fdt/libfdt/fdt_sw.c

/*
 * libfdt - Flat Device Tree manipulation
 * Copyright (C) 2006 David Gibson, IBM Corporation.
 *
 * libfdt is dual licensed: you can use it either under the terms of
 * the GPL, or the BSD license, at your option.
 *
 *  a) This library is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of the
 *     License, or (at your option) any later version.
 *
 *     This library is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public
 *     License along with this library; if not, write to the Free
 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
 *     MA 02110-1301 USA
 *
 * Alternatively,
 *
 *  b) Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *     1. Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *     2. Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "libfdt_env.h"
#include "fdt.h"
#include "libfdt.h"
#include "libfdt_internal.h"

static int _fdt_sw_check_header(void *fdt)
{
    if (fdt_magic(fdt) != FDT_SW_MAGIC)
        return -FDT_ERR_BADMAGIC;
    /* FIXME: should check more details about the header state */
    return 0;
}

#define FDT_SW_CHECK_HEADER(fdt) \
    { \
        int err; \
        if ((err = _fdt_sw_check_header(fdt)) != 0) \
            return err; \
    }

static void *_fdt_grab_space(void *fdt, size_t len)
{
    int offset = fdt_size_dt_struct(fdt);
    int spaceleft;

    spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt)
        - fdt_size_dt_strings(fdt);

    if ((offset + len < offset) || (offset + len > spaceleft))
        return NULL;

    fdt_set_size_dt_struct(fdt, offset + len);
    return _fdt_offset_ptr_w(fdt, offset);
}

int fdt_create(void *buf, int bufsize)
{
    void *fdt = buf;

    if (bufsize < sizeof(struct fdt_header))
        return -FDT_ERR_NOSPACE;

    memset(buf, 0, bufsize);

    fdt_set_magic(fdt, FDT_SW_MAGIC);
    fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION);
    fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
    fdt_set_totalsize(fdt,  bufsize);

    fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
                          sizeof(struct fdt_reserve_entry)));
    fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
    fdt_set_off_dt_strings(fdt, bufsize);

    return 0;
}

int fdt_resize(void *fdt, void *buf, int bufsize)
{
    size_t headsize, tailsize;
    char *oldtail, *newtail;

    FDT_SW_CHECK_HEADER(fdt);

    headsize = fdt_off_dt_struct(fdt);
    tailsize = fdt_size_dt_strings(fdt);

    if ((headsize + tailsize) > bufsize)
        return -FDT_ERR_NOSPACE;

    oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize;
    newtail = (char *)buf + bufsize - tailsize;

    /* Two cases to avoid clobbering data if the old and new
     * buffers partially overlap */
    if (buf <= fdt) {
        memmove(buf, fdt, headsize);
        memmove(newtail, oldtail, tailsize);
    } else {
        memmove(newtail, oldtail, tailsize);
        memmove(buf, fdt, headsize);
    }

    fdt_set_off_dt_strings(buf, bufsize);
    fdt_set_totalsize(buf, bufsize);

    return 0;
}

int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
{
    struct fdt_reserve_entry *re;
    int offset;

    FDT_SW_CHECK_HEADER(fdt);

    if (fdt_size_dt_struct(fdt))
        return -FDT_ERR_BADSTATE;

    offset = fdt_off_dt_struct(fdt);
    if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
        return -FDT_ERR_NOSPACE;

    re = (struct fdt_reserve_entry *)((char *)fdt + offset);
    re->address = cpu_to_fdt64(addr);
    re->size = cpu_to_fdt64(size);

    fdt_set_off_dt_struct(fdt, offset + sizeof(*re));

    return 0;
}

int fdt_finish_reservemap(void *fdt)
{
    return fdt_add_reservemap_entry(fdt, 0, 0);
}

int fdt_begin_node(void *fdt, const char *name)
{
    struct fdt_node_header *nh;
    int namelen = strlen(name) + 1;

    FDT_SW_CHECK_HEADER(fdt);

    nh = _fdt_grab_space(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
    if (! nh)
        return -FDT_ERR_NOSPACE;

    nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
    memcpy(nh->name, name, namelen);
    return 0;
}

int fdt_end_node(void *fdt)
{
    fdt32_t *en;

    FDT_SW_CHECK_HEADER(fdt);

    en = _fdt_grab_space(fdt, FDT_TAGSIZE);
    if (! en)
        return -FDT_ERR_NOSPACE;

    *en = cpu_to_fdt32(FDT_END_NODE);
    return 0;
}

static int _fdt_find_add_string(void *fdt, const char *s)
{
    char *strtab = (char *)fdt + fdt_totalsize(fdt);
    const char *p;
    int strtabsize = fdt_size_dt_strings(fdt);
    int len = strlen(s) + 1;
    int struct_top, offset;

    p = _fdt_find_string(strtab - strtabsize, strtabsize, s);
    if (p)
        return p - strtab;

    /* Add it */
    offset = -strtabsize - len;
    struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
    if (fdt_totalsize(fdt) + offset < struct_top)
        return 0; /* no more room :( */

    memcpy(strtab + offset, s, len);
    fdt_set_size_dt_strings(fdt, strtabsize + len);
    return offset;
}

int fdt_property(void *fdt, const char *name, const void *val, int len)
{
    struct fdt_property *prop;
    int nameoff;

    FDT_SW_CHECK_HEADER(fdt);

    nameoff = _fdt_find_add_string(fdt, name);
    if (nameoff == 0)
        return -FDT_ERR_NOSPACE;

    prop = _fdt_grab_space(fdt, sizeof(*prop) + FDT_TAGALIGN(len));
    if (! prop)
        return -FDT_ERR_NOSPACE;

    prop->tag = cpu_to_fdt32(FDT_PROP);
    prop->nameoff = cpu_to_fdt32(nameoff);
    prop->len = cpu_to_fdt32(len);
    memcpy(prop->data, val, len);
    return 0;
}

int fdt_finish(void *fdt)
{
    char *p = (char *)fdt;
    fdt32_t *end;
    int oldstroffset, newstroffset;
    uint32_t tag;
    int offset, nextoffset;

    FDT_SW_CHECK_HEADER(fdt);

    /* Add terminator */
    end = _fdt_grab_space(fdt, sizeof(*end));
    if (! end)
        return -FDT_ERR_NOSPACE;
    *end = cpu_to_fdt32(FDT_END);

    /* Relocate the string table */
    oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt);
    newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
    memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt));
    fdt_set_off_dt_strings(fdt, newstroffset);

    /* Walk the structure, correcting string offsets */
    offset = 0;
    while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) {
        if (tag == FDT_PROP) {
            struct fdt_property *prop =
                _fdt_offset_ptr_w(fdt, offset);
            int nameoff;

            nameoff = fdt32_to_cpu(prop->nameoff);
            nameoff += fdt_size_dt_strings(fdt);
            prop->nameoff = cpu_to_fdt32(nameoff);
        }
        offset = nextoffset;
    }
    if (nextoffset < 0)
        return nextoffset;

    /* Finally, adjust the header */
    fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt));
    fdt_set_magic(fdt, FDT_MAGIC);
    return 0;
}