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2026-08-09 22:20:01 +08:00
parent 8717ea8f20
commit 2a50fa58c7
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CODE/sdk/include/deshab/fat32.h
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/* deshab/fat32.h - Deshab SDK FAT32 读写库 + VFAT LFN 长文件名解析（static inline，无库）
*
* 本头为 Deshab SDK 的一部分，整合自：
* - CODE/tools/fat32_lfn.h（LFN 长文件名解析）
* - CODE/tools/fat32_io.h（FAT32 读写库）
* 合并为单一头文件，基础类型 u8/u16/u32/u64/i64 由 "types.h" 提供。
*/
#ifndef DESHAB_FAT32_H
#define DESHAB_FAT32_H
#include "types.h"
/* =====================================================================
* 第一部分：LFN 长文件名解析（原 fat32_lfn.h）
* =====================================================================
*
* FAT32 LFN 原理：
* 目录项中 attr==0x0F 的是 LFN 片段项。每项含 13 个 UTF-16 LE 字符
* （name1[5] + name2[6] + name3[2]），按逆序存储——序号最高（带 0x40
* 标志）的项最先出现，序号递减，最后紧跟一个 8.3 短目录项作为“主项”。
* 短名项的 checksum（由 name11 计算）用于校验整条 LFN 链完整性。
*
* 用法（在目录遍历循环中）：
* fat32_lfn_buf lfn;
* fat32_lfn_init(&lfn);
* // 外层簇遍历循环——lfn 必须跨簇存活（LFN 链可能跨簇边界）
* while (遍历目录簇) {
* for (每个 32 字节目录项 e) {
* if (name[0]==0) 目录结束;
* if (name[0]==0xE5) { fat32_lfn_init(&lfn); continue; }
* int is_short = fat32_lfn_process(&lfn, entry_ptr);
* if (is_short) {
* // lfn.valid==1 时有完整 LFN，可 fat32_lfn_to_ascii 取名
* // 用 fat32_lfn_match 匹配长名或 8.3 短名
* }
* }
* }
*
* 注意：fat32_lfn_buf 必须在簇遍历循环**外**声明，跨簇切换时不清空，
* 以支持跨簇边界的 LFN 链。
*/
/* LFN 最大字符数（FAT32 规范最多 20 个 LFN 项 = 260 字符） */
#define FAT32_LFN_MAX 260
/* LFN 收集缓冲（栈/局部变量分配） */
typedef struct {
u16 chars[FAT32_LFN_MAX]; /* UTF-16 LE 累积字符（正序） */
int count; /* 有效字符数（不含 0x0000 终止符/0xFFFF 填充） */
u8 checksum; /* LFN 链 checksum（来自 0x40 标志项） */
int valid; /* 1=LFN 链完整且 checksum 与短名项匹配 */
} fat32_lfn_buf;
/* 初始化/清空 LFN 缓冲 */
static inline void fat32_lfn_init(fat32_lfn_buf *buf) {
buf->count = 0;
buf->valid = 0;
buf->checksum = 0;
for (int i = 0; i < FAT32_LFN_MAX; i++) buf->chars[i] = 0;
}
/* 计算 8.3 短名（11 字节）的 LFN checksum。
* 标准 FAT32 算法：cksum = ((cksum & 1) << 7) + (cksum >> 1) + name[i] */
static inline u8 fat32_lfn_checksum(const u8 name11[11]) {
u8 cksum = 0;
for (int i = 0; i < 11; i++) {
cksum = (u8)(((cksum & 1) << 7) + (cksum >> 1) + name11[i]);
}
return cksum;
}
/* 处理一个 32 字节目录项。自动判断 LFN 项 / 短名项 / 已删除项。
*
* 调用方对目录遍历中的每个条目（跳过 name[0]==0 结束符后）调用此函数。
* - LFN 项（attr==0x0F）：收集 13 个 UTF-16 字符到 buf，返回 0
* - 已删除项（name[0]==0xE5）：清空 buf，返回 0
* - 短名项：校验 checksum，设 buf->valid，返回 1
*
* 返回 1=刚处理的是短名项（此时可检查 buf->valid 判断是否有有效 LFN），
* 0=LFN 项或已删除项。
*
* 注意：遇到带 0x40 标志的 LFN 项（链开始）时自动重置 buf。
* 遇到已删除项时自动清空 buf（防止残留 LFN 污染下一个文件）。 */
static inline int fat32_lfn_process(fat32_lfn_buf *buf, const u8 *entry) {
u8 attr = entry[11];
/* 已删除项：清空 LFN 缓冲 */
if (entry[0] == 0xE5) {
fat32_lfn_init(buf);
return 0;
}
/* LFN 项（attr == 0x0F） */
if (attr == 0x0F) {
u8 seq = entry[0];
u8 ord = (u8)(seq & 0x3F); /* 序号 1-20 */
if (ord == 0 || ord > 20) {
fat32_lfn_init(buf);
return 0;
}
/* 带 0x40 标志 = LFN 链开始（最高序号项），重置缓冲 */
if (seq & 0x40) {
int prev_cksum = buf->checksum;
fat32_lfn_init(buf);
buf->checksum = entry[13];
(void)prev_cksum;
}
/* 提取 13 个 UTF-16 LE 字符，放到 (ord-1)*13 位置（正序） */
int base = (ord - 1) * 13;
if (base + 13 > FAT32_LFN_MAX) {
fat32_lfn_init(buf);
return 0;
}
/* name1: entry[1..10] = 5 个 UTF-16 LE 字符 */
for (int i = 0; i < 5; i++) {
u16 c = (u16)entry[1 + i * 2] | ((u16)entry[2 + i * 2] << 8);
buf->chars[base + i] = c;
}
/* name2: entry[14..25] = 6 个 UTF-16 LE 字符 */
for (int i = 0; i < 6; i++) {
u16 c = (u16)entry[14 + i * 2] | ((u16)entry[15 + i * 2] << 8);
buf->chars[base + 5 + i] = c;
}
/* name3: entry[28..31] = 2 个 UTF-16 LE 字符 */
for (int i = 0; i < 2; i++) {
u16 c = (u16)entry[28 + i * 2] | ((u16)entry[29 + i * 2] << 8);
buf->chars[base + 11 + i] = c;
}
return 0; /* LFN 项，还不是短名项 */
}
/* 短名项：校验 checksum */
u8 cksum = fat32_lfn_checksum(entry);
if (buf->checksum != 0 && buf->checksum == cksum) {
/* LFN 链有效——计算实际字符数（截断于 0x0000 终止符或 0xFFFF 填充符） */
int n = 0;
for (int i = 0; i < FAT32_LFN_MAX; i++) {
if (buf->chars[i] == 0x0000 || buf->chars[i] == 0xFFFF) break;
n++;
}
buf->count = n;
buf->valid = 1;
} else {
/* checksum 不匹配或无 LFN 链：清空，回退 8.3 */
fat32_lfn_init(buf);
}
return 1; /* 短名项处理完毕 */
}
/* 从 LFN 缓冲提取 ASCII 名（UTF-16->ASCII 缩窄，仅 BMP U+0000..U+007F）。
* out_cap 为 out 缓冲容量（含 NUL）。
* 返回字符串长度（不含 NUL），-1=无有效 LFN 或含非 ASCII 字符。 */
static inline int fat32_lfn_to_ascii(const fat32_lfn_buf *buf, char *out, int out_cap) {
if (!buf->valid || buf->count == 0 || out_cap <= 0) return -1;
int n = buf->count;
if (n >= out_cap) n = out_cap - 1;
for (int i = 0; i < n; i++) {
u16 c = buf->chars[i];
if (c > 0x7F) return -1; /* 含非 ASCII 字符 */
out[i] = (char)(u8)c;
}
out[n] = 0;
return n;
}
/* ASCII 大小写不敏感字符串比较 */
static inline int fat32_lfn_streq_ci(const char *a, const char *b) {
if (!a || !b) return 0;
while (*a && *b) {
char ca = *a, cb = *b;
if (ca >= 'a' && ca <= 'z') ca = (char)(ca - 32);
if (cb >= 'a' && cb <= 'z') cb = (char)(cb - 32);
if (ca != cb) return 0;
a++; b++;
}
return *a == *b;
}
/* 判断 ASCII 字符串是否以指定后缀结尾（大小写不敏感）。
* 例如 fat32_lfn_ends_with_ci("libtest.so", ".so") -> 1 */
static inline int fat32_lfn_ends_with_ci(const char *s, const char *suffix) {
if (!s || !suffix) return 0;
int sl = 0, xl = 0;
while (s[sl]) sl++;
while (suffix[xl]) xl++;
if (xl > sl || xl == 0) return 0;
for (int i = 0; i < xl; i++) {
char a = s[sl - xl + i];
char b = suffix[i];
if (a >= 'a' && a <= 'z') a = (char)(a - 32);
if (b >= 'a' && b <= 'z') b = (char)(b - 32);
if (a != b) return 0;
}
return 1;
}
/* 匹配目录项：优先匹配 LFN 长名（大小写不敏感），回退 8.3 短名。
* buf : LFN 收集缓冲（短名项处理后）
* name11 : 短名项的 11 字节 8.3 名
* target_long: 目标长名（ASCII，可为 NULL=不匹配长名）
* target83 : 目标 8.3 名（11 字节，可为 NULL=不匹配 8.3）
* 返回 1=匹配，0=不匹配。
* FAT32 规范：文件名查找大小写不敏感。 */
static inline int fat32_lfn_match(const fat32_lfn_buf *buf, const u8 name11[11],
const char *target_long, const char *target83) {
/* 1. 优先匹配 LFN 长名 */
if (buf->valid && buf->count > 0 && target_long) {
char ascii[FAT32_LFN_MAX];
int n = fat32_lfn_to_ascii(buf, ascii, sizeof(ascii));
if (n >= 0 && fat32_lfn_streq_ci(ascii, target_long)) return 1;
}
/* 2. 回退 8.3 短名匹配（精确比较 11 字节） */
if (target83 && name11) {
for (int i = 0; i < 11; i++) {
if (name11[i] != (u8)target83[i]) return 0;
}
return 1;
}
return 0;
}
/* 从 8.3 短名（11 字节）生成可显示 ASCII 字符串（如 "README.TXT"）。
* 与 fat32_io.h 的 f32_name_from_83 功能相同，独立提供以避免循环依赖。 */
static inline void fat32_lfn_short_to_str(const u8 name11[11], char out[13]) {
int p = 0;
for (int j = 0; j < 8; j++) {
if (name11[j] == ' ') break;
out[p++] = (char)name11[j];
}
if (name11[8] != ' ') {
out[p++] = '.';
for (int j = 8; j < 11; j++) {
if (name11[j] == ' ') break;
out[p++] = (char)name11[j];
}
}
out[p] = 0;
}
/* =====================================================================
* 第二部分：FAT32 读写库（原 fat32_io.h）
* =====================================================================
*
* 通过 f32_init() 注入 block_read/block_write 函数指针（来自 dkm_kernel_api + 0xA8）。
*
* 能力：FAT32 根目录文件的读/写/删/列举，支持 FAT 链跟随、多簇文件。
* 限制：仅根目录（不支持子目录，Phase 2.2 fileman 将扩展）；单文件最大 256KB。
*
* 用法：
* f32_init(block_read, block_write) - 初始化（block_write 可为 NULL，仅读场景）
* f32_name_to_83("file.txt", name11) - "file.txt" -> 11 字符 8.3 名
* f32_read_root_file(name11, &data, &size) - 读根目录文件到 f32_data 缓冲
* f32_write_root_file(name11, data, size) - 写/替换根目录文件
* f32_delete_root_file(name11) - 删除根目录文件
* f32_list_root(emit_cb, user_data) - 列举根目录
*
* 缓冲区：每个包含本头的 .elf 独立持有 256KB g_disk + 4KB g_cluster + 256KB g_fdata（共 ~516KB BSS）。
* 与 net_stack.h 同模式，接受 static 缓冲的代价以换取无库依赖。
*/
/* ---- block 设备函数类型（与 shell/DSK 一致：index 参数固定 0） ---- */
typedef int (*f32_block_read_fn)(u32 index, u64 lba, u32 count, void *buf);
typedef int (*f32_block_write_fn)(u32 index, u64 lba, u32 count, const void *buf);
static f32_block_read_fn f32_blk_read = 0;
static f32_block_write_fn f32_blk_write = 0;
/* ---- FAT32 BPB / 目录项结构（packed，与 DSK/shell 一致） ---- */
typedef struct __attribute__((packed)) {
u8 jmp[3]; char oem[8]; u16 bps; u8 spc; u16 rsvd; u8 fc; u16 root_ent;
u16 ts16; u8 media; u16 spf16; u16 spt; u16 heads; u32 hidden; u32 ts32;
u32 spf; u16 flags; u16 ver; u32 root_clus; u16 fsi; u16 bkboot;
u8 res[12]; u8 drv; u8 ntfl; u8 sig; u32 ser; char lbl[11]; char typ[8];
u8 code[420]; u16 boot_sig;
} f32_bpb;
typedef struct __attribute__((packed)) {
char name[11]; u8 attr; u8 ntr; u8 ctenth;
u16 ctime; u16 cdate; u16 adate; u16 chigh;
u16 wtime; u16 wdate; u16 clow; u32 fsize;
} f32_dirent;
/* ---- 内部小工具 ---- */
static inline u32 f32_r32(const u8 *p) { return (u32)p[0]|((u32)p[1]<<8)|((u32)p[2]<<16)|((u32)p[3]<<24); }
static inline u16 f32_r16(const u8 *p) { return (u16)p[0]|((u16)p[1]<<8); }
static inline int f32_neq11(const char *a, const char *b) {
for (int i = 0; i < 11; i++) if (a[i] != b[i]) return 0;
return 1;
}
/* ---- 批量读写缓冲区（与 DSK/shell 对齐：256 扇区覆盖 BPB+FAT+根目录+小文件） ---- */
/* 文件数据缓冲大小可由包含者在 include 前 #define F32_DATA_BYTES 覆盖
* （cmd.elf 需要装载 2MB+ 的 PE64 程序，定义为 4MB；其余默认 256KB）。 */
#ifndef F32_DATA_BYTES
#define F32_DATA_BYTES 262144
#endif
static u8 f32_disk[131072]; /* 256 扇区 BPB+FAT+根目录缓存 */
static u8 f32_cluster[4096]; /* 单簇缓冲 */
static u8 f32_data[F32_DATA_BYTES]; /* 文件数据缓冲 */
static int f32_disk_loaded = 0; /* f32_disk 是否已加载 BPB+FAT */
/* 初始化：注入 block_read/block_write 函数指针 */
static inline void f32_init(f32_block_read_fn rd, f32_block_write_fn wr) {
f32_blk_read = rd;
f32_blk_write = wr;
f32_disk_loaded = 0;
}
static inline int f32_read_sectors(u32 lba, u32 count, u8 *out) {
return f32_blk_read ? f32_blk_read(0, lba, count, out) : -1;
}
static inline int f32_write_sectors(u32 lba, u32 count, const u8 *buf) {
return f32_blk_write ? f32_blk_write(0, lba, count, buf) : -1;
}
/* 确保 f32_disk 已加载 BPB+FAT+根目录（256 扇区） */
static inline int f32_disk_load(void) {
if (f32_disk_loaded) return 0;
if (f32_read_sectors(0, 256, f32_disk) != 0) return -1;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
if (bpb->boot_sig != 0xAA55 || bpb->bps != 512) return -2;
if (bpb->spf == 0 || bpb->root_clus < 2) return -3;
f32_disk_loaded = 1;
return 0;
}
/* ---- 8.3 名字转换 ---- */
/* "file.txt" / "NAME" -> 11 字符 8.3 名（大写，空格填充）
* 返回 0 成功，-1 失败（过长或非法字符） */
static inline int f32_name_to_83(const char *in, char out[11]) {
for (int i = 0; i < 11; i++) out[i] = ' ';
int inlen = 0;
while (in[inlen] && inlen < 13) inlen++;
if (inlen == 0 || inlen > 12) return -1;
int dot = -1;
for (int i = 0; i < inlen; i++) if (in[i] == '.') dot = i;
int base_end = (dot >= 0) ? dot : inlen;
if (base_end == 0 || base_end > 8) return -1;
for (int j = 0; j < base_end; j++) {
char c = in[j];
if (c >= 'a' && c <= 'z') c -= 32;
if (c == '.' || c == ' ' || c == '/' || c == '\\') return -1;
out[j] = c;
}
if (dot >= 0) {
int extlen = inlen - dot - 1;
if (extlen > 3) return -1;
for (int j = 0; j < extlen; j++) {
char c = in[dot + 1 + j];
if (c >= 'a' && c <= 'z') c -= 32;
if (c == '.' || c == ' ' || c == '/' || c == '\\') return -1;
out[8 + j] = c;
}
}
return 0;
}
/* 11 字符 8.3 名 -> 可显示字符串（如 "README.TXT"） */
static inline void f32_name_from_83(const char in[11], char out[13]) {
int p = 0;
for (int j = 0; j < 8; j++) {
if (in[j] == ' ') break;
out[p++] = in[j];
}
if (in[8] != ' ') {
out[p++] = '.';
for (int j = 8; j < 11; j++) {
if (in[j] == ' ') break;
out[p++] = in[j];
}
}
out[p] = 0;
}
/* ---- 根目录文件查找 ---- */
/* 在根目录簇链中查找 11 字符名，输出首簇号与文件大小 */
static inline int f32_find_in_root(const u8 *clus, u32 clus_sectors, const char *target,
u32 *out_clus, u32 *out_size, u32 *out_idx) {
const f32_dirent *dir = (const f32_dirent *)clus;
for (u32 e = 0; e * 32 < clus_sectors * 512; e++) {
if (dir[e].name[0] == 0) break;
if ((u8)dir[e].name[0] == 0xE5) continue;
if (dir[e].attr == 0x0F) continue;
if (dir[e].attr & 0x08) continue;
if (f32_neq11(dir[e].name, target)) {
*out_clus = (u32)f32_r16((const u8*)&dir[e].clow) | ((u32)f32_r16((const u8*)&dir[e].chigh) << 16);
*out_size = dir[e].fsize;
if (out_idx) *out_idx = e;
return 0;
}
}
return -1;
}
/* 读取根目录下指定 8.3 名文件到 f32_data。
* 返回 0 成功，*out_data 指向 f32_data，*out_size 为字节数；非 0 失败。 */
static inline int f32_read_root_file(const char *name11, u8 **out_data, u32 *out_size) {
if (f32_disk_load() != 0) return -1;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 spc = bpb->spc;
u32 clus = bpb->root_clus;
u32 found_clus = 0, found_size = 0;
int found = 0;
while (clus >= 2 && clus < 0x0FFFFFF8 && !found) {
u32 lba = data_lba + (clus - 2) * spc;
const u8 *cb;
if ((u64)lba * 512 + (u64)spc * 512 <= 256ULL * 512)
cb = f32_disk + (u64)lba * 512;
else {
if (f32_read_sectors(lba, 8, f32_cluster) != 0) return -4;
cb = f32_cluster;
}
if (f32_find_in_root(cb, spc, name11, &found_clus, &found_size, 0) == 0) { found = 1; break; }
u32 fo = fat_byte_off + clus * 4;
if (fo + 4 > sizeof(f32_disk)) break;
clus = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
if (!found) return -5;
if (found_size > sizeof(f32_data)) return -6;
u8 *dst = f32_data; u32 remaining = found_size; u32 fc = found_clus;
while (fc >= 2 && fc < 0x0FFFFFF8 && remaining > 0) {
u32 fc_lba = data_lba + (fc - 2) * spc;
u32 fc_bytes = spc * 512;
if (fc_bytes > remaining) fc_bytes = remaining;
const u8 *fb;
if ((u64)fc_lba * 512 + (u64)spc * 512 <= 256ULL * 512)
fb = f32_disk + (u64)fc_lba * 512;
else {
if (f32_read_sectors(fc_lba, 8, f32_cluster) != 0) return -7;
fb = f32_cluster;
}
for (u32 b = 0; b < fc_bytes; b++) dst[b] = fb[b];
dst += fc_bytes; remaining -= fc_bytes;
u32 fo = fat_byte_off + fc * 4;
if (fo + 4 > sizeof(f32_disk)) break;
fc = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
*out_data = f32_data; *out_size = found_size;
return 0;
}
/* 写入根目录下指定 8.3 名文件（存在则替换，不存在则新建）。
* 依赖 f32_disk 已加载 BPB+FAT。返回 0 成功。 */
static inline int f32_write_root_file(const char *name11, const u8 *data, u32 size) {
if (f32_disk_load() != 0) return -1;
if (!f32_blk_write) return -10;
/* 写入前重新加载 BPB+FAT，保证与盘上一致 */
if (f32_read_sectors(0, 256, f32_disk) != 0) return -2;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 spc = bpb->spc;
u32 fat_lba = bpb->rsvd;
u32 fat_sectors = bpb->spf;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 root_clus = bpb->root_clus;
u32 cluster_bytes = spc * 512;
u32 root_lba = data_lba + (root_clus - 2) * spc;
u8 *root_buf = f32_disk + (u64)root_lba * 512;
u32 max_entries = cluster_bytes / 32;
f32_dirent *dir = (f32_dirent *)root_buf;
int free_entry = -1;
u32 existing_clus = 0;
int found = 0;
u32 existing_idx = 0;
for (u32 e = 0; e < max_entries; e++) {
if (dir[e].name[0] == 0) { if (free_entry < 0) free_entry = (int)e; break; }
if ((u8)dir[e].name[0] == 0xE5) { if (free_entry < 0) free_entry = (int)e; continue; }
if (dir[e].attr == 0x0F) continue;
if (dir[e].attr & 0x08) continue;
if (f32_neq11(dir[e].name, name11)) {
existing_clus = (u32)f32_r16((const u8*)&dir[e].clow) | ((u32)f32_r16((const u8*)&dir[e].chigh) << 16);
found = 1; existing_idx = e;
if (free_entry < 0) free_entry = (int)e;
break;
}
}
u32 bytes_needed = size > 0 ? size : 1;
u32 clusters_needed = (bytes_needed + cluster_bytes - 1) / cluster_bytes;
u32 first_clus = 0;
u32 prev_clus = 0;
if (found && existing_clus >= 2) {
first_clus = existing_clus;
u32 cur = existing_clus;
u32 count = 0;
while (cur >= 2 && cur < 0x0FFFFFF8 && count < clusters_needed) {
prev_clus = cur;
u32 fo = fat_byte_off + cur * 4;
if (fo + 4 > sizeof(f32_disk)) break;
cur = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
count++;
}
while (count < clusters_needed) {
u32 newc = 0;
for (u32 c = 2; c < (fat_sectors * 512) / 4; c++) {
u32 fo = fat_byte_off + c * 4;
if (fo + 4 > sizeof(f32_disk)) break;
if ((f32_r32(f32_disk + fo) & 0x0FFFFFFF) == 0) { newc = c; break; }
}
if (newc == 0) return -3;
u32 pfo = fat_byte_off + prev_clus * 4;
if (pfo + 4 <= sizeof(f32_disk)) {
f32_disk[pfo] = (u8)(newc & 0xFF);
f32_disk[pfo+1] = (u8)((newc >> 8) & 0xFF);
f32_disk[pfo+2] = (u8)((newc >> 16) & 0xFF);
f32_disk[pfo+3] = (u8)((newc >> 24) & 0x0F);
}
prev_clus = newc;
count++;
}
if (prev_clus >= 2) {
u32 fo = fat_byte_off + prev_clus * 4;
if (fo + 4 <= sizeof(f32_disk)) {
f32_disk[fo] = 0xF8; f32_disk[fo+1] = 0xFF; f32_disk[fo+2] = 0xFF; f32_disk[fo+3] = 0x0F;
}
}
/* 释放多余旧簇 */
u32 next = 0;
u32 fo = fat_byte_off + prev_clus * 4;
if (fo + 4 <= sizeof(f32_disk)) next = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
while (next >= 2 && next < 0x0FFFFFF8) {
u32 nfo = fat_byte_off + next * 4;
u32 nn = 0;
if (nfo + 4 <= sizeof(f32_disk)) nn = f32_r32(f32_disk + nfo) & 0x0FFFFFFF;
f32_disk[nfo] = 0; f32_disk[nfo+1] = 0; f32_disk[nfo+2] = 0; f32_disk[nfo+3] = 0;
next = nn;
}
} else {
if (free_entry < 0) return -4;
for (u32 i = 0; i < clusters_needed; i++) {
u32 newc = 0;
for (u32 c = 2; c < (fat_sectors * 512) / 4; c++) {
u32 fo = fat_byte_off + c * 4;
if (fo + 4 > sizeof(f32_disk)) break;
if ((f32_r32(f32_disk + fo) & 0x0FFFFFFF) == 0) { newc = c; break; }
}
if (newc == 0) return -3;
if (i == 0) first_clus = newc;
if (prev_clus >= 2) {
u32 pfo = fat_byte_off + prev_clus * 4;
f32_disk[pfo] = (u8)(newc & 0xFF);
f32_disk[pfo+1] = (u8)((newc >> 8) & 0xFF);
f32_disk[pfo+2] = (u8)((newc >> 16) & 0xFF);
f32_disk[pfo+3] = (u8)((newc >> 24) & 0x0F);
}
prev_clus = newc;
}
if (prev_clus >= 2) {
u32 fo = fat_byte_off + prev_clus * 4;
f32_disk[fo] = 0xF8; f32_disk[fo+1] = 0xFF; f32_disk[fo+2] = 0xFF; f32_disk[fo+3] = 0x0F;
}
}
/* 写数据到簇 */
u32 remaining = size;
const u8 *src = data;
u32 cur = first_clus;
u32 ci = 0;
while (cur >= 2 && cur < 0x0FFFFFF8 && ci < clusters_needed) {
u32 clba = data_lba + (cur - 2) * spc;
u32 chunk = remaining < cluster_bytes ? remaining : cluster_bytes;
if ((u64)clba * 512 + cluster_bytes <= 256ULL * 512) {
u8 *dst = f32_disk + (u64)clba * 512;
for (u32 b = 0; b < chunk; b++) dst[b] = src[b];
for (u32 b = chunk; b < cluster_bytes; b++) dst[b] = 0;
} else {
if (f32_read_sectors(clba, spc, f32_cluster) != 0) return -5;
for (u32 b = 0; b < chunk; b++) f32_cluster[b] = src[b];
for (u32 b = chunk; b < cluster_bytes; b++) f32_cluster[b] = 0;
if (f32_write_sectors(clba, spc, f32_cluster) != 0) return -6;
}
src += chunk; remaining -= chunk; ci++;
u32 fo = fat_byte_off + cur * 4;
if (fo + 4 > sizeof(f32_disk)) break;
cur = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
/* 更新目录项 */
u32 entry_idx = found ? existing_idx : (u32)free_entry;
f32_dirent *e = &dir[entry_idx];
if (!found) {
for (int i = 0; i < 11; i++) e->name[i] = name11[i];
e->attr = 0x20; e->ntr = 0; e->ctenth = 0; e->ctime = 0; e->cdate = 0; e->adate = 0;
}
e->chigh = (u16)((first_clus >> 16) & 0xFFFF);
e->clow = (u16)(first_clus & 0xFFFF);
e->fsize = size;
/* 回写 FAT（两份）+ 根目录 + 缓冲区内的数据簇 */
for (u32 f = 0; f < bpb->fc; f++) {
u32 flba = fat_lba + f * fat_sectors;
if (f32_write_sectors(flba, fat_sectors, f32_disk + (u64)flba * 512) != 0) return -7;
}
u32 root_dir_lba = data_lba + (root_clus - 2) * spc;
if ((u64)root_dir_lba * 512 + cluster_bytes <= 256ULL * 512) {
if (f32_write_sectors(root_dir_lba, spc, f32_disk + (u64)root_dir_lba * 512) != 0) return -8;
}
cur = first_clus; ci = 0;
while (cur >= 2 && cur < 0x0FFFFFF8 && ci < clusters_needed) {
u32 clba = data_lba + (cur - 2) * spc;
if ((u64)clba * 512 + cluster_bytes <= 256ULL * 512) {
if (f32_write_sectors(clba, spc, f32_disk + (u64)clba * 512) != 0) return -9;
}
u32 fo = fat_byte_off + cur * 4;
if (fo + 4 > sizeof(f32_disk)) break;
cur = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
ci++;
}
f32_disk_loaded = 0; /* 下次操作重新加载，避免使用脏缓存 */
return 0;
}
/* 在指定目录簇中写入文件（存在则替换，不存在则新建）。
* 泛化自 f32_write_root_file：目录可跨簇链，目录项回写到其所在簇。
* dir_clus : 目标目录首簇（0 = 根目录）
* name11 : 11 字符 8.3 名
* 返回 0 成功；负值失败（-4 = 目录链无空闲槽，不扩展目录簇链）。
* 注意：仅 8.3 短名匹配/创建，不生成 LFN 项。 */
static inline int f32_write_file_in_dir(u32 dir_clus, const char *name11, const u8 *data, u32 size) {
if (f32_disk_load() != 0) return -1;
if (!f32_blk_write) return -10;
/* 写入前重新加载 BPB+FAT，保证与盘上一致 */
if (f32_read_sectors(0, 256, f32_disk) != 0) return -2;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 spc = bpb->spc;
u32 fat_lba = bpb->rsvd;
u32 fat_sectors = bpb->spf;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 cluster_bytes = spc * 512;
if (dir_clus == 0) dir_clus = bpb->root_clus;
/* 第一遍：沿目录簇链查找现有项与空闲槽，记录其所在簇与索引 */
u32 found_clus = 0, existing_clus = 0;
int found = 0;
u32 found_idx = 0, free_idx = 0;
u32 free_slot_clus = 0;
int have_free = 0;
u32 dclus = dir_clus;
while (dclus >= 2 && dclus < 0x0FFFFFF8 && !found) {
u32 dlba = data_lba + (dclus - 2) * spc;
const u8 *db;
if ((u64)dlba * 512 + cluster_bytes <= 256ULL * 512)
db = f32_disk + (u64)dlba * 512;
else {
if (f32_read_sectors(dlba, spc, f32_cluster) != 0) return -11;
db = f32_cluster;
}
const f32_dirent *dir = (const f32_dirent *)db;
u32 max_entries = cluster_bytes / 32;
for (u32 e = 0; e < max_entries; e++) {
if (dir[e].name[0] == 0) {
if (!have_free) { have_free = 1; free_slot_clus = dclus; free_idx = e; }
goto scan_done; /* 0x00 = 目录结尾 */
}
if ((u8)dir[e].name[0] == 0xE5) {
if (!have_free) { have_free = 1; free_slot_clus = dclus; free_idx = e; }
continue;
}
if (dir[e].attr == 0x0F) continue;
if (dir[e].attr & 0x08) continue;
if (f32_neq11(dir[e].name, name11)) {
existing_clus = (u32)f32_r16((const u8*)&dir[e].clow) | ((u32)f32_r16((const u8*)&dir[e].chigh) << 16);
found = 1; found_idx = e; found_clus = dclus;
if (!have_free) { have_free = 1; free_slot_clus = dclus; free_idx = e; }
break;
}
}
if (found) break;
u32 fo = fat_byte_off + dclus * 4;
if (fo + 4 > sizeof(f32_disk)) break;
dclus = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
scan_done:
; /* C89: 标签后必须是语句 */
u32 bytes_needed = size > 0 ? size : 1;
u32 clusters_needed = (bytes_needed + cluster_bytes - 1) / cluster_bytes;
u32 first_clus = 0;
u32 prev_clus = 0;
if (found && existing_clus >= 2) {
first_clus = existing_clus;
u32 cur = existing_clus;
u32 count = 0;
while (cur >= 2 && cur < 0x0FFFFFF8 && count < clusters_needed) {
prev_clus = cur;
u32 fo = fat_byte_off + cur * 4;
if (fo + 4 > sizeof(f32_disk)) break;
cur = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
count++;
}
while (count < clusters_needed) {
u32 newc = 0;
for (u32 c = 2; c < (fat_sectors * 512) / 4; c++) {
u32 fo = fat_byte_off + c * 4;
if (fo + 4 > sizeof(f32_disk)) break;
if ((f32_r32(f32_disk + fo) & 0x0FFFFFFF) == 0) { newc = c; break; }
}
if (newc == 0) return -3;
u32 pfo = fat_byte_off + prev_clus * 4;
if (pfo + 4 <= sizeof(f32_disk)) {
f32_disk[pfo] = (u8)(newc & 0xFF);
f32_disk[pfo+1] = (u8)((newc >> 8) & 0xFF);
f32_disk[pfo+2] = (u8)((newc >> 16) & 0xFF);
f32_disk[pfo+3] = (u8)((newc >> 24) & 0x0F);
}
prev_clus = newc;
count++;
}
if (prev_clus >= 2) {
u32 fo = fat_byte_off + prev_clus * 4;
if (fo + 4 <= sizeof(f32_disk)) {
f32_disk[fo] = 0xF8; f32_disk[fo+1] = 0xFF; f32_disk[fo+2] = 0xFF; f32_disk[fo+3] = 0x0F;
}
}
/* 释放多余旧簇 */
u32 next = 0;
u32 fo = fat_byte_off + prev_clus * 4;
if (fo + 4 <= sizeof(f32_disk)) next = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
while (next >= 2 && next < 0x0FFFFFF8) {
u32 nfo = fat_byte_off + next * 4;
u32 nn = 0;
if (nfo + 4 <= sizeof(f32_disk)) nn = f32_r32(f32_disk + nfo) & 0x0FFFFFFF;
f32_disk[nfo] = 0; f32_disk[nfo+1] = 0; f32_disk[nfo+2] = 0; f32_disk[nfo+3] = 0;
next = nn;
}
} else {
if (!have_free) return -4; /* 目录链满，不扩展 */
for (u32 i = 0; i < clusters_needed; i++) {
u32 newc = 0;
for (u32 c = 2; c < (fat_sectors * 512) / 4; c++) {
u32 fo = fat_byte_off + c * 4;
if (fo + 4 > sizeof(f32_disk)) break;
if ((f32_r32(f32_disk + fo) & 0x0FFFFFFF) == 0) { newc = c; break; }
}
if (newc == 0) return -3;
if (i == 0) first_clus = newc;
if (prev_clus >= 2) {
u32 pfo = fat_byte_off + prev_clus * 4;
f32_disk[pfo] = (u8)(newc & 0xFF);
f32_disk[pfo+1] = (u8)((newc >> 8) & 0xFF);
f32_disk[pfo+2] = (u8)((newc >> 16) & 0xFF);
f32_disk[pfo+3] = (u8)((newc >> 24) & 0x0F);
}
prev_clus = newc;
}
if (prev_clus >= 2) {
u32 fo = fat_byte_off + prev_clus * 4;
f32_disk[fo] = 0xF8; f32_disk[fo+1] = 0xFF; f32_disk[fo+2] = 0xFF; f32_disk[fo+3] = 0x0F;
}
}
/* 写数据到簇（窗口内直接改 f32_disk，窗口外 RMW） */
u32 remaining = size;
const u8 *src = data;
u32 cur = first_clus;
u32 ci = 0;
while (cur >= 2 && cur < 0x0FFFFFF8 && ci < clusters_needed) {
u32 clba = data_lba + (cur - 2) * spc;
u32 chunk = remaining < cluster_bytes ? remaining : cluster_bytes;
if ((u64)clba * 512 + cluster_bytes <= 256ULL * 512) {
u8 *dst = f32_disk + (u64)clba * 512;
for (u32 b = 0; b < chunk; b++) dst[b] = src[b];
for (u32 b = chunk; b < cluster_bytes; b++) dst[b] = 0;
} else {
if (f32_read_sectors(clba, spc, f32_cluster) != 0) return -5;
for (u32 b = 0; b < chunk; b++) f32_cluster[b] = src[b];
for (u32 b = chunk; b < cluster_bytes; b++) f32_cluster[b] = 0;
if (f32_write_sectors(clba, spc, f32_cluster) != 0) return -6;
}
src += chunk; remaining -= chunk; ci++;
u32 fo = fat_byte_off + cur * 4;
if (fo + 4 > sizeof(f32_disk)) break;
cur = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
/* 更新目录项（所在簇可能不在窗口内，需 RMW） */
u32 entry_clus = found ? found_clus : free_slot_clus;
u32 entry_idx = found ? found_idx : free_idx;
u32 elba = data_lba + (entry_clus - 2) * spc;
u8 *ebuf;
int ebuf_windowed = ((u64)elba * 512 + cluster_bytes <= 256ULL * 512);
if (ebuf_windowed) ebuf = f32_disk + (u64)elba * 512;
else {
if (f32_read_sectors(elba, spc, f32_cluster) != 0) return -12;
ebuf = f32_cluster;
}
f32_dirent *e = &((f32_dirent *)ebuf)[entry_idx];
if (!found) {
for (int i = 0; i < 11; i++) e->name[i] = name11[i];
e->attr = 0x20; e->ntr = 0; e->ctenth = 0; e->ctime = 0; e->cdate = 0; e->adate = 0;
e->wtime = 0; e->wdate = 0;
}
e->chigh = (u16)((first_clus >> 16) & 0xFFFF);
e->clow = (u16)(first_clus & 0xFFFF);
e->fsize = size;
/* 回写 FAT（两份）+ 目录项簇 + 窗口内数据簇 */
for (u32 f = 0; f < bpb->fc; f++) {
u32 flba = fat_lba + f * fat_sectors;
if (f32_write_sectors(flba, fat_sectors, f32_disk + (u64)flba * 512) != 0) return -7;
}
if (ebuf_windowed) {
if (f32_write_sectors(elba, spc, f32_disk + (u64)elba * 512) != 0) return -8;
} else {
if (f32_write_sectors(elba, spc, f32_cluster) != 0) return -8;
}
cur = first_clus; ci = 0;
while (cur >= 2 && cur < 0x0FFFFFF8 && ci < clusters_needed) {
u32 clba = data_lba + (cur - 2) * spc;
if ((u64)clba * 512 + cluster_bytes <= 256ULL * 512) {
if (f32_write_sectors(clba, spc, f32_disk + (u64)clba * 512) != 0) return -9;
}
u32 fo = fat_byte_off + cur * 4;
if (fo + 4 > sizeof(f32_disk)) break;
cur = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
ci++;
}
f32_disk_loaded = 0; /* 下次操作重新加载，避免使用脏缓存 */
return 0;
}
/* 删除根目录下指定 8.3 名文件：清空簇链 + 标记目录项为 0xE5。
* 返回 0 成功，-1 未找到，其他负值失败。 */
static inline int f32_delete_root_file(const char *name11) {
if (f32_disk_load() != 0) return -2;
if (!f32_blk_write) return -10;
if (f32_read_sectors(0, 256, f32_disk) != 0) return -3;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 spc = bpb->spc;
u32 fat_lba = bpb->rsvd;
u32 fat_sectors = bpb->spf;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 root_clus = bpb->root_clus;
u32 root_lba = data_lba + (root_clus - 2) * spc;
u8 *root_buf = f32_disk + (u64)root_lba * 512;
u32 max_entries = (spc * 512) / 32;
f32_dirent *dir = (f32_dirent *)root_buf;
u32 found_idx = 0xFFFFFFFFu;
for (u32 e = 0; e < max_entries; e++) {
if (dir[e].name[0] == 0) break;
if ((u8)dir[e].name[0] == 0xE5) continue;
if (dir[e].attr == 0x0F) continue;
if (dir[e].attr & 0x08) continue;
if (f32_neq11(dir[e].name, name11)) { found_idx = e; break; }
}
if (found_idx == 0xFFFFFFFFu) return -1;
/* 释放簇链 */
u32 cur = (u32)f32_r16((const u8*)&dir[found_idx].clow) | ((u32)f32_r16((const u8*)&dir[found_idx].chigh) << 16);
while (cur >= 2 && cur < 0x0FFFFFF8) {
u32 fo = fat_byte_off + cur * 4;
u32 next = 0;
if (fo + 4 <= sizeof(f32_disk)) next = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
f32_disk[fo] = 0; f32_disk[fo+1] = 0; f32_disk[fo+2] = 0; f32_disk[fo+3] = 0;
cur = next;
}
/* 标记目录项为已删除 */
dir[found_idx].name[0] = (char)0xE5;
/* 回写 FAT + 根目录 */
for (u32 f = 0; f < bpb->fc; f++) {
u32 flba = fat_lba + f * fat_sectors;
if (f32_write_sectors(flba, fat_sectors, f32_disk + (u64)flba * 512) != 0) return -4;
}
if (f32_write_sectors(root_lba, spc, f32_disk + (u64)root_lba * 512) != 0) return -5;
f32_disk_loaded = 0;
return 0;
}
/* 列举根目录条目回调签名：返回 0 继续，非 0 停止 */
typedef int (*f32_list_cb)(const char *name, u32 size, u8 attr, void *user_data);
/* 列出根目录所有文件/目录，调用回调输出。
* 回调返回非 0 立即停止。返回 0 成功（含回调提前停止），负值失败。 */
static inline int f32_list_root(f32_list_cb emit, void *user_data) {
if (f32_disk_load() != 0) return -1;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 spc = bpb->spc;
u32 clus = bpb->root_clus;
while (clus >= 2 && clus < 0x0FFFFFF8) {
u32 lba = data_lba + (clus - 2) * spc;
const u8 *cb;
if ((u64)lba * 512 + (u64)spc * 512 <= 256ULL * 512)
cb = f32_disk + (u64)lba * 512;
else {
if (f32_read_sectors(lba, 8, f32_cluster) != 0) return -4;
cb = f32_cluster;
}
const f32_dirent *dir = (const f32_dirent *)cb;
for (u32 e = 0; e * 32 < spc * 512; e++) {
if (dir[e].name[0] == 0) goto done;
if ((u8)dir[e].name[0] == 0xE5) continue;
if (dir[e].attr == 0x0F) continue;
if (dir[e].attr & 0x08) continue;
char disp[13];
f32_name_from_83(dir[e].name, disp);
if (emit(disp, dir[e].fsize, dir[e].attr, user_data) != 0) goto done;
}
u32 fo = fat_byte_off + clus * 4;
if (fo + 4 > sizeof(f32_disk)) break;
clus = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
done:
return 0;
}
/* ---- 子目录遍历支持（Phase 2.2 fileman 扩展） ---- */
/* 目录条目（供 fileman 等工具使用） */
typedef struct {
char name[13]; /* 8.3 显示名 */
u32 clus; /* 首簇号 */
u32 size; /* 文件大小（目录为 0） */
u8 attr;
u8 is_dir;
u8 has_lfn; /* 1=long_name 字段有效 */
char long_name[260]; /* LFN 长文件名（ASCII） */
} f32_entry;
typedef int (*f32_list_entry_cb)(const f32_entry *e, void *user_data);
/* 列举指定目录簇的内容（含 LFN 长文件名）。
* dir_clus = 0 表示根目录（自动从 BPB 取 root_clus）。
* 回调返回非 0 立即停止。返回 0 成功，负值失败。 */
static inline int f32_list_dir(u32 dir_clus, f32_list_entry_cb emit, void *user_data) {
if (f32_disk_load() != 0) return -1;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 spc = bpb->spc;
u32 clus = (dir_clus == 0) ? bpb->root_clus : dir_clus;
/* LFN 缓冲必须在簇循环外声明：跨簇 LFN 链需要持续存活 */
fat32_lfn_buf lfn;
fat32_lfn_init(&lfn);
while (clus >= 2 && clus < 0x0FFFFFF8) {
u32 lba = data_lba + (clus - 2) * spc;
const u8 *cb;
if ((u64)lba * 512 + (u64)spc * 512 <= 256ULL * 512)
cb = f32_disk + (u64)lba * 512;
else {
if (f32_read_sectors(lba, 8, f32_cluster) != 0) return -4;
cb = f32_cluster;
}
const u8 *entries = (const u8 *)cb;
u32 entry_count = (spc * 512) / 32;
for (u32 e = 0; e < entry_count; e++) {
const u8 *entry = entries + e * 32;
if (entry[0] == 0) goto done;
if ((u8)entry[0] == 0xE5) {
/* 已删除项：清空 LFN 缓冲防止残留污染 */
fat32_lfn_init(&lfn);
continue;
}
const f32_dirent *de = (const f32_dirent *)entry;
int is_short = fat32_lfn_process(&lfn, entry);
if (!is_short) continue; /* LFN 片段，等待短名项 */
if (de->attr & 0x08) continue; /* 卷标 */
/* 跳过 "." 和 ".." 条目 */
if (de->name[0] == '.' && (de->name[1] == ' ' || de->name[1] == '.'))
continue;
f32_entry fe;
f32_name_from_83(de->name, fe.name);
fe.clus = (u32)f32_r16((const u8*)&de->clow) | ((u32)f32_r16((const u8*)&de->chigh) << 16);
fe.size = de->fsize;
fe.attr = de->attr;
fe.is_dir = (de->attr & 0x10) ? 1 : 0;
fe.has_lfn = 0;
fe.long_name[0] = 0;
if (lfn.valid) {
int ln = fat32_lfn_to_ascii(&lfn, fe.long_name, sizeof(fe.long_name));
if (ln >= 0) fe.has_lfn = 1;
}
if (emit(&fe, user_data) != 0) goto done;
/* 短名项处理完毕，重置 LFN 缓冲等待下一条链 */
fat32_lfn_init(&lfn);
}
u32 fo = fat_byte_off + clus * 4;
if (fo + 4 > sizeof(f32_disk)) break;
clus = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
done:
return 0;
}
/* 按首簇号 + 大小读取文件内容到 out_buf。
* out_buf 至少 size 字节容量。返回 0 成功，负值失败。 */
static inline int f32_read_file_by_clus(u32 clus, u32 size, u8 *out_buf, u32 buf_cap) {
if (f32_disk_load() != 0) return -1;
if (size > buf_cap) size = buf_cap;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 spc = bpb->spc;
u32 remaining = size;
u8 *dst = out_buf;
u32 fc = clus;
while (fc >= 2 && fc < 0x0FFFFFF8 && remaining > 0) {
u32 fc_lba = data_lba + (fc - 2) * spc;
u32 fc_bytes = spc * 512;
if (fc_bytes > remaining) fc_bytes = remaining;
const u8 *fb;
if ((u64)fc_lba * 512 + (u64)spc * 512 <= 256ULL * 512)
fb = f32_disk + (u64)fc_lba * 512;
else {
if (f32_read_sectors(fc_lba, 8, f32_cluster) != 0) return -7;
fb = f32_cluster;
}
for (u32 b = 0; b < fc_bytes; b++) dst[b] = fb[b];
dst += fc_bytes; remaining -= fc_bytes;
u32 fo = fat_byte_off + fc * 4;
if (fo + 4 > sizeof(f32_disk)) break;
fc = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
return 0;
}
/* ---- LFN 长文件名支持（Phase 1 SYSTEM/lib 兼容层） ---- */
/* 在指定目录簇中按长文件名查找文件/子目录。
* dir_clus : 起始目录簇（0=根目录）
* long_name : 目标长文件名（ASCII，大小写不敏感）；为 NULL 时仅按 8.3 短名匹配
* is_dir : 1 只匹配子目录，0 只匹配文件
* out_clus : 输出首簇号
* out_size : 输出文件大小
* 返回 0 成功，-1 未找到 / 错误。
* LFN 缓冲跨簇遍历持续存活，支持跨簇边界的 LFN 链。 */
static inline int f32_find_in_dir_lfn(u32 dir_clus, const char *long_name,
int is_dir, u32 *out_clus, u32 *out_size) {
if (f32_disk_load() != 0) return -1;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 data_lba = bpb->rsvd + (u32)bpb->fc * bpb->spf;
u32 fat_byte_off = bpb->rsvd * 512;
u32 spc = bpb->spc;
u32 clus = (dir_clus == 0) ? bpb->root_clus : dir_clus;
/* LFN 缓冲必须在簇循环外声明：跨簇 LFN 链需要持续存活 */
fat32_lfn_buf lfn;
fat32_lfn_init(&lfn);
while (clus >= 2 && clus < 0x0FFFFFF8) {
u32 lba = data_lba + (clus - 2) * spc;
const u8 *cb;
if ((u64)lba * 512 + (u64)spc * 512 <= 256ULL * 512)
cb = f32_disk + (u64)lba * 512;
else {
if (f32_read_sectors(lba, 8, f32_cluster) != 0) return -4;
cb = f32_cluster;
}
const u8 *entries = (const u8 *)cb;
u32 entry_count = (spc * 512) / 32;
for (u32 e = 0; e < entry_count; e++) {
const u8 *entry = entries + e * 32;
if (entry[0] == 0) goto not_found;
if ((u8)entry[0] == 0xE5) {
fat32_lfn_init(&lfn);
continue;
}
const f32_dirent *de = (const f32_dirent *)entry;
int is_short = fat32_lfn_process(&lfn, entry);
if (!is_short) continue; /* LFN 片段 */
if (de->attr & 0x08) {
fat32_lfn_init(&lfn);
continue; /* 卷标 */
}
int entry_is_dir = (de->attr & 0x10) ? 1 : 0;
if (entry_is_dir != is_dir) {
fat32_lfn_init(&lfn);
continue;
}
/* 先尝试 LFN 长名匹配，再回退 8.3 匹配 */
int matched = 0;
if (lfn.valid && long_name) {
char ascii[FAT32_LFN_MAX];
int n = fat32_lfn_to_ascii(&lfn, ascii, sizeof(ascii));
if (n >= 0 && fat32_lfn_streq_ci(ascii, long_name)) matched = 1;
}
if (!matched && long_name) {
/* 用短名构造 8.3 显示串与目标比较（大小写不敏感） */
char short_disp[13];
fat32_lfn_short_to_str((const u8 *)de->name, short_disp);
if (fat32_lfn_streq_ci(short_disp, long_name)) matched = 1;
}
if (matched) {
*out_clus = (u32)f32_r16((const u8 *)&de->clow) |
((u32)f32_r16((const u8 *)&de->chigh) << 16);
*out_size = de->fsize;
return 0;
}
fat32_lfn_init(&lfn);
}
u32 fo = fat_byte_off + clus * 4;
if (fo + 4 > sizeof(f32_disk)) break;
clus = f32_r32(f32_disk + fo) & 0x0FFFFFFF;
}
not_found:
return -1;
}
/* 按 '/' 分隔的路径定位最终目录簇。
* path : 路径（如 "lib" 或 "system/deshab64"），每段为长文件名
* out_clus : 输出目录簇号
* 返回 0 成功，-1 失败。空路径返回根目录簇。 */
static inline int f32_find_path_dir_lfn(const char *path, u32 *out_clus) {
if (!path || !out_clus) return -1;
if (f32_disk_load() != 0) return -1;
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
u32 cur = bpb->root_clus;
u32 pos = 0;
u32 path_len = 0;
while (path[path_len]) path_len++;
/* 空路径或仅 "/" -> 根目录 */
if (path_len == 0 || (path_len == 1 && path[0] == '/')) {
*out_clus = cur;
return 0;
}
while (pos < path_len) {
/* 跳过前导 '/' */
while (pos < path_len && path[pos] == '/') pos++;
if (pos >= path_len) break;
/* 提取路径组件（到下一个 '/' 或结尾） */
char comp[260];
u32 ci = 0;
while (pos < path_len && path[pos] != '/' && ci + 1 < sizeof(comp)) {
comp[ci++] = path[pos++];
}
comp[ci] = 0;
if (ci == 0) continue;
u32 sub_clus = 0, sub_size = 0;
if (f32_find_in_dir_lfn(cur, comp, 1, &sub_clus, &sub_size) != 0) return -1;
cur = sub_clus;
}
*out_clus = cur;
return 0;
}
/* 按长路径读取文件到 f32_data 缓冲。
* path : '/' 分隔的长文件名路径（如 "lib/libtest.so"）
* out_data : 返回 f32_data 内的指针
* out_size : 返回文件大小
* 返回 0 成功，负值失败。 */
static inline int f32_read_path_lfn(const char *path, u8 **out_data, u32 *out_size) {
if (!path || !out_data || !out_size) return -1;
if (f32_disk_load() != 0) return -1;
/* 分离目录部分与文件名 */
u32 path_len = 0;
while (path[path_len]) path_len++;
u32 last_slash = 0xFFFFFFFFu;
for (u32 i = 0; i < path_len; i++) {
if (path[i] == '/') last_slash = i;
}
const char *fname = (last_slash == 0xFFFFFFFFu) ? path : path + last_slash + 1;
/* 定位父目录簇 */
u32 dir_clus = 0;
if (last_slash == 0xFFFFFFFFu) {
/* 无 '/' -> 根目录 */
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
dir_clus = bpb->root_clus;
} else {
char dirpath[260];
u32 dn = last_slash;
if (dn >= sizeof(dirpath)) dn = sizeof(dirpath) - 1;
for (u32 i = 0; i < dn; i++) dirpath[i] = path[i];
dirpath[dn] = 0;
if (f32_find_path_dir_lfn(dirpath, &dir_clus) != 0) return -2;
}
/* 在父目录中查找文件 */
u32 file_clus = 0, file_size = 0;
if (f32_find_in_dir_lfn(dir_clus, fname, 0, &file_clus, &file_size) != 0) return -3;
if (file_size > sizeof(f32_data)) return -4;
/* 读取文件数据 */
if (f32_read_file_by_clus(file_clus, file_size, f32_data, sizeof(f32_data)) != 0) return -5;
*out_data = f32_data;
*out_size = file_size;
return 0;
}
/* 按长路径写入文件（存在则替换，不存在则在父目录中新建 8.3 项）。
* path : '/' 分隔路径（如 "system/deshab64/FUCK"），文件名段必须可转 8.3
* 返回 0 成功，负值失败（-6 = 文件名不是合法 8.3）。 */
static inline int f32_write_path_lfn(const char *path, const u8 *data, u32 size) {
if (!path || !data) return -1;
if (f32_disk_load() != 0) return -1;
u32 path_len = 0;
while (path[path_len]) path_len++;
u32 last_slash = 0xFFFFFFFFu;
for (u32 i = 0; i < path_len; i++) {
if (path[i] == '/') last_slash = i;
}
const char *fname = (last_slash == 0xFFFFFFFFu) ? path : path + last_slash + 1;
u32 dir_clus = 0;
if (last_slash == 0xFFFFFFFFu) {
const f32_bpb *bpb = (const f32_bpb *)f32_disk;
dir_clus = bpb->root_clus;
} else {
char dirpath[260];
u32 dn = last_slash;
if (dn >= sizeof(dirpath)) dn = sizeof(dirpath) - 1;
for (u32 i = 0; i < dn; i++) dirpath[i] = path[i];
dirpath[dn] = 0;
if (f32_find_path_dir_lfn(dirpath, &dir_clus) != 0) return -2;
}
char name11[11];
if (f32_name_to_83(fname, name11) != 0) return -6;
return f32_write_file_in_dir(dir_clus, name11, data, size);
}
#endif /* DESHAB_FAT32_H */