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
  24 BSS_STACK(4*1024);
  25
  26 extern int platform_specific_init(void) __attribute__((weak));
  27
  28 void 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 }