/* This program 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 3 of the License, or (at your option) any later version. This program 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 program. If not, see <http://www.gnu.org/licenses/>. */ /* implement a file store for embedded firmware images */ #include "AP_ROMFS.h" #include "tinf.h" #include <AP_Math/crc.h> #ifdef HAL_HAVE_AP_ROMFS_EMBEDDED_H #include <ap_romfs_embedded.h> #else const AP_ROMFS::embedded_file AP_ROMFS::files[] = {}; #endif /* find an embedded file */ const uint8_t *AP_ROMFS::find_file(const char *name, uint32_t &size, uint32_t &crc) { for (uint16_t i=0; i<ARRAY_SIZE(files); i++) { if (strcmp(name, files[i].filename) == 0) { size = files[i].size; crc = files[i].crc; return files[i].contents; } } return nullptr; } /* find a compressed file and uncompress it. Space for decompressed data comes from malloc. Caller must be careful to free the resulting data after use. The next byte after the file data is guaranteed to be null */ const uint8_t *AP_ROMFS::find_decompress(const char *name, uint32_t &size) { uint32_t compressed_size = 0; uint32_t crc; const uint8_t *compressed_data = find_file(name, compressed_size, crc); if (!compressed_data) { return nullptr; } #ifdef HAL_ROMFS_UNCOMPRESSED size = compressed_size; return compressed_data; #else // last 4 bytes of gzip file are length of decompressed data const uint8_t *p = &compressed_data[compressed_size-4]; uint32_t decompressed_size = p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24; uint8_t *decompressed_data = (uint8_t *)malloc(decompressed_size + 1); if (!decompressed_data) { return nullptr; } // explicitly null terimnate the data decompressed_data[decompressed_size] = 0; TINF_DATA *d = (TINF_DATA *)malloc(sizeof(TINF_DATA)); if (!d) { ::free(decompressed_data); return nullptr; } uzlib_uncompress_init(d, NULL, 0); d->source = compressed_data; d->source_limit = compressed_data + compressed_size - 4; // assume gzip format int res = uzlib_gzip_parse_header(d); if (res != TINF_OK) { ::free(decompressed_data); ::free(d); return nullptr; } d->dest = decompressed_data; d->destSize = decompressed_size; // we don't check CRC, as it just wastes flash space for constant // ROMFS data res = uzlib_uncompress(d); ::free(d); if (res != TINF_OK) { ::free(decompressed_data); return nullptr; } if (crc32_small(0, decompressed_data, decompressed_size) != crc) { ::free(decompressed_data); return nullptr; } size = decompressed_size; return decompressed_data; #endif } // free returned data void AP_ROMFS::free(const uint8_t *data) { #ifndef HAL_ROMFS_UNCOMPRESSED ::free(const_cast<uint8_t *>(data)); #endif } /* directory listing interface. Start with ofs=0. Returns pathnames that match dirname prefix. Ends with nullptr return when no more files found */ const char *AP_ROMFS::dir_list(const char *dirname, uint16_t &ofs) { const size_t dlen = strlen(dirname); for ( ; ofs < ARRAY_SIZE(files); ofs++) { if (strncmp(dirname, files[ofs].filename, dlen) == 0 && files[ofs].filename[dlen] == '/') { // found one return files[ofs++].filename; } } return nullptr; }