shared/start/bsp-fdt.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /*
0004  * Copyright (C) 2015, 2017 embedded brains GmbH & Co. KG
0005  *
0006  * Redistribution and use in source and binary forms, with or without
0007  * modification, are permitted provided that the following conditions
0008  * are met:
0009  * 1. Redistributions of source code must retain the above copyright
0010  *    notice, this list of conditions and the following disclaimer.
0011  * 2. Redistributions in binary form must reproduce the above copyright
0012  *    notice, this list of conditions and the following disclaimer in the
0013  *    documentation and/or other materials provided with the distribution.
0014  *
0015  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0016  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0017  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0018  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0019  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0020  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0021  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0022  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0023  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0024  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0025  * POSSIBILITY OF SUCH DAMAGE.
0026  */
0027
0028 #include <sys/param.h>
0029
0030 #include <libfdt.h>
0031
0032 #include <bsp/fdt.h>
0033 #include <bsp/linker-symbols.h>
0034
0035 #ifdef BSP_DTB_IS_SUPPORTED
0036 #include BSP_DTB_HEADER_PATH
0037 #endif
0038
0039 #ifndef BSP_FDT_IS_SUPPORTED
0040 #warning "BSP FDT support indication not defined"
0041 #endif
0042
0043 #ifndef BSP_FDT_BLOB_SIZE_MAX
0044 #define BSP_FDT_BLOB_SIZE_MAX 0
0045 #endif
0046
0047 #ifdef BSP_FDT_BLOB_READ_ONLY
0048 static RTEMS_ALIGNED(8) const uint32_t
0049 bsp_fdt_blob[BSP_FDT_BLOB_SIZE_MAX / sizeof(uint32_t)] =
0050   { 0xdeadbeef };
0051 #else
0052 static RTEMS_ALIGNED(8) uint32_t
0053 bsp_fdt_blob[BSP_FDT_BLOB_SIZE_MAX / sizeof(uint32_t)];
0054 #endif
0055
0056 void bsp_fdt_copy(const void *src)
0057 {
0058   const volatile uint32_t *s = (const uint32_t *) src;
0059 #ifdef BSP_FDT_BLOB_COPY_TO_READ_ONLY_LOAD_AREA
0060   uint32_t *d = (uint32_t *) ((uintptr_t) &bsp_fdt_blob[0]
0061     - (uintptr_t) bsp_section_rodata_begin
0062     + (uintptr_t) bsp_section_rodata_load_begin);
0063 #else
0064   uint32_t *d = RTEMS_DECONST(uint32_t *, &bsp_fdt_blob[0]);
0065 #endif
0066
0067   if (s != d) {
0068     size_t m = MIN(sizeof(bsp_fdt_blob), fdt_totalsize(src));
0069     size_t aligned_size = roundup2(m, CPU_CACHE_LINE_BYTES);
0070     size_t n = (m + sizeof(*d) - 1) / sizeof(*d);
0071     size_t i;
0072
0073     for (i = 0; i < n; ++i) {
0074       d[i] = s[i];
0075     }
0076
0077     rtems_cache_flush_multiple_data_lines(d, aligned_size);
0078   }
0079 }
0080
0081 const void *bsp_fdt_get(void)
0082 {
0083 #ifdef BSP_DTB_IS_SUPPORTED
0084   return system_dtb;
0085 #else
0086   return &bsp_fdt_blob[0];
0087 #endif
0088 }