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                 /*
  60                  * Check if the kernel image (without bss) would overwrite the
  61                  * bootwrapper. The device tree has been moved in fdt_init()
  62                  * to an area allocated with malloc() (somewhere past _end).
  63                  */
  64                 if ((unsigned long)_start < ei.loadsize)
  65                         fatal("Insufficient memory for kernel at address 0!"
  66                                " (_start=%p, uncompressed size=%08lx)\n\r",
  67                                _start, ei.loadsize);
  68
  69                 if ((unsigned long)_end < ei.memsize)
  70                         fatal("The final kernel image would overwrite the "
  71                                         "device tree\n\r");
  72         }
  73
  74         /* Finally, gunzip the kernel */
  75         printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
  76                vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
  77         /* discard up to the actual load data */
  78         gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
  79         len = gunzip_finish(&gzstate, addr, ei.loadsize);
  80         if (len != ei.loadsize)
  81                 fatal("ran out of data!  only got 0x%x of 0x%lx bytes.\n\r",
  82                                 len, ei.loadsize);
  83         printf("done 0x%x bytes\n\r", len);
  84
  85         flush_cache(addr, ei.loadsize);
  86
  87         return (struct addr_range){addr, ei.memsize};
  88 }
  89
  90 static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
  91                                      unsigned long initrd_addr,
  92                                      unsigned long initrd_size)
  93 {
  94         /* If we have an image attached to us, it overrides anything
  95          * supplied by the loader. */
  96         if (_initrd_end > _initrd_start) {
  97                 printf("Attached initrd image at 0x%p-0x%p\n\r",
  98                        _initrd_start, _initrd_end);
  99                 initrd_addr = (unsigned long)_initrd_start;
 100                 initrd_size = _initrd_end - _initrd_start;
 101         } else if (initrd_size > 0) {
 102                 printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
 103                        initrd_addr, initrd_addr + initrd_size);
 104         }
 105
 106         /* If there's no initrd at all, we're done */
 107         if (! initrd_size)
 108                 return (struct addr_range){0, 0};
 109
 110         /*
 111          * If the initrd is too low it will be clobbered when the
 112          * kernel relocates to its final location.  In this case,
 113          * allocate a safer place and move it.
 114          */
 115         if (initrd_addr < vmlinux.size) {
 116                 void *old_addr = (void *)initrd_addr;
 117
 118                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 119                        initrd_size);
 120                 initrd_addr = (unsigned long)malloc(initrd_size);
 121                 if (! initrd_addr)
 122                         fatal("Can't allocate memory for initial "
 123                                "ramdisk !\n\r");
 124                 printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 125                        initrd_addr, old_addr, initrd_size);
 126                 memmove((void *)initrd_addr, old_addr, initrd_size);
 127         }
 128
 129         printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 130
 131         /* Tell the kernel initrd address via device tree */
 132         setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
 133         setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
 134
 135         return (struct addr_range){(void *)initrd_addr, initrd_size};
 136 }
 137
 138 /* A buffer that may be edited by tools operating on a zImage binary so as to
 139  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 140  * The buffer is put in it's own section so that tools may locate it easier.
 141  */
 142 static char cmdline[COMMAND_LINE_SIZE]
 143         __attribute__((__section__("__builtin_cmdline")));
 144
 145 static void prep_cmdline(void *chosen)
 146 {
 147         if (cmdline[0] == '\0')
 148                 getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1);
 149
 150         printf("\n\rLinux/PowerPC load: %s", cmdline);
 151         /* If possible, edit the command line */
 152         if (console_ops.edit_cmdline)
 153                 console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
 154         printf("\n\r");
 155
 156         /* Put the command line back into the devtree for the kernel */
 157         setprop_str(chosen, "bootargs", cmdline);
 158 }
 159
 160 struct platform_ops platform_ops;
 161 struct dt_ops dt_ops;
 162 struct console_ops console_ops;
 163 struct loader_info loader_info;
 164
 165 void start(void)
 166 {
 167         struct addr_range vmlinux, initrd;
 168         kernel_entry_t kentry;
 169         unsigned long ft_addr = 0;
 170         void *chosen;
 171
 172         /* Do this first, because malloc() could clobber the loader's
 173          * command line.  Only use the loader command line if a
 174          * built-in command line wasn't set by an external tool */
 175         if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
 176                 memmove(cmdline, loader_info.cmdline,
 177                         min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
 178
 179         if (console_ops.open && (console_ops.open() < 0))
 180                 exit();
 181         if (platform_ops.fixups)
 182                 platform_ops.fixups();
 183
 184         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 185                _start, get_sp());
 186
 187         /* Ensure that the device tree has a /chosen node */
 188         chosen = finddevice("/chosen");
 189         if (!chosen)
 190                 chosen = create_node(NULL, "chosen");
 191
 192         vmlinux = prep_kernel();
 193         initrd = prep_initrd(vmlinux, chosen,
 194                              loader_info.initrd_addr, loader_info.initrd_size);
 195         prep_cmdline(chosen);
 196
 197         printf("Finalizing device tree...");
 198         if (dt_ops.finalize)
 199                 ft_addr = dt_ops.finalize();
 200         if (ft_addr)
 201                 printf(" flat tree at 0x%lx\n\r", ft_addr);
 202         else
 203                 printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
 204
 205         if (console_ops.close)
 206                 console_ops.close();
 207
 208         kentry = (kernel_entry_t) vmlinux.addr;
 209         if (ft_addr)
 210                 kentry(ft_addr, 0, NULL);
 211         else
 212                 kentry((unsigned long)initrd.addr, initrd.size,
 213                        loader_info.promptr);
 214
 215         /* console closed so printf in fatal below may not work */
 216         fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 217 }