Christopher Haster
a368d3a07c
Yes this is more expensive, since small programs need to rewrite the whole block in order to conform to the block device API. However, it reduces code duplication and keeps all of the test-related block device emulation in lfs_testbd. Some people have used lfs_filebd/lfs_rambd as a starting point for new block devices and I think it should be clear that erase does not need to have side effects. Though to be fair this also just means we should have more examples of block devices...
131 lines
4.3 KiB
C
131 lines
4.3 KiB
C
/*
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* Block device emulated in RAM
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*
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* Copyright (c) 2022, The littlefs authors.
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* Copyright (c) 2017, Arm Limited. All rights reserved.
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include "bd/lfs_rambd.h"
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int lfs_rambd_createcfg(const struct lfs_config *cfg,
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const struct lfs_rambd_config *bdcfg) {
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LFS_RAMBD_TRACE("lfs_rambd_createcfg(%p {.context=%p, "
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".read=%p, .prog=%p, .erase=%p, .sync=%p, "
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".read_size=%"PRIu32", .prog_size=%"PRIu32", "
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".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
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"%p {.buffer=%p})",
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(void*)cfg, cfg->context,
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(void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
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(void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
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cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count,
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(void*)bdcfg, bdcfg->buffer);
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lfs_rambd_t *bd = cfg->context;
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bd->cfg = bdcfg;
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// allocate buffer?
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if (bd->cfg->buffer) {
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bd->buffer = bd->cfg->buffer;
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} else {
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bd->buffer = lfs_malloc(cfg->block_size * cfg->block_count);
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if (!bd->buffer) {
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LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
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return LFS_ERR_NOMEM;
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}
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}
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// zero for reproducibility
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memset(bd->buffer, 0, cfg->block_size * cfg->block_count);
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LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);
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return 0;
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}
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int lfs_rambd_create(const struct lfs_config *cfg) {
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LFS_RAMBD_TRACE("lfs_rambd_create(%p {.context=%p, "
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".read=%p, .prog=%p, .erase=%p, .sync=%p, "
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".read_size=%"PRIu32", .prog_size=%"PRIu32", "
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".block_size=%"PRIu32", .block_count=%"PRIu32"})",
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(void*)cfg, cfg->context,
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(void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
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(void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
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cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count);
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static const struct lfs_rambd_config defaults = {0};
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int err = lfs_rambd_createcfg(cfg, &defaults);
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LFS_RAMBD_TRACE("lfs_rambd_create -> %d", err);
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return err;
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}
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int lfs_rambd_destroy(const struct lfs_config *cfg) {
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LFS_RAMBD_TRACE("lfs_rambd_destroy(%p)", (void*)cfg);
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// clean up memory
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lfs_rambd_t *bd = cfg->context;
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if (!bd->cfg->buffer) {
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lfs_free(bd->buffer);
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}
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LFS_RAMBD_TRACE("lfs_rambd_destroy -> %d", 0);
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return 0;
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}
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int lfs_rambd_read(const struct lfs_config *cfg, lfs_block_t block,
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lfs_off_t off, void *buffer, lfs_size_t size) {
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LFS_RAMBD_TRACE("lfs_rambd_read(%p, "
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"0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
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(void*)cfg, block, off, buffer, size);
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lfs_rambd_t *bd = cfg->context;
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// check if read is valid
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LFS_ASSERT(block < cfg->block_count);
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LFS_ASSERT(off % cfg->read_size == 0);
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LFS_ASSERT(size % cfg->read_size == 0);
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LFS_ASSERT(off+size <= cfg->block_size);
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// read data
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memcpy(buffer, &bd->buffer[block*cfg->block_size + off], size);
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LFS_RAMBD_TRACE("lfs_rambd_read -> %d", 0);
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return 0;
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}
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int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
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lfs_off_t off, const void *buffer, lfs_size_t size) {
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LFS_RAMBD_TRACE("lfs_rambd_prog(%p, "
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"0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
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(void*)cfg, block, off, buffer, size);
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lfs_rambd_t *bd = cfg->context;
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// check if write is valid
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LFS_ASSERT(block < cfg->block_count);
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LFS_ASSERT(off % cfg->prog_size == 0);
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LFS_ASSERT(size % cfg->prog_size == 0);
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LFS_ASSERT(off+size <= cfg->block_size);
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// program data
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memcpy(&bd->buffer[block*cfg->block_size + off], buffer, size);
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LFS_RAMBD_TRACE("lfs_rambd_prog -> %d", 0);
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return 0;
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}
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int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
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LFS_RAMBD_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
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// check if erase is valid
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LFS_ASSERT(block < cfg->block_count);
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// erase is a noop
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(void)block;
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LFS_RAMBD_TRACE("lfs_rambd_erase -> %d", 0);
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return 0;
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}
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int lfs_rambd_sync(const struct lfs_config *cfg) {
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LFS_RAMBD_TRACE("lfs_rambd_sync(%p)", (void*)cfg);
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// sync is a noop
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(void)cfg;
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LFS_RAMBD_TRACE("lfs_rambd_sync -> %d", 0);
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return 0;
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}
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