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 "gunzip_util.h"
  19 #include "reg.h"
  20
  21 static struct gunzip_state gzstate;
  22
  23 struct addr_range {
  24         void *addr;
  25         unsigned long size;
  26 };
  27
  28 #undef DEBUG
  29
  30 static struct addr_range prep_kernel(void)
  31 {
  32         char elfheader[256];
  33         void *vmlinuz_addr = _vmlinux_start;
  34         unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
  35         void *addr = 0;
  36         struct elf_info ei;
  37         int len;
  38
  39         /* gunzip the ELF header of the kernel */
  40         gunzip_start(&gzstate, vmlinuz_addr, vmlinuz_size);
  41         gunzip_exactly(&gzstate, elfheader, sizeof(elfheader));
  42
  43         if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
  44                 fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
  45
  46         if (platform_ops.image_hdr)
  47                 platform_ops.image_hdr(elfheader);
  48
  49         /* We need to alloc the memsize: gzip will expand the kernel
  50          * text/data, then possible rubbish we don't care about. But
  51          * the kernel bss must be claimed (it will be zero'd by the
  52          * kernel itself)
  53          */
  54         printf("Allocating 0x%lx bytes for kernel ...\n\r", ei.memsize);
  55
  56         if (platform_ops.vmlinux_alloc) {
  57                 addr = platform_ops.vmlinux_alloc(ei.memsize);
  58         } else {
  59                 if ((unsigned long)_start < ei.memsize)
  60                         fatal("Insufficient memory for kernel at address 0!"
  61                                " (_start=%p)\n\r", _start);
  62         }
  63
  64         /* Finally, gunzip the kernel */
  65         printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
  66                vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
  67         /* discard up to the actual load data */
  68         gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
  69         len = gunzip_finish(&gzstate, addr, ei.loadsize);
  70         if (len != ei.loadsize)
  71                 fatal("ran out of data!  only got 0x%x of 0x%lx bytes.\n\r",
  72                                 len, ei.loadsize);
  73         printf("done 0x%x bytes\n\r", len);
  74
  75         flush_cache(addr, ei.loadsize);
  76
  77         return (struct addr_range){addr, ei.memsize};
  78 }
  79
  80 static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
  81                                      unsigned long initrd_addr,
  82                                      unsigned long initrd_size)
  83 {
  84         /* If we have an image attached to us, it overrides anything
  85          * supplied by the loader. */
  86         if (_initrd_end > _initrd_start) {
  87                 printf("Attached initrd image at 0x%p-0x%p\n\r",
  88                        _initrd_start, _initrd_end);
  89                 initrd_addr = (unsigned long)_initrd_start;
  90                 initrd_size = _initrd_end - _initrd_start;
  91         } else if (initrd_size > 0) {
  92                 printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
  93                        initrd_addr, initrd_addr + initrd_size);
  94         }
  95
  96         /* If there's no initrd at all, we're done */
  97         if (! initrd_size)
  98                 return (struct addr_range){0, 0};
  99
 100         /*
 101          * If the initrd is too low it will be clobbered when the
 102          * kernel relocates to its final location.  In this case,
 103          * allocate a safer place and move it.
 104          */
 105         if (initrd_addr < vmlinux.size) {
 106                 void *old_addr = (void *)initrd_addr;
 107
 108                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 109                        initrd_size);
 110                 initrd_addr = (unsigned long)malloc(initrd_size);
 111                 if (! initrd_addr)
 112                         fatal("Can't allocate memory for initial "
 113                                "ramdisk !\n\r");
 114                 printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 115                        initrd_addr, old_addr, initrd_size);
 116                 memmove((void *)initrd_addr, old_addr, initrd_size);
 117         }
 118
 119         printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 120
 121         /* Tell the kernel initrd address via device tree */
 122         setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
 123         setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
 124
 125         return (struct addr_range){(void *)initrd_addr, initrd_size};
 126 }
 127
 128 /* A buffer that may be edited by tools operating on a zImage binary so as to
 129  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 130  * The buffer is put in it's own section so that tools may locate it easier.
 131  */
 132 static char cmdline[COMMAND_LINE_SIZE]
 133         __attribute__((__section__("__builtin_cmdline")));
 134
 135 static void prep_cmdline(void *chosen)
 136 {
 137         if (cmdline[0] == '\0')
 138                 getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1);
 139
 140         printf("\n\rLinux/PowerPC load: %s", cmdline);
 141         /* If possible, edit the command line */
 142         if (console_ops.edit_cmdline)
 143                 console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
 144         printf("\n\r");
 145
 146         /* Put the command line back into the devtree for the kernel */
 147         setprop_str(chosen, "bootargs", cmdline);
 148 }
 149
 150 struct platform_ops platform_ops;
 151 struct dt_ops dt_ops;
 152 struct console_ops console_ops;
 153 struct loader_info loader_info;
 154
 155 void start(void)
 156 {
 157         struct addr_range vmlinux, initrd;
 158         kernel_entry_t kentry;
 159         unsigned long ft_addr = 0;
 160         void *chosen;
 161
 162         /* Do this first, because malloc() could clobber the loader's
 163          * command line.  Only use the loader command line if a
 164          * built-in command line wasn't set by an external tool */
 165         if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
 166                 memmove(cmdline, loader_info.cmdline,
 167                         min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
 168
 169         if (console_ops.open && (console_ops.open() < 0))
 170                 exit();
 171         if (platform_ops.fixups)
 172                 platform_ops.fixups();
 173
 174         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 175                _start, get_sp());
 176
 177         /* Ensure that the device tree has a /chosen node */
 178         chosen = finddevice("/chosen");
 179         if (!chosen)
 180                 chosen = create_node(NULL, "chosen");
 181
 182         vmlinux = prep_kernel();
 183         initrd = prep_initrd(vmlinux, chosen,
 184                              loader_info.initrd_addr, loader_info.initrd_size);
 185         prep_cmdline(chosen);
 186
 187         printf("Finalizing device tree...");
 188         if (dt_ops.finalize)
 189                 ft_addr = dt_ops.finalize();
 190         if (ft_addr)
 191                 printf(" flat tree at 0x%lx\n\r", ft_addr);
 192         else
 193                 printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
 194
 195         if (console_ops.close)
 196                 console_ops.close();
 197
 198         kentry = (kernel_entry_t) vmlinux.addr;
 199         if (ft_addr)
 200                 kentry(ft_addr, 0, NULL);
 201         else
 202                 kentry((unsigned long)initrd.addr, initrd.size,
 203                        loader_info.promptr);
 204
 205         /* console closed so printf in fatal below may not work */
 206         fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 207 }