ardupilot/libraries/AP_ROMFS/AP_ROMFS.cpp

99 lines
2.7 KiB
C++

/*
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"
#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)
{
for (uint16_t i=0; i<ARRAY_SIZE(files); i++) {
if (strcmp(name, files[i].filename) == 0) {
size = files[i].size;
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.
*/
uint8_t *AP_ROMFS::find_decompress(const char *name, uint32_t &size)
{
uint32_t compressed_size;
const uint8_t *compressed_data = find_file(name, compressed_size);
if (!compressed_data) {
return nullptr;
}
// 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);
if (!decompressed_data) {
return nullptr;
}
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;
}
size = decompressed_size;
return decompressed_data;
}