arch/powerpc/boot/main.c

   1 /*
   2  * Copyright (C) Paul Mackerras 1997.
   3  *
   4  * Updates for PPC64 by Todd Inglett, Dave Engebretsen & Peter Bergner.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11 #include <stdarg.h>
  12 #include <stddef.h>
  13 #include "elf.h"
  14 #include "page.h"
  15 #include "string.h"
  16 #include "stdio.h"
  17 #include "prom.h"
  18 #include "zlib.h"
  19
  20 extern void flush_cache(void *, unsigned long);
  21
  22
  23 /* Value picked to match that used by yaboot */
  24 #define PROG_START      0x01400000      /* only used on 64-bit systems */
  25 #define RAM_END         (512<<20)       /* Fixme: use OF */
  26 #define ONE_MB          0x100000
  27
  28 extern char _start[];
  29 extern char __bss_start[];
  30 extern char _end[];
  31 extern char _vmlinux_start[];
  32 extern char _vmlinux_end[];
  33 extern char _initrd_start[];
  34 extern char _initrd_end[];
  35
  36 /* A buffer that may be edited by tools operating on a zImage binary so as to
  37  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
  38  * The buffer is put in it's own section so that tools may locate it easier.
  39  */
  40 static char builtin_cmdline[512]
  41         __attribute__((section("__builtin_cmdline")));
  42
  43
  44 struct addr_range {
  45         unsigned long addr;
  46         unsigned long size;
  47         unsigned long memsize;
  48 };
  49 static struct addr_range vmlinux;
  50 static struct addr_range vmlinuz;
  51 static struct addr_range initrd;
  52
  53 static unsigned long elfoffset;
  54
  55 static char scratch[46912];     /* scratch space for gunzip, from zlib_inflate_workspacesize() */
  56 static char elfheader[256];
  57
  58
  59 typedef void (*kernel_entry_t)( unsigned long,
  60                                 unsigned long,
  61                                 void *,
  62                                 void *);
  63
  64
  65 #undef DEBUG
  66
  67 static unsigned long claim_base;
  68
  69 #define HEAD_CRC        2
  70 #define EXTRA_FIELD     4
  71 #define ORIG_NAME       8
  72 #define COMMENT         0x10
  73 #define RESERVED        0xe0
  74
  75 static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
  76 {
  77         z_stream s;
  78         int r, i, flags;
  79
  80         /* skip header */
  81         i = 10;
  82         flags = src[3];
  83         if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
  84                 printf("bad gzipped data\n\r");
  85                 exit();
  86         }
  87         if ((flags & EXTRA_FIELD) != 0)
  88                 i = 12 + src[10] + (src[11] << 8);
  89         if ((flags & ORIG_NAME) != 0)
  90                 while (src[i++] != 0)
  91                         ;
  92         if ((flags & COMMENT) != 0)
  93                 while (src[i++] != 0)
  94                         ;
  95         if ((flags & HEAD_CRC) != 0)
  96                 i += 2;
  97         if (i >= *lenp) {
  98                 printf("gunzip: ran out of data in header\n\r");
  99                 exit();
 100         }
 101
 102         if (zlib_inflate_workspacesize() > sizeof(scratch)) {
 103                 printf("gunzip needs more mem\n");
 104                 exit();
 105         }
 106         memset(&s, 0, sizeof(s));
 107         s.workspace = scratch;
 108         r = zlib_inflateInit2(&s, -MAX_WBITS);
 109         if (r != Z_OK) {
 110                 printf("inflateInit2 returned %d\n\r", r);
 111                 exit();
 112         }
 113         s.next_in = src + i;
 114         s.avail_in = *lenp - i;
 115         s.next_out = dst;
 116         s.avail_out = dstlen;
 117         r = zlib_inflate(&s, Z_FULL_FLUSH);
 118         if (r != Z_OK && r != Z_STREAM_END) {
 119                 printf("inflate returned %d msg: %s\n\r", r, s.msg);
 120                 exit();
 121         }
 122         *lenp = s.next_out - (unsigned char *) dst;
 123         zlib_inflateEnd(&s);
 124 }
 125
 126 static unsigned long try_claim(unsigned long size)
 127 {
 128         unsigned long addr = 0;
 129
 130         for(; claim_base < RAM_END; claim_base += ONE_MB) {
 131 #ifdef DEBUG
 132                 printf("    trying: 0x%08lx\n\r", claim_base);
 133 #endif
 134                 addr = (unsigned long)claim(claim_base, size, 0);
 135                 if ((void *)addr != (void *)-1)
 136                         break;
 137         }
 138         if (addr == 0)
 139                 return 0;
 140         claim_base = PAGE_ALIGN(claim_base + size);
 141         return addr;
 142 }
 143
 144 static int is_elf64(void *hdr)
 145 {
 146         Elf64_Ehdr *elf64 = hdr;
 147         Elf64_Phdr *elf64ph;
 148         unsigned int i;
 149
 150         if (!(elf64->e_ident[EI_MAG0]  == ELFMAG0       &&
 151               elf64->e_ident[EI_MAG1]  == ELFMAG1       &&
 152               elf64->e_ident[EI_MAG2]  == ELFMAG2       &&
 153               elf64->e_ident[EI_MAG3]  == ELFMAG3       &&
 154               elf64->e_ident[EI_CLASS] == ELFCLASS64    &&
 155               elf64->e_ident[EI_DATA]  == ELFDATA2MSB   &&
 156               elf64->e_type            == ET_EXEC       &&
 157               elf64->e_machine         == EM_PPC64))
 158                 return 0;
 159
 160         elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
 161                                  (unsigned long)elf64->e_phoff);
 162         for (i = 0; i < (unsigned int)elf64->e_phnum; i++, elf64ph++)
 163                 if (elf64ph->p_type == PT_LOAD)
 164                         break;
 165         if (i >= (unsigned int)elf64->e_phnum)
 166                 return 0;
 167
 168         elfoffset = (unsigned long)elf64ph->p_offset;
 169         vmlinux.size = (unsigned long)elf64ph->p_filesz + elfoffset;
 170         vmlinux.memsize = (unsigned long)elf64ph->p_memsz + elfoffset;
 171
 172 #if defined(PROG_START)
 173         /*
 174          * Maintain a "magic" minimum address. This keeps some older
 175          * firmware platforms running.
 176          */
 177
 178         if (claim_base < PROG_START)
 179                 claim_base = PROG_START;
 180 #endif
 181
 182         return 1;
 183 }
 184
 185 static int is_elf32(void *hdr)
 186 {
 187         Elf32_Ehdr *elf32 = hdr;
 188         Elf32_Phdr *elf32ph;
 189         unsigned int i;
 190
 191         if (!(elf32->e_ident[EI_MAG0]  == ELFMAG0       &&
 192               elf32->e_ident[EI_MAG1]  == ELFMAG1       &&
 193               elf32->e_ident[EI_MAG2]  == ELFMAG2       &&
 194               elf32->e_ident[EI_MAG3]  == ELFMAG3       &&
 195               elf32->e_ident[EI_CLASS] == ELFCLASS32    &&
 196               elf32->e_ident[EI_DATA]  == ELFDATA2MSB   &&
 197               elf32->e_type            == ET_EXEC       &&
 198               elf32->e_machine         == EM_PPC))
 199                 return 0;
 200
 201         elf32 = (Elf32_Ehdr *)elfheader;
 202         elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
 203         for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
 204                 if (elf32ph->p_type == PT_LOAD)
 205                         break;
 206         if (i >= elf32->e_phnum)
 207                 return 0;
 208
 209         elfoffset = elf32ph->p_offset;
 210         vmlinux.size = elf32ph->p_filesz + elf32ph->p_offset;
 211         vmlinux.memsize = elf32ph->p_memsz + elf32ph->p_offset;
 212         return 1;
 213 }
 214
 215 void export_cmdline(void* chosen_handle)
 216 {
 217         int len;
 218         char cmdline[2] = { 0, 0 };
 219
 220         if (builtin_cmdline[0] == 0)
 221                 return;
 222
 223         len = getprop(chosen_handle, "bootargs", cmdline, sizeof(cmdline));
 224         if (len > 0 && cmdline[0] != 0)
 225                 return;
 226
 227         setprop(chosen_handle, "bootargs", builtin_cmdline,
 228                 strlen(builtin_cmdline) + 1);
 229 }
 230
 231
 232 void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
 233 {
 234         int len;
 235         kernel_entry_t kernel_entry;
 236
 237         memset(__bss_start, 0, _end - __bss_start);
 238
 239         prom = (int (*)(void *)) promptr;
 240         chosen_handle = finddevice("/chosen");
 241         if (chosen_handle == (void *) -1)
 242                 exit();
 243         if (getprop(chosen_handle, "stdout", &stdout, sizeof(stdout)) != 4)
 244                 exit();
 245
 246         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r", _start, sp);
 247
 248         /*
 249          * The first available claim_base must be above the end of the
 250          * the loaded kernel wrapper file (_start to _end includes the
 251          * initrd image if it is present) and rounded up to a nice
 252          * 1 MB boundary for good measure.
 253          */
 254
 255         claim_base = _ALIGN_UP((unsigned long)_end, ONE_MB);
 256
 257         vmlinuz.addr = (unsigned long)_vmlinux_start;
 258         vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
 259
 260         /* gunzip the ELF header of the kernel */
 261         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 262                 len = vmlinuz.size;
 263                 gunzip(elfheader, sizeof(elfheader),
 264                                 (unsigned char *)vmlinuz.addr, &len);
 265         } else
 266                 memcpy(elfheader, (const void *)vmlinuz.addr, sizeof(elfheader));
 267
 268         if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
 269                 printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
 270                 exit();
 271         }
 272
 273         /* We need to claim the memsize plus the file offset since gzip
 274          * will expand the header (file offset), then the kernel, then
 275          * possible rubbish we don't care about. But the kernel bss must
 276          * be claimed (it will be zero'd by the kernel itself)
 277          */
 278         printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
 279         vmlinux.addr = try_claim(vmlinux.memsize);
 280         if (vmlinux.addr == 0) {
 281                 printf("Can't allocate memory for kernel image !\n\r");
 282                 exit();
 283         }
 284
 285         /*
 286          * Now we try to claim memory for the initrd (and copy it there)
 287          */
 288         initrd.size = (unsigned long)(_initrd_end - _initrd_start);
 289         initrd.memsize = initrd.size;
 290         if ( initrd.size > 0 ) {
 291                 printf("Allocating 0x%lx bytes for initrd ...\n\r", initrd.size);
 292                 initrd.addr = try_claim(initrd.size);
 293                 if (initrd.addr == 0) {
 294                         printf("Can't allocate memory for initial ramdisk !\n\r");
 295                         exit();
 296                 }
 297                 a1 = initrd.addr;
 298                 a2 = initrd.size;
 299                 printf("initial ramdisk moving 0x%lx <- 0x%lx (0x%lx bytes)\n\r",
 300                        initrd.addr, (unsigned long)_initrd_start, initrd.size);
 301                 memmove((void *)initrd.addr, (void *)_initrd_start, initrd.size);
 302                 printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd.addr));
 303         }
 304
 305         /* Eventually gunzip the kernel */
 306         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 307                 printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
 308                        vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
 309                 len = vmlinuz.size;
 310                 gunzip((void *)vmlinux.addr, vmlinux.memsize,
 311                         (unsigned char *)vmlinuz.addr, &len);
 312                 printf("done 0x%lx bytes\n\r", len);
 313         } else {
 314                 memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,vmlinuz.size);
 315         }
 316
 317         export_cmdline(chosen_handle);
 318
 319         /* Skip over the ELF header */
 320 #ifdef DEBUG
 321         printf("... skipping 0x%lx bytes of ELF header\n\r",
 322                         elfoffset);
 323 #endif
 324         vmlinux.addr += elfoffset;
 325
 326         flush_cache((void *)vmlinux.addr, vmlinux.size);
 327
 328         kernel_entry = (kernel_entry_t)vmlinux.addr;
 329 #ifdef DEBUG
 330         printf( "kernel:\n\r"
 331                 "        entry addr = 0x%lx\n\r"
 332                 "        a1         = 0x%lx,\n\r"
 333                 "        a2         = 0x%lx,\n\r"
 334                 "        prom       = 0x%lx,\n\r"
 335                 "        bi_recs    = 0x%lx,\n\r",
 336                 (unsigned long)kernel_entry, a1, a2,
 337                 (unsigned long)prom, NULL);
 338 #endif
 339
 340         kernel_entry(a1, a2, prom, NULL);
 341
 342         printf("Error: Linux kernel returned to zImage bootloader!\n\r");
 343
 344         exit();
 345 }
 346