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 "zlib.h"
  18 #include "ops.h"
  19 #include "flatdevtree.h"
  20
  21 extern void flush_cache(void *, unsigned long);
  22
  23 extern char _start[];
  24 extern char __bss_start[];
  25 extern char _end[];
  26 extern char _vmlinux_start[];
  27 extern char _vmlinux_end[];
  28 extern char _initrd_start[];
  29 extern char _initrd_end[];
  30 extern char _dtb_start[];
  31 extern char _dtb_end[];
  32
  33 struct addr_range {
  34         unsigned long addr;
  35         unsigned long size;
  36         unsigned long memsize;
  37 };
  38 static struct addr_range vmlinux;
  39 static struct addr_range vmlinuz;
  40 static struct addr_range initrd;
  41
  42 static unsigned long elfoffset;
  43 static int is_64bit;
  44
  45 /* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
  46 static char scratch[46912];
  47 static char elfheader[256];
  48
  49 typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
  50
  51 #undef DEBUG
  52
  53 #define HEAD_CRC        2
  54 #define EXTRA_FIELD     4
  55 #define ORIG_NAME       8
  56 #define COMMENT         0x10
  57 #define RESERVED        0xe0
  58
  59 static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
  60 {
  61         z_stream s;
  62         int r, i, flags;
  63
  64         /* skip header */
  65         i = 10;
  66         flags = src[3];
  67         if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
  68                 printf("bad gzipped data\n\r");
  69                 exit();
  70         }
  71         if ((flags & EXTRA_FIELD) != 0)
  72                 i = 12 + src[10] + (src[11] << 8);
  73         if ((flags & ORIG_NAME) != 0)
  74                 while (src[i++] != 0)
  75                         ;
  76         if ((flags & COMMENT) != 0)
  77                 while (src[i++] != 0)
  78                         ;
  79         if ((flags & HEAD_CRC) != 0)
  80                 i += 2;
  81         if (i >= *lenp) {
  82                 printf("gunzip: ran out of data in header\n\r");
  83                 exit();
  84         }
  85
  86         if (zlib_inflate_workspacesize() > sizeof(scratch)) {
  87                 printf("gunzip needs more mem\n");
  88                 exit();
  89         }
  90         memset(&s, 0, sizeof(s));
  91         s.workspace = scratch;
  92         r = zlib_inflateInit2(&s, -MAX_WBITS);
  93         if (r != Z_OK) {
  94                 printf("inflateInit2 returned %d\n\r", r);
  95                 exit();
  96         }
  97         s.next_in = src + i;
  98         s.avail_in = *lenp - i;
  99         s.next_out = dst;
 100         s.avail_out = dstlen;
 101         r = zlib_inflate(&s, Z_FULL_FLUSH);
 102         if (r != Z_OK && r != Z_STREAM_END) {
 103                 printf("inflate returned %d msg: %s\n\r", r, s.msg);
 104                 exit();
 105         }
 106         *lenp = s.next_out - (unsigned char *) dst;
 107         zlib_inflateEnd(&s);
 108 }
 109
 110 static int is_elf64(void *hdr)
 111 {
 112         Elf64_Ehdr *elf64 = hdr;
 113         Elf64_Phdr *elf64ph;
 114         unsigned int i;
 115
 116         if (!(elf64->e_ident[EI_MAG0]  == ELFMAG0       &&
 117               elf64->e_ident[EI_MAG1]  == ELFMAG1       &&
 118               elf64->e_ident[EI_MAG2]  == ELFMAG2       &&
 119               elf64->e_ident[EI_MAG3]  == ELFMAG3       &&
 120               elf64->e_ident[EI_CLASS] == ELFCLASS64    &&
 121               elf64->e_ident[EI_DATA]  == ELFDATA2MSB   &&
 122               elf64->e_type            == ET_EXEC       &&
 123               elf64->e_machine         == EM_PPC64))
 124                 return 0;
 125
 126         elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
 127                                  (unsigned long)elf64->e_phoff);
 128         for (i = 0; i < (unsigned int)elf64->e_phnum; i++, elf64ph++)
 129                 if (elf64ph->p_type == PT_LOAD)
 130                         break;
 131         if (i >= (unsigned int)elf64->e_phnum)
 132                 return 0;
 133
 134         elfoffset = (unsigned long)elf64ph->p_offset;
 135         vmlinux.size = (unsigned long)elf64ph->p_filesz + elfoffset;
 136         vmlinux.memsize = (unsigned long)elf64ph->p_memsz + elfoffset;
 137
 138         is_64bit = 1;
 139         return 1;
 140 }
 141
 142 static int is_elf32(void *hdr)
 143 {
 144         Elf32_Ehdr *elf32 = hdr;
 145         Elf32_Phdr *elf32ph;
 146         unsigned int i;
 147
 148         if (!(elf32->e_ident[EI_MAG0]  == ELFMAG0       &&
 149               elf32->e_ident[EI_MAG1]  == ELFMAG1       &&
 150               elf32->e_ident[EI_MAG2]  == ELFMAG2       &&
 151               elf32->e_ident[EI_MAG3]  == ELFMAG3       &&
 152               elf32->e_ident[EI_CLASS] == ELFCLASS32    &&
 153               elf32->e_ident[EI_DATA]  == ELFDATA2MSB   &&
 154               elf32->e_type            == ET_EXEC       &&
 155               elf32->e_machine         == EM_PPC))
 156                 return 0;
 157
 158         elf32 = (Elf32_Ehdr *)elfheader;
 159         elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
 160         for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
 161                 if (elf32ph->p_type == PT_LOAD)
 162                         break;
 163         if (i >= elf32->e_phnum)
 164                 return 0;
 165
 166         elfoffset = elf32ph->p_offset;
 167         vmlinux.size = elf32ph->p_filesz + elf32ph->p_offset;
 168         vmlinux.memsize = elf32ph->p_memsz + elf32ph->p_offset;
 169         return 1;
 170 }
 171
 172 static void prep_kernel(unsigned long a1, unsigned long a2)
 173 {
 174         int len;
 175
 176         vmlinuz.addr = (unsigned long)_vmlinux_start;
 177         vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
 178
 179         /* gunzip the ELF header of the kernel */
 180         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 181                 len = vmlinuz.size;
 182                 gunzip(elfheader, sizeof(elfheader),
 183                                 (unsigned char *)vmlinuz.addr, &len);
 184         } else
 185                 memcpy(elfheader, (const void *)vmlinuz.addr,
 186                        sizeof(elfheader));
 187
 188         if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
 189                 printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
 190                 exit();
 191         }
 192         if (platform_ops.image_hdr)
 193                 platform_ops.image_hdr(elfheader);
 194
 195         /* We need to alloc the memsize plus the file offset since gzip
 196          * will expand the header (file offset), then the kernel, then
 197          * possible rubbish we don't care about. But the kernel bss must
 198          * be claimed (it will be zero'd by the kernel itself)
 199          */
 200         printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
 201         vmlinux.addr = (unsigned long)malloc(vmlinux.memsize);
 202         if (vmlinux.addr == 0) {
 203                 printf("Can't allocate memory for kernel image !\n\r");
 204                 exit();
 205         }
 206
 207         /*
 208          * Now find the initrd
 209          *
 210          * First see if we have an image attached to us.  If so
 211          * allocate memory for it and copy it there.
 212          */
 213         initrd.size = (unsigned long)(_initrd_end - _initrd_start);
 214         initrd.memsize = initrd.size;
 215         if (initrd.size > 0) {
 216                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 217                        initrd.size);
 218                 initrd.addr = (unsigned long)malloc((u32)initrd.size);
 219                 if (initrd.addr == 0) {
 220                         printf("Can't allocate memory for initial "
 221                                         "ramdisk !\n\r");
 222                         exit();
 223                 }
 224                 printf("initial ramdisk moving 0x%lx <- 0x%lx "
 225                         "(0x%lx bytes)\n\r", initrd.addr,
 226                         (unsigned long)_initrd_start, initrd.size);
 227                 memmove((void *)initrd.addr, (void *)_initrd_start,
 228                         initrd.size);
 229                 printf("initrd head: 0x%lx\n\r",
 230                                 *((unsigned long *)initrd.addr));
 231         } else if (a2 != 0) {
 232                 /* Otherwise, see if yaboot or another loader gave us an initrd */
 233                 initrd.addr = a1;
 234                 initrd.memsize = initrd.size = a2;
 235                 printf("Using loader supplied initrd at 0x%lx (0x%lx bytes)\n\r",
 236                        initrd.addr, initrd.size);
 237         }
 238
 239         /* Eventually gunzip the kernel */
 240         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 241                 printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
 242                        vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
 243                 len = vmlinuz.size;
 244                 gunzip((void *)vmlinux.addr, vmlinux.memsize,
 245                         (unsigned char *)vmlinuz.addr, &len);
 246                 printf("done 0x%lx bytes\n\r", len);
 247         } else {
 248                 memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,
 249                         vmlinuz.size);
 250         }
 251
 252         /* Skip over the ELF header */
 253 #ifdef DEBUG
 254         printf("... skipping 0x%lx bytes of ELF header\n\r",
 255                         elfoffset);
 256 #endif
 257         vmlinux.addr += elfoffset;
 258
 259         flush_cache((void *)vmlinux.addr, vmlinux.size);
 260 }
 261
 262 /* A buffer that may be edited by tools operating on a zImage binary so as to
 263  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 264  * The buffer is put in it's own section so that tools may locate it easier.
 265  */
 266 static char builtin_cmdline[COMMAND_LINE_SIZE]
 267         __attribute__((__section__("__builtin_cmdline")));
 268
 269 static void get_cmdline(char *buf, int size)
 270 {
 271         void *devp;
 272         int len = strlen(builtin_cmdline);
 273
 274         buf[0] = '\0';
 275
 276         if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */
 277                 len = min(len, size-1);
 278                 strncpy(buf, builtin_cmdline, len);
 279                 buf[len] = '\0';
 280         }
 281         else if ((devp = finddevice("/chosen")))
 282                 getprop(devp, "bootargs", buf, size);
 283 }
 284
 285 static void set_cmdline(char *buf)
 286 {
 287         void *devp;
 288
 289         if ((devp = finddevice("/chosen")))
 290                 setprop(devp, "bootargs", buf, strlen(buf) + 1);
 291 }
 292
 293 struct platform_ops platform_ops;
 294 struct dt_ops dt_ops;
 295 struct console_ops console_ops;
 296
 297 void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
 298 {
 299         kernel_entry_t kentry;
 300         char cmdline[COMMAND_LINE_SIZE];
 301         unsigned long ft_addr = 0;
 302
 303         memset(__bss_start, 0, _end - __bss_start);
 304         memset(&platform_ops, 0, sizeof(platform_ops));
 305         memset(&dt_ops, 0, sizeof(dt_ops));
 306         memset(&console_ops, 0, sizeof(console_ops));
 307
 308         if (platform_init(promptr, _dtb_start, _dtb_end))
 309                 exit();
 310         if (console_ops.open && (console_ops.open() < 0))
 311                 exit();
 312         if (platform_ops.fixups)
 313                 platform_ops.fixups();
 314
 315         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 316                _start, sp);
 317
 318         prep_kernel(a1, a2);
 319
 320         /* If cmdline came from zimage wrapper or if we can edit the one
 321          * in the dt, print it out and edit it, if possible.
 322          */
 323         if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) {
 324                 get_cmdline(cmdline, COMMAND_LINE_SIZE);
 325                 printf("\n\rLinux/PowerPC load: %s", cmdline);
 326                 if (console_ops.edit_cmdline)
 327                         console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
 328                 printf("\n\r");
 329                 set_cmdline(cmdline);
 330         }
 331
 332         printf("Finalizing device tree...");
 333         if (dt_ops.finalize)
 334                 ft_addr = dt_ops.finalize();
 335         if (ft_addr)
 336                 printf(" flat tree at 0x%lx\n\r", ft_addr);
 337         else
 338                 printf(" using OF tree (promptr=%p)\n\r", promptr);
 339
 340         if (console_ops.close)
 341                 console_ops.close();
 342
 343         kentry = (kernel_entry_t) vmlinux.addr;
 344         if (ft_addr)
 345                 kentry(ft_addr, 0, NULL);
 346         else
 347                 /* XXX initrd addr/size should be passed in properties */
 348                 kentry(initrd.addr, initrd.size, promptr);
 349
 350         /* console closed so printf below may not work */
 351         printf("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 352         exit();
 353 }