arch/powerpc/boot/simpleboot.c

   1 /*
   2  * The simple platform -- for booting when firmware doesn't supply a device
   3  *                        tree or any platform configuration information.
   4  *                        All data is extracted from an embedded device tree
   5  *                        blob.
   6  *
   7  * Authors: Scott Wood <scottwood@freescale.com>
   8  *          Grant Likely <grant.likely@secretlab.ca>
   9  *
  10  * Copyright (c) 2007 Freescale Semiconductor, Inc.
  11  * Copyright (c) 2008 Secret Lab Technologies Ltd.
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License version 2 as published
  15  * by the Free Software Foundation.
  16  */
  17
  18 #include "ops.h"
  19 #include "types.h"
  20 #include "io.h"
  21 #include "stdio.h"
  22 #include "libfdt/libfdt.h"
  23
  24 BSS_STACK(4*1024);
  25
  26 void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
  27                    unsigned long r6, unsigned long r7)
  28 {
  29         const u32 *na, *ns, *reg, *timebase;
  30         u64 memsize64;
  31         int node, size, i;
  32
  33         /* Make sure FDT blob is sane */
  34         if (fdt_check_header(_dtb_start) != 0)
  35                 fatal("Invalid device tree blob\n");
  36
  37         /* Find the #address-cells and #size-cells properties */
  38         node = fdt_path_offset(_dtb_start, "/");
  39         if (node < 0)
  40                 fatal("Cannot find root node\n");
  41         na = fdt_getprop(_dtb_start, node, "#address-cells", &size);
  42         if (!na || (size != 4))
  43                 fatal("Cannot find #address-cells property");
  44         ns = fdt_getprop(_dtb_start, node, "#size-cells", &size);
  45         if (!ns || (size != 4))
  46                 fatal("Cannot find #size-cells property");
  47
  48         /* Find the memory range */
  49         node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
  50                                              "memory", sizeof("memory"));
  51         if (node < 0)
  52                 fatal("Cannot find memory node\n");
  53         reg = fdt_getprop(_dtb_start, node, "reg", &size);
  54         if (size < (*na+*ns) * sizeof(u32))
  55                 fatal("cannot get memory range\n");
  56
  57         /* Only interested in memory based at 0 */
  58         for (i = 0; i < *na; i++)
  59                 if (*reg++ != 0)
  60                         fatal("Memory range is not based at address 0\n");
  61
  62         /* get the memsize and trucate it to under 4G on 32 bit machines */
  63         memsize64 = 0;
  64         for (i = 0; i < *ns; i++)
  65                 memsize64 = (memsize64 << 32) | *reg++;
  66         if (sizeof(void *) == 4 && memsize64 >= 0x100000000ULL)
  67                 memsize64 = 0xffffffff;
  68
  69         /* finally, setup the timebase */
  70         node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
  71                                              "cpu", sizeof("cpu"));
  72         if (!node)
  73                 fatal("Cannot find cpu node\n");
  74         timebase = fdt_getprop(_dtb_start, node, "timebase-frequency", &size);
  75         if (timebase && (size == 4))
  76                 timebase_period_ns = 1000000000 / *timebase;
  77
  78         /* Now we have the memory size; initialize the heap */
  79         simple_alloc_init(_end, memsize64 - (unsigned long)_end, 32, 64);
  80
  81         /* prepare the device tree and find the console */
  82         fdt_init(_dtb_start);
  83         serial_console_init();
  84 }