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 extern void flush_cache(void *, unsigned long);
  21
  22
  23 /* Value picked to match that used by yaboot */
  24 #define PROG_START      0x01400000
  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 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 #define HEAD_CRC        2
  60 #define EXTRA_FIELD     4
  61 #define ORIG_NAME       8
  62 #define COMMENT         0x10
  63 #define RESERVED        0xe0
  64
  65 static void gunzip(void *dst, int dstlen, unsigned char *src, int *lenp)
  66 {
  67         z_stream s;
  68         int r, i, flags;
  69
  70         /* skip header */
  71         i = 10;
  72         flags = src[3];
  73         if (src[2] != Z_DEFLATED || (flags & RESERVED) != 0) {
  74                 printf("bad gzipped data\n\r");
  75                 exit();
  76         }
  77         if ((flags & EXTRA_FIELD) != 0)
  78                 i = 12 + src[10] + (src[11] << 8);
  79         if ((flags & ORIG_NAME) != 0)
  80                 while (src[i++] != 0)
  81                         ;
  82         if ((flags & COMMENT) != 0)
  83                 while (src[i++] != 0)
  84                         ;
  85         if ((flags & HEAD_CRC) != 0)
  86                 i += 2;
  87         if (i >= *lenp) {
  88                 printf("gunzip: ran out of data in header\n\r");
  89                 exit();
  90         }
  91
  92         if (zlib_inflate_workspacesize() > sizeof(scratch)) {
  93                 printf("gunzip needs more mem\n");
  94                 exit();
  95         }
  96         memset(&s, 0, sizeof(s));
  97         s.workspace = scratch;
  98         r = zlib_inflateInit2(&s, -MAX_WBITS);
  99         if (r != Z_OK) {
 100                 printf("inflateInit2 returned %d\n\r", r);
 101                 exit();
 102         }
 103         s.next_in = src + i;
 104         s.avail_in = *lenp - i;
 105         s.next_out = dst;
 106         s.avail_out = dstlen;
 107         r = zlib_inflate(&s, Z_FULL_FLUSH);
 108         if (r != Z_OK && r != Z_STREAM_END) {
 109                 printf("inflate returned %d msg: %s\n\r", r, s.msg);
 110                 exit();
 111         }
 112         *lenp = s.next_out - (unsigned char *) dst;
 113         zlib_inflateEnd(&s);
 114 }
 115
 116 static unsigned long try_claim(unsigned long size)
 117 {
 118         unsigned long addr = 0;
 119
 120         for(; claim_base < RAM_END; claim_base += ONE_MB) {
 121 #ifdef DEBUG
 122                 printf("    trying: 0x%08lx\n\r", claim_base);
 123 #endif
 124                 addr = (unsigned long)claim(claim_base, size, 0);
 125                 if ((void *)addr != (void *)-1)
 126                         break;
 127         }
 128         if (addr == 0)
 129                 return 0;
 130         claim_base = PAGE_ALIGN(claim_base + size);
 131         return addr;
 132 }
 133
 134 void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
 135 {
 136         unsigned long i;
 137         int len;
 138         kernel_entry_t kernel_entry;
 139         Elf64_Ehdr *elf64;
 140         Elf64_Phdr *elf64ph;
 141
 142         memset(__bss_start, 0, _end - __bss_start);
 143
 144         prom = (int (*)(void *)) promptr;
 145         chosen_handle = finddevice("/chosen");
 146         if (chosen_handle == (void *) -1)
 147                 exit();
 148         if (getprop(chosen_handle, "stdout", &stdout, sizeof(stdout)) != 4)
 149                 exit();
 150         stderr = stdout;
 151         if (getprop(chosen_handle, "stdin", &stdin, sizeof(stdin)) != 4)
 152                 exit();
 153
 154         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r", _start, sp);
 155
 156         /*
 157          * The first available claim_base must be above the end of the
 158          * the loaded kernel wrapper file (_start to _end includes the
 159          * initrd image if it is present) and rounded up to a nice
 160          * 1 MB boundary for good measure.
 161          */
 162
 163         claim_base = _ALIGN_UP((unsigned long)_end, ONE_MB);
 164
 165 #if defined(PROG_START)
 166         /*
 167          * Maintain a "magic" minimum address. This keeps some older
 168          * firmware platforms running.
 169          */
 170
 171         if (claim_base < PROG_START)
 172                 claim_base = PROG_START;
 173 #endif
 174
 175         vmlinuz.addr = (unsigned long)_vmlinux_start;
 176         vmlinuz.size = (unsigned long)(_vmlinux_end - _vmlinux_start);
 177
 178         /* gunzip the ELF header of the kernel */
 179         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 180                 len = vmlinuz.size;
 181                 gunzip(elfheader, sizeof(elfheader),
 182                                 (unsigned char *)vmlinuz.addr, &len);
 183         } else
 184                 memcpy(elfheader, (const void *)vmlinuz.addr, sizeof(elfheader));
 185
 186         elf64 = (Elf64_Ehdr *)elfheader;
 187         if ( elf64->e_ident[EI_MAG0]  != ELFMAG0        ||
 188              elf64->e_ident[EI_MAG1]  != ELFMAG1        ||
 189              elf64->e_ident[EI_MAG2]  != ELFMAG2        ||
 190              elf64->e_ident[EI_MAG3]  != ELFMAG3        ||
 191              elf64->e_ident[EI_CLASS] != ELFCLASS64     ||
 192              elf64->e_ident[EI_DATA]  != ELFDATA2MSB    ||
 193              elf64->e_type            != ET_EXEC        ||
 194              elf64->e_machine         != EM_PPC64 )
 195         {
 196                 printf("Error: not a valid PPC64 ELF file!\n\r");
 197                 exit();
 198         }
 199
 200         elf64ph = (Elf64_Phdr *)((unsigned long)elf64 +
 201                                 (unsigned long)elf64->e_phoff);
 202         for(i=0; i < (unsigned int)elf64->e_phnum ;i++,elf64ph++) {
 203                 if (elf64ph->p_type == PT_LOAD && elf64ph->p_offset != 0)
 204                         break;
 205         }
 206         vmlinux.size = (unsigned long)elf64ph->p_filesz +
 207                 (unsigned long)elf64ph->p_offset;
 208         /* We need to claim the memsize plus the file offset since gzip
 209          * will expand the header (file offset), then the kernel, then
 210          * possible rubbish we don't care about. But the kernel bss must
 211          * be claimed (it will be zero'd by the kernel itself)
 212          */
 213         vmlinux.memsize = (unsigned long)elf64ph->p_memsz +
 214                 (unsigned long)elf64ph->p_offset;
 215         printf("Allocating 0x%lx bytes for kernel ...\n\r", vmlinux.memsize);
 216         vmlinux.addr = try_claim(vmlinux.memsize);
 217         if (vmlinux.addr == 0) {
 218                 printf("Can't allocate memory for kernel image !\n\r");
 219                 exit();
 220         }
 221
 222         /*
 223          * Now we try to claim memory for the initrd (and copy it there)
 224          */
 225         initrd.size = (unsigned long)(_initrd_end - _initrd_start);
 226         initrd.memsize = initrd.size;
 227         if ( initrd.size > 0 ) {
 228                 printf("Allocating 0x%lx bytes for initrd ...\n\r", initrd.size);
 229                 initrd.addr = try_claim(initrd.size);
 230                 if (initrd.addr == 0) {
 231                         printf("Can't allocate memory for initial ramdisk !\n\r");
 232                         exit();
 233                 }
 234                 a1 = initrd.addr;
 235                 a2 = initrd.size;
 236                 printf("initial ramdisk moving 0x%lx <- 0x%lx (0x%lx bytes)\n\r",
 237                        initrd.addr, (unsigned long)_initrd_start, initrd.size);
 238                 memmove((void *)initrd.addr, (void *)_initrd_start, initrd.size);
 239                 printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd.addr));
 240         }
 241
 242         /* Eventually gunzip the kernel */
 243         if (*(unsigned short *)vmlinuz.addr == 0x1f8b) {
 244                 printf("gunzipping (0x%lx <- 0x%lx:0x%0lx)...",
 245                        vmlinux.addr, vmlinuz.addr, vmlinuz.addr+vmlinuz.size);
 246                 len = vmlinuz.size;
 247                 gunzip((void *)vmlinux.addr, vmlinux.memsize,
 248                         (unsigned char *)vmlinuz.addr, &len);
 249                 printf("done 0x%lx bytes\n\r", len);
 250         } else {
 251                 memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,vmlinuz.size);
 252         }
 253
 254         /* Skip over the ELF header */
 255 #ifdef DEBUG
 256         printf("... skipping 0x%lx bytes of ELF header\n\r",
 257                         (unsigned long)elf64ph->p_offset);
 258 #endif
 259         vmlinux.addr += (unsigned long)elf64ph->p_offset;
 260
 261         flush_cache((void *)vmlinux.addr, vmlinux.size);
 262
 263         kernel_entry = (kernel_entry_t)vmlinux.addr;
 264 #ifdef DEBUG
 265         printf( "kernel:\n\r"
 266                 "        entry addr = 0x%lx\n\r"
 267                 "        a1         = 0x%lx,\n\r"
 268                 "        a2         = 0x%lx,\n\r"
 269                 "        prom       = 0x%lx,\n\r"
 270                 "        bi_recs    = 0x%lx,\n\r",
 271                 (unsigned long)kernel_entry, a1, a2,
 272                 (unsigned long)prom, NULL);
 273 #endif
 274
 275         kernel_entry( a1, a2, prom, NULL );
 276
 277         printf("Error: Linux kernel returned to zImage bootloader!\n\r");
 278
 279         exit();
 280 }
 281