Changeset 0182e5cc in mainline for uspace/srv/fs/fat/fat_fat.c

Timestamp:

2011-05-24T19:56:11Z (13 years ago)

Author:

Oleg Romanenko <romanenko.oleg@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

a1467102

Parents:

88a27f1

Message:

1. Rewrite and clean fat_get_cluster_fat12
2. Support MIPS and other arch with only alligned memory access.
3. Fix incompatibilities with BigEndian.
4. Tested on IA32 and on MIPS32 EndianBig (GXEmul):

FAT12,16 reading and writing. FAT32 only reading. FAT32 writing - not tested!

5. Some fixes for FAT32: reading hi and lo part of node cluster number from fat_dentry_t,

but its need more fixes to change size of cluster number from uint16_t to uint32_t etc.

File:

• uspace/srv/fs/fat/fat_fat.c (modified) (11 diffs)

uspace/srv/fs/fat/fat_fat.c

@@ -299 +299 @@
 {
         block_t *b, *b1;
+        uint16_t byte1, byte2;
         aoff64_t offset;
         int rc;
 
         offset = (clst + clst/2);
-
         rc = block_get(&b, devmap_handle, RSCNT(bs) + SF(bs) * fatno +
             offset / BPS(bs), BLOCK_FLAGS_NONE);
         if (rc != EOK)
                 return rc;
+
+        byte1 = ((uint8_t*) b->data)[offset];
 
         /* This cluster access spans a sector boundary. Check only for FAT12 */
@@ -324 +326 @@
                         * first byte of next sector
                         */
-                        *value  = *(uint8_t *)(b->data + BPS(bs) - 1);
-                        *value |= *(uint8_t *)(b1->data) << 8;
+                        byte2 = ((uint8_t*) b1->data)[0];
 
                         rc = block_put(b1);
@@ -340 +341 @@
         }
         else
-                *value = *(uint16_t *)(b->data + offset % BPS(bs));
-
+                byte2 = ((uint8_t*) b->data)[offset+1];
+
+#ifdef __BE__   
+        *value = byte2 | (byte1 << 8);
+#else
+        *value = byte1 | (byte2 << 8);
+#endif
+
+        *value = uint16_t_le2host(*value);
         if (IS_ODD(clst))
-                *value = (*value) >> 4;
+                *value = *value >> 4;
         else
-                *value = (*value) & FAT12_MASK;
-
-        *value = uint16_t_le2host(*value);
+                *value = *value & FAT12_MASK;
+
         rc = block_put(b);
 
@@ -408 +415 @@
                 return rc;
 
-        *value = uint32_t_le2host(*(uint32_t *)(b->data + offset % BPS(bs)) & FAT32_MASK);
+        *value = uint32_t_le2host(*(uint32_t *)(b->data + offset % BPS(bs))) & FAT32_MASK;
 
         rc = block_put(b);
@@ -433 +440 @@
         assert(fatno < FATCNT(bs));
 
-        if (FAT_IS_FAT12(bs))
+        if (FAT_IS_FAT12(bs)) {
                 rc = fat_get_cluster_fat12(bs, devmap_handle, fatno, clst, value);
-        else if (FAT_IS_FAT32(bs))
-                rc = fat_get_cluster_fat32(bs, devmap_handle, fatno, clst, value);
-        else
-                rc = fat_get_cluster_fat16(bs, devmap_handle, fatno, clst, value);
+        }
+        else {
+                if (FAT_IS_FAT32(bs))
+                        rc = fat_get_cluster_fat32(bs, devmap_handle, fatno, clst, value);
+                else
+                        rc = fat_get_cluster_fat16(bs, devmap_handle, fatno, clst, value);
+        }
 
         return rc;
@@ -459 +469 @@
         block_t *b, *b1=NULL;
         aoff64_t offset;
+        uint16_t byte1, byte2;
         int rc;
 
         offset = (clst + clst/2);
-
         rc = block_get(&b, devmap_handle, RSCNT(bs) + SF(bs) * fatno +
             offset / BPS(bs), BLOCK_FLAGS_NONE);
@@ -468 +478 @@
                 return rc;
 
-        value = host2uint32_t_le(value);
-
-        uint16_t temp;
+        byte1 = ((uint8_t*) b->data)[offset];
         bool border = false;
         /* This cluster access spans a sector boundary. Check only for FAT12 */
@@ -487 +495 @@
                         * first byte of next sector
                         */
-                        temp  = *(uint8_t *)(b->data + BPS(bs) - 1);
-                        temp |= *(uint8_t *)(b1->data) << 8;
+                        byte2 = ((uint8_t*) b1->data)[0];
                         border = true;
                 }
@@ -498 +505 @@
         }
         else
-                temp = *(uint16_t *)(b->data + offset % BPS(bs));
+                byte2 = ((uint8_t*) b->data)[offset+1];
 
         if (IS_ODD(clst)) {
-                temp &= 0x000f;
-                temp |= value << 4;
-        }
-        else {
-                temp &= 0xf000;
-                temp |= value & FAT12_MASK;
-        }
-
+                byte1 &= 0x0f;
+                byte2 = 0;
+                value = (value << 4);
+        } else {
+                byte1 = 0;
+                byte2 &= 0xf0;
+                value &= FAT12_MASK;
+        }
+
+        byte1 = byte1 | (value & 0xff);
+        byte2 = byte2 | (value >> 8);
+
+        ((uint8_t*) b->data)[offset] = byte1;
         if (border) {
-                *(uint8_t *)(b->data + BPS(bs) - 1) = temp & 0xff;
-                *(uint8_t *)(b1->data) = temp >> 8;
+                ((uint8_t*) b1->data)[0] = byte2;
+
                 b1->dirty = true;
-        } else
-                *(uint16_t *)(b->data + offset % BPS(bs)) = temp;
-
-        if (b1 && b1->dirty) {
                 rc = block_put(b1);
                 if (rc != EOK) {
@@ -522 +530 @@
                         return rc;
                 }
-        }
+        } else 
+                ((uint8_t*) b->data)[offset+1] = byte2;
 
         b->dirty = true;        /* need to sync block */
@@ -554 +563 @@
                 return rc;
 
-        *(uint16_t *)(b->data + offset % BPS(bs)) = host2uint32_t_le(value);
+        *(uint16_t *)(b->data + offset % BPS(bs)) = host2uint16_t_le(value);
 
         b->dirty = true;        /* need to sync block */