 void write_asm_data(FILE *, FILE *);
  50
  51 unsigned int elfhdr_size = 65536;
  52
  53 int main(int argc, char *argv[])
  54 {
  55         FILE *in, *out;
  56         int argptr = 1;
  57         int prep = 0;
  58         int asmoutput = 0;
  59
  60         if (argc < 3 || argc > 4) {
  61                 fprintf(stderr, "usage: %s [-pbp] [-asm] <boot-file> <image>\n",
  62                         argv[0]);
  63                 exit(-1);
  64         }
  65
  66 /* needs to handle args more elegantly -- but this is a small/simple program */
  67
  68         /* check for -pbp */
  69         if (!strcmp(argv[argptr], "-pbp")) {
  70                 prep = 1;
  71                 argptr++;
  72         }
  73
  74         /* check for -asm */
  75         if (!strcmp(argv[argptr], "-asm")) {
  76                 asmoutput = 1;
  77                 argptr++;
  78         }
  79
  80         /* input file */
  81         if (!strcmp(argv[argptr], "-"))
  82                 in = stdin;
  83         else if (!(in = fopen(argv[argptr], "r")))
  84                 exit(-1);
  85         argptr++;
  86
  87         /* output file */
  88         if (!strcmp(argv[argptr], "-"))
  89                 out = stdout;
  90         else if (!(out = fopen(argv[argptr], "w")))
  91                 exit(-1);
  92         argptr++;
  93
  94         /* skip elf header in input file */
  95         /*if ( !prep )*/
  96         fseek(in, elfhdr_size, SEEK_SET);
  97
  98         /* write prep partition if necessary */
  99         if (prep)
 100                 write_prep_partition(in, out);
 101
 102         /* write input image to bootimage */
 103         if (asmoutput)
 104                 write_asm_data(in, out);
 105         else
 106                 copy_image(in, out);
 107
 108         return 0;
 109 }
 110
 111 void store_le32(unsigned int v, unsigned char *p)
 112 {
 113         p[0] = v;
 114         p[1] = v >>= 8;
 115         p[2] = v >>= 8;
 116         p[3] = v >> 8;
 117 }
 118
 119 void write_prep_partition(FILE *in, FILE *out)
 120 {
 121         unsigned char block[512];
 122         partition_entry_t pe;
 123         unsigned char *entry  = block;
 124         unsigned char *length = block + 4;
 125         long pos = ftell(in), size;
 126
 127         if (fseek(in, 0, SEEK_END) < 0) {
 128                 fprintf(stderr,"info failed\n");
 129                 exit(-1);
 130         }
 131         size = ftell(in);
 132         if (fseek(in, pos, SEEK_SET) < 0) {
 133                 fprintf(stderr,"info failed\n");
 134                 exit(-1);
 135         }
 136
 137         memset(block, '\0', sizeof(block));
 138
 139         /* set entry point and boot image size skipping over elf header */
 140         store_le32(0x400/*+65536*/, entry);
 141         store_le32(size-elfhdr_size+0x400, length);
 142
 143         /* sets magic number for msdos partition (used by linux) */
 144         block[510] = 0x55;
 145         block[511] = 0xAA;
 146
 147         /*
 148         * Build a "PReP" partition table entry in the boot record
 149         *  - "PReP" may only look at the system_indicator
 150         */
 151         pe.boot_indicator   = BootActive;
 152         pe.system_indicator = SystemPrep;
 153         /*
 154         * The first block of the diskette is used by this "boot record" which
 155         * actually contains the partition table. (The first block of the
 156         * partition contains the boot image, but I digress...)  We'll set up
 157         * one partition on the diskette and it shall contain the rest of the
 158         * diskette.
 159         */
 160         pe.starting_head     = 0;       /* zero-based                        */
 161         pe.starting_sector   = 2;       /* one-based                         */
 162         pe.starting_cylinder = 0;       /* zero-based                        */
 163         pe.ending_head       = 1;       /* assumes two heads                 */
 164         pe.ending_sector     = 18;      /* assumes 18 sectors/track          */
 165         pe.ending_cylinder   = 79;      /* assumes 80 cylinders/diskette     */
 166
 167         /*
 168         * The "PReP" software ignores the above fields and just looks at
 169         * the next two.
 170         *   - size of the diskette is (assumed to be)
 171         *     (2 tracks/cylinder)(18 sectors/tracks)(80 cylinders/diskette)
 172         *   - unlike the above sector numbers, the beginning sector is zero-based!
 173         */
 174 #if 0
 175         store_le32(1, pe.beginning_sector);
 176 #else
 177         /* This has to be 0 on the PowerStack? */
 178         store_le32(0, pe.beginning_sector);
 179 #endif
 180
 181         store_le32(2*18*80-1, pe.number_of_sectors);
 182
 183         memcpy(&block[0x1BE], &pe, sizeof(pe));
 184
 185         fwrite(block, sizeof(block), 1, out);
 186         fwrite(entry, 4, 1, out);
 187         fwrite(length, 4, 1, out);
 188         /* set file position to 2nd sector where image will be written */
 189         fseek( out, 0x400, SEEK_SET );
 190 }
 191
 192
 193
 194 void copy_image(FILE *in, FILE *out)
 195 {
 196         char buf[SIZE];
 197         int n;
 198
 199         while ( (n = fread(buf, 1, SIZE, in)) > 0 )
 200                 fwrite(buf, 1, n, out);
 201 }
 202
 203
 204 void
 205 write_asm_data(FILE *in, FILE *out)
 206 {
 207         int i, cnt, pos = 0;
 208         unsigned int cksum = 0, val;
 209         unsigned char *lp;
 210         unsigned char buf[SIZE];
 211         size_t len;
 212
 213         fputs("\t.data\n\t.globl input_data\ninput_data:\n", out);
 214         while ((len = fread(buf, 1, sizeof(buf), in)) > 0) {
 215                 cnt = 0;
 216                 lp = buf;
 217                 /* Round up to longwords */
 218                 while (len & 3)
 219                         buf[len++] = '\0';
 220                 for (i = 0;  i < len;  i += 4) {
 221                         if (cnt == 0)
 222                                 fputs("\t.long\t", out);
 223                         fprintf(out, "0x%02X%02X%02X%02X",
 224                                 lp[0], lp[1], lp[2], lp[3]);
 225                         val = *(unsigned long *)lp;
 226                         cksum ^= val;
 227                         lp += 4;
 228                         if (++cnt == 4) {
 229                                 cnt = 0;
 230                                 fprintf(out, " # %x \n", pos+i-12);
 231                         } else {
 232                                 fputs(",", out);
 233                         }
 234                 }
 235                 if (cnt)
 236                         fputs("0\n", out);
 237                 pos += len;
 238         }
 239         fprintf(out, "\t.globl input_len\ninput_len:\t.long\t0x%x\n", pos);
 240         fprintf(stderr, "cksum = %x\n", cksum);
 241 }