diff options
Diffstat (limited to 'nuttx/fs/nxffs/nxffs_util.c')
-rw-r--r-- | nuttx/fs/nxffs/nxffs_util.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/nuttx/fs/nxffs/nxffs_util.c b/nuttx/fs/nxffs/nxffs_util.c new file mode 100644 index 000000000..ea2e97967 --- /dev/null +++ b/nuttx/fs/nxffs/nxffs_util.c @@ -0,0 +1,181 @@ +/**************************************************************************** + * fs/nxffs/nxffs_util.c + * + * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * References: Linux/Documentation/filesystems/romfs.txt + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <string.h> + +#include "nxffs.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Public Types + ****************************************************************************/ + +/**************************************************************************** + * Public Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: nxffs_rdle16 + * + * Description: + * Get a (possibly unaligned) 16-bit little endian value. + * + * Input Parameters: + * val - A pointer to the first byte of the little endian value. + * + * Returned Value: + * A uint16_t representing the whole 16-bit integer value + * + ****************************************************************************/ + +uint16_t nxffs_rdle16(FAR const uint8_t *val) +{ + return (uint16_t)val[1] << 8 | (uint16_t)val[0]; +} + +/**************************************************************************** + * Name: nxffs_wrle16 + * + * Description: + * Put a (possibly unaligned) 16-bit little endian value. + * + * Input Parameters: + * dest - A pointer to the first byte to save the little endian value. + * val - The 16-bit value to be saved. + * + * Returned Value: + * None + * + ****************************************************************************/ + +void nxffs_wrle16(uint8_t *dest, uint16_t val) +{ + dest[0] = val & 0xff; /* Little endian means LS byte first in byte stream */ + dest[1] = val >> 8; +} + +/**************************************************************************** + * Name: nxffs_rdle32 + * + * Description: + * Get a (possibly unaligned) 32-bit little endian value. + * + * Input Parameters: + * val - A pointer to the first byte of the little endian value. + * + * Returned Value: + * A uint32_t representing the whole 32-bit integer value + * + ****************************************************************************/ + +uint32_t nxffs_rdle32(FAR const uint8_t *val) +{ + /* Little endian means LS halfword first in byte stream */ + + return (uint32_t)nxffs_rdle16(&val[2]) << 16 | (uint32_t)nxffs_rdle16(val); +} + +/**************************************************************************** + * Name: nxffs_wrle32 + * + * Description: + * Put a (possibly unaligned) 32-bit little endian value. + * + * Input Parameters: + * dest - A pointer to the first byte to save the little endian value. + * val - The 32-bit value to be saved. + * + * Returned Value: + * None + * + ****************************************************************************/ + +void nxffs_wrle32(uint8_t *dest, uint32_t val) +{ + /* Little endian means LS halfword first in byte stream */ + + nxffs_wrle16(dest, (uint16_t)(val & 0xffff)); + nxffs_wrle16(dest+2, (uint16_t)(val >> 16)); +} + +/**************************************************************************** + * Name: nxffs_erased + * + * Description: + * Check if a block of memory is in the erased state. + * + * Input Parameters: + * buffer - Address of the start of the memory to check. + * buflen - The number of bytes to check. + * + * Returned Values: + * The number of erased bytes found at the beginning of the memory region. + * + ****************************************************************************/ + +size_t nxffs_erased(FAR const uint8_t *buffer, size_t buflen) +{ + size_t nerased = 0; + + for (; nerased < buflen; nerased++) + { + if (*buffer != CONFIG_NXFFS_ERASEDSTATE) + { + break; + } + buffer++; + } + + return nerased; +} |