arch/ppc64/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 static void gunzip(void *, int, unsigned char *, int *);
  21 extern void flush_cache(void *, unsigned long);
  22
  23
  24 /* Value picked to match that used by yaboot */
  25 #define PROG_START      0x01400000
  26 #define RAM_END         (512<<20) // Fixme: use OF */
  27 #define ONE_MB          0x100000
  28
  29 extern char _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 = {0, 0, 0};
  42 static struct addr_range vmlinuz = {0, 0, 0};
  43 static struct addr_range initrd  = {0, 0, 0};
  44
  45 static char scratch[46912];     /* scratch space for gunzip, from zlib_inflate_workspacesize() */
  46 static char elfheader[256];
  47
  48
  49 typedef void (*kernel_entry_t)( unsigned long,
  50                                 unsigned long,
  51                                 void *,
  52                                 void *);
  53
  54
  55 #undef DEBUG
  56
  57 static unsigned long claim_base;
  58
  59 static unsigned long try_claim(unsigned long size)
  60 {
  61         unsigned long addr = 0;
  62
  63         for(; claim_base < RAM_END; claim_base += ONE_MB) {
  64 #ifdef DEBUG
  65                 printf("    trying: 0x%08lx\n\r", claim_base);
  66 #endif
  67                 addr = (unsigned long)claim(claim_base, size, 0);
  68                 if ((void *)addr != (void *)-1)
  69                         break;
  70         }
  71         if (addr == 0)
  72                 return 0;
  73         claim_base = PAGE_ALIGN(claim_base + size);
  74         return addr;
  75 }
  76
  77 void start(unsigned long a1, unsigned long a2, void *promptr)
  78 {
  79         unsigned long i;
  80         int len;
  81         kernel_entry_t kernel_entry;
  82         Elf64_Ehdr *elf64;
  83         Elf64_Phdr *elf64ph;
  84
  85         prom = (int (*)(void *)) promptr;
  86         chosen_handle = finddevice("/chosen");
  87         if (chosen_handle == (void *) -1)
  88                 exit();
  89         if (getprop(chosen_handle, "stdout", &stdout, sizeof(stdout)) != 4)
  90                 exit();
  91         stderr = stdout;
  92         if (getprop(chosen_handle, "stdin", &stdin, sizeof(stdin)) != 4)
  93                 exit();
  94
  95         printf("\n\rzImage starting: loaded at 0x%lx\n\r", (unsigned long) _start);
  96
  97         /*
  98          * The first available claim_base must be above the end of the
  99          * the loaded kernel wrapper file (_start to _end includes the
 100          * initrd image if it is present) and rounded up to a nice
 101          * 1 MB boundary for good measure.
 102          */
 103
 104         claim_base = _ALIGN_UP((unsigned long)_end, ONE_MB);
 105
 106 #if defined(PROG_START)
 107         /*
 108          * Maintain a "magic" minimum address. This keeps some older
 109          * firmware platforms running.
 110          */
 111
 112         if (claim_base < PROG_START)
 113                 claim_base = PROG_START;
 114 #endif
 115
 116         vmlinuz.addr = (unsigned long)_vmlinux_start;
 117         vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
 118
 119         /* gunzip the ELF header of the kernel */
 120         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 121                 len = vmlinuz.size;
 122                 gunzip(elfheader, sizeof(elfheader),
 123                                 (unsigned char *)vmlinuz.addr, &len);
 124         } else
 125                 memcpy(elfheader, (const void *)vmlinuz.addr, sizeof(elfheader));
 126
 127         elf64 = (Elf64_Ehdr *)elfheader;
 128         if ( elf64->e_ident[EI_MAG0]  != ELFMAG0        ||
 129              elf64->e_ident[EI_MAG1]  != ELFMAG1        ||
 130              elf64->e_ident[EI_MAG2]  != ELFMAG2        ||
 131              elf64->e_ident[EI_MAG3]  != ELFMAG3        ||
 132              elf64->e_ident[EI_CLASS] != ELFCLASS64     ||
 133              elf64->e_ident[EI_DATA]  != ELFDATA2MSB    ||
 134              elf64->e_type            != ET_EXEC        ||
 135              elf64->e_machine         != EM_PPC64 )
 136         {
 137                 printf("Error: not a valid PPC64 ELF file!\n\r");
 138                 exit();
 139         }
 140
 141         elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
 142                                 (unsigned long)elf64->e_phoff);
 143         for(i=0; i < (unsigned int)elf64->e_phnum ;i++,elf64ph++) {
 144                 if (elf64ph->p_type == PT_LOAD && elf64ph->p_offset != 0)
 145                         break;
 146         }
 147         vmlinux.size = (unsigned long)elf64ph->p_filesz;
 148         vmlinux.memsize = (unsigned long)elf64ph->p_memsz;
 149         printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
 150         vmlinux.addr = try_claim(vmlinux.memsize);
 151         if (vmlinux.addr == 0) {
 152                 printf("Can't allocate memory for kernel image !\n\r");
 153                 exit();
 154         }
 155
 156         /*
 157          * Now we try to claim memory for the initrd (and copy it there)
 158          */
 159         initrd.size = (unsigned long)(_initrd_end - _initrd_start);
 160         initrd.memsize = initrd.size;
 161         if ( initrd.size > 0 ) {
 162                 printf("Allocating 0x%lx bytes for initrd ...\n\r", initrd.size);
 163                 initrd.addr = try_claim(initrd.size);
 164                 if (initrd.addr == 0) {
 165                         printf("Can't allocate memory for initial ramdisk !\n\r");
 166                         exit();
 167                 }
 168                 a1 = initrd.addr;
 169                 a2 = initrd.size;
 170                 printf("initial ramdisk moving 0x%lx <- 0x%lx (0x%lx bytes)\n\r",
 171                        initrd.addr, (unsigned long)_initrd_start, initrd.size);
 172                 memmove((void *)initrd.addr, (void *)_initrd_start, initrd.size);
 173                 printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd.addr));
 174         }
 175
 176         /* Eventually gunzip the kernel */
 177         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 178                 printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
 179                        vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
 180                 len = vmlinuz.size;
 181                 gunzip((void *)vmlinux.addr, vmlinux.memsize,
 182                         (unsigned char *)vmlinuz.addr, &len);
 183                 printf("done 0x%lx bytes\n\r", len);
 184         } else {
 185                 memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,vmlinuz.size);
 186         }
 187
 188         /* Skip over the ELF header */
 189 #ifdef DEBUG
 190         printf("... skipping 0x%lx bytes of ELF header\n\r",
 191                         (unsigned long)elf64ph->p_offset);
 192 #endif
 193         vmlinux.addr += (unsigned long)elf64ph->p_offset;
 194
 195         flush_cache((void *)vmlinux.addr, vmlinux.size);
 196
 197         kernel_entry = (kernel_entry_t)vmlinux.addr;
 198 #ifdef DEBUG
 199         printf( "kernel:\n\r"
 200                 "        entry addr = 0x%lx\n\r"
 201                 "        a1         = 0x%lx,\n\r"
 202                 "        a2         = 0x%lx,\n\r"
 203                 "        prom       = 0x%lx,\n\r"
 204                 "        bi_recs    = 0x%lx,\n\r",
 205                 (unsigned long)kernel_entry, a1, a2,
 206                 (unsigned long)prom, NULL);
 207 #endif
 208
 209         kernel_entry( a1, a2, prom, NULL );
 210
 211         printf("Error: Linux kernel returned to zImage bootloader!\n\r");
 212
 213         exit();
 214 }
 215
 216 #define HEAD_CRC        2
 217 #define EXTRA_FIELD     4
 218 #define ORIG_NAME       8
 219 #define COMMENT         0x10
 220 #define RESERVED        0xe0
 221
 222 static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
 223 {
 224         z_stream s;
 225         int r, i, flags;
 226
 227         /* skip header */
 228         i = 10;
 229         flags = src[3];
 230         if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
 231                 printf("bad gzipped data\n\r");
 232                 exit();
 233         }
 234         if ((flags & EXTRA_FIELD) != 0)
 235                 i = 12 + src[10] + (src[11] << 8);
 236         if ((flags & ORIG_NAME) != 0)
 237                 while (src[i++] != 0)
 238                         ;
 239         if ((flags & COMMENT) != 0)
 240                 while (src[i++] != 0)
 241                         ;
 242         if ((flags & HEAD_CRC) != 0)
 243                 i += 2;
 244         if (i >= *lenp) {
 245                 printf("gunzip: ran out of data in header\n\r");
 246                 exit();
 247         }
 248
 249         if (zlib_inflate_workspacesize() > sizeof(scratch)) {
 250                 printf("gunzip needs more mem\n");
 251                 exit();
 252         }
 253         memset(&s, 0, sizeof(s));
 254         s.workspace = scratch;
 255         r = zlib_inflateInit2(&s, -MAX_WBITS);
 256         if (r != Z_OK) {
 257                 printf("inflateInit2 returned %d\n\r", r);
 258                 exit();
 259         }
 260         s.next_in = src + i;
 261         s.avail_in = *lenp - i;
 262         s.next_out = dst;
 263         s.avail_out = dstlen;
 264         r = zlib_inflate(&s, Z_FULL_FLUSH);
 265         if (r != Z_OK && r != Z_STREAM_END) {
 266                 printf("inflate returned %d msg: %s\n\r", r, s.msg);
 267                 exit();
 268         }
 269         *lenp = s.next_out - (unsigned char *) dst;
 270         zlib_inflateEnd(&s);
 271 }
 272