f676b45151
This adds a filesystem which is backed by the host's filesystem. It is modeled off of sandboxfs, which has very similar aims. Semihosting doesn't support listing directories (except with SYS_SYSTEM), so neither do we. it's possible to optimize a bit for the common case of reading a whole file by omitting a call to smh_seek, but this is left as a future optimization. Signed-off-by: Sean Anderson <sean.anderson@seco.com>
116 lines
2.1 KiB
C
116 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2022, Sean Anderson <sean.anderson@seco.com>
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* Copyright (c) 2012, Google Inc.
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*/
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#include <common.h>
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#include <fs.h>
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#include <malloc.h>
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#include <os.h>
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#include <semihosting.h>
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#include <semihostingfs.h>
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int smh_fs_set_blk_dev(struct blk_desc *rbdd, struct disk_partition *info)
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{
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/*
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* Only accept a NULL struct blk_desc for the semihosting, which is when
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* hostfs interface is used
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*/
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return !!rbdd;
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}
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static int smh_fs_read_at(const char *filename, loff_t pos, void *buffer,
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loff_t maxsize, loff_t *actread)
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{
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long fd, size, ret;
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fd = smh_open(filename, MODE_READ | MODE_BINARY);
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if (fd < 0)
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return fd;
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ret = smh_seek(fd, pos);
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if (ret < 0) {
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smh_close(fd);
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return ret;
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}
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if (!maxsize) {
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size = smh_flen(fd);
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if (ret < 0) {
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smh_close(fd);
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return size;
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}
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maxsize = size;
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}
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size = smh_read(fd, buffer, maxsize);
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smh_close(fd);
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if (size < 0)
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return size;
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*actread = size;
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return 0;
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}
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static int smh_fs_write_at(const char *filename, loff_t pos, void *buffer,
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loff_t towrite, loff_t *actwrite)
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{
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long fd, size, ret;
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fd = smh_open(filename, MODE_READ | MODE_BINARY | MODE_PLUS);
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if (fd < 0)
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return fd;
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ret = smh_seek(fd, pos);
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if (ret < 0) {
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smh_close(fd);
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return ret;
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}
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ret = smh_write(fd, buffer, towrite, &size);
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smh_close(fd);
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*actwrite = size;
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return ret;
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}
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int smh_fs_size(const char *filename, loff_t *result)
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{
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long fd, size;
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fd = smh_open(filename, MODE_READ | MODE_BINARY);
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if (fd < 0)
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return fd;
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size = smh_flen(fd);
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smh_close(fd);
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if (size < 0)
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return size;
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*result = size;
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return 0;
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}
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int smh_fs_read(const char *filename, void *buf, loff_t offset, loff_t len,
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loff_t *actread)
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{
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int ret;
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ret = smh_fs_read_at(filename, offset, buf, len, actread);
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if (ret)
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printf("** Unable to read file %s **\n", filename);
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return ret;
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}
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int smh_fs_write(const char *filename, void *buf, loff_t offset,
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loff_t len, loff_t *actwrite)
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{
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int ret;
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ret = smh_fs_write_at(filename, offset, buf, len, actwrite);
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if (ret)
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printf("** Unable to write file %s **\n", filename);
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return ret;
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}
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