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 "ops.h"
  18 #include "reg.h"
  19
  20 struct addr_range {
  21         void *addr;
  22         unsigned long size;
  23 };
  24
  25 #undef DEBUG
  26
  27 static struct addr_range prep_kernel(void)
  28 {
  29         char elfheader[256];
  30         unsigned char *vmlinuz_addr = (unsigned char *)_vmlinux_start;
  31         unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
  32         void *addr = 0;
  33         struct elf_info ei;
  34         long len;
  35         int uncompressed_image = 0;
  36
  37         len = partial_decompress(vmlinuz_addr, vmlinuz_size,
  38                 elfheader, sizeof(elfheader), 0);
  39         /* assume uncompressed data if -1 is returned */
  40         if (len == -1) {
  41                 uncompressed_image = 1;
  42                 memcpy(elfheader, vmlinuz_addr, sizeof(elfheader));
  43                 printf("No valid compressed data found, assume uncompressed data\n\r");
  44         }
  45
  46         if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
  47                 fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
  48
  49         if (platform_ops.image_hdr)
  50                 platform_ops.image_hdr(elfheader);
  51
  52         /* We need to alloc the memsize: gzip will expand the kernel
  53          * text/data, then possible rubbish we don't care about. But
  54          * the kernel bss must be claimed (it will be zero'd by the
  55          * kernel itself)
  56          */
  57         printf("Allocating 0x%lx bytes for kernel...\n\r", ei.memsize);
  58
  59         if (platform_ops.vmlinux_alloc) {
  60                 addr = platform_ops.vmlinux_alloc(ei.memsize);
  61         } else {
  62                 /*
  63                  * Check if the kernel image (without bss) would overwrite the
  64                  * bootwrapper. The device tree has been moved in fdt_init()
  65                  * to an area allocated with malloc() (somewhere past _end).
  66                  */
  67                 if ((unsigned long)_start < ei.loadsize)
  68                         fatal("Insufficient memory for kernel at address 0!"
  69                                " (_start=%p, uncompressed size=%08lx)\n\r",
  70                                _start, ei.loadsize);
  71
  72                 if ((unsigned long)_end < ei.memsize)
  73                         fatal("The final kernel image would overwrite the "
  74                                         "device tree\n\r");
  75         }
  76
  77         if (uncompressed_image) {
  78                 memcpy(addr, vmlinuz_addr + ei.elfoffset, ei.loadsize);
  79                 printf("0x%lx bytes of uncompressed data copied\n\r",
  80                        ei.loadsize);
  81                 goto out;
  82         }
  83
  84         /* Finally, decompress the kernel */
  85         printf("Decompressing (0x%p <- 0x%p:0x%p)...\n\r", addr,
  86                vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
  87
  88         len = partial_decompress(vmlinuz_addr, vmlinuz_size,
  89                 addr, ei.loadsize, ei.elfoffset);
  90
  91         if (len < 0)
  92                 fatal("Decompression failed with error code %ld\n\r", len);
  93
  94         if (len != ei.loadsize)
  95                  fatal("Decompression error: got 0x%lx bytes, expected 0x%lx.\n\r",
  96                          len, ei.loadsize);
  97
  98         printf("Done! Decompressed 0x%lx bytes\n\r", len);
  99 out:
 100         flush_cache(addr, ei.loadsize);
 101
 102         return (struct addr_range){addr, ei.memsize};
 103 }
 104
 105 static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
 106                                      unsigned long initrd_addr,
 107                                      unsigned long initrd_size)
 108 {
 109         /* If we have an image attached to us, it overrides anything
 110          * supplied by the loader. */
 111         if (_initrd_end > _initrd_start) {
 112                 printf("Attached initrd image at 0x%p-0x%p\n\r",
 113                        _initrd_start, _initrd_end);
 114                 initrd_addr = (unsigned long)_initrd_start;
 115                 initrd_size = _initrd_end - _initrd_start;
 116         } else if (initrd_size > 0) {
 117                 printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
 118                        initrd_addr, initrd_addr + initrd_size);
 119         }
 120
 121         /* If there's no initrd at all, we're done */
 122         if (! initrd_size)
 123                 return (struct addr_range){0, 0};
 124
 125         /*
 126          * If the initrd is too low it will be clobbered when the
 127          * kernel relocates to its final location.  In this case,
 128          * allocate a safer place and move it.
 129          */
 130         if (initrd_addr < vmlinux.size) {
 131                 void *old_addr = (void *)initrd_addr;
 132
 133                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 134                        initrd_size);
 135                 initrd_addr = (unsigned long)malloc(initrd_size);
 136                 if (! initrd_addr)
 137                         fatal("Can't allocate memory for initial "
 138                                "ramdisk !\n\r");
 139                 printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 140                        initrd_addr, old_addr, initrd_size);
 141                 memmove((void *)initrd_addr, old_addr, initrd_size);
 142         }
 143
 144         printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 145
 146         /* Tell the kernel initrd address via device tree */
 147         setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
 148         setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
 149
 150         return (struct addr_range){(void *)initrd_addr, initrd_size};
 151 }
 152
 153 /* A buffer that may be edited by tools operating on a zImage binary so as to
 154  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 155  * The buffer is put in it's own section so that tools may locate it easier.
 156  */
 157 static char cmdline[BOOT_COMMAND_LINE_SIZE]
 158         __attribute__((__section__("__builtin_cmdline")));
 159
 160 static void prep_cmdline(void *chosen)
 161 {
 162         unsigned int getline_timeout = 5000;
 163         int v;
 164         int n;
 165
 166         /* Wait-for-input time */
 167         n = getprop(chosen, "linux,cmdline-timeout", &v, sizeof(v));
 168         if (n == sizeof(v))
 169                 getline_timeout = v;
 170
 171         if (cmdline[0] == '\0')
 172                 getprop(chosen, "bootargs", cmdline, BOOT_COMMAND_LINE_SIZE-1);
 173
 174         printf("\n\rLinux/PowerPC load: %s", cmdline);
 175
 176         /* If possible, edit the command line */
 177         if (console_ops.edit_cmdline && getline_timeout)
 178                 console_ops.edit_cmdline(cmdline, BOOT_COMMAND_LINE_SIZE, getline_timeout);
 179
 180         printf("\n\r");
 181
 182         /* Put the command line back into the devtree for the kernel */
 183         setprop_str(chosen, "bootargs", cmdline);
 184 }
 185
 186 struct platform_ops platform_ops;
 187 struct dt_ops dt_ops;
 188 struct console_ops console_ops;
 189 struct loader_info loader_info;
 190
 191 void start(void)
 192 {
 193         struct addr_range vmlinux, initrd;
 194         kernel_entry_t kentry;
 195         unsigned long ft_addr = 0;
 196         void *chosen;
 197
 198         /* Do this first, because malloc() could clobber the loader's
 199          * command line.  Only use the loader command line if a
 200          * built-in command line wasn't set by an external tool */
 201         if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
 202                 memmove(cmdline, loader_info.cmdline,
 203                         min(loader_info.cmdline_len, BOOT_COMMAND_LINE_SIZE-1));
 204
 205         if (console_ops.open && (console_ops.open() < 0))
 206                 exit();
 207         if (platform_ops.fixups)
 208                 platform_ops.fixups();
 209
 210         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 211                _start, get_sp());
 212
 213         /* Ensure that the device tree has a /chosen node */
 214         chosen = finddevice("/chosen");
 215         if (!chosen)
 216                 chosen = create_node(NULL, "chosen");
 217
 218         vmlinux = prep_kernel();
 219         initrd = prep_initrd(vmlinux, chosen,
 220                              loader_info.initrd_addr, loader_info.initrd_size);
 221         prep_cmdline(chosen);
 222
 223         printf("Finalizing device tree...");
 224         if (dt_ops.finalize)
 225                 ft_addr = dt_ops.finalize();
 226         if (ft_addr)
 227                 printf(" flat tree at 0x%lx\n\r", ft_addr);
 228         else
 229                 printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
 230
 231         if (console_ops.close)
 232                 console_ops.close();
 233
 234         kentry = (kernel_entry_t) vmlinux.addr;
 235         if (ft_addr) {
 236                 if(platform_ops.kentry)
 237                         platform_ops.kentry(ft_addr, vmlinux.addr);
 238                 else
 239                         kentry(ft_addr, 0, NULL);
 240         }
 241         else
 242                 kentry((unsigned long)initrd.addr, initrd.size,
 243                        loader_info.promptr);
 244
 245         /* console closed so printf in fatal below may not work */
 246         fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 247 }