63 lines
2.1 KiB
C
63 lines
2.1 KiB
C
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/*
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* volume_id - reads filesystem label and uuid
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*
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* Copyright (C) 2018 Sven-Göran Bergh <sgb@systemaxion.se>
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*
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* Licensed under GPLv2, see file LICENSE in this source tree.
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*/
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//config:config FEATURE_VOLUMEID_LFS
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//config: bool "LittleFS filesystem"
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//config: default y
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//config: depends on VOLUMEID && FEATURE_BLKID_TYPE
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//config: help
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//config: LittleFS is a small fail-safe filesystem designed for embedded
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//config: systems. It has strong copy-on-write guarantees and storage on disk
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//config: is always kept in a valid state. It also provides a form of dynamic
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//config: wear levelling for systems that can not fit a full flash translation
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//config: layer.
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//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_LFS) += lfs.o
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#include "volume_id_internal.h"
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#define LFS_SB1_OFFSET 0x10
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#define LFS_MAGIC_NAME "littlefs"
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#define LFS_MAGIC_LEN 8
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// The superblock is stored in the first metadata pair, i.e the first two blocks.
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struct lfs_super_block { // A block in a metadata pair
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// /* 0x00 */ uint32_t rev_count; // Revision count
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// /* 0x04 */ uint32_t dir_size; // Directory size
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// /* 0x08 */ uint64_t tail_ptr; // Tail pointer
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/* 0x10 */ uint8_t entry_type; // Entry type
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/* 0x11 */ uint8_t entry_len; // Entry length
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/* 0x12 */ uint8_t att_len; // Attribute length
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/* 0x13 */ uint8_t name_len; // Name length
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/* 0x14 */ uint64_t root_dir; // Root directory
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/* 0x1C */ uint32_t block_size; // Block size
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/* 0x20 */ uint32_t block_count; // Block count
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/* 0x24 */ uint16_t ver_major; // Version major
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/* 0x26 */ uint16_t ver_minor; // Version minor
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/* 0x28 */ uint8_t magic[LFS_MAGIC_LEN]; // Magic string "littlefs"
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// /* 0x30 */ uint32_t crc; // CRC-32 checksum
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} PACKED;
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int FAST_FUNC volume_id_probe_lfs(struct volume_id *id /*,uint64_t off*/)
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{
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struct lfs_super_block *sb;
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// Go for primary super block (ignore second sb)
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dbg("lfs: probing at offset 0x%x", LFS_SB1_OFFSET);
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sb = volume_id_get_buffer(id, LFS_SB1_OFFSET, sizeof(*sb));
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if (!sb)
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return -1;
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if (memcmp(sb->magic, LFS_MAGIC_NAME, LFS_MAGIC_LEN) != 0)
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return -1;
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IF_FEATURE_BLKID_TYPE(id->type = LFS_MAGIC_NAME);
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return 0;
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}
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