arch/powerpc/boot/simpleboot.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * The simple platform -- for booting when firmware doesn't supply a device
   4  *                        tree or any platform configuration information.
   5  *                        All data is extracted from an embedded device tree
   6  *                        blob.
   7  *
   8  * Authors: Scott Wood <scottwood@freescale.com>
   9  *          Grant Likely <grant.likely@secretlab.ca>
  10  *
  11  * Copyright (c) 2007 Freescale Semiconductor, Inc.
  12  * Copyright (c) 2008 Secret Lab Technologies Ltd.
  13  */
  14
  15 #include "ops.h"
  16 #include "types.h"
  17 #include "io.h"
  18 #include "stdio.h"
  19 #include <libfdt.h>
  20
  21 BSS_STACK(4*1024);
  22
  23 extern int platform_specific_init(void) __attribute__((weak));
  24
  25 void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
  26                    unsigned long r6, unsigned long r7)
  27 {
  28         const u32 *na, *ns, *reg, *timebase;
  29         u64 memsize64;
  30         int node, size, i;
  31
  32         /* Make sure FDT blob is sane */
  33         if (fdt_check_header(_dtb_start) != 0)
  34                 fatal("Invalid device tree blob\n");
  35
  36         /* Find the #address-cells and #size-cells properties */
  37         node = fdt_path_offset(_dtb_start, "/");
  38         if (node < 0)
  39                 fatal("Cannot find root node\n");
  40         na = fdt_getprop(_dtb_start, node, "#address-cells", &size);
  41         if (!na || (size != 4))
  42                 fatal("Cannot find #address-cells property");
  43         ns = fdt_getprop(_dtb_start, node, "#size-cells", &size);
  44         if (!ns || (size != 4))
  45                 fatal("Cannot find #size-cells property");
  46
  47         /* Find the memory range */
  48         node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
  49                                              "memory", sizeof("memory"));
  50         if (node < 0)
  51                 fatal("Cannot find memory node\n");
  52         reg = fdt_getprop(_dtb_start, node, "reg", &size);
  53         if (size < (*na+*ns) * sizeof(u32))
  54                 fatal("cannot get memory range\n");
  55
  56         /* Only interested in memory based at 0 */
  57         for (i = 0; i < *na; i++)
  58                 if (*reg++ != 0)
  59                         fatal("Memory range is not based at address 0\n");
  60
  61         /* get the memsize and truncate it to under 4G on 32 bit machines */
  62         memsize64 = 0;
  63         for (i = 0; i < *ns; i++)
  64                 memsize64 = (memsize64 << 32) | *reg++;
  65         if (sizeof(void *) == 4 && memsize64 >= 0x100000000ULL)
  66                 memsize64 = 0xffffffff;
  67
  68         /* finally, setup the timebase */
  69         node = fdt_node_offset_by_prop_value(_dtb_start, -1, "device_type",
  70                                              "cpu", sizeof("cpu"));
  71         if (!node)
  72                 fatal("Cannot find cpu node\n");
  73         timebase = fdt_getprop(_dtb_start, node, "timebase-frequency", &size);
  74         if (timebase && (size == 4))
  75                 timebase_period_ns = 1000000000 / *timebase;
  76
  77         /* Now we have the memory size; initialize the heap */
  78         simple_alloc_init(_end, memsize64 - (unsigned long)_end, 32, 64);
  79
  80         /* prepare the device tree and find the console */
  81         fdt_init(_dtb_start);
  82
  83         if (platform_specific_init)
  84                 platform_specific_init();
  85
  86         serial_console_init();
  87 }