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
  31 struct addr_range {
  32         unsigned long addr;
  33         unsigned long size;
  34         unsigned long memsize;
  35 };
  36 static struct addr_range vmlinux;
  37 static struct addr_range vmlinuz;
  38 static struct addr_range initrd;
  39
  40 static unsigned long elfoffset;
  41 static int is_64bit;
  42
  43 /* scratch space for gunzip; 46912 is from zlib_inflate_workspacesize() */
  44 static char scratch[46912];
  45 static char elfheader[256];
  46
  47 typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
  48
  49 #undef DEBUG
  50
  51 #define HEAD_CRC        2
  52 #define EXTRA_FIELD     4
  53 #define ORIG_NAME       8
  54 #define COMMENT         0x10
  55 #define RESERVED        0xe0
  56
  57 static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
  58 {
  59         z_stream s;
  60         int r, i, flags;
  61
  62         /* skip header */
  63         i = 10;
  64         flags = src[3];
  65         if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
  66                 printf("bad gzipped data\n\r");
  67                 exit();
  68         }
  69         if ((flags & EXTRA_FIELD) != 0)
  70                 i = 12 + src[10] + (src[11] << 8);
  71         if ((flags & ORIG_NAME) != 0)
  72                 while (src[i++] != 0)
  73                         ;
  74         if ((flags & COMMENT) != 0)
  75                 while (src[i++] != 0)
  76                         ;
  77         if ((flags & HEAD_CRC) != 0)
  78                 i += 2;
  79         if (i >= *lenp) {
  80                 printf("gunzip: ran out of data in header\n\r");
  81                 exit();
  82         }
  83
  84         if (zlib_inflate_workspacesize() > sizeof(scratch)) {
  85                 printf("gunzip needs more mem\n");
  86                 exit();
  87         }
  88         memset(&s, 0, sizeof(s));
  89         s.workspace = scratch;
  90         r = zlib_inflateInit2(&s, -MAX_WBITS);
  91         if (r != Z_OK) {
  92                 printf("inflateInit2 returned %d\n\r", r);
  93                 exit();
  94         }
  95         s.next_in = src + i;
  96         s.avail_in = *lenp - i;
  97         s.next_out = dst;
  98         s.avail_out = dstlen;
  99         r = zlib_inflate(&s, Z_FULL_FLUSH);
 100         if (r != Z_OK && r != Z_STREAM_END) {
 101                 printf("inflate returned %d msg: %s\n\r", r, s.msg);
 102                 exit();
 103         }
 104         *lenp = s.next_out - (unsigned char *) dst;
 105         zlib_inflateEnd(&s);
 106 }
 107
 108 static int is_elf64(void *hdr)
 109 {
 110         Elf64_Ehdr *elf64 = hdr;
 111         Elf64_Phdr *elf64ph;
 112         unsigned int i;
 113
 114         if (!(elf64->e_ident[EI_MAG0]  == ELFMAG0       &&
 115               elf64->e_ident[EI_MAG1]  == ELFMAG1       &&
 116               elf64->e_ident[EI_MAG2]  == ELFMAG2       &&
 117               elf64->e_ident[EI_MAG3]  == ELFMAG3       &&
 118               elf64->e_ident[EI_CLASS] == ELFCLASS64    &&
 119               elf64->e_ident[EI_DATA]  == ELFDATA2MSB   &&
 120               elf64->e_type            == ET_EXEC       &&
 121               elf64->e_machine         == EM_PPC64))
 122                 return 0;
 123
 124         elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
 125                                  (unsigned long)elf64->e_phoff);
 126         for (i = 0; i < (unsigned int)elf64->e_phnum; i++, elf64ph++)
 127                 if (elf64ph->p_type == PT_LOAD)
 128                         break;
 129         if (i >= (unsigned int)elf64->e_phnum)
 130                 return 0;
 131
 132         elfoffset = (unsigned long)elf64ph->p_offset;
 133         vmlinux.size = (unsigned long)elf64ph->p_filesz + elfoffset;
 134         vmlinux.memsize = (unsigned long)elf64ph->p_memsz + elfoffset;
 135
 136         is_64bit = 1;
 137         return 1;
 138 }
 139
 140 static int is_elf32(void *hdr)
 141 {
 142         Elf32_Ehdr *elf32 = hdr;
 143         Elf32_Phdr *elf32ph;
 144         unsigned int i;
 145
 146         if (!(elf32->e_ident[EI_MAG0]  == ELFMAG0       &&
 147               elf32->e_ident[EI_MAG1]  == ELFMAG1       &&
 148               elf32->e_ident[EI_MAG2]  == ELFMAG2       &&
 149               elf32->e_ident[EI_MAG3]  == ELFMAG3       &&
 150               elf32->e_ident[EI_CLASS] == ELFCLASS32    &&
 151               elf32->e_ident[EI_DATA]  == ELFDATA2MSB   &&
 152               elf32->e_type            == ET_EXEC       &&
 153               elf32->e_machine         == EM_PPC))
 154                 return 0;
 155
 156         elf32 = (Elf32_Ehdr *)elfheader;
 157         elf32ph = (Elf32_Phdr *) ((unsigned long)elf32 + elf32->e_phoff);
 158         for (i = 0; i < elf32->e_phnum; i++, elf32ph++)
 159                 if (elf32ph->p_type == PT_LOAD)
 160                         break;
 161         if (i >= elf32->e_phnum)
 162                 return 0;
 163
 164         elfoffset = elf32ph->p_offset;
 165         vmlinux.size = elf32ph->p_filesz + elf32ph->p_offset;
 166         vmlinux.memsize = elf32ph->p_memsz + elf32ph->p_offset;
 167         return 1;
 168 }
 169
 170 static void prep_kernel(unsigned long *a1, unsigned long *a2)
 171 {
 172         int len;
 173
 174         vmlinuz.addr = (unsigned long)_vmlinux_start;
 175         vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
 176
 177         /* gunzip the ELF header of the kernel */
 178         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 179                 len = vmlinuz.size;
 180                 gunzip(elfheader, sizeof(elfheader),
 181                                 (unsigned char *)vmlinuz.addr, &len);
 182         } else
 183                 memcpy(elfheader, (const void *)vmlinuz.addr,
 184                        sizeof(elfheader));
 185
 186         if (!is_elf64(elfheader) && !is_elf32(elfheader)) {
 187                 printf("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
 188                 exit();
 189         }
 190         if (platform_ops.image_hdr)
 191                 platform_ops.image_hdr(elfheader);
 192
 193         /* We need to alloc the memsize plus the file offset since gzip
 194          * will expand the header (file offset), then the kernel, then
 195          * possible rubbish we don't care about. But the kernel bss must
 196          * be claimed (it will be zero'd by the kernel itself)
 197          */
 198         printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
 199         vmlinux.addr = (unsigned long)malloc(vmlinux.memsize);
 200         if (vmlinux.addr == 0) {
 201                 printf("Can't allocate memory for kernel image !\n\r");
 202                 exit();
 203         }
 204
 205         /*
 206          * Now we try to alloc memory for the initrd (and copy it there)
 207          */
 208         initrd.size = (unsigned long)(_initrd_end - _initrd_start);
 209         initrd.memsize = initrd.size;
 210         if ( initrd.size > 0 ) {
 211                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 212                        initrd.size);
 213                 initrd.addr = (unsigned long)malloc((u32)initrd.size);
 214                 if (initrd.addr == 0) {
 215                         printf("Can't allocate memory for initial "
 216                                         "ramdisk !\n\r");
 217                         exit();
 218                 }
 219                 *a1 = initrd.addr;
 220                 *a2 = initrd.size;
 221                 printf("initial ramdisk moving 0x%lx <- 0x%lx "
 222                         "(0x%lx bytes)\n\r", initrd.addr,
 223                         (unsigned long)_initrd_start, initrd.size);
 224                 memmove((void *)initrd.addr, (void *)_initrd_start,
 225                         initrd.size);
 226                 printf("initrd head: 0x%lx\n\r",
 227                                 *((unsigned long *)initrd.addr));
 228         }
 229
 230         /* Eventually gunzip the kernel */
 231         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 232                 printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
 233                        vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
 234                 len = vmlinuz.size;
 235                 gunzip((void *)vmlinux.addr, vmlinux.memsize,
 236                         (unsigned char *)vmlinuz.addr, &len);
 237                 printf("done 0x%lx bytes\n\r", len);
 238         } else {
 239                 memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,
 240                         vmlinuz.size);
 241         }
 242
 243         /* Skip over the ELF header */
 244 #ifdef DEBUG
 245         printf("... skipping 0x%lx bytes of ELF header\n\r",
 246                         elfoffset);
 247 #endif
 248         vmlinux.addr += elfoffset;
 249
 250         flush_cache((void *)vmlinux.addr, vmlinux.size);
 251 }
 252
 253 void __attribute__ ((weak)) ft_init(void *dt_blob)
 254 {
 255 }
 256
 257 /* A buffer that may be edited by tools operating on a zImage binary so as to
 258  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 259  * The buffer is put in it's own section so that tools may locate it easier.
 260  */
 261 static char builtin_cmdline[COMMAND_LINE_SIZE]
 262         __attribute__((__section__("__builtin_cmdline")));
 263
 264 static void get_cmdline(char *buf, int size)
 265 {
 266         void *devp;
 267         int len = strlen(builtin_cmdline);
 268
 269         buf[0] = '\0';
 270
 271         if (len > 0) { /* builtin_cmdline overrides dt's /chosen/bootargs */
 272                 len = min(len, size-1);
 273                 strncpy(buf, builtin_cmdline, len);
 274                 buf[len] = '\0';
 275         }
 276         else if ((devp = finddevice("/chosen")))
 277                 getprop(devp, "bootargs", buf, size);
 278 }
 279
 280 static void set_cmdline(char *buf)
 281 {
 282         void *devp;
 283
 284         if ((devp = finddevice("/chosen")))
 285                 setprop(devp, "bootargs", buf, strlen(buf) + 1);
 286 }
 287
 288 /* Section where ft can be tacked on after zImage is built */
 289 union blobspace {
 290         struct boot_param_header hdr;
 291         char space[8*1024];
 292 } dt_blob __attribute__((__section__("__builtin_ft")));
 293
 294 struct platform_ops platform_ops;
 295 struct dt_ops dt_ops;
 296 struct console_ops console_ops;
 297
 298 void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
 299 {
 300         int have_dt = 0;
 301         kernel_entry_t kentry;
 302         char cmdline[COMMAND_LINE_SIZE];
 303
 304         memset(__bss_start, 0, _end - __bss_start);
 305         memset(&platform_ops, 0, sizeof(platform_ops));
 306         memset(&dt_ops, 0, sizeof(dt_ops));
 307         memset(&console_ops, 0, sizeof(console_ops));
 308
 309         /* Override the dt_ops and device tree if there was an flat dev
 310          * tree attached to the zImage.
 311          */
 312         if (dt_blob.hdr.magic == OF_DT_HEADER) {
 313                 have_dt = 1;
 314                 ft_init(&dt_blob);
 315         }
 316
 317         if (platform_init(promptr))
 318                 exit();
 319         if (console_ops.open && (console_ops.open() < 0))
 320                 exit();
 321         if (platform_ops.fixups)
 322                 platform_ops.fixups();
 323
 324         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 325                _start, sp);
 326
 327         prep_kernel(&a1, &a2);
 328
 329         /* If cmdline came from zimage wrapper or if we can edit the one
 330          * in the dt, print it out and edit it, if possible.
 331          */
 332         if ((strlen(builtin_cmdline) > 0) || console_ops.edit_cmdline) {
 333                 get_cmdline(cmdline, COMMAND_LINE_SIZE);
 334                 printf("\n\rLinux/PowerPC load: %s", cmdline);
 335                 if (console_ops.edit_cmdline)
 336                         console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
 337                 printf("\n\r");
 338                 set_cmdline(cmdline);
 339         }
 340
 341         if (console_ops.close)
 342                 console_ops.close();
 343
 344         kentry = (kernel_entry_t) vmlinux.addr;
 345         if (have_dt)
 346                 kentry(dt_ops.ft_addr(), 0, NULL);
 347         else
 348                 /* XXX initrd addr/size should be passed in properties */
 349                 kentry(a1, a2, promptr);
 350
 351         /* console closed so printf below may not work */
 352         printf("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 353         exit();
 354 }