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