fygue: fix FAT cluster resolution + support stat() for directory + support stat(), lseek() and write() (EROFS) for file

CMakeLists.txt

@@ -268,6 +268,8 @@ set(SOURCES
   src/fs/fygue/fygue_dir_lseek.c
   src/fs/fygue/fygue_dir_write.c
   src/fs/fygue/fygue_dir_close.c
+  src/fs/fygue/fygue_file_lseek.c
+  src/fs/fygue/fygue_file_write.c
   src/fs/fygue/fat/cluster.c
   src/fs/fygue/fat/initialize.c
   src/fs/fygue/fat/fat_dir_read.c

src/fs/fygue/fat/cluster.c

@@ -2,29 +2,64 @@
 ** fygue/fat/cluster   - FAT cluster handling
 */
 #include "fat.h"
+#include "../flash/flash.h"
 
 //---
 // Public
 //---
 
-/* fygue_fat_cluster_get_next() - find the next cluster ID of a file */
+/* fygue_fat_cluster_get_next() - find the next cluster ID of a file
+ *
+ * returns
+ *  -7  next cluster unused (0x0000)
+ *  -6  next cluster end (0xffff)
+ *  -5  internal error
+ *  -4  provided cluster unused (0x0000)
+ *  -3  provided cluster end (0xffff)
+ *  -2  provided invalid cluster (root or "out of fat")
+ *  -1  argument error
+ *   0  success
+ *
+ * todo
+ *   - ensure FAT1 information is the same ? */
 int fygue_fat_cluster_get_next(struct fygue_fat *fat, int *cluster_current)
 {
     uint16_t *fat0;
+    int nb_entry_per_sector;
+    int cluster_sector;
+    int cluster_real;
     int cluster;
+    int rc;
 
     if (fat == NULL || cluster_current == NULL)
         return -1;
     cluster = *cluster_current;
+    if (cluster == 0xffff)
+        return -3;
+    if (cluster == 0x0000)
+        return -4;
     if (cluster <= 1)
         return -2;
     if (cluster >= fat->ClusterCount)
         return -2;
-    fat0 = (void*)fat->FAT0Addr;
+    nb_entry_per_sector = fat->SectorSize / 2;
-    if (fat0[cluster] == 0xffff)
+    cluster_sector = cluster / nb_entry_per_sector;
-        return -3;
+    cluster_real = cluster - (cluster_sector * nb_entry_per_sector);
-    *cluster_current = fat0[cluster];
+    rc = fygue_fat_sector_get_addr(
-    return 0;
+        fat,
+        (void*)&fat0,
+        fat->FAT0SectorID + cluster_sector
+    );
+    if (rc < 0)
+        return -5;
+    rc = 0;
+    cluster = FAT_WORD(fat0[cluster_real]);
+    if (cluster == 0xffff)
+        rc = -6;
+    if (cluster == 0x0000)
+        rc = -7;
+    *cluster_current = cluster;
+    return rc;
 }
 
 /* fygue_fat_cluster_get_sector() - get sector ID from cluster ID */

src/fs/fygue/fat/fat.h

@@ -44,8 +44,6 @@ struct fygue_fat
     int FAT1SectorID;
     int RootSectorID;
     int DataSectorID;
-    uintptr_t FAT0Addr;
-    uintptr_t FAT1Addr;
     uintptr_t RootAddr;
     uintptr_t BPB;
     struct {

src/fs/fygue/fat/initialize.c

@@ -147,23 +147,26 @@ static int _fygue_fat_configure(struct fygue_fat *fat)
 }
 
 /* _fygue_fat_prepare() - prepare logic information */
-static int _fygue_fat_prepare(struct fygue_fat *fat) {
+static int _fygue_fat_prepare(struct fygue_fat *fat)
+{
     int rc;
 
-    rc = fygue_flash_cmap_lsector_get_addr(
+#if 0
-        &fat->_flash.cmap,
+    rc = fygue_fat_sector_get_addr(
+        fat,
         &fat->FAT0Addr,
         fat->FAT0SectorID
     );
     if (rc != 0)
         return -1;
-    rc = fygue_flash_cmap_lsector_get_addr(
+    rc = fygue_fat_sector_get_addr(
-        &fat->_flash.cmap,
+        fat,
         (void*)&fat->FAT1Addr,
         fat->FAT1SectorID
     );
     if (rc != 0)
         return -1;
+#endif
     rc = fygue_flash_cmap_lsector_get_addr(
         &fat->_flash.cmap,
         &fat->RootAddr,

src/fs/fygue/fygue.c

@@ -85,8 +85,8 @@ int fygue_resolve(char const * const path, struct fygue_resolve *resolve)
 
 const fs_descriptor_type_t fygue_descriptor_type = {
     .read   = NULL,
-    .write  = NULL,
+    .write  = (void*)&fygue_file_write,
-    .lseek  = NULL,
+    .lseek  = (void*)&fygue_file_lseek,
     .close  = NULL,
 };
 
@@ -94,5 +94,5 @@ const fs_descriptor_type_t fygue_dir_descriptor_type = {
     .read   = (void*)&fygue_dir_read,
     .write  = (void*)&fygue_dir_write,
     .lseek  = (void*)&fygue_dir_lseek,
-    .close  = NULL,
+    .close  = (void*)&fygue_dir_close,
 };

src/fs/fygue/fygue.h

@@ -65,6 +65,7 @@ struct fygue_resolve {
         struct {
             off_t cursor;
             struct fygue_fat_file fat;
+            off_t size;
         } file;
         struct {
             struct fygue_fat_dir fat;
@@ -94,6 +95,10 @@ extern int fygue_resolve(
     struct fygue_resolve *resolve
 );
 
+//---
+// Directory interface
+//---
+
 /* fygue_dir_read(): directory read implementation */
 extern int fygue_dir_read(
     struct fygue_descriptor *desc,
@@ -115,6 +120,27 @@ ssize_t fygue_dir_write(
     size_t size
 );
 
+/* fygue_dir_close(): close directory */
+extern int fygue_dir_close(struct fygue_descriptor *desc);
+
+//---
+// File interface
+//---
+
+/* fygue_file_lseek(): seek directory */
+extern off_t fygue_file_lseek(
+    struct fygue_descriptor *desc,
+    off_t offset,
+    int whence
+);
+
+/* fygue_file_write(): write directory (EROFS) */
+extern ssize_t fygue_file_write(
+    struct fygue_descriptor *desc,
+    void *buffer,
+    size_t size
+);
+
 #ifdef __cplusplus
 }
 #endif

src/fs/fygue/fygue_dir_close.c

@@ -3,6 +3,7 @@
 #include "fygue.h"
 #include "fat/fat.h"
 
+/* fygue_dir_close(): close directory */
 int fygue_dir_close(struct fygue_descriptor *desc)
 {
     struct fygue_fsinfo *fsinfo;

src/fs/fygue/fygue_dir_lseek.c

@@ -26,10 +26,15 @@ off_t fygue_dir_lseek(
     off_t offset,
     int whence
 ) {
+    ENOTSUP_IF_NOT_FYGUE(-1);
     if (desc == NULL || desc->resolve.type != FYGUE_FILE_TYPE_DIR) {
         errno = EBADF;
         return -1;
     }
+    if (whence != SEEK_CUR && whence != SEEK_SET && whence != SEEK_END) {
+        errno = EINVAL;
+        return -1;
+    }
     if(whence == SEEK_CUR)
         offset += desc->resolve.dir.pos;
     if(whence == SEEK_END) {

src/fs/fygue/fygue_file_lseek.c

@@ -0,0 +1,28 @@
+#include "fygue.h"
+
+/* fygue_file_lseek(): seek directory */
+off_t fygue_file_lseek(
+    struct fygue_descriptor *desc,
+    off_t offset,
+    int whence
+) {
+    ENOTSUP_IF_NOT_FYGUE(-1);
+    if (desc == NULL || desc->resolve.type != FYGUE_FILE_TYPE_FILE) {
+        errno = EBADF;
+        return -1;
+    }
+    if (whence != SEEK_CUR && whence != SEEK_SET && whence != SEEK_END) {
+        errno = EINVAL;
+        return -1;
+    }
+    if(whence == SEEK_CUR)
+        offset += desc->resolve.dir.pos;
+    if(whence == SEEK_END)
+        offset += desc->resolve.file.size;
+    if(offset < 0 || offset >= desc->resolve.file.size + 1) {
+        errno = EINVAL;
+        return -1;
+    }
+    desc->resolve.file.cursor = offset;
+    return desc->resolve.file.cursor;
+}

src/fs/fygue/fygue_file_write.c

@@ -0,0 +1,22 @@
+#include "fygue.h"
+
+/* fygue_file_write(): write directory (EISDIR) */
+ssize_t fygue_file_write(
+    struct fygue_descriptor *desc,
+    void *buffer,
+    size_t size
+) {
+    ENOTSUP_IF_NOT_FYGUE(-1);
+    if (desc == NULL || desc->resolve.type != FYGUE_FILE_TYPE_FILE) {
+        errno = EBADF;
+        return -1;
+    }
+    if (buffer == NULL) {
+        errno = EFAULT;
+        return -1;
+    }
+    if (size == 0)
+        return 0;
+    errno = EROFS;
+    return -1;
+}