1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/pkg/landfall-examples/msc_block_server/msc_region_accessor.cc Tue Feb 27 17:27:25 2024 +0100
1.3 @@ -0,0 +1,97 @@
1.4 +/*
1.5 + * A memory card region accessor.
1.6 + *
1.7 + * Copyright (C) 2021, 2024 Paul Boddie <paul@boddie.org.uk>
1.8 + *
1.9 + * This program is free software; you can redistribute it and/or
1.10 + * modify it under the terms of the GNU General Public License as
1.11 + * published by the Free Software Foundation; either version 2 of
1.12 + * the License, or (at your option) any later version.
1.13 + *
1.14 + * This program is distributed in the hope that it will be useful,
1.15 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.17 + * GNU General Public License for more details.
1.18 + *
1.19 + * You should have received a copy of the GNU General Public License
1.20 + * along with this program; if not, write to the Free Software
1.21 + * Foundation, Inc., 51 Franklin Street, Fifth Floor,
1.22 + * Boston, MA 02110-1301, USA
1.23 + */
1.24 +
1.25 +#include <string.h>
1.26 +
1.27 +#include <algorithm>
1.28 +
1.29 +#include "msc_region_accessor.h"
1.30 +
1.31 +
1.32 +
1.33 +MscRegionAccessor::MscRegionAccessor(MscRegionOperations *ops,
1.34 + uint32_t start_block, uint32_t num_blocks,
1.35 + fileid_t fileid)
1.36 +: Accessor(fileid), _ops(ops)
1.37 +{
1.38 + // NOTE: Block size assumption employed.
1.39 +
1.40 + _start = start_block * 512;
1.41 + _size = num_blocks * 512;
1.42 +}
1.43 +
1.44 +/* Return the size of the file. */
1.45 +
1.46 +offset_t MscRegionAccessor::get_size()
1.47 +{
1.48 + return _size;
1.49 +}
1.50 +
1.51 +/* Update the size of the file. */
1.52 +
1.53 +void MscRegionAccessor::set_size(offset_t size)
1.54 +{
1.55 + (void) size;
1.56 +}
1.57 +
1.58 +/* Data transfer helper methods. */
1.59 +
1.60 +/* Fill the populated portion of a flexpage. */
1.61 +
1.62 +void MscRegionAccessor::fill_populated(Flexpage *flexpage)
1.63 +{
1.64 + offset_t filepos = flexpage->base_offset;
1.65 + offset_t populated_size = std::min(flexpage->size, _size - filepos);
1.66 +
1.67 + /* Tag the region with file state. */
1.68 +
1.69 + flexpage->region->fill(fileid, filepos);
1.70 +
1.71 + /* Fill the region with file content. */
1.72 +
1.73 + _ops->read(flexpage->base_addr, flexpage->base_addr_physical,
1.74 + _start + filepos, populated_size);
1.75 +
1.76 + /* Pad the flexpage with zero. */
1.77 +
1.78 + if (populated_size < flexpage->size)
1.79 + memset((void *) (flexpage->base_addr + populated_size), 0,
1.80 + flexpage->size - populated_size);
1.81 +}
1.82 +
1.83 +/* Flush the populated portion of a flexpage. */
1.84 +
1.85 +void MscRegionAccessor::flush_populated(Flexpage *flexpage)
1.86 +{
1.87 + offset_t filepos = flexpage->base_offset;
1.88 + offset_t populated_size = std::min(flexpage->size, _size - filepos);
1.89 +
1.90 + /* Remove the file state tag from the region. */
1.91 +
1.92 + flexpage->region->flush();
1.93 +
1.94 + /* Flush the file content. */
1.95 +
1.96 + _ops->write(flexpage->base_addr, flexpage->base_addr_physical,
1.97 + _start + filepos, populated_size);
1.98 +}
1.99 +
1.100 +// vim: tabstop=4 expandtab shiftwidth=4