devtree.c

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/*
 *  linux/arch/arm/kernel/devtree.c
 *
 *  Copyright (C) 2009 Canonical Ltd. <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/mach/arch.h>
#include <asm/mach-types.h>

void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
    arm_add_memory(base, size);
}

void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
{
    return alloc_bootmem_align(size, align);
}

void __init arm_dt_memblock_reserve(void)
{
    u64 *reserve_map, base, size;

    if (!initial_boot_params)
        return;

    /* Reserve the dtb region */
    memblock_reserve(virt_to_phys(initial_boot_params),
             be32_to_cpu(initial_boot_params->totalsize));

    /*
     * Process the reserve map.  This will probably overlap the initrd
     * and dtb locations which are already reserved, but overlaping
     * doesn't hurt anything
     */
    reserve_map = ((void*)initial_boot_params) +
            be32_to_cpu(initial_boot_params->off_mem_rsvmap);
    while (1) {
        base = be64_to_cpup(reserve_map++);
        size = be64_to_cpup(reserve_map++);
        if (!size)
            break;
        memblock_reserve(base, size);
    }
}

struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
{
    struct boot_param_header *devtree;
    struct machine_desc *mdesc, *mdesc_best = NULL;
    unsigned int score, mdesc_score = ~1;
    unsigned long dt_root;
    const char *model;

    if (!dt_phys)
        return NULL;

    devtree = phys_to_virt(dt_phys);

    /* check device tree validity */
    if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
        return NULL;

    /* Search the mdescs for the 'best' compatible value match */
    initial_boot_params = devtree;
    dt_root = of_get_flat_dt_root();
    for_each_machine_desc(mdesc) {
        score = of_flat_dt_match(dt_root, mdesc->dt_compat);
        if (score > 0 && score < mdesc_score) {
            mdesc_best = mdesc;
            mdesc_score = score;
        }
    }
    if (!mdesc_best) {
        const char *prop;
        long size;

        early_print("\nError: unrecognized/unsupported "
                "device tree compatible list:\n[ ");

        prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
        while (size > 0) {
            early_print("'%s' ", prop);
            size -= strlen(prop) + 1;
            prop += strlen(prop) + 1;
        }
        early_print("]\n\n");

        dump_machine_table(); /* does not return */
    }

    model = of_get_flat_dt_prop(dt_root, "model", NULL);
    if (!model)
        model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
    if (!model)
        model = "<unknown>";
    pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);

    /* Retrieve various information from the /chosen node */
    of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
    /* Initialize {size,address}-cells info */
    of_scan_flat_dt(early_init_dt_scan_root, NULL);
    /* Setup memory, calling early_init_dt_add_memory_arch */
    of_scan_flat_dt(early_init_dt_scan_memory, NULL);

    /* Change machine number to match the mdesc we're using */
    __machine_arch_type = mdesc_best->nr;

    return mdesc_best;
}