LXR linux/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
  21BSS_STACK(4*1024);
  22
  23extern int platform_specific_init(void) __attribute__((weak));
  24
  25void 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}
  88