feat: FS-E strict filesystem mode - ext4 rw driver, FAT32 big-disk fix, forced re-login

- CODE/dsk/ext4.c: minimal full ext4 read/write (GPT probe, feature gate,
  extent depth 0/1 rw, block/inode alloc-free, dir insert, write-verify);
  boot selftest PASS on p2. Unsupported features panic (FS-E2x), zero fallback.
- DSK fat32 write: on-demand FAT entry RMW + chunked free-cluster scan
  (fixes "no free clusters" on 5.3G ESP); rec_len shrink offset (+4) and
  chunk alignment fixes. USER.CONF write-verify ok, firstInit flip ok.
- First-boot: wizard -> persist -> forced login (FS-E06 if skipped/failed)
  -> desktop. login.elf loaded via system/user/use fallback.
- FirstInit network page: Connect now panics NET-E01 (no wlan stack);
  Save (config only) is the only path forward.
- FirstInit/DSK fatal: ohMyLogo lotus fatal screen (NET-E01 / FS-E series).
- Boot screen: Logo.png image removed, "DESHAB P01" text centered only;
  dcp/xj logos regenerated from TEXTURES/.
- run_qemu.bat: main GPT image on SATA ide.0 (AHCI provider must see ext4).

CODE/UTSM/dkm/kernel_api.c

@@ -3,6 +3,9 @@
 #include <utsm/idt.h>
 #include <utsm/net.h>
 #include <utsm/mm.h>
+#include <utsm/dma.h>
+#include <utsm/drr.h>
+#include <utsm/utrw.h>
 #include <utsm/panic.h>
 
 static void dkm_api_info(const char *msg) {
@@ -81,13 +84,57 @@ static dkm_kernel_api g_kernel_api = {
     .mm_map_mmio = 0,
     .mm_unmap_mmio = 0,
     .register_apic_eoi = 0,
-    .sched = 0
+    .sched = 0,
+    .kapi = 0
 };
 
 const dkm_kernel_api *dkm_get_kernel_api(void) {
     return &g_kernel_api;
 }
 
+/* ===================================================================
+ *  D3: 按名导出表（kapi）——自由也要有地图
+ * =================================================================== */
+
+static const dkm_kapi_entry g_kapi_entries[] = {
+    { "log.info",           (void *)dkm_api_info },
+    { "log.warn",           (void *)dkm_api_warn },
+    { "log.error",          (void *)dkm_api_error },
+    { "log.panic",          (void *)dkm_api_panic },
+    { "dma.alloc_pages",    (void *)dma_alloc_pages },
+    { "irq.register",       (void *)irq_register },
+    { "irq.vector_alloc",   (void *)irq_vector_alloc },
+    { "irq.vector_free",    (void *)irq_vector_free },
+    { "mm.map_mmio",        (void *)mm_map_mmio },
+    { "mm.unmap_mmio",      (void *)mm_unmap_mmio },
+    { "apic.register_eoi",  (void *)idt_register_apic_eoi },
+    { "drr.snapshot_dirty", (void *)drr_ckpt_snapshot_dirty },
+    { "drr.rollback_pages", (void *)drr_rollback_pages },
+    { "utrw.debug_dump",    (void *)utrw_debug_dump_page },
+};
+
+static int kapi_lookup(const char *name, void **out_fn) {
+    if (!name) return -1;
+    for (u32 i = 0; i < sizeof(g_kapi_entries) / sizeof(g_kapi_entries[0]); i++) {
+        const dkm_kapi_entry *e = &g_kapi_entries[i];
+        const char *a = e->name, *b = name;
+        while (*a && *a == *b) { a++; b++; }
+        if (*a == 0 && *b == 0) {
+            if (out_fn) *out_fn = e->fn;
+            return 0;
+        }
+    }
+    return -1;
+}
+
+static const dkm_kapi_table g_kapi_table = {
+    .magic = DKM_KAPI_MAGIC,
+    .version = DKM_KAPI_VERSION,
+    .count = sizeof(g_kapi_entries) / sizeof(g_kapi_entries[0]),
+    .entries = g_kapi_entries,
+    .lookup = kapi_lookup,
+};
+
 #include "../arch/x86_64/limine.h"
 extern volatile struct limine_rsdp_request g_rsdp_request;
 extern volatile struct limine_framebuffer_request g_fb_request;
@@ -127,4 +174,6 @@ void dkm_fill_platform_info(void) {
     /* B7 阶段3: 暴露动态向量分配器（MSI/MSI-X 设备驱动使用） */
     g_kernel_api.irq_vector_alloc = irq_vector_alloc;
     g_kernel_api.irq_vector_free = irq_vector_free;
+    /* D3: 按名导出表挂入 kernel_api（尾部追加，ABI 兼容） */
+    g_kernel_api.kapi = &g_kapi_table;
 }

CODE/UTSM/dkm/kernel_api.d

@@ -1,7 +1,9 @@
 dkm/kernel_api.o: dkm\kernel_api.c include\utsm\dkm.h \
   include\utsm\types.h include\utsm\dma.h include\utsm\block.h \
   include\utsm\net.h include\utsm\paging.h include\utsm\log.h \
-  include\utsm\idt.h include\utsm\mm.h include\utsm\panic.h \
+  include\utsm\idt.h include\utsm\mm.h include\utsm\drr.h \
+  include\utsm\config.h include\utsm\utrw.h include\utsm\status.h \
+  include\utsm\capability.h include\utsm\panic.h \
   dkm\..\arch\x86_64\limine.h
 include\utsm\dkm.h:
 include\utsm\types.h:
@@ -12,5 +14,10 @@ include\utsm\paging.h:
 include\utsm\log.h:
 include\utsm\idt.h:
 include\utsm\mm.h:
+include\utsm\drr.h:
+include\utsm\config.h:
+include\utsm\utrw.h:
+include\utsm\status.h:
+include\utsm\capability.h:
 include\utsm\panic.h:
 dkm\..\arch\x86_64\limine.h:

CODE/UTSM/include/utsm/dkm.h

@@ -33,6 +33,30 @@
 struct dkm_kernel_api;
 struct dkm_driver_handle;
 
+/* ===================================================================
+ *  D3: 内核 API 按名导出表（kapi）
+ *
+ *  "自由也要有地图。" 固定偏移 struct ABI 之外的按名查找层：
+ *  驱动/用户态可枚举内核服务并按名取函数指针。
+ *  通过 kernel_api 尾部追加的 ->kapi 指针访问（ABI 兼容）。
+ * =================================================================== */
+typedef struct {
+    const char *name;   /* 如 "log.info"、"dma.alloc_pages" */
+    void *fn;           /* 服务函数指针（签名见对应服务头） */
+} dkm_kapi_entry;
+
+typedef struct {
+    u32 magic;          /* DKM_KAPI_MAGIC */
+    u32 version;        /* DKM_KAPI_VERSION */
+    u32 count;          /* entries 数量 */
+    const dkm_kapi_entry *entries;
+    /* 按名查找：命中返回 0 并写 out_fn；未命中 -1 */
+    int (*lookup)(const char *name, void **out_fn);
+} dkm_kapi_table;
+
+#define DKM_KAPI_MAGIC   0x4b415049u  /* "KAPI" */
+#define DKM_KAPI_VERSION 1u
+
 typedef struct dkm_driver_desc {
     u32 magic;
     u16 abi_version;
@@ -133,6 +157,9 @@ typedef struct dkm_kernel_api {
      * 驱动可用：task_create/uptime/sleep/current_task_slot。
      * DSK 以 api+0xA8 硬偏移读 block 的约定不受影响（仅尾部追加）。 */
     const utsm_sched_api *sched;
+    /* D3: 按名导出表（尾部追加，ABI 兼容）。驱动/用户态枚举内核服务并
+     * 按名取函数指针；固定偏移 struct 字段不受影响。 */
+    const dkm_kapi_table *kapi;
 } dkm_kernel_api;
 
 typedef enum dkm_driver_state {
@@ -160,6 +187,7 @@ typedef struct dkm_builtin_driver {
 void dkm_init(void);
 /* D4: 设置当前驱动日志颜色上下文（driver_init 前设置，返回后清 0） */
 void dkm_log_set_driver(const char *name);
+
 int dkm_load_builtin(const dkm_builtin_driver *driver);
 void dkm_scan_boot_modules(void);
 void dsm_load_by_manifest(void);

CODE/UTSM/kernel/gen_panic_logo.py

@@ -1,9 +1,9 @@
-#!/usr/bin/env python3
+#!/usr/bin/env python3
-"""Generate panic_logo_data.inc from ohMyLogo.png (root).
+"""Generate RGBA8888 C array from a PNG (panic screen / login intro logo).
 
-- Downscale logo to 384px wide (keep aspect), RGBA8888
+- Downscale logo to target width (keep aspect), RGBA8888
-- Sample the 4 corners (averaged) as the panic-screen background color
+- Sample the 4 corners (averaged) as background color
-Usage: python gen_panic_logo.py <ohMyLogo.png> <panic_logo_data.inc>
+Usage: python gen_panic_logo.py <src.png> <out.c> [target_width]
 """
 import sys
 from PIL import Image
@@ -16,10 +16,11 @@ TARGET_W = 384
 def main() -> None:
     src = sys.argv[1] if len(sys.argv) > 1 else SRC
     dst = sys.argv[2] if len(sys.argv) > 2 else DST
+    target_w = int(sys.argv[3]) if len(sys.argv) > 3 else TARGET_W
     im = Image.open(src).convert("RGBA")
     w0, h0 = im.size
-    scale = TARGET_W / w0
+    scale = target_w / w0
-    w, h = TARGET_W, max(1, round(h0 * scale))
+    w, h = target_w, max(1, round(h0 * scale))
     im = im.resize((w, h), Image.LANCZOS)
     px = im.load()
 

CODE/UTSM/test/utsm_selftest.c

@@ -1,6 +1,8 @@
 #include <utsm/utsm.h>
 #include <utsm/pckc.h>
 #include <utsm/crypto.h>
+#include <utsm/dma.h>
+#include <utsm/dkm.h>
 #include <utsm/log.h>
 #include <utsm/segment.h>
 #include <utsm/arena.h>
@@ -190,6 +192,38 @@ int utsm_selftest_run(void) {
         log_info("[UTSM] selftest unsealed segment ok (plain storage)");
     }
 
+    /* ==== D3: 按名导出表（kapi）——按名取服务并调用 ==== */
+    {
+        const dkm_kernel_api *api = dkm_get_kernel_api();
+        if (!api->kapi || api->kapi->magic != DKM_KAPI_MAGIC) {
+            log_error("[UTSM] selftest kapi table missing");
+            return UTSM_ERR_INVALID;
+        }
+        void *fn = 0;
+        if (api->kapi->lookup("log.info", &fn) != 0) {
+            log_error("[UTSM] selftest kapi lookup log.info failed");
+            return UTSM_ERR_INVALID;
+        }
+        void (*klog)(const char *) = (void (*)(const char *))fn;
+        klog("[UTSM] selftest kapi: log.info via export table");
+        if (api->kapi->lookup("dma.alloc_pages", &fn) != 0) {
+            log_error("[UTSM] selftest kapi lookup dma failed");
+            return UTSM_ERR_INVALID;
+        }
+        int (*kalloc)(u64, u64, u64, dkm_dma_buffer *) = (int (*)(u64, u64, u64, dkm_dma_buffer *))fn;
+        dkm_dma_buffer kbuf;
+        if (kalloc(1, 4096, 0xFFFFFFFFULL, &kbuf) != 0 || !kbuf.virt) {
+            log_error("[UTSM] selftest kapi dma alloc failed");
+            return UTSM_ERR_INVALID;
+        }
+        if (api->kapi->lookup("no.such.service", &fn) == 0) {
+            log_error("[UTSM] selftest kapi negative lookup failed");
+            return UTSM_ERR_INVALID;
+        }
+        log_hex64("[UTSM] selftest kapi entries=", api->kapi->count);
+        log_info("[UTSM] selftest kapi ok");
+    }
+
     /* ==== SCHED-1: O(1) runqueue 语义（合成 TCB，协作式，无 tick） ==== */
     /* ==== SCHED-1 + SCHED-2: runqueue / block-wake（tick 竞态保护） ==== */
     {

CODE/UTSM/test/utsm_selftest.d

@@ -4,9 +4,10 @@ test/utsm_selftest.o: test\utsm_selftest.c include\utsm\utsm.h \
   include\utsm\segment.h include\utsm\dirty.h include\utsm\utrw.h \
   include\utsm\vmm.h include\utsm\linux_loader.h include\utsm\ipc_shm.h \
   ..\utsm-ipc\ipc_proto.h include\utsm\hypercall.h include\utsm\pckc.h \
-  include\utsm\crypto.h include\utsm\log.h include\utsm\arena.h \
+  include\utsm\crypto.h include\utsm\dma.h include\utsm\dkm.h \
-  include\utsm\drr.h include\utsm\sched_ext.h include\utsm\sched.h \
+  include\utsm\block.h include\utsm\net.h include\utsm\paging.h \
-  test\chacha_kat.inc
+  include\utsm\log.h include\utsm\arena.h include\utsm\drr.h \
+  include\utsm\sched_ext.h include\utsm\sched.h test\chacha_kat.inc
 include\utsm\utsm.h:
 include\utsm\types.h:
 include\utsm\status.h:
@@ -24,6 +25,11 @@ include\utsm\ipc_shm.h:
 include\utsm\hypercall.h:
 include\utsm\pckc.h:
 include\utsm\crypto.h:
+include\utsm\dma.h:
+include\utsm\dkm.h:
+include\utsm\block.h:
+include\utsm\net.h:
+include\utsm\paging.h:
 include\utsm\log.h:
 include\utsm\arena.h:
 include\utsm\drr.h:

CODE/dsk/ext4.c

@@ -0,0 +1,737 @@
+/* ext4.c — minimal full read-write ext4 driver for DSK (p2 data partition)
+ * 见 ext4.h 头注释。严格错误策略：任何错误 fatal panic，零降级。 */
+
+#include "ext4.h"
+
+/* ---------------- IO 回调与日志 ---------------- */
+static ext4_block_read_fn  rd_fn;
+static ext4_block_write_fn wr_fn;
+static void (*fatalf)(const char *sym);
+static void (*logl_fn)(const char *s);
+static void (*logh_fn)(const char *p, ext4_u64 v);
+
+/* ---------------- 小端读取 ---------------- */
+static ext4_u16 r16(const ext4_u8 *p) { return (ext4_u16)(p[0] | (p[1] << 8)); }
+static ext4_u32 r32(const ext4_u8 *p) {
+    return (ext4_u32)p[0] | ((ext4_u32)p[1] << 8) |
+           ((ext4_u32)p[2] << 16) | ((ext4_u32)p[3] << 24);
+}
+static ext4_u64 r64(const ext4_u8 *p) { return (ext4_u64)r32(p) | ((ext4_u64)r32(p + 4) << 32); }
+static void w32(ext4_u8 *p, ext4_u32 v) { p[0]=v&0xFF; p[1]=(v>>8)&0xFF; p[2]=(v>>16)&0xFF; p[3]=(v>>24)&0xFF; }
+static void w16(ext4_u8 *p, ext4_u16 v) { p[0]=v&0xFF; p[1]=(v>>8)&0xFF; }
+
+/* ---------------- 状态 ---------------- */
+static ext4_u64 g_part_lba;        /* ext4 分区起始 LBA */
+static ext4_u32 g_block_size;      /* 4096 */
+static ext4_u32 g_sec_per_block;   /* 8 */
+static ext4_u32 g_inodes_per_group;
+static ext4_u32 g_blocks_per_group;
+static ext4_u32 g_inode_size;
+static ext4_u32 g_first_data_block;
+static ext4_u32 g_desc_size;
+static ext4_u32 g_group_count;
+static ext4_u64 g_blocks_count;
+static ext4_u8  g_sb[1024];        /* superblock（1024B） */
+static ext4_u8  g_gdt[16384];      /* 组描述符表缓存（≤512 组 × 32B） */
+#define EXT4_MAX_FILE (8u * 1024u * 1024u)
+static ext4_u8  g_fdata[EXT4_MAX_FILE];   /* 读文件静态缓冲 */
+static ext4_u8  g_blk[4096];       /* 元数据块 scratch（位图/目录/inode 表） */
+static ext4_u8  g_blk2[4096];      /* 第二 scratch（inode 表与目录并行操作） */
+
+#define EXT4_SUPER_MAGIC  0xEF53
+#define EXT4_ROOT_INO     2
+
+/* incompat feature 位 */
+#define INCOMPAT_FILETYPE      0x0002u
+#define INCOMPAT_RECOVER       0x0004u
+#define INCOMPAT_META_BG       0x0010u
+#define INCOMPAT_EXTENTS       0x0040u
+#define INCOMPAT_64BIT         0x0080u
+#define INCOMPAT_MMP           0x0100u
+#define INCOMPAT_FLEX_BG       0x0200u
+#define INCOMPAT_METADATA_CSUM 0x0400u
+#define INCOMPAT_INLINE_DATA   0x8000u
+#define INCOMPAT_SUPPORTED (INCOMPAT_FILETYPE | INCOMPAT_EXTENTS | INCOMPAT_FLEX_BG)
+
+/* inode flags */
+#define EXT4_NODUMP_FL 0x00000004u
+#define EXT4_EXTENTS_FL 0x00080000u
+
+/* ---------------- 底层 IO（失败即 fatal） ---------------- */
+static void rd_sec(ext4_u64 lba, ext4_u32 cnt, void *buf) {
+    if (rd_fn(0, lba, cnt, buf) != 0) fatalf("FS-E20 EXT4 BLOCK READ FAILED");
+}
+static void wr_sec(ext4_u64 lba, ext4_u32 cnt, const void *buf) {
+    if (wr_fn(0, lba, cnt, buf) != 0) fatalf("FS-E21 EXT4 BLOCK WRITE FAILED");
+}
+/* 块号 → LBA */
+static ext4_u64 blk_lba(ext4_u32 blk) { return g_part_lba + (ext4_u64)blk * g_sec_per_block; }
+static void rd_blk(ext4_u32 blk, void *buf)  { rd_sec(blk_lba(blk), g_sec_per_block, buf); }
+static void wr_blk(ext4_u32 blk, const void *buf) { wr_sec(blk_lba(blk), g_sec_per_block, buf); }
+
+/* ---------------- GPT 探测 ext4 分区 ---------------- */
+static void gpt_find_ext4(void) {
+    ext4_u8 gpt[512];
+    rd_sec(1, 1, gpt);
+    if (gpt[0] != 'E' || gpt[1] != 'F' || gpt[2] != 'I' || gpt[3] != ' ')
+        fatalf("FS-E22 GPT SIGNATURE NOT FOUND");
+    ext4_u64 ent_lba = r64(gpt + 0x48);
+    ext4_u32 ent_num = r32(gpt + 0x50);
+    ext4_u32 ent_sz  = r32(gpt + 0x54);
+    if (ent_sz < 128 || ent_num == 0 || ent_num > 128)
+        fatalf("FS-E23 GPT ENTRY TABLE INVALID");
+    static ext4_u8 ents[128 * 128];
+    rd_sec(ent_lba, (ent_num * ent_sz + 511) / 512, ents);
+    for (ext4_u32 i = 0; i < ent_num; i++) {
+        const ext4_u8 *e = ents + i * ent_sz;
+        static const ext4_u8 linux_guid[16] = {
+            0xAF,0x3D,0xC6,0x0F, 0x83,0x84, 0x72,0x47,
+            0x8E,0x79, 0x3D,0x69,0xD8,0x47,0x7D,0xE4 };
+        int is_linux = 1;
+        for (int j = 0; j < 16; j++) if (e[j] != linux_guid[j]) { is_linux = 0; break; }
+        if (!is_linux) continue;
+        ext4_u64 start = r64(e + 0x20);
+        if (start == 0) continue;
+        /* 探测 superblock 魔数（offset 1024 处 0xEF53） */
+        ext4_u8 sb_probe[1024];
+        rd_sec(start + 2, 2, sb_probe);
+        if (r16(sb_probe + 0x38) == EXT4_SUPER_MAGIC) {
+            g_part_lba = start;
+            for (int j = 0; j < 1024; j++) g_sb[j] = sb_probe[j];
+            return;
+        }
+    }
+    fatalf("FS-E24 EXT4 PARTITION NOT FOUND IN GPT");
+}
+
+/* ---------------- 挂载 ---------------- */
+int ext4_mount(ext4_block_read_fn rd, ext4_block_write_fn wr,
+               void (*fatal)(const char *sym), void (*logl)(const char *s),
+               void (*logh)(const char *p, ext4_u64 v)) {
+    rd_fn = rd; wr_fn = wr; fatalf = fatal; logl_fn = logl; logh_fn = logh;
+    gpt_find_ext4();
+    logh_fn("[EXT4] partition LBA=", g_part_lba);
+    if (r16(g_sb + 0x38) != EXT4_SUPER_MAGIC) fatalf("FS-E25 SUPERBLOCK MAGIC MISMATCH");
+
+    ext4_u32 log_bs = r32(g_sb + 0x18);
+    if (log_bs != 2) fatalf("FS-E26 UNSUPPORTED BLOCKSIZE (need 4096)");
+    g_block_size = 4096; g_sec_per_block = 8;
+
+    g_first_data_block   = r32(g_sb + 0x14);
+    g_blocks_per_group   = r32(g_sb + 0x20);
+    g_inodes_per_group   = r32(g_sb + 0x28);
+    g_inode_size         = r16(g_sb + 0x58);
+    g_desc_size          = r16(g_sb + 0xFE);   /* s_desc_size @ 0xFE（0xFA 是 hash_seed） */
+    if (g_desc_size < 32) g_desc_size = 32;
+    g_blocks_count       = r32(g_sb + 0x04);
+
+    ext4_u32 incompat = r32(g_sb + 0x60);
+    if (incompat & INCOMPAT_RECOVER)        fatalf("FS-E27 JOURNAL DIRTY (RECOVER SET)");
+    if (incompat & (INCOMPAT_64BIT | INCOMPAT_METADATA_CSUM | INCOMPAT_MMP |
+                    INCOMPAT_INLINE_DATA | INCOMPAT_META_BG))
+        fatalf("FS-E28 UNSUPPORTED EXT4 FEATURE");
+    if (incompat & ~INCOMPAT_SUPPORTED)     fatalf("FS-E28 UNSUPPORTED EXT4 FEATURE");
+
+    ext4_u16 state = r16(g_sb + 0x3A);
+    if (state != 1) fatalf("FS-E29 FILESYSTEM NOT CLEAN");
+
+    if (g_inode_size != 256) fatalf("FS-E2A UNSUPPORTED INODE SIZE");
+    if (g_first_data_block != 0) fatalf("FS-E2B UNEXPECTED FIRST DATA BLOCK");
+    if (g_blocks_per_group != 32768) fatalf("FS-E2C UNEXPECTED BLOCKS PER GROUP");
+
+    g_group_count = (ext4_u32)((g_blocks_count - g_first_data_block + g_blocks_per_group - 1) / g_blocks_per_group);
+    if (g_group_count == 0) g_group_count = 1;
+    if ((ext4_u64)g_group_count * g_desc_size > sizeof(g_gdt))
+        fatalf("FS-E2D GROUP DESCRIPTOR TABLE OVERFLOW");
+    /* 组描述符表位于 block 1（first_data_block==0 时） */
+    rd_blk(1, g_gdt);
+    logh_fn("[EXT4] groups=", g_group_count);
+
+    /* mount 即写 sb（mnt_count++），验证写通道，失败即 panic */
+    ext4_u16 mnt = r16(g_sb + 0x34);
+    w16(g_sb + 0x34, (ext4_u16)(mnt + 1));
+    {
+        ext4_u8 sbw[1024];
+        for (int i = 0; i < 1024; i++) sbw[i] = g_sb[i];
+        wr_sec(g_part_lba + 2, 2, sbw);
+        ext4_u8 sbr[1024];
+        rd_sec(g_part_lba + 2, 2, sbr);
+        if (r16(sbr + 0x34) != (ext4_u16)(mnt + 1)) fatalf("FS-E2E SB WRITE VERIFY FAILED");
+    }
+    logl_fn("[EXT4] mounted");
+    return 0;
+}
+
+/* ---------------- 组描述符访问 ---------------- */
+/* 32B 组描述符：0x00 block_bitmap, 0x04 inode_bitmap, 0x08 inode_table,
+ * 0x0C free_blocks_lo(u16), 0x0E free_inodes_lo(u16), 0x10 used_dirs(u16) */
+static ext4_u32 gd_block_bitmap(ext4_u32 g)  { return r32(g_gdt + (ext4_u64)g * g_desc_size + 0x00); }
+static ext4_u32 gd_inode_bitmap(ext4_u32 g)  { return r32(g_gdt + (ext4_u64)g * g_desc_size + 0x04); }
+static ext4_u32 gd_inode_table(ext4_u32 g)   { return r32(g_gdt + (ext4_u64)g * g_desc_size + 0x08); }
+static ext4_u16 gd_free_blocks(ext4_u32 g)   { return r16(g_gdt + (ext4_u64)g * g_desc_size + 0x0C); }
+static ext4_u16 gd_free_inodes(ext4_u32 g)   { return r16(g_gdt + (ext4_u64)g * g_desc_size + 0x0E); }
+
+static void gd_set_free_blocks(ext4_u32 g, ext4_u16 v) { w16(g_gdt + (ext4_u64)g * g_desc_size + 0x0C, v); }
+static void gd_set_free_inodes(ext4_u32 g, ext4_u16 v) { w16(g_gdt + (ext4_u64)g * g_desc_size + 0x0E, v); }
+
+static void gdt_flush(void) { wr_blk(1, g_gdt); }
+
+/* ---------------- inode 读写 ---------------- */
+/* inode 结构关键偏移（256B）：
+ * 0x00 mode 0x02 uid 0x04 size_lo 0x1A links 0x1C blocks_lo(512B)
+ * 0x20 flags 0x28 i_block[15] 0x6C size_high */
+static void read_inode(ext4_u32 ino, ext4_u8 *dst) {
+    if (ino < 2) fatalf("FS-E2F BAD INODE NUMBER");
+    ext4_u32 g = (ino - 1) / g_inodes_per_group;
+    ext4_u32 idx = (ino - 1) % g_inodes_per_group;
+    ext4_u32 table = gd_inode_table(g);
+    ext4_u32 per_block = g_block_size / g_inode_size;   /* 16 */
+    rd_blk(table + idx / per_block, g_blk);
+    for (ext4_u32 i = 0; i < g_inode_size; i++)
+        dst[i] = g_blk[(ext4_u64)(idx % per_block) * g_inode_size + i];
+}
+static void write_inode(ext4_u32 ino, const ext4_u8 *src) {
+    if (ino < 2) fatalf("FS-E2F BAD INODE NUMBER");
+    ext4_u32 g = (ino - 1) / g_inodes_per_group;
+    ext4_u32 idx = (ino - 1) % g_inodes_per_group;
+    ext4_u32 table = gd_inode_table(g);
+    ext4_u32 per_block = g_block_size / g_inode_size;
+    rd_blk(table + idx / per_block, g_blk);
+    for (ext4_u32 i = 0; i < g_inode_size; i++)
+        g_blk[(ext4_u64)(idx % per_block) * g_inode_size + i] = src[i];
+    wr_blk(table + idx / per_block, g_blk);
+}
+
+/* ---------------- 块分配/回收 ---------------- */
+static void sb_dec_free_blocks(void) {
+    ext4_u32 v = r32(g_sb + 0x0C);
+    if (v == 0) fatalf("FS-E30 FREE BLOCK COUNT UNDERFLOW");
+    w32(g_sb + 0x0C, v - 1);
+    /* sb 稍后统一 flush（写文件末尾），避免多次 1KB IO */
+}
+static void sb_inc_free_blocks(void) {
+    w32(g_sb + 0x0C, r32(g_sb + 0x0C) + 1);
+}
+static void sb_flush(void) {
+    ext4_u8 sbw[1024];
+    for (int i = 0; i < 1024; i++) sbw[i] = g_sb[i];
+    wr_sec(g_part_lba + 2, 2, sbw);
+}
+
+/* 分配 1 个数据块，返回物理块号。立即落盘位图与组描述符。 */
+static ext4_u32 block_alloc(void) {
+    for (ext4_u32 g = 0; g < g_group_count; g++) {
+        if (gd_free_blocks(g) == 0) continue;
+        rd_blk(gd_block_bitmap(g), g_blk);
+        for (ext4_u32 byte = 0; byte < g_block_size; byte++) {
+            if (g_blk[byte] == 0xFF) continue;
+            for (int bit = 0; bit < 8; bit++) {
+                if (g_blk[byte] & (1u << bit)) continue;
+                ext4_u64 blk = (ext4_u64)g * g_blocks_per_group + (ext4_u64)byte * 8 + bit;
+                if (blk >= g_blocks_count) fatalf("FS-E31 BLOCK ALLOC OUT OF RANGE");
+                g_blk[byte] |= (ext4_u8)(1u << bit);
+                wr_blk(gd_block_bitmap(g), g_blk);
+                gd_set_free_blocks(g, (ext4_u16)(gd_free_blocks(g) - 1));
+                gdt_flush();
+                sb_dec_free_blocks();
+                /* 新块需清零（目录块/文件尾块） */
+                for (ext4_u32 i = 0; i < g_block_size; i++) g_blk2[i] = 0;
+                wr_blk((ext4_u32)blk, g_blk2);
+                return (ext4_u32)blk;
+            }
+        }
+    }
+    fatalf("FS-E32 NO FREE BLOCKS");
+    return 0;
+}
+
+/* 回收 1 个块 */
+static void block_free(ext4_u32 blk) {
+    ext4_u32 g = (ext4_u32)(blk / g_blocks_per_group);
+    ext4_u32 off = (ext4_u32)(blk % g_blocks_per_group);
+    rd_blk(gd_block_bitmap(g), g_blk);
+    if (!(g_blk[off / 8] & (1u << (off % 8)))) fatalf("FS-E33 DOUBLE FREE DETECTED");
+    g_blk[off / 8] &= (ext4_u8)~(1u << (off % 8));
+    wr_blk(gd_block_bitmap(g), g_blk);
+    gd_set_free_blocks(g, (ext4_u16)(gd_free_blocks(g) + 1));
+    gdt_flush();
+    sb_inc_free_blocks();
+}
+
+/* ---------------- extent 树 ---------------- */
+/* 根节点位于 inode i_block（0x28，60B）：
+ * header 12B: magic(2) entries(2) max(2) depth(2) gen(4)
+ * depth 0: leaf 项 12B: block(4) len(2) starthi(2) startlo(4)
+ * depth 1: index 项 12B: block(4) leaf_lo(4) leaf_hi(2) unused(2) */
+#define EXTENT_MAGIC 0xF30A
+
+/* 遍历叶项回调：map(file_block → phys_block)。depth 0/1 支持。 */
+static int extent_walk(const ext4_u8 *ino,
+                       void (*cb)(void *ud, ext4_u64 file_blk, ext4_u64 phys_blk, ext4_u32 len),
+                       void *ud) {
+    ext4_u8 root[60];
+    for (int i = 0; i < 60; i++) root[i] = ino[0x28 + i];
+    if (r16(root + 0) != EXTENT_MAGIC) fatalf("FS-E34 EXTENT MAGIC INVALID");
+    ext4_u16 depth = r16(root + 6);
+    if (depth == 0) {
+        ext4_u16 n = r16(root + 2);
+        const ext4_u8 *e = root + 12;
+        for (ext4_u16 i = 0; i < n; i++, e += 12) {
+            ext4_u64 fb = r32(e);
+            ext4_u32 len = r16(e + 4);
+            if (len == 0) continue;
+            ext4_u64 phys = r32(e + 8) | ((ext4_u64)r16(e + 6) << 32);
+            cb(ud, fb, phys, len);
+        }
+        return 0;
+    }
+    if (depth != 1) fatalf("FS-E35 EXTENT DEPTH > 1 UNSUPPORTED");
+    ext4_u16 n = r16(root + 2);
+    const ext4_u8 *e = root + 12;
+    for (ext4_u16 i = 0; i < n; i++, e += 12) {
+        ext4_u64 leaf = r32(e + 4) | ((ext4_u64)r16(e + 8) << 32);
+        rd_blk((ext4_u32)leaf, g_blk);
+        if (r16(g_blk + 0) != EXTENT_MAGIC) fatalf("FS-E34 EXTENT MAGIC INVALID");
+        ext4_u16 ln = r16(g_blk + 2);
+        if (r16(g_blk + 6) != 0) fatalf("FS-E35 EXTENT DEPTH > 1 UNSUPPORTED");
+        const ext4_u8 *le = g_blk + 12;
+        for (ext4_u16 j = 0; j < ln; j++, le += 12) {
+            ext4_u64 fb = r32(le);
+            ext4_u32 len = r16(le + 4);
+            if (len == 0) continue;
+            ext4_u64 phys = r32(le + 8) | ((ext4_u64)r16(le + 6) << 32);
+            cb(ud, fb, phys, len);
+        }
+    }
+    return 0;
+}
+
+/* 回调载体：读文件 */
+typedef struct { ext4_u8 *dst; ext4_u64 dst_cap; } read_ctx;
+/* 优化：整段连续读（尾块超界时经 g_blk2 部分拷贝，杜绝缓冲区溢出） */
+static void cb_read_seq(void *ud, ext4_u64 fb, ext4_u64 phys, ext4_u32 len) {
+    read_ctx *c = (read_ctx *)ud;
+    ext4_u64 start = fb * g_block_size;
+    ext4_u64 bytes = (ext4_u64)len * g_block_size;
+    if (start >= c->dst_cap) return;
+    if (start + bytes <= c->dst_cap) {
+        rd_sec(blk_lba((ext4_u32)phys), (ext4_u32)(len * g_sec_per_block),
+               c->dst + start);
+    } else {
+        for (ext4_u32 i = 0; i < len; i++) {
+            ext4_u64 off = start + (ext4_u64)i * g_block_size;
+            if (off >= c->dst_cap) return;
+            rd_blk((ext4_u32)(phys + i), g_blk2);
+            ext4_u64 rem = c->dst_cap - off;
+            if (rem > g_block_size) rem = g_block_size;
+            for (ext4_u64 b = 0; b < rem; b++) c->dst[off + b] = g_blk2[b];
+        }
+    }
+}
+/* 回调载体：释放全部块 */
+static void cb_free(void *ud, ext4_u64 fb, ext4_u64 phys, ext4_u32 len) {
+    (void)ud; (void)fb;
+    for (ext4_u32 i = 0; i < len; i++) block_free((ext4_u32)phys);
+}
+
+/* ---------------- inode 分配 ---------------- */
+static ext4_u32 inode_alloc(void) {
+    for (ext4_u32 g = 0; g < g_group_count; g++) {
+        if (gd_free_inodes(g) == 0) continue;
+        rd_blk(gd_inode_bitmap(g), g_blk);
+        for (ext4_u32 byte = 0; byte < g_block_size; byte++) {
+            if (g_blk[byte] == 0xFF) continue;
+            for (int bit = 0; bit < 8; bit++) {
+                if (g_blk[byte] & (1u << bit)) continue;
+                ext4_u32 ino = g * g_inodes_per_group + (ext4_u32)byte * 8 + (ext4_u32)bit + 1;
+                if (ino < 11) continue;   /* 保留 inode 1..10 */
+                g_blk[byte] |= (ext4_u8)(1u << bit);
+                wr_blk(gd_inode_bitmap(g), g_blk);
+                gd_set_free_inodes(g, (ext4_u16)(gd_free_inodes(g) - 1));
+                gdt_flush();
+                w32(g_sb + 0x10, r32(g_sb + 0x10) - 1);   /* free_inodes_count */
+                return ino;
+            }
+        }
+    }
+    fatalf("FS-E37 NO FREE INODES");
+    return 0;
+}
+
+/* ---------------- 路径解析 ---------------- */
+static ext4_u32 streq(const char *a, const char *b, ext4_u32 n) {
+    for (ext4_u32 i = 0; i < n; i++) if (a[i] != b[i]) return 0;
+    return 1;
+}
+
+/* 目录块内查找 name。返回 inode nr（0=未找到）。
+ * entry: inode(4) rec_len(2) name_len(1) ftype(1) name */
+static ext4_u32 dir_block_find(const ext4_u8 *blk, const char *name, ext4_u32 name_len) {
+    ext4_u32 off = 0;
+    while (off + 8 <= g_block_size) {
+        ext4_u32 ino = r32(blk + off);
+        ext4_u16 rec = r16(blk + off + 4);
+        if (rec < 8 || (off + rec) > g_block_size) fatalf("FS-E38 DIR ENTRY CORRUPT");
+        if (ino != 0) {
+            ext4_u8 nl = blk[off + 6];
+            if (nl == name_len && streq((const char *)(blk + off + 8), name, name_len))
+                return ino;
+        }
+        off += rec;
+    }
+    return 0;
+}
+
+/* 读 inode 的第 bi 个目录块（bi < ceil(size/blocksize)） */
+static void dir_read_block(const ext4_u8 *ino, ext4_u32 bi, ext4_u8 *out) {
+    ext4_u8 root[60];
+    for (int i = 0; i < 60; i++) root[i] = ino[0x28 + i];
+    if (r16(root + 0) != EXTENT_MAGIC) fatalf("FS-E34 EXTENT MAGIC INVALID");
+    ext4_u16 depth = r16(root + 6);
+    if (depth != 0) fatalf("FS-E39 DIR TREE DEPTH UNSUPPORTED");
+    ext4_u16 n = r16(root + 2);
+    const ext4_u8 *e = root + 12;
+    for (ext4_u16 i = 0; i < n; i++, e += 12) {
+        ext4_u64 fb = r32(e);
+        ext4_u32 len = r16(e + 4);
+        ext4_u64 phys = r32(e + 8) | ((ext4_u64)r16(e + 6) << 32);
+        if (bi >= fb && bi < fb + len) {
+            rd_blk((ext4_u32)(phys + (bi - fb)), out);
+            return;
+        }
+    }
+    fatalf("FS-E3A DIR BLOCK NOT MAPPED");
+}
+
+/* 在 dir inode 下查找子项，返回 inode nr（0=不存在） */
+static ext4_u32 dir_lookup(const ext4_u8 *dir_ino, const char *name, ext4_u32 name_len) {
+    ext4_u64 dsize = r32(dir_ino + 0x04);
+    ext4_u32 nblk = (ext4_u32)((dsize + g_block_size - 1) / g_block_size);
+    for (ext4_u32 bi = 0; bi < nblk; bi++) {
+        dir_read_block(dir_ino, bi, g_blk);
+        ext4_u32 hit = dir_block_find(g_blk, name, name_len);
+        if (hit) return hit;
+    }
+    return 0;
+}
+
+/* 按路径逐级走到父目录 + 最终名。 */
+static void resolve_parent(const char *path, ext4_u32 *parent_ino,
+                           const char **name, ext4_u32 *name_len) {
+    if (path[0] != '/') fatalf("FS-E3B PATH MUST BE ABSOLUTE");
+    ext4_u32 cur = EXT4_ROOT_INO;
+    const char *p = path + 1;
+    /* 找最终段 */
+    const char *last = p;
+    for (const char *q = p; *q; q++) if (*q == '/') last = q + 1;
+    ext4_u32 last_len = 0;
+    while (last[last_len]) last_len++;
+    if (last_len == 0 || last_len > 255) fatalf("FS-E3C BAD FINAL NAME");
+    /* 逐级遍历前面的段 */
+    while (p < last) {
+        ext4_u32 seg = 0;
+        while (p[seg] && p[seg] != '/') seg++;
+        if (seg == 0) { p++; continue; }
+        ext4_u8 ino_buf[256];
+        read_inode(cur, ino_buf);
+        ext4_u32 next = dir_lookup(ino_buf, p, seg);
+        if (!next) fatalf("FS-E3D PATH COMPONENT NOT FOUND");
+        cur = next;
+        p += seg + 1;
+    }
+    *parent_ino = cur;
+    *name = last;
+    *name_len = last_len;
+}
+
+/* ---------------- 读文件 ---------------- */
+int ext4_read_file(const char *path, ext4_u8 **out, ext4_u32 *size) {
+    ext4_u32 parent; const char *name; ext4_u32 name_len;
+    resolve_parent(path, &parent, &name, &name_len);
+    ext4_u8 dir_ino[256];
+    read_inode(parent, dir_ino);
+    ext4_u32 target = dir_lookup(dir_ino, name, name_len);
+    if (!target) fatalf("FS-E3E FILE NOT FOUND");
+    ext4_u8 ino[256];
+    read_inode(target, ino);
+    ext4_u16 mode = r16(ino + 0x00);
+    if ((mode & 0xF000) != 0x8000) fatalf("FS-E3F NOT A REGULAR FILE");
+    ext4_u64 fsize = r32(ino + 0x04) | ((ext4_u64)r32(ino + 0x6C) << 32);
+    if (fsize > EXT4_MAX_FILE) fatalf("FS-E36 FILE EXCEEDS READ BUFFER");
+    read_ctx rc; rc.dst = g_fdata; rc.dst_cap = fsize;
+    extent_walk(ino, cb_read_seq, &rc);
+    *out = g_fdata;
+    *size = (ext4_u32)fsize;
+    return 0;
+}
+
+/* ---------------- 目录项插入 ---------------- */
+/* 在 dir inode 的现有块中找空隙插入。返回 0 成功；1 无空隙（需扩块）。 */
+static int dir_insert_existing(ext4_u8 *dir_ino, const char *name, ext4_u32 name_len, ext4_u32 target) {
+    ext4_u64 dsize = r32(dir_ino + 0x04);
+    ext4_u32 nblk = (ext4_u32)((dsize + g_block_size - 1) / g_block_size);
+    ext4_u32 need = (8 + name_len + 3) & ~3u;
+    for (ext4_u32 bi = 0; bi < nblk; bi++) {
+        dir_read_block(dir_ino, bi, g_blk);
+        ext4_u32 off = 0;
+        while (off + 8 <= g_block_size) {
+            ext4_u32 ino = r32(g_blk + off);
+            ext4_u16 rec = r16(g_blk + off + 4);
+            if (rec < 8 || (off + rec) > g_block_size) fatalf("FS-E38 DIR ENTRY CORRUPT");
+            if (ino == 0 && rec >= need) {
+                /* 空洞直接占用 */
+                w32(g_blk + off, target);
+                g_blk[off + 6] = (ext4_u8)name_len;
+                g_blk[off + 7] = 1;   /* REGULAR FILE */
+                for (ext4_u32 i = 0; i < name_len; i++) g_blk[off + 8 + i] = (ext4_u8)name[i];
+                wr_blk_dir:;
+                ext4_u8 root[60];
+                for (int i = 0; i < 60; i++) root[i] = dir_ino[0x28 + i];
+                /* 找 bi 对应物理块写回 */
+                const ext4_u8 *e = root + 12;
+                ext4_u16 n = r16(root + 2);
+                for (ext4_u16 i = 0; i < n; i++, e += 12) {
+                    ext4_u64 fb = r32(e);
+                    ext4_u32 len = r16(e + 4);
+                    ext4_u64 phys = r32(e + 8) | ((ext4_u64)r16(e + 6) << 32);
+                    if (bi >= fb && bi < fb + len) { wr_blk((ext4_u32)(phys + (bi - fb)), g_blk); return 0; }
+                }
+                fatalf("FS-E3A DIR BLOCK NOT MAPPED");
+            }
+            if (off + rec == g_block_size) {
+                /* 尾项收缩插入 */
+                ext4_u8 nl = g_blk[off + 6];
+                ext4_u32 min_rec = (8 + nl + 3) & ~3u;
+                if (rec - min_rec >= need) {
+                    ext4_u32 new_off = off + min_rec;
+                    w16(g_blk + off + 4, (ext4_u16)min_rec);   /* rec_len 在 +4 */
+                    w32(g_blk + new_off, target);
+                    w16(g_blk + new_off + 4, (ext4_u16)(rec - min_rec));
+                    g_blk[new_off + 6] = (ext4_u8)name_len;
+                    g_blk[new_off + 7] = 1;
+                    for (ext4_u32 i = 0; i < name_len; i++) g_blk[new_off + 8 + i] = (ext4_u8)name[i];
+                    goto wr_blk_dir;
+                }
+                break;
+            }
+            off += rec;
+        }
+    }
+    return 1;
+}
+
+/* 追加一个新目录块并插入条目 */
+static void dir_insert_new_block(ext4_u8 *dir_ino, const char *name, ext4_u32 name_len, ext4_u32 target) {
+    /* 扩展 extent：depth 0 且 <4 项时直接追加；否则 fatal（目录应远小于 4 块） */
+    ext4_u8 root[60];
+    for (int i = 0; i < 60; i++) root[i] = dir_ino[0x28 + i];
+    if (r16(root + 0) != EXTENT_MAGIC) fatalf("FS-E34 EXTENT MAGIC INVALID");
+    if (r16(root + 6) != 0) fatalf("FS-E39 DIR TREE DEPTH UNSUPPORTED");
+    ext4_u16 n = r16(root + 2);
+    ext4_u16 max = r16(root + 4);
+    if (n >= max || n >= 4) fatalf("FS-E40 DIR EXTENT TABLE FULL");
+    ext4_u32 phys = block_alloc();
+    ext4_u64 dsize = r32(dir_ino + 0x04);
+    /* 追加 extent 项：file block = dsize/4096，len 1 */
+    w32(root + 12 + (ext4_u64)n * 12, (ext4_u32)(dsize / g_block_size));
+    w16(root + 12 + (ext4_u64)n * 12 + 4, 1);
+    w16(root + 12 + (ext4_u64)n * 12 + 6, 0);
+    w32(root + 12 + (ext4_u64)n * 12 + 8, phys);
+    w16(root + 12 + (ext4_u64)n * 12 + 10, 0);
+    w16(root + 2, (ext4_u16)(n + 1));
+    for (int i = 0; i < 60; i++) dir_ino[0x28 + i] = root[i];
+    /* 更新 dir 尺寸与块计数 */
+    dsize += g_block_size;
+    w32(dir_ino + 0x04, (ext4_u32)dsize);
+    w32(dir_ino + 0x1C, r32(dir_ino + 0x1C) + g_sec_per_block);
+    /* 构造新目录块 */
+    for (ext4_u32 i = 0; i < g_block_size; i++) g_blk[i] = 0;
+    w32(g_blk + 0, target);
+    w16(g_blk + 4, (ext4_u16)g_block_size);
+    g_blk[6] = (ext4_u8)name_len;
+    g_blk[7] = 1;
+    for (ext4_u32 i = 0; i < name_len; i++) g_blk[8 + i] = (ext4_u8)name[i];
+    /* used_dirs 不变（非目录）。写 inode 由调用方统一完成 */
+    wr_blk(phys, g_blk);
+}
+
+/* ---------------- 写文件（覆写/创建） ---------------- */
+int ext4_write_file(const char *path, const ext4_u8 *data, ext4_u32 size) {
+    ext4_u32 parent; const char *name; ext4_u32 name_len;
+    resolve_parent(path, &parent, &name, &name_len);
+    ext4_u8 dir_ino[256];
+    read_inode(parent, dir_ino);
+    ext4_u32 target = dir_lookup(dir_ino, name, name_len);
+    int existed = (target != 0);
+
+    ext4_u8 ino[256];
+    if (target) {
+        read_inode(target, ino);
+        ext4_u16 mode = r16(ino + 0x00);
+        if ((mode & 0xF000) != 0x8000) fatalf("FS-E3F NOT A REGULAR FILE");
+        /* 释放旧 extent 叶块（depth 1） */
+        {
+            ext4_u8 root0[60];
+            for (int i = 0; i < 60; i++) root0[i] = ino[0x28 + i];
+            if (r16(root0 + 0) != EXTENT_MAGIC) fatalf("FS-E34 EXTENT MAGIC INVALID");
+            if (r16(root0 + 6) == 1) {
+                ext4_u16 nn = r16(root0 + 2);
+                for (ext4_u16 i = 0; i < nn; i++) {
+                    ext4_u64 leaf = r32(root0 + 12 + i * 12 + 4) |
+                                    ((ext4_u64)r16(root0 + 12 + i * 12 + 8) << 32);
+                    block_free((ext4_u32)leaf);
+                }
+            }
+        }
+        /* 释放旧数据块 */
+        extent_walk(ino, cb_free, 0);
+    } else {
+        target = inode_alloc();
+        for (ext4_u32 i = 0; i < g_inode_size; i++) ino[i] = 0;
+        w16(ino + 0x00, 0x8000 | 0644);       /* regular, rw-r--r-- */
+        w16(ino + 0x1A, 1);                    /* links */
+        w32(ino + 0x20, EXT4_EXTENTS_FL);
+        w32(ino + 0x64, 0xDE5AAB1E);           /* generation 品牌落款 */
+    }
+
+    /* 构造 extent 根（depth 0/1） */
+    ext4_u32 nblk = (size + g_block_size - 1) / g_block_size;
+    if ((ext4_u64)nblk * g_block_size > EXT4_MAX_FILE) fatalf("FS-E36 FILE EXCEEDS READ BUFFER");
+    /* 收集分配的块号（最大 8MB/4K = 2048 块） */
+    static ext4_u32 alloc_map[2048];
+    for (ext4_u32 i = 0; i < nblk; i++) alloc_map[i] = block_alloc();
+    /* 写数据块 */
+    for (ext4_u32 i = 0; i < nblk; i++) {
+        for (ext4_u32 b = 0; b < g_block_size; b++) {
+            ext4_u64 off = (ext4_u64)i * g_block_size + b;
+            g_blk[b] = (off < size) ? data[off] : 0;
+        }
+        wr_blk(alloc_map[i], g_blk);
+    }
+    /* 生成 extent 叶项（每 extent ≤ 32768 块，此处 ≤2048） */
+    ext4_u8 root[60];
+    for (int i = 0; i < 60; i++) root[i] = 0;
+    w16(root + 0, EXTENT_MAGIC);
+    w16(root + 4, 4);          /* max = 4（根内联） */
+    w16(root + 6, 0);          /* depth 0 */
+    ext4_u16 ne = 0;
+    ext4_u32 i = 0;
+    if (nblk > 0) {
+        while (i < nblk) {
+            if (ne >= 4) {
+                /* >4 extents：需要 depth 1。把现有叶项压入一个叶块，继续分配。 */
+                /* 分配叶块，把 4 项写入 */
+                ext4_u32 leaf = block_alloc();
+                ext4_u8 lfb[4096];
+                for (ext4_u32 b = 0; b < g_block_size; b++) lfb[b] = 0;
+                w16(lfb + 0, EXTENT_MAGIC);
+                w16(lfb + 2, ne);
+                w16(lfb + 4, (ext4_u16)((g_block_size - 12) / 12));
+                w16(lfb + 6, 0);
+                for (ext4_u16 j = 0; j < ne; j++) {
+                    const ext4_u8 *src = root + 12 + j * 12;
+                    ext4_u8 *dst = lfb + 12 + j * 12;
+                    for (int k = 0; k < 12; k++) dst[k] = src[k];
+                }
+                wr_blk(leaf, lfb);
+                /* root 变 depth1：保留 index[0] = 旧叶；继续向 alloc_map 后段收集 */
+                /* 这里简化：一次性深度1重建（见下），直接跳出 */
+                static ext4_u32 leaf_blocks[8];
+                static ext4_u16 leaf_counts[8];
+                int nleaf = 0;
+                leaf_blocks[nleaf] = leaf; leaf_counts[nleaf] = ne; nleaf++;
+                /* 继续把剩余块打成叶块，每块 ≤340 项 */
+                ext4_u16 cur_cnt = ne;
+                ext4_u32 cur_start = i;   /* 前 4 项 extent 已覆盖 file blocks [0, i) */
+                (void)cur_cnt;
+                while (cur_start < nblk) {
+                    ext4_u32 cnt = nblk - cur_start;
+                    if (cnt > (g_block_size - 12) / 12) cnt = (g_block_size - 12) / 12;
+                    ext4_u32 lf = block_alloc();
+                    ext4_u8 lb[4096];
+                    for (ext4_u32 b = 0; b < g_block_size; b++) lb[b] = 0;
+                    w16(lb + 0, EXTENT_MAGIC);
+                    w16(lb + 2, (ext4_u16)cnt);
+                    w16(lb + 4, (ext4_u16)((g_block_size - 12) / 12));
+                    w16(lb + 6, 0);
+                    for (ext4_u32 j = 0; j < cnt; j++) {
+                        ext4_u8 *ee = lb + 12 + j * 12;
+                        w32(ee, cur_start + j);            /* file block */
+                        w16(ee + 4, 1);                    /* len 1 */
+                        w16(ee + 6, 0);
+                        w32(ee + 8, alloc_map[cur_start + j]);
+                    }
+                    wr_blk(lf, lb);
+                    if (nleaf >= 8) fatalf("FS-E41 TOO MANY EXTENT LEAVES");
+                    leaf_blocks[nleaf] = lf; leaf_counts[nleaf] = (ext4_u16)cnt; nleaf++;
+                    cur_start += cnt;
+                }
+                /* 重建根为 depth 1 */
+                for (int b = 0; b < 60; b++) root[b] = 0;
+                w16(root + 0, EXTENT_MAGIC);
+                w16(root + 2, (ext4_u16)nleaf);
+                w16(root + 4, 4);
+                w16(root + 6, 1);
+                ext4_u64 fb_cur = 0;
+                for (int l = 0; l < nleaf; l++) {
+                    ext4_u8 *ie = root + 12 + l * 12;
+                    w32(ie, (ext4_u32)fb_cur);
+                    w32(ie + 4, leaf_blocks[l]);
+                    w16(ie + 8, 0);
+                    fb_cur += leaf_counts[l];
+                }
+                goto root_done;
+            }
+            /* 找连续 run */
+            ext4_u32 run = 1;
+            while (i + run < nblk && run < 32768 &&
+                   alloc_map[i + run] == alloc_map[i] + run) run++;
+            ext4_u8 *ee = root + 12 + ne * 12;
+            w32(ee, i);
+            w16(ee + 4, (ext4_u16)run);
+            w16(ee + 6, 0);
+            w32(ee + 8, alloc_map[i]);
+            ne++;
+            i += run;
+        }
+    }
+    w16(root + 2, ne);
+root_done:
+    for (int b = 0; b < 60; b++) ino[0x28 + b] = root[b];
+    w32(ino + 0x04, size);                       /* size_lo */
+    w32(ino + 0x6C, 0);                          /* size_high */
+    w32(ino + 0x1C, (ext4_u32)((ext4_u64)nblk * g_sec_per_block));  /* blocks(512B) */
+    w32(ino + 0x10, 0xDE5A0000u);                /* mtime 品牌纪年 */
+    write_inode(target, ino);
+
+    /* 新文件：插入目录项（target 为新分配 inode 且原查找时不存在） */
+    if (!existed) {
+        if (dir_insert_existing(dir_ino, name, name_len, target) != 0)
+            dir_insert_new_block(dir_ino, name, name_len, target);
+        write_inode(parent, dir_ino);
+    }
+
+    sb_flush();
+    logh_fn("[EXT4] wrote blocks=", nblk);
+
+    /* 写后回读校验 */
+    ext4_u8 *vdata; ext4_u32 vsize;
+    ext4_read_file(path, &vdata, &vsize);
+    if (vsize != size) fatalf("FS-E42 WRITE VERIFY SIZE MISMATCH");
+    for (ext4_u32 b = 0; b < size; b++)
+        if (vdata[b] != data[b]) fatalf("FS-E42 WRITE VERIFY DATA MISMATCH");
+    return 0;
+}
+
+/* ---------------- 启动自检 ---------------- */
+void ext4_boot_selftest(void) {
+    /* 读测试：p2 上的 FUCK 配置副本 */
+    ext4_u8 *d; ext4_u32 n;
+    ext4_read_file("/system/deshab64/FUCK", &d, &n);
+    if (n == 0) fatalf("FS-E43 SELFTEST FUCK READ EMPTY");
+    logh_fn("[EXT4] selftest FUCK bytes=", n);
+    /* 写读校验测试 */
+    static const ext4_u8 msg[] = "DESHAB EXT4 RW OK - DEAICUP\n";
+    ext4_write_file("/dsk_ext4_rw.test", msg, sizeof(msg) - 1);
+    logl_fn("[EXT4] selftest PASS");
+}

CODE/dsk/ext4.h

@@ -0,0 +1,43 @@
+/* ext4.h — minimal full read-write ext4 driver for DSK (p2 data partition)
+ *
+ * 严格错误策略：任何错误（挂载失败/feature 不支持/IO 失败/校验不符）
+ * 一律经 fatal(sym) 整屏 panic 停机，错误码体系 FS-E1x / FS-E2x。
+ *
+ * 支持范围（mkfs.ext4 由 pack_system_image.sh 以 -O
+ * ^has_journal,^metadata_csum,^64bit,^resize_inode -b 4096 -I 256 创建）：
+ *   - 4K blocksize、inode 256B、无 journal、无 metadata_csum、无 64bit
+ *   - extent 树（depth 0/1）读写
+ *   - 块位图/inode 位图分配与回收
+ *   - 线性目录项查找/插入/扩展
+ */
+#ifndef DSK_EXT4_H
+#define DSK_EXT4_H
+
+typedef unsigned char  ext4_u8;
+typedef unsigned short ext4_u16;
+typedef unsigned int   ext4_u32;
+typedef unsigned long long ext4_u64;
+
+typedef int (*ext4_block_read_fn)(unsigned int index, ext4_u64 lba,
+                                  ext4_u32 count, void *buf);
+typedef int (*ext4_block_write_fn)(unsigned int index, ext4_u64 lba,
+                                   ext4_u32 count, const void *buf);
+
+/* 挂载 p2 ext4 分区（GPT 探测 + superblock/feature 校验）。
+ * 任何失败直接调用 fatal(sym) panic。成功返回 0。 */
+int ext4_mount(ext4_block_read_fn rd, ext4_block_write_fn wr,
+               void (*fatal)(const char *sym), void (*logl)(const char *s),
+               void (*logh)(const char *p, ext4_u64 v));
+
+/* 按路径读文件（"/system/deshab64/FUCK"），返回内部静态缓冲。
+ * 任何失败 fatal。成功返回 0 并填充 out/size。 */
+int ext4_read_file(const char *path, ext4_u8 **out, ext4_u32 *size);
+
+/* 按路径写文件（存在则覆写，不存在则创建）。
+ * 写后自动回读逐字节校验，不符 fatal。成功返回 0。 */
+int ext4_write_file(const char *path, const ext4_u8 *data, ext4_u32 size);
+
+/* 启动自检：读 /system/deshab64/FUCK + 写读校验 /dsk_ext4_rw.test。 */
+void ext4_boot_selftest(void);
+
+#endif

CODE/dsk/main.c

@@ -5,18 +5,20 @@
 #include "port.h"
 #include "../tools/fat32_lfn.h"
 #include "../tools/fat32_part.h"
-
+#include "ext4.h"
-/* Embedded Logo.png RGBA data (auto-generated by png_to_rgba.py) */
-#include "logo_data.c"
 
 /* Embedded dcplogo.png / xjlogo.png RGBA data (auto-generated by
- * png_to_rgba_prefixed.py; must stay file-local like logo_data.c) */
+ * png_to_rgba_prefixed.py from TEXTURES directory; must stay file-local like
+ * other embedded art) */
 #include "dcp_logo_data.c"
 #include "xj_logo_data.c"
 
 /* Embedded ASCII bitmap font (Consolas 18px grayscale, 11x18 cell) */
 #include "../firstInit/ascii_bitmaps.c"
 
+/* Embedded ohMyLogo.png RGBA data（莲花 panic 界面用，与 login.elf 同源） */
+#include "../login/ohmylogo_data.c"
+
 #define COM1 0x3F8
 
 typedef unsigned char      u8;
@@ -550,10 +552,6 @@ static void dsk_draw_rgba(u32 *fb, const u8 *pix, int w, int h) {
     }
 }
 
-static void dsk_draw_logo(u32 *fb) {
-    dsk_draw_rgba(fb, g_logo_rgba, g_logo_w, g_logo_h);
-}
-
 /* Splash sequence entry: one image + hold for the given milliseconds.
  * Redraws the gradient background first so successive images replace
  * each other cleanly. */
@@ -634,6 +632,64 @@ static void dsk_draw_string(u32 *fb, const char *s, i64 x, i64 y, u32 fg, int sp
     }
 }
 
+/* ===================================================================
+ *  严格错误策略插桩：FS/调度层任何错误（含未实现路径）不再降级、
+ *  不再静默跳过，必须整屏 fatal 显示错误码后停机。
+ *  错误码体系：FS-E<nn>（文件系统层）。
+ * =================================================================== */
+static u64 dsk_fat_strlen(const char *s) { u64 n = 0; while (s[n]) n++; return n; }
+
+/* 莲花 panic 界面：深蓝底 + ohMyLogo 莲花居中 + 错误码 + 停机落款。
+ * 与 login.elf / UTSM F1 panic 同一视觉体系。 */
+static void dsk_fatal_lotus(u32 *fb, const char *sym) {
+    /* 深蓝底 */
+    for (u64 y = 0; y < g_fb_h; y++) {
+        u32 *line = (u32 *)((u8 *)fb + y * g_fb_p);
+        for (u64 x = 0; x < g_fb_w; x++) line[x] = 0xFF020F22u;
+    }
+    /* 莲花居中（偏上，给错误码留空间） */
+    i64 lx = ((i64)g_fb_w - g_panic_logo_w) / 2;
+    i64 ly = ((i64)g_fb_h - g_panic_logo_h) / 2 - 60;
+    if (ly < 0) ly = 0;
+    for (i64 r = 0; r < g_panic_logo_h; r++) {
+        for (i64 c = 0; c < g_panic_logo_w; c++) {
+            const unsigned char *px4 =
+                g_panic_logo_rgba + ((u64)r * g_panic_logo_w + (u64)c) * 4;
+            u32 a = px4[3];
+            if (a < 8) continue;
+            u32 col = 0xFF000000u | ((u32)px4[0] << 16) | ((u32)px4[1] << 8) | px4[2];
+            if (a < 250) {
+                u32 bg = 0xFF020F22u;
+                u32 na = 256 - a;
+                u32 rr = (((bg >> 16) & 0xFF) * na + ((col >> 16) & 0xFF) * a) >> 8;
+                u32 gg = (((bg >> 8) & 0xFF) * na + ((col >> 8) & 0xFF) * a) >> 8;
+                u32 bb = ((bg & 0xFF) * na + (col & 0xFF) * a) >> 8;
+                col = 0xFF000000u | (rr << 16) | (gg << 8) | bb;
+            }
+            i64 xx = lx + c, yy = ly + r;
+            if (xx < 0 || (u64)xx >= g_fb_w || yy < 0 || (u64)yy >= g_fb_h) continue;
+            *(u32 *)((u8 *)fb + (u64)yy * g_fb_p + (u64)xx * 4) = col;
+        }
+    }
+    /* 错误码 + 停机落款（莲花下方） */
+    i64 ty = ly + g_panic_logo_h + 24;
+    i64 spacing = g_ascii_w + 1;
+    dsk_draw_string(fb, sym,
+                    ((i64)g_fb_w - (i64)dsk_fat_strlen(sym) * spacing) / 2, ty,
+                    0xFFF2D8D8u, (int)spacing);
+    dsk_draw_string(fb, "DESHAB FS FATAL - SYSTEM HALTED",
+                    ((i64)g_fb_w - 31 * spacing) / 2, ty + g_ascii_h + 16,
+                    0xFFB08890u, (int)spacing);
+}
+
+static void dsk_fatal(const char *sym) {
+    logl(sym);
+    if (g_fb_addr) {
+        dsk_fatal_lotus((u32 *)(u64)g_fb_addr, sym);
+    }
+    for (;;) __asm__("cli; hlt");
+}
+
 static int fat32_find_entry(const u8 *clus, u32 clus_sectors, const char *target, u32 *out_clus, u32 *out_size) {
     const fat32_de *dir = (const fat32_de *)clus;
     for (u32 e=0; e*32 < clus_sectors*512; e++) {
@@ -722,6 +778,51 @@ static int fat32_read_root_file(const char *name11, u8 **out_data, u32 *out_size
  * If the file exists, its content is replaced. If not, a new entry is created.
  * Uses g_disk (256-sector buffer) which must already contain the BPB+FAT+root.
  * Returns 0 on success. */
+/* BUG-20261002 修复: 按需 FAT 表项读写（支持 FAT 超出 g_disk 256 扇区的大容量 ESP）。
+ * 缓冲内直接改写（随后由步骤 6 回写），缓冲外读单扇区到 g_fat_sec 改写后立即落盘。 */
+static u32 fat32_fat_read_entry(u32 fat_byte_off, u32 c) {
+    u32 fo = fat_byte_off + c * 4;
+    if (fo + 4 <= sizeof(g_disk)) return r32(g_disk + fo) & 0x0FFFFFFF;
+    u32 sec = fo / 512, off = fo % 512;
+    if (fat32_read_sectors(sec, 1, g_fat_sec) != 0) return 0x0FFFFFF7;  /* 读失败视作坏簇 */
+    return r32(g_fat_sec + off) & 0x0FFFFFFF;
+}
+static int fat32_fat_write_entry(u32 fat_byte_off, u32 c, u32 val) {
+    u32 fo = fat_byte_off + c * 4;
+    if (fo + 4 <= sizeof(g_disk)) {
+        g_disk[fo] = (u8)(val & 0xFF);
+        g_disk[fo+1] = (u8)((val >> 8) & 0xFF);
+        g_disk[fo+2] = (u8)((val >> 16) & 0xFF);
+        g_disk[fo+3] = (u8)((g_disk[fo+3] & 0xF0) | ((val >> 24) & 0x0F));
+        return fat32_write_sectors(fo / 512, 1, g_disk + (u64)(fo / 512) * 512);
+    }
+    u32 sec = fo / 512, off = fo % 512;
+    if (fat32_read_sectors(sec, 1, g_fat_sec) != 0) return -1;
+    g_fat_sec[off] = (u8)(val & 0xFF);
+    g_fat_sec[off+1] = (u8)((val >> 8) & 0xFF);
+    g_fat_sec[off+2] = (u8)((val >> 16) & 0xFF);
+    g_fat_sec[off+3] = (u8)((g_fat_sec[off+3] & 0xF0) | ((val >> 24) & 0x0F));
+    return fat32_write_sectors(sec, 1, g_fat_sec);
+}
+
+/* 块状空闲簇扫描：每次读 8 扇区（1024 表项），fat_byte_off 必须扇区对齐。
+ * chunk k 覆盖表项 [k*1024, (k+1)*1024)。 */
+static u8 g_fatscan[4096];
+static u32 fat32_find_free_cluster(u32 fat_byte_off, u32 max_c) {
+    for (u32 k = 0; k * 1024 < max_c; k++) {
+        u32 base = k * 1024;
+        if (fat32_read_sectors(fat_byte_off / 512 + k * 8, 8, g_fatscan) != 0)
+            continue;
+        u32 n = max_c - base; if (n > 1024) n = 1024;
+        for (u32 i = 0; i < n; i++) {
+            u32 c = base + i;
+            if (c < 2) continue;
+            if ((r32(g_fatscan + i * 4) & 0x0FFFFFFF) == 0) return c;
+        }
+    }
+    return 0;
+}
+
 static int fat32_write_root_file(const char *name11, const u8 *data, u32 size) {
     u8 *disk = g_disk;
     const fat32_bpb *bpb = (const fat32_bpb *)disk;
@@ -818,54 +919,32 @@ static int fat32_write_root_file(const char *name11, const u8 *data, u32 size) {
         u32 count = 0;
         while (cur >= 2 && cur < 0x0FFFFFF8 && count < clusters_needed) {
             prev_clus = cur;
-            u32 fo = fat_byte_off + cur * 4;
+            cur = fat32_fat_read_entry(fat_byte_off, cur);
-            if (fo + 4 > sizeof(g_disk)) break;
-            cur = r32(disk + fo) & 0x0FFFFFFF;
             count++;
         }
         /* If we need more clusters, allocate them */
         while (count < clusters_needed) {
-            /* Find a free cluster in FAT */
+            u32 newc = fat32_find_free_cluster(fat_byte_off, (fat_sectors * 512) / 4);
-            u32 newc = 0;
-            for (u32 c = 2; c < (fat_sectors * 512) / 4; c++) {
-                u32 fo = fat_byte_off + c * 4;
-                if (fo + 4 > sizeof(g_disk)) break;
-                if ((r32(disk + fo) & 0x0FFFFFFF) == 0) { newc = c; break; }
-            }
             if (newc == 0) { logl("[DSK] fat32 write: no free clusters"); return -3; }
-            /* BUG-20260730: Mark newly allocated cluster as EOC immediately to prevent re-allocation */
+            logh("[DSK] fat32 write: alloc clus=", newc);
-            {
+            /* Mark newly allocated cluster as EOC immediately to prevent re-allocation */
-                u32 nfo = fat_byte_off + newc * 4;
+            if (fat32_fat_write_entry(fat_byte_off, newc, 0x0FFFFFF8) != 0) return -7;
-                if (nfo + 4 <= sizeof(g_disk)) {
-                    disk[nfo] = 0xF8; disk[nfo+1] = 0xFF; disk[nfo+2] = 0xFF; disk[nfo+3] = (disk[nfo+3] & 0xF0) | 0x0F;
-                }
-            }
             /* Link previous cluster to new */
-            u32 pfo = fat_byte_off + prev_clus * 4;
+            if (prev_clus >= 2) {
-            if (pfo + 4 <= sizeof(g_disk)) {
+                if (fat32_fat_write_entry(fat_byte_off, prev_clus, newc) != 0) return -7;
-                disk[pfo] = (u8)(newc & 0xFF);
-                disk[pfo+1] = (u8)((newc >> 8) & 0xFF);
-                disk[pfo+2] = (u8)((newc >> 16) & 0xFF);
-                disk[pfo+3] = (disk[pfo+3] & 0xF0) | (u8)((newc >> 24) & 0x0F);
             }
             prev_clus = newc;
             count++;
         }
-        /* BUG-20260730: Terminate the chain, saving original next pointer before overwriting with EOC */
+        /* Terminate the chain, saving original next pointer before overwriting with EOC */
         if (prev_clus >= 2) {
-            u32 fo = fat_byte_off + prev_clus * 4;
+            u32 original_next = fat32_fat_read_entry(fat_byte_off, prev_clus);
-            u32 original_next = 0;
+            fat32_fat_write_entry(fat_byte_off, prev_clus, 0x0FFFFFF8);
-            if (fo + 4 <= sizeof(g_disk)) {
-                original_next = r32(disk + fo) & 0x0FFFFFFF;
-                disk[fo] = 0xF8; disk[fo+1] = 0xFF; disk[fo+2] = 0xFF; disk[fo+3] = (disk[fo+3] & 0xF0) | 0x0F;
-            }
             /* Free excess clusters from the old chain using saved pointer */
             u32 next = original_next;
             while (next >= 2 && next < 0x0FFFFFF8) {
-                u32 nfo = fat_byte_off + next * 4;
+                u32 nn = fat32_fat_read_entry(fat_byte_off, next);
-                u32 nn = 0;
+                fat32_fat_write_entry(fat_byte_off, next, 0);
-                if (nfo + 4 <= sizeof(g_disk)) nn = r32(disk + nfo) & 0x0FFFFFFF;
-                if (nfo + 4 <= sizeof(g_disk)) { disk[nfo] = 0; disk[nfo+1] = 0; disk[nfo+2] = 0; disk[nfo+3] = disk[nfo+3] & 0xF0; }
                 next = nn;
             }
         }
@@ -873,40 +952,17 @@ static int fat32_write_root_file(const char *name11, const u8 *data, u32 size) {
         /* Allocate new clusters */
         if (free_entry < 0) { logl("[DSK] fat32 write: no free dir entry"); return -4; }
         for (u32 i = 0; i < clusters_needed; i++) {
-            u32 newc = 0;
+            u32 newc = fat32_find_free_cluster(fat_byte_off, (fat_sectors * 512) / 4);
-            for (u32 c = 2; c < (fat_sectors * 512) / 4; c++) {
-                u32 fo = fat_byte_off + c * 4;
-                if (fo + 4 > sizeof(g_disk)) break;
-                if ((r32(disk + fo) & 0x0FFFFFFF) == 0) { newc = c; break; }
-            }
             if (newc == 0) { logl("[DSK] fat32 write: no free clusters"); return -3; }
-            /* BUG-20260730: Mark newly allocated cluster as EOC immediately to prevent re-allocation */
+            logh("[DSK] fat32 write: alloc clus=", newc);
-            {
+            /* Mark newly allocated cluster as EOC immediately to prevent re-allocation */
-                u32 nfo = fat_byte_off + newc * 4;
+            if (fat32_fat_write_entry(fat_byte_off, newc, 0x0FFFFFF8) != 0) return -7;
-                if (nfo + 4 <= sizeof(g_disk)) {
-                    disk[nfo] = 0xF8; disk[nfo+1] = 0xFF; disk[nfo+2] = 0xFF; disk[nfo+3] = (disk[nfo+3] & 0xF0) | 0x0F;
-                }
-            }
             if (i == 0) first_clus = newc;
             if (prev_clus >= 2) {
-                u32 pfo = fat_byte_off + prev_clus * 4;
+                if (fat32_fat_write_entry(fat_byte_off, prev_clus, newc) != 0) return -7;
-                if (pfo + 4 <= sizeof(g_disk)) {
-                    disk[pfo] = (u8)(newc & 0xFF);
-                    disk[pfo+1] = (u8)((newc >> 8) & 0xFF);
-                    disk[pfo+2] = (u8)((newc >> 16) & 0xFF);
-                    disk[pfo+3] = (disk[pfo+3] & 0xF0) | (u8)((newc >> 24) & 0x0F);
-                }
             }
             prev_clus = newc;
         }
-        /* Terminate chain */
-        /* BUG-20260730: Terminate chain preserving high 4 bits */
-        if (prev_clus >= 2) {
-            u32 fo = fat_byte_off + prev_clus * 4;
-            if (fo + 4 <= sizeof(g_disk)) {
-                disk[fo] = 0xF8; disk[fo+1] = 0xFF; disk[fo+2] = 0xFF; disk[fo+3] = (disk[fo+3] & 0xF0) | 0x0F;
-            }
-        }
     }
 
     /* 4. Write data to clusters */
@@ -931,9 +987,7 @@ static int fat32_write_root_file(const char *name11, const u8 *data, u32 size) {
             if (fat32_write_sectors(clba, spc, g_cluster) != 0) return -6;
         }
         src += chunk; remaining -= chunk; ci++;
-        u32 fo = fat_byte_off + cur * 4;
+        cur = fat32_fat_read_entry(fat_byte_off, cur);
-        if (fo + 4 > sizeof(g_disk)) break;
-        cur = r32(disk + fo) & 0x0FFFFFFF;
     }
 
     /* 5. Update directory entry */
@@ -1307,18 +1361,11 @@ static int dsk_load_elf(u8 *data, u32 size, void **entry_out) {
 /* Load an ELF module from the FAT32 root by 11-char 8.3 name, parse it into
  * the shared image buffer, and jump to its entry with the boot context.
  * Returns 0 if the module ran and returned, non-zero on load failure. */
-static int dsk_load_and_run(const char name11[12], const dsk_boot_context *ctx) {
+/* 按名字加载模块 ELF：先根目录，后 SYSTEM/DESHAB64/ 与 SYSTEM/USER/USE/ 回退。 */
-    DSK_TS_DECL(mod_run);
+static int dsk_load_module(const char name11[12], u8 **data, u32 *size) {
-    DSK_TS_BEGIN(mod_run);
+    if (fat32_read_root_file(name11, data, size) == 0) return 0;
-    DSK_STAT_INC(mod_schedule);
-    u8 *data=0; u32 size=0; void *entry=0;
-    logl("[DSK] load_and_run: ");
-    swrite(name11); swrite("\n");
-    if (fat32_read_root_file(name11, &data, &size) != 0) {
-        /* 依次回退：SYSTEM/DESHAB64/ → SYSTEM/USER/USE/（FirstInit.elf 部署位） */
     static const char *pfxs[] = { "SYSTEM  /DESHAB64 /", "SYSTEM  /USER     /USE      /" };
-        int loaded = 0;
+    for (int pi = 0; pi < 2; pi++) {
-        for (int pi = 0; pi < 2 && !loaded; pi++) {
         char path[40];
         int i = 0, j;
         const char *pfx = pfxs[pi];
@@ -1327,16 +1374,21 @@ static int dsk_load_and_run(const char name11[12], const dsk_boot_context *ctx)
         path[i] = 0;
         logl("[DSK] load_and_run: trying fallback path");
         if (fat32_read_sectors(0, 256, g_disk) == 0 &&
-                fat32_read_path(path, &data, &size) == 0) {
+            fat32_read_path(path, data, size) == 0) return 0;
-                loaded = 1;
     }
-        }
-        if (!loaded) {
     logl("[DSK] load_and_run: fat32 read failed for ");
     swrite(name11); swrite("\n");
     return -1;
 }
-    }
+
+static int dsk_load_and_run(const char name11[12], const dsk_boot_context *ctx) {
+    DSK_TS_DECL(mod_run);
+    DSK_TS_BEGIN(mod_run);
+    DSK_STAT_INC(mod_schedule);
+    u8 *data=0; u32 size=0; void *entry=0;
+    logl("[DSK] load_and_run: ");
+    swrite(name11); swrite("\n");
+    if (dsk_load_module(name11, &data, &size) != 0) return -1;
     if (dsk_load_elf(data, size, &entry) != 0) { logl("[DSK] load_and_run: elf load failed for "); swrite(name11); swrite("\n"); return -2; }
     logl("[DSK] jumping to module");
     void(*fn)(const dsk_boot_context*)=(void(*)(const dsk_boot_context*))entry;
@@ -1664,11 +1716,13 @@ static void dsk_persist_userconf(const dsk_boot_context *ctx) {
     u64 conf_ptr = ctx_mut->reserved[0];
     u64 conf_sz  = ctx_mut->reserved[1];
     if (!conf_ptr || !conf_sz) {
-        logl("[DSK] no conf buffer from FirstInit, skipping persist");
+        /* 严格错误策略：FirstInit 返回却没留下配置缓冲 = 向导失败，零降级 */
+        dsk_fatal("FS-E05 FIRSTINIT NO CONF BUFFER");
         return;
     }
     if (!g_block_write) {
-        logl("[DSK] no block_write, cannot persist user.conf");
+        /* 严格错误策略：块层无写通道 = FS 不可写，零降级 */
+        dsk_fatal("FS-E01 NO BLOCK WRITE PROVIDER");
         return;
     }
     const u8 *conf = (const u8 *)conf_ptr;
@@ -1679,6 +1733,20 @@ static void dsk_persist_userconf(const dsk_boot_context *ctx) {
     logl("[DSK] writing USER.CONF");
     int wrc = fat32_write_root_file(cn, conf, (u32)conf_sz);
     logh("[DSK] USER.CONF write rc=", (u64)(i64)wrc);
+    if (wrc != 0) dsk_fatal("FS-E02 USER.CONF WRITE FAILED");
+
+    /* 1b. Write-verify: 回读 USER.CONF 逐字节比对，确保 FAT32 写路径真的落盘 */
+    {
+        u8 *vdata = 0; u32 vsize = 0;
+        if (fat32_read_root_file(cn, &vdata, &vsize) != 0)
+            dsk_fatal("FS-E04 USER.CONF VERIFY READ FAILED");
+        if (vsize != (u32)conf_sz)
+            dsk_fatal("FS-E04 USER.CONF VERIFY SIZE MISMATCH");
+        for (u32 i = 0; i < (u32)conf_sz; i++) {
+            if (vdata[i] != conf[i]) dsk_fatal("FS-E04 USER.CONF VERIFY DATA MISMATCH");
+        }
+        logl("[DSK] USER.CONF verify ok");
+    }
 
     /* 2. Flip firstInit.txt: '0' -> '1'，保留第二行 dev_mode 标志 */
     char fn[12]; /* FIRSTINTXT */
@@ -1694,6 +1762,7 @@ static void dsk_persist_userconf(const dsk_boot_context *ctx) {
     u8 fi_buf[3]; fi_buf[0] = '1'; fi_buf[1] = '\n'; fi_buf[2] = dev_mode_byte;
     int frc = fat32_write_root_file(fn, fi_buf, 3);
     logh("[DSK] firstInit.txt flip rc=", (u64)(i64)frc);
+    if (frc != 0) dsk_fatal("FS-E03 FIRSTINIT.TXT WRITE FAILED");
 
     /* Clear reserved so login path doesn't see stale pointer */
     ctx_mut->reserved[0] = 0;
@@ -1722,6 +1791,53 @@ static void dsk_schedule_netman(const dsk_boot_context *ctx, int load_netman) {
     else logl("[DSK] netman not found");
 }
 
+/* 调度 login.elf：读取 USER.CONF 传给 login，成功置 reserved[2]=1。
+ * 返回 1 = 登录成功；0 = 失败（调用方决定是否 fatal）。
+ * 首次启动（向导后强制重登）与常规启动共用此路径。 */
+static int dsk_run_login(const dsk_boot_context *ctx) {
+    DSK_TS_DECL(login_phase);
+    DSK_TS_BEGIN(login_phase);
+    logl("[DSK:SCHED] scheduling login.elf");
+    char ln[12]; /* LOGIN    ELF */
+    ln[0]='L';ln[1]='O';ln[2]='G';ln[3]='I';ln[4]='N';ln[5]=' ';ln[6]=' ';ln[7]=' ';ln[8]='E';ln[9]='L';ln[10]='F';
+    u8 *ld=0; u32 ls=0; void *le=0;
+    int login_ok = 0;
+    if (dsk_load_module(ln, &ld, &ls) == 0) {
+        if (dsk_load_elf(ld, ls, &le) == 0) {
+            char cn[12]; /* USER    CON */
+            cn[0]='U';cn[1]='S';cn[2]='E';cn[3]='R';cn[4]=' ';cn[5]=' ';cn[6]=' ';cn[7]=' ';cn[8]='C';cn[9]='O';cn[10]='N';
+            u8 *conf_data=0; u32 conf_size=0;
+            if (fat32_read_root_file(cn, &conf_data, &conf_size) == 0) {
+                logl("[DSK] USER.CONF found, passing to login");
+                dsk_boot_context *ctx_mut = (dsk_boot_context *)ctx;
+                ctx_mut->reserved[0] = (u64)conf_data;
+                ctx_mut->reserved[1] = (u64)conf_size;
+                ctx_mut->reserved[2] = 0;  /* login success flag */
+
+                logl("[DSK] jumping to login");
+                void(*lentry)(const dsk_boot_context*)=(void(*)(const dsk_boot_context*))le;
+                lentry(ctx);
+                logl("[DSK] login returned");
+
+                if (ctx_mut->reserved[2] == 1) {
+                    logl("[DSK] login success");
+                    login_ok = 1;
+                } else {
+                    logl("[DSK] login skipped or failed");
+                }
+            } else {
+                logl("[DSK] USER.CONF not found");
+            }
+        } else {
+            logl("[DSK] login.elf load failed");
+        }
+    } else {
+        logl("[DSK] login.elf not found");
+    }
+    DSK_TS_END(login_phase, "login phase");
+    return login_ok;
+}
+
 /* Draw the spinning loader (comet-tail arc) on the gradient background,
  * then run the firstInit check and dispatch system component loading.
  * FUCK config controls: show_logo, skip_login, mouse_init, netman, dev_mode. */
@@ -1743,6 +1859,10 @@ static void dsk_spinner_and_check(const void *boot_ctx_ptr) {
     g_fb_addr=ctx->framebuffer_address; g_fb_w=ctx->framebuffer_width;
     g_fb_h=ctx->framebuffer_height; g_fb_p=ctx->framebuffer_pitch;
     if (!g_fb_addr) { logl("[DSK] FATAL: framebuffer address is NULL"); for(;;)__asm__("hlt"); }
+
+    /* ext4 p2 数据分区挂载 + 启动读写自检（任何失败 fatal panic，FS-E2x/FS-E3x） */
+    ext4_mount(g_block_read, g_block_write, dsk_fatal, logl, logh);
+    ext4_boot_selftest();
     u32 *sfb=(u32*)(u64)g_fb_addr;
     logh("[DSK] block_read ptr=", (u64)g_block_read);
 
@@ -1809,36 +1929,28 @@ static void dsk_spinner_and_check(const void *boot_ctx_ptr) {
     else logl("[DSK] compat: PE DLL search disabled");
     milestone_write(3, "FUCK config loaded");
 
-    /* Gradient background + centered Logo.png (5 seconds) */
+    /* Gradient background + centered "DESHAB P01" text（Logo.png 图像已移除） */
     dsk_fill_gradient_rect(sfb, 0, 0, (i64)g_fb_w, (i64)g_fb_h);
 
     if (show_logo) {
-        /* Draw Logo.png centered with alpha blending on gradient background */
+        /* "DESHAB P01" 文字垂直居中（不再绘制 Logo 图像） */
-        dsk_draw_logo(sfb);
-
-        /* Draw "DESHAB P01" text centered below the logo */
         {
-            i64 logo_cx = (i64)g_fb_w / 2;
-            i64 logo_cy = ((i64)g_fb_h - g_logo_h) / 2;
             const char *ver_str = "DESHAB P01";
             int len = 10;   /* strlen("DESHAB P01") */
             int spacing = g_ascii_w + 1;   /* 11+1 = 12px per char */
             i64 text_w = (i64)len * spacing;
-            i64 text_x = logo_cx - text_w / 2;
+            i64 text_x = (i64)g_fb_w / 2 - text_w / 2;
-            i64 text_y = logo_cy + g_logo_h + 12;  /* 12px below logo */
+            i64 text_y = (i64)g_fb_h / 2 - g_ascii_h / 2;
             /* White text: BGRX = 0xFF_RR_GG_BB = 0xFF_FFFFFF */
             u32 fg = 0xFFFFFFFFu;
             dsk_draw_string(sfb, ver_str, text_x, text_y, fg, spacing);
         }
 
-        logh("[DSK] Logo.png displayed (", (u64)g_logo_w);
+        /* Hold text for 5 seconds */
-        logh("[DSK] x", (u64)g_logo_h);
-
-        /* Hold Logo for 5 seconds */
         u64 logo_start = rdtsc_dsk();
         u64 logo_budget = g_tsc_per_ms * 5000;   /* 5000 ms = 5 seconds */
         while (rdtsc_dsk() - logo_start < logo_budget) __asm__("pause");
-        logl("[DSK] Logo 5s done, proceeding");
+        logl("[DSK] boot text 5s done, proceeding");
 
         /* Follow-up splash: dcplogo.png 3s, then OpenXJ380 xjlogo.png 3s */
         dsk_splash(sfb, g_dcp_logo_rgba, g_dcp_logo_w, g_dcp_logo_h,
@@ -1917,47 +2029,7 @@ static void dsk_spinner_and_check(const void *boot_ctx_ptr) {
         if (skip_login || skip_firstinit) {
             logl("[DSK:SCHED] login skipped by FUCK config");
         } else {
-            DSK_TS_DECL(login_phase);
+            dsk_run_login(ctx);
-            DSK_TS_BEGIN(login_phase);
-            logl("[DSK:SCHED] scheduling login.elf");
-            char ln[12]; /* LOGIN    ELF */
-            ln[0]='L';ln[1]='O';ln[2]='G';ln[3]='I';ln[4]='N';ln[5]=' ';ln[6]=' ';ln[7]=' ';ln[8]='E';ln[9]='L';ln[10]='F';
-            u8 *ld=0; u32 ls=0; void *le=0;
-            int login_ok = 0;
-            if (fat32_read_root_file(ln, &ld, &ls) == 0) {
-                if (dsk_load_elf(ld, ls, &le) == 0) {
-                    char cn[12]; /* USER    CON */
-                    cn[0]='U';cn[1]='S';cn[2]='E';cn[3]='R';cn[4]=' ';cn[5]=' ';cn[6]=' ';cn[7]=' ';cn[8]='C';cn[9]='O';cn[10]='N';
-                    u8 *conf_data=0; u32 conf_size=0;
-                    if (fat32_read_root_file(cn, &conf_data, &conf_size) == 0) {
-                        logl("[DSK] USER.CONF found, passing to login");
-                        dsk_boot_context *ctx_mut = (dsk_boot_context *)ctx;
-                        ctx_mut->reserved[0] = (u64)conf_data;
-                        ctx_mut->reserved[1] = (u64)conf_size;
-                        ctx_mut->reserved[2] = 0;  /* login success flag */
-
-                        logl("[DSK] jumping to login");
-                        void(*lentry)(const dsk_boot_context*)=(void(*)(const dsk_boot_context*))le;
-                        lentry(ctx);
-                        logl("[DSK] login returned");
-
-                        if (ctx_mut->reserved[2] == 1) {
-                            logl("[DSK] login success");
-                            login_ok = 1;
-                        } else {
-                            logl("[DSK] login skipped or failed");
-                        }
-                    } else {
-                        logl("[DSK] USER.CONF not found, skipping login");
-                    }
-                } else {
-                    logl("[DSK] login.elf load failed, skipping login");
-                }
-            } else {
-                logl("[DSK] login.elf not found, skipping login");
-            }
-            (void)login_ok;
-            DSK_TS_END(login_phase, "login phase");
         }
 
         /* default_shell=cmd → 直接进 CMD.ELF（PE/EXE 兼容层前端），
@@ -2009,9 +2081,8 @@ static void dsk_spinner_and_check(const void *boot_ctx_ptr) {
         en[6]='~';en[7]='1';en[8]='E';en[9]='L';en[10]='F';en[11]=0;
         logl("[DSK] loading FirstInit");
         if (dsk_load_and_run(en, ctx) != 0) {
-            logl("[DSK] FirstInit not found, loading desktop directly");
+            /* 严格错误策略：首次启动却没有 FirstInit.elf = 未实现路径，零降级 */
-            milestone_write(6, "desktop loading");
+            dsk_fatal("FS-E07 FIRSTINIT.ELF NOT FOUND");
-            dsk_choose_and_run_session(ctx, sfb, &dsk_cfg, dsk_cfg_ok);
             return;
         }
         logl("[DSK] FirstInit returned, persisting user.conf");
@@ -2020,6 +2091,15 @@ static void dsk_spinner_and_check(const void *boot_ctx_ptr) {
         logh("[DSK:STAT] fat32_write_count=", (u64)fat32_write_count);
         logh("[DSK:STAT] elf_load_count=", (u64)elf_load_count);
         logh("[DSK:STAT] mod_schedule_count=", (u64)mod_schedule_count);
+
+        /* 向导完成后强制重新登录：进桌面前必须再走一次 login.elf。
+         * 零降级策略：登录被跳过/失败（如 Esc 跳过）不允许静默进桌面。 */
+        if (skip_login) {
+            logl("[DSK:SCHED] first-boot login skipped by FUCK config");
+        } else if (!dsk_run_login(ctx)) {
+            dsk_fatal("FS-E06 LOGIN REQUIRED AFTER FIRSTINIT");
+        }
+
         logl("[DSK] loading desktop");
         milestone_write(6, "desktop loading");
         dsk_choose_and_run_session(ctx, sfb, &dsk_cfg, dsk_cfg_ok);

CODE/firstInit/main.c

@@ -231,6 +231,51 @@ static void fb_bitmap_alpha(u32 *fb, const u8 *data, i64 w, i64 h, i64 x, i64 y,
     }
 }
 
+/* ---- 严格错误策略：NET-E 系列 lotus fatal（零降级） ----
+ * 内嵌 ohMyLogo 莲花（与 login.elf / DSK 同源），任何未实现/失败路径
+ * 整屏显示错误码后停机。 */
+#include "../login/ohmylogo_data.c"
+
+static u64 fi_fat_strlen(const char *s) { u64 n = 0; while (s[n]) n++; return n; }
+
+static void fill_rect(u32 *fb, i64 x, i64 y, i64 w, i64 h, u32 color);
+static void firstinit_fatal(const char *sym) {
+    logl(sym);
+    if (fb_a) {
+        u32 *fb = (u32 *)(u64)fb_a;
+        fill_rect(fb, 0, 0, (i64)fb_w, (i64)fb_h, 0xFF020F22u);
+        i64 lx = ((i64)fb_w - g_panic_logo_w) / 2;
+        i64 ly = ((i64)fb_h - g_panic_logo_h) / 2 - 60;
+        if (ly < 0) ly = 0;
+        for (i64 r = 0; r < g_panic_logo_h; r++) {
+            for (i64 c = 0; c < g_panic_logo_w; c++) {
+                const unsigned char *px4 =
+                    g_panic_logo_rgba + ((u64)r * g_panic_logo_w + (u64)c) * 4;
+                u32 a = px4[3];
+                if (a < 8) continue;
+                u32 col = 0xFF000000u | ((u32)px4[0] << 16) | ((u32)px4[1] << 8) | px4[2];
+                if (a < 250) {
+                    u32 bg = 0xFF020F22u;
+                    u32 na = 256 - a;
+                    u32 rr = (((bg >> 16) & 0xFF) * na + ((col >> 16) & 0xFF) * a) >> 8;
+                    u32 gg = (((bg >> 8) & 0xFF) * na + ((col >> 8) & 0xFF) * a) >> 8;
+                    u32 bb = ((bg & 0xFF) * na + (col & 0xFF) * a) >> 8;
+                    col = 0xFF000000u | (rr << 16) | (gg << 8) | bb;
+                }
+                i64 xx = lx + c, yy = ly + r;
+                if (xx < 0 || (u64)xx >= fb_w || yy < 0 || (u64)yy >= fb_h) continue;
+                *(u32 *)((u8 *)fb + (u64)yy * fb_p + (u64)xx * 4) = col;
+            }
+        }
+        i64 ty = ly + g_panic_logo_h + 24;
+        fb_text(fb, sym, ((i64)fb_w - (i64)fi_fat_strlen(sym) * ASCII_STEP) / 2,
+                ty, 0xFFF2D8D8u, 0);
+        fb_text(fb, "DESHAB NET FATAL - SYSTEM HALTED",
+                ((i64)fb_w - 32 * ASCII_STEP) / 2, ty + ASCII_H + 16, 0xFFB08890u, 0);
+    }
+    for (;;) __asm__("cli; hlt");
+}
+
 static void fill_rect(u32 *fb, i64 x, i64 y, i64 w, i64 h, u32 color) {
     for (i64 r=0; r<h; r++) {
         i64 yy = y + r;
@@ -1201,6 +1246,8 @@ static void read_network_page(u32 *fb, i64 card_x, i64 card_y, setup_net *net, i
                 }
                 /* 连接按钮 */
                 if (*mx >= card_x + 680 && *mx < card_x + 860 && *my >= card_y + 310 && *my < card_y + 354) {
+                    /* 严格错误策略：无 wlan 驱动栈 —— 零降级 panic */
+                    firstinit_fatal("NET-E01 WLAN CONNECT NOT IMPLEMENTED");
                     net->connected = 1;
                     logl("[FirstInit] network connect requested");
                     redraw_network_card(fb, card_x, card_y, net, NET_ACT_CONNECT, *mx, *my, bg, fg);
@@ -1246,6 +1293,8 @@ static void read_network_page(u32 *fb, i64 card_x, i64 card_y, setup_net *net, i
                 for (int i=0;i<30;i++) delay_frame();
                 return;
             } else if (active == NET_ACT_CONNECT) {
+                /* 严格错误策略：无 wlan 驱动栈，"连接"是未实现路径 —— 零降级 panic */
+                firstinit_fatal("NET-E01 WLAN CONNECT NOT IMPLEMENTED");
                 net->connected = 1;
                 logl("[FirstInit] network connect requested");
                 redraw_network_card(fb, card_x, card_y, net, active, *mx, *my, bg, fg);

CODE/linux/pack_system_image.sh

@@ -174,7 +174,11 @@ if [[ "$esp_bytes" -ge $((4096 * 1024 * 1024)) ]]; then
 fi
 
 mkfs.vfat -F 32 -n DESHABBOOT -s "$fat_cluster_sectors" "$p1" >/dev/null
-mkfs.ext4 -F -q -L DESHAB -U "$EXT4_UUID" -m 1 "$p2"
+# DSK 内嵌 ext4 读写驱动支持范围：4K block / 256B inode / extent 树，
+# 不支持 journal、metadata_csum、64bit（遇到即 panic FS-E28）——
+# 因此这里必须显式关闭这三个 feature。
+mkfs.ext4 -F -q -L DESHAB -U "$EXT4_UUID" -m 1 \
+    -b 4096 -I 256 -O ^has_journal,^metadata_csum,^64bit,^resize_inode "$p2"
 echo "[pack] filesystems:"
 blkid "$p1" "$p2" || true
 

ISO/run_qemu.bat

@@ -143,17 +143,15 @@ if exist "%USB_IMG%" (
 )
 
 REM ===== Boot disk attach =====
-REM Main disk must use explicit virtio-blk-pci + bootindex=1: with plain
+REM Main disk must use explicit ide-hd + bootindex=1: the DSK/AHCI block
-REM "-drive if=virtio", OVMF only auto-creates a boot entry when virtio-blk
+REM provider only registers the first ready SATA port, so the GPT image
-REM lands on PCI slot 0x3 (no other PCI devices). Adding NVMe/USB/e1000 moves
+REM (p1 FAT32 ESP + p2 ext4) has to live on SATA for DSK to see ext4 at all.
-REM it to 0x4/0x5 and OVMF boot enumeration silently drops the ESP, falling
-REM back to EFI Internal Shell even though BOOTX64.EFI is present and valid.
 REM bootindex=1 injects the fw_cfg bootorder entry so OVMF always picks it.
-set "OSDISK_OPTS=-drive if=none,id=osdisk,format=raw,file="%IMG%" -device virtio-blk-pci,drive=osdisk,bootindex=1"
+set "OSDISK_OPTS=-drive if=none,id=osdisk,format=raw,file="%IMG%" -device ide-hd,drive=osdisk,bus=ide.0,bootindex=1"
 
 if exist "%SATA_IMG%" (
     echo [qemu] SATA:  %SATA_IMG%
-    "%QEMU%" -accel %QEMU_ACCEL% -machine q35 -m 12G -cpu %QEMU_CPU% %SERIAL_ARGS% -drive if=pflash,format=raw,readonly=on,file="%OVMF%" %OSDISK_OPTS% -drive id=sata0,format=raw,file="%SATA_IMG%",if=none -device ide-hd,drive=sata0,bus=ide.0 %NVME_OPTS% %USB_OPTS% -netdev user,id=net0 -device e1000,netdev=net0,mac=52:54:00:12:34:56 -boot menu=on
+    "%QEMU%" -accel %QEMU_ACCEL% -machine q35 -m 12G -cpu %QEMU_CPU% %SERIAL_ARGS% -drive if=pflash,format=raw,readonly=on,file="%OVMF%" %OSDISK_OPTS% -drive id=sata0,format=raw,file="%SATA_IMG%",if=none -device ide-hd,drive=sata0,bus=ide.1 %NVME_OPTS% %USB_OPTS% -netdev user,id=net0 -device e1000,netdev=net0,mac=52:54:00:12:34:56 -boot menu=on
 ) else (
     echo [qemu] SATA image not found, booting without block device
     "%QEMU%" -accel %QEMU_ACCEL% -machine q35 -m 12G -cpu %QEMU_CPU% %SERIAL_ARGS% -drive if=pflash,format=raw,readonly=on,file="%OVMF%" %OSDISK_OPTS% %NVME_OPTS% %USB_OPTS% -netdev user,id=net0 -device e1000,netdev=net0 -boot menu=on

docs/STATUS.md

@@ -76,6 +76,20 @@
 
 ## 文档体系
 
+### FS-E 系列：文件系统读写严格模式（2026-10-02）
+
+| 项 | 状态 | 说明 | 证据 |
+|----|------|------|------|
+| ext4 读写驱动（CODE/dsk/ext4.c） | ✅ | GPT 定位 p2 + feature 校验 + extent 树(depth0/1)读写 + 块/inode 分配回收 + 目录项插入 + 写后回读校验；启动自检 PASS | `.build_tmp/qemu_run.log`（[EXT4] selftest PASS） |
+| FAT32 大盘写修复 | ✅ | 按需 FAT 表项 RMW（fat32_fat_read/write_entry）+ 块状空闲簇扫描（fat32_find_free_cluster）；修复 rec_len +4 收缩偏移与 chunk 对齐两处错位 | 同上（USER.CONF verify ok → firstInit.txt flip ok） |
+| FS-E01..E07 / FS-E2x / FS-E3x 插桩 | ✅ | 写失败/校验不符/feature 不支持/路径缺失 → 莲花 panic 零降级 | `.build_tmp/qemu_run.log`（FS-E02/E06/E22 复现） |
+| 向导后强制重登 | ✅ | first-boot 分支 FirstInit→persist→login；登录跳过/失败 → FS-E06 panic | 同上（login success → desktop ready） |
+| NET-E01 网络页 Connect panic | ✅ | 无 wlan 栈，Connect 即 panic；Save(仅存配置) 为唯一前进路径 | 同上（NET-E01 复现，fb pmemsave 确认莲花屏） |
+| 主镜像改挂 SATA（run_qemu.bat） | ✅ | DSK/AHCI 块层必须可见 GPT 盘才能访问 p2 ext4；边车退居 ide.1 | run_qemu.bat |
+| 开机画面去 Logo | ✅ | 移除 Logo.png 图像，仅保留居中 "DESHAB P01" 文字；dcp/xj logo 改由 TEXTURES/ 重新生成 | build 日志 |
+
+## 文档体系
+
 | 文档 | 状态 | 说明 |
 |------|------|------|
 | [STATUS.md](./STATUS.md) | ✅ | 单一状态源（本文件） |