Implement storedevs, prepare to port littlefs

kernel/fs/littlefs/bd/lfs_filebd.c

@@ -0,0 +1,167 @@
+/*
+ * Block device emulated in a file
+ *
+ * Copyright (c) 2022, The littlefs authors.
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include "bd/lfs_filebd.h"
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+int lfs_filebd_create(const struct lfs_config *cfg, const char *path,
+        const struct lfs_filebd_config *bdcfg) {
+    LFS_FILEBD_TRACE("lfs_filebd_create(%p {.context=%p, "
+                ".read=%p, .prog=%p, .erase=%p, .sync=%p}, "
+                "\"%s\", "
+                "%p {.read_size=%"PRIu32", .prog_size=%"PRIu32", "
+                ".erase_size=%"PRIu32", .erase_count=%"PRIu32"})",
+            (void*)cfg, cfg->context,
+            (void*)(uintptr_t)cfg->read, (void*)(uintptr_t)cfg->prog,
+            (void*)(uintptr_t)cfg->erase, (void*)(uintptr_t)cfg->sync,
+            path,
+            (void*)bdcfg,
+            bdcfg->read_size, bdcfg->prog_size, bdcfg->erase_size,
+            bdcfg->erase_count);
+    lfs_filebd_t *bd = cfg->context;
+    bd->cfg = bdcfg;
+
+    // open file
+    #ifdef _WIN32
+    bd->fd = open(path, O_RDWR | O_CREAT | O_BINARY, 0666);
+    #else
+    bd->fd = open(path, O_RDWR | O_CREAT, 0666);
+    #endif
+
+    if (bd->fd < 0) {
+        int err = -errno;
+        LFS_FILEBD_TRACE("lfs_filebd_create -> %d", err);
+        return err;
+    }
+
+    LFS_FILEBD_TRACE("lfs_filebd_create -> %d", 0);
+    return 0;
+}
+
+int lfs_filebd_destroy(const struct lfs_config *cfg) {
+    LFS_FILEBD_TRACE("lfs_filebd_destroy(%p)", (void*)cfg);
+    lfs_filebd_t *bd = cfg->context;
+    int err = close(bd->fd);
+    if (err < 0) {
+        err = -errno;
+        LFS_FILEBD_TRACE("lfs_filebd_destroy -> %d", err);
+        return err;
+    }
+    LFS_FILEBD_TRACE("lfs_filebd_destroy -> %d", 0);
+    return 0;
+}
+
+int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, void *buffer, lfs_size_t size) {
+    LFS_FILEBD_TRACE("lfs_filebd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+            (void*)cfg, block, off, buffer, size);
+    lfs_filebd_t *bd = cfg->context;
+
+    // check if read is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->read_size == 0);
+    LFS_ASSERT(size % bd->cfg->read_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
+
+    // zero for reproducibility (in case file is truncated)
+    memset(buffer, 0, size);
+
+    // read
+    off_t res1 = lseek(bd->fd,
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
+    if (res1 < 0) {
+        int err = -errno;
+        LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
+        return err;
+    }
+
+    ssize_t res2 = read(bd->fd, buffer, size);
+    if (res2 < 0) {
+        int err = -errno;
+        LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
+        return err;
+    }
+
+    LFS_FILEBD_TRACE("lfs_filebd_read -> %d", 0);
+    return 0;
+}
+
+int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, const void *buffer, lfs_size_t size) {
+    LFS_FILEBD_TRACE("lfs_filebd_prog(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+            (void*)cfg, block, off, buffer, size);
+    lfs_filebd_t *bd = cfg->context;
+
+    // check if write is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+    LFS_ASSERT(off  % bd->cfg->prog_size == 0);
+    LFS_ASSERT(size % bd->cfg->prog_size == 0);
+    LFS_ASSERT(off+size <= bd->cfg->erase_size);
+
+    // program data
+    off_t res1 = lseek(bd->fd,
+            (off_t)block*bd->cfg->erase_size + (off_t)off, SEEK_SET);
+    if (res1 < 0) {
+        int err = -errno;
+        LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
+        return err;
+    }
+
+    ssize_t res2 = write(bd->fd, buffer, size);
+    if (res2 < 0) {
+        int err = -errno;
+        LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
+        return err;
+    }
+
+    LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", 0);
+    return 0;
+}
+
+int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
+    LFS_FILEBD_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32" (%"PRIu32"))",
+            (void*)cfg, block, ((lfs_filebd_t*)cfg->context)->cfg->erase_size);
+    lfs_filebd_t *bd = cfg->context;
+
+    // check if erase is valid
+    LFS_ASSERT(block < bd->cfg->erase_count);
+
+    // erase is a noop
+    (void)block;
+
+    LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", 0);
+    return 0;
+}
+
+int lfs_filebd_sync(const struct lfs_config *cfg) {
+    LFS_FILEBD_TRACE("lfs_filebd_sync(%p)", (void*)cfg);
+
+    // file sync
+    lfs_filebd_t *bd = cfg->context;
+    #ifdef _WIN32
+    int err = FlushFileBuffers((HANDLE) _get_osfhandle(bd->fd)) ? 0 : -1;
+    #else
+    int err = fsync(bd->fd);
+    #endif
+    if (err) {
+        err = -errno;
+        LFS_FILEBD_TRACE("lfs_filebd_sync -> %d", 0);
+        return err;
+    }
+
+    LFS_FILEBD_TRACE("lfs_filebd_sync -> %d", 0);
+    return 0;
+}