LXR linux/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.h>
  23
  24BSS_STACK(4*1024);
  25
  26extern int platform_specific_init(void) __attribute__((weak));
  27
  28void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
  29                   unsigned long r6, unsigned long r7)
  30{
  31        const u32 *na, *ns, *reg, *timebase;
  32        u64 memsize64;
  33        int node, size, i;
  34
  35        /* Make sure FDT blob is sane */
  36        if (fdt_check_header(_dtb_start) != 0)
  37                fatal("Invalid device tree blob\n");
  38
  39        /* Find the #address-cells and #size-cells properties */
  40        node = fdt_path_offset(_dtb_start, "/");
  41        if (node < 0)
  42                fatal("Cannot find root node\n");
  43        na = fdt_getprop(_dtb_start, node, "#address-cells", &size);
  44        if (!na || (size != 4))
  45                fatal("Cannot find #address-cells property");
  46        ns = fdt_getprop(_dtb_start, node, "#size-cells", &size);
  47        if (!ns || (size != 4))
  48                fatal("Cannot find #size-cells property");
  49
  50        /* Find the memory range */
  51        node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
  52                                             "memory", sizeof("memory"));
  53        if (node < 0)
  54                fatal("Cannot find memory node\n");
  55        reg = fdt_getprop(_dtb_start, node, "reg", &size);
  56        if (size < (*na+*ns) * sizeof(u32))
  57                fatal("cannot get memory range\n");
  58
  59        /* Only interested in memory based at 0 */
  60        for (i = 0; i < *na; i++)
  61                if (*reg++ != 0)
  62                        fatal("Memory range is not based at address 0\n");
  63
  64        /* get the memsize and truncate it to under 4G on 32 bit machines */
  65        memsize64 = 0;
  66        for (i = 0; i < *ns; i++)
  67                memsize64 = (memsize64 << 32) | *reg++;
  68        if (sizeof(void *) == 4 && memsize64 >= 0x100000000ULL)
  69                memsize64 = 0xffffffff;
  70
  71        /* finally, setup the timebase */
  72        node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
  73                                             "cpu", sizeof("cpu"));
  74        if (!node)
  75                fatal("Cannot find cpu node\n");
  76        timebase = fdt_getprop(_dtb_start, node, "timebase-frequency", &size);
  77        if (timebase && (size == 4))
  78                timebase_period_ns = 1000000000 / *timebase;
  79
  80        /* Now we have the memory size; initialize the heap */
  81        simple_alloc_init(_end, memsize64 - (unsigned long)_end, 32, 64);
  82
  83        /* prepare the device tree and find the console */
  84        fdt_init(_dtb_start);
  85
  86        if (platform_specific_init)
  87                platform_specific_init();
  88
  89        serial_console_init();
  90}
  91