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73d60926a0
At present, the blob containing a device tree is passed to the various fdt_*() functions as a (struct fdt_header *) i.e. a pointer to the header structure at the beginning of the blob. This patch changes all the functions so that they instead take a (void *) pointing to the blob. Under some circumstances can avoid the need for the caller to cast a blob pointer into a (struct fdt_header *) before passing it to the fdt_*() functions. Using a (void *) also reduce the temptation for users of the library to directly dereference toe (struct fdt_header *) to access header fields. Instead they must use the fdt_get_header() or fdt_set_header() macros, or the fdt_magic(), fdt_totalsize() etc. wrappers around them which are safer, since they will always handle endian conversion. With this change, the whole-tree moving, or manipulating functions: fdt_move(), fdt_open_into() and fdt_pack() no longer need to return a pointer to the "new" tree. The given (void *) buffer pointer they take can instead be used directly by the caller as the new tree. Those functions are thus changed to instead return an error code (which in turn reduces the number of functions using the ugly encoding of error values into pointers). Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
124 lines
2.9 KiB
C
124 lines
2.9 KiB
C
/*
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* libfdt - Flat Device Tree manipulation
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* Copyright (C) 2006 David Gibson, IBM Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either version 2.1 of
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* the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libfdt_env.h"
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#include <fdt.h>
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#include <libfdt.h>
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#include "libfdt_internal.h"
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int _fdt_check_header(const void *fdt)
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{
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if (fdt_magic(fdt) == FDT_MAGIC) {
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/* Complete tree */
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if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
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return FDT_ERR_BADVERSION;
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if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION)
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return FDT_ERR_BADVERSION;
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} else if (fdt_magic(fdt) == SW_MAGIC) {
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/* Unfinished sequential-write blob */
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if (fdt_size_dt_struct(fdt) == 0)
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return FDT_ERR_BADSTATE;
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} else {
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return FDT_ERR_BADMAGIC;
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}
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return 0;
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}
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void *fdt_offset_ptr(const void *fdt, int offset, int len)
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{
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void *p;
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if (fdt_version(fdt) >= 0x11)
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if (((offset + len) < offset)
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|| ((offset + len) > fdt_size_dt_struct(fdt)))
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return NULL;
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p = _fdt_offset_ptr(fdt, offset);
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if (p + len < p)
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return NULL;
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return p;
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}
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uint32_t _fdt_next_tag(const void *fdt, int offset, int *nextoffset)
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{
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const uint32_t *tagp, *lenp;
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uint32_t tag;
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const char *p;
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if (offset % FDT_TAGSIZE)
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return -1;
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tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE);
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if (! tagp)
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return FDT_END; /* premature end */
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tag = fdt32_to_cpu(*tagp);
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offset += FDT_TAGSIZE;
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switch (tag) {
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case FDT_BEGIN_NODE:
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/* skip name */
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do {
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p = fdt_offset_ptr(fdt, offset++, 1);
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} while (p && (*p != '\0'));
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if (! p)
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return FDT_END;
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break;
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case FDT_PROP:
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lenp = fdt_offset_ptr(fdt, offset + FDT_TAGSIZE, sizeof(*lenp));
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if (! lenp)
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return FDT_END;
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/* skip name offset, length and value */
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offset += 2*FDT_TAGSIZE + fdt32_to_cpu(*lenp);
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break;
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}
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if (nextoffset)
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*nextoffset = ALIGN(offset, FDT_TAGSIZE);
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return tag;
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}
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const char *_fdt_find_string(const char *strtab, int tabsize, const char *s)
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{
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int len = strlen(s) + 1;
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const char *last = strtab + tabsize - len;
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const char *p;
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for (p = strtab; p <= last; p++)
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if (memeq(p, s, len))
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return p;
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return NULL;
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}
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int fdt_move(const void *fdt, void *buf, int bufsize)
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{
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int err = _fdt_check_header(fdt);
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if (err)
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return err;
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if (fdt_totalsize(fdt) > bufsize)
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return FDT_ERR_NOSPACE;
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memmove(buf, fdt, fdt_totalsize(fdt));
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return FDT_ERR_OK;
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}
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