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 "flatdevtree.h"
  20 #include "reg.h"
  21
  22 extern char _start[];
  23 extern char __bss_start[];
  24 extern char _end[];
  25 extern char _vmlinux_start[];
  26 extern char _vmlinux_end[];
  27 extern char _initrd_start[];
  28 extern char _initrd_end[];
  29 extern char _dtb_start[];
  30 extern char _dtb_end[];
  31
  32 static struct gunzip_state gzstate;
  33
  34 struct addr_range {
  35         void *addr;
  36         unsigned long size;
  37 };
  38
  39 typedef void (*kernel_entry_t)(unsigned long, unsigned long, void *);
  40
  41 #undef DEBUG
  42
  43 static struct addr_range prep_kernel(void)
  44 {
  45         char elfheader[256];
  46         void *vmlinuz_addr = _vmlinux_start;
  47         unsigned long vmlinuz_size = _vmlinux_end - _vmlinux_start;
  48         void *addr = 0;
  49         struct elf_info ei;
  50         int len;
  51
  52         /* gunzip the ELF header of the kernel */
  53         gunzip_start(&gzstate, vmlinuz_addr, vmlinuz_size);
  54         gunzip_exactly(&gzstate, elfheader, sizeof(elfheader));
  55
  56         if (!parse_elf64(elfheader, &ei) && !parse_elf32(elfheader, &ei))
  57                 fatal("Error: not a valid PPC32 or PPC64 ELF file!\n\r");
  58
  59         if (platform_ops.image_hdr)
  60                 platform_ops.image_hdr(elfheader);
  61
  62         /* We need to alloc the memsize: gzip will expand the kernel
  63          * text/data, then possible rubbish we don't care about. But
  64          * the kernel bss must be claimed (it will be zero'd by the
  65          * kernel itself)
  66          */
  67         printf("Allocating 0x%lx bytes for kernel ...\n\r", ei.memsize);
  68
  69         if (platform_ops.vmlinux_alloc) {
  70                 addr = platform_ops.vmlinux_alloc(ei.memsize);
  71         } else {
  72                 if ((unsigned long)_start < ei.memsize)
  73                         fatal("Insufficient memory for kernel at address 0!"
  74                                " (_start=%p)\n\r", _start);
  75         }
  76
  77         /* Finally, gunzip the kernel */
  78         printf("gunzipping (0x%p <- 0x%p:0x%p)...", addr,
  79                vmlinuz_addr, vmlinuz_addr+vmlinuz_size);
  80         /* discard up to the actual load data */
  81         gunzip_discard(&gzstate, ei.elfoffset - sizeof(elfheader));
  82         len = gunzip_finish(&gzstate, addr, ei.loadsize);
  83         if (len != ei.loadsize)
  84                 fatal("ran out of data!  only got 0x%x of 0x%lx bytes.\n\r",
  85                                 len, ei.loadsize);
  86         printf("done 0x%x bytes\n\r", len);
  87
  88         flush_cache(addr, ei.loadsize);
  89
  90         return (struct addr_range){addr, ei.memsize};
  91 }
  92
  93 static struct addr_range prep_initrd(struct addr_range vmlinux, void *chosen,
  94                                      unsigned long initrd_addr,
  95                                      unsigned long initrd_size)
  96 {
  97         /* If we have an image attached to us, it overrides anything
  98          * supplied by the loader. */
  99         if (_initrd_end > _initrd_start) {
 100                 printf("Attached initrd image at 0x%p-0x%p\n\r",
 101                        _initrd_start, _initrd_end);
 102                 initrd_addr = (unsigned long)_initrd_start;
 103                 initrd_size = _initrd_end - _initrd_start;
 104         } else if (initrd_size > 0) {
 105                 printf("Using loader supplied ramdisk at 0x%lx-0x%lx\n\r",
 106                        initrd_addr, initrd_addr + initrd_size);
 107         }
 108
 109         /* If there's no initrd at all, we're done */
 110         if (! initrd_size)
 111                 return (struct addr_range){0, 0};
 112
 113         /*
 114          * If the initrd is too low it will be clobbered when the
 115          * kernel relocates to its final location.  In this case,
 116          * allocate a safer place and move it.
 117          */
 118         if (initrd_addr < vmlinux.size) {
 119                 void *old_addr = (void *)initrd_addr;
 120
 121                 printf("Allocating 0x%lx bytes for initrd ...\n\r",
 122                        initrd_size);
 123                 initrd_addr = (unsigned long)malloc(initrd_size);
 124                 if (! initrd_addr)
 125                         fatal("Can't allocate memory for initial "
 126                                "ramdisk !\n\r");
 127                 printf("Relocating initrd 0x%lx <- 0x%p (0x%lx bytes)\n\r",
 128                        initrd_addr, old_addr, initrd_size);
 129                 memmove((void *)initrd_addr, old_addr, initrd_size);
 130         }
 131
 132         printf("initrd head: 0x%lx\n\r", *((unsigned long *)initrd_addr));
 133
 134         /* Tell the kernel initrd address via device tree */
 135         setprop_val(chosen, "linux,initrd-start", (u32)(initrd_addr));
 136         setprop_val(chosen, "linux,initrd-end", (u32)(initrd_addr+initrd_size));
 137
 138         return (struct addr_range){(void *)initrd_addr, initrd_size};
 139 }
 140
 141 /* A buffer that may be edited by tools operating on a zImage binary so as to
 142  * edit the command line passed to vmlinux (by setting /chosen/bootargs).
 143  * The buffer is put in it's own section so that tools may locate it easier.
 144  */
 145 static char cmdline[COMMAND_LINE_SIZE]
 146         __attribute__((__section__("__builtin_cmdline")));
 147
 148 static void prep_cmdline(void *chosen)
 149 {
 150         if (cmdline[0] == '\0')
 151                 getprop(chosen, "bootargs", cmdline, COMMAND_LINE_SIZE-1);
 152
 153         printf("\n\rLinux/PowerPC load: %s", cmdline);
 154         /* If possible, edit the command line */
 155         if (console_ops.edit_cmdline)
 156                 console_ops.edit_cmdline(cmdline, COMMAND_LINE_SIZE);
 157         printf("\n\r");
 158
 159         /* Put the command line back into the devtree for the kernel */
 160         setprop_str(chosen, "bootargs", cmdline);
 161 }
 162
 163 struct platform_ops platform_ops;
 164 struct dt_ops dt_ops;
 165 struct console_ops console_ops;
 166 struct loader_info loader_info;
 167
 168 void start(void)
 169 {
 170         struct addr_range vmlinux, initrd;
 171         kernel_entry_t kentry;
 172         unsigned long ft_addr = 0;
 173         void *chosen;
 174
 175         /* Do this first, because malloc() could clobber the loader's
 176          * command line.  Only use the loader command line if a
 177          * built-in command line wasn't set by an external tool */
 178         if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
 179                 memmove(cmdline, loader_info.cmdline,
 180                         min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
 181
 182         if (console_ops.open && (console_ops.open() < 0))
 183                 exit();
 184         if (platform_ops.fixups)
 185                 platform_ops.fixups();
 186
 187         printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 188                _start, get_sp());
 189
 190         /* Ensure that the device tree has a /chosen node */
 191         chosen = finddevice("/chosen");
 192         if (!chosen)
 193                 chosen = create_node(NULL, "chosen");
 194
 195         vmlinux = prep_kernel();
 196         initrd = prep_initrd(vmlinux, chosen,
 197                              loader_info.initrd_addr, loader_info.initrd_size);
 198         prep_cmdline(chosen);
 199
 200         printf("Finalizing device tree...");
 201         if (dt_ops.finalize)
 202                 ft_addr = dt_ops.finalize();
 203         if (ft_addr)
 204                 printf(" flat tree at 0x%lx\n\r", ft_addr);
 205         else
 206                 printf(" using OF tree (promptr=%p)\n\r", loader_info.promptr);
 207
 208         if (console_ops.close)
 209                 console_ops.close();
 210
 211         kentry = (kernel_entry_t) vmlinux.addr;
 212         if (ft_addr)
 213                 kentry(ft_addr, 0, NULL);
 214         else
 215                 kentry((unsigned long)initrd.addr, initrd.size,
 216                        loader_info.promptr);
 217
 218         /* console closed so printf in fatal below may not work */
 219         fatal("Error: Linux kernel returned to zImage boot wrapper!\n\r");
 220 }