Changeset ffee7bf in mainline

Timestamp:

2012-02-18T15:44:21Z (13 years ago)

Author:

Maurizio Lombardi <m.lombardi85@…>

Branches:

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

Children:

6b3cda3

Parents:

e872326

Message:

mkexfat: compute the cluster size needed to index the entire device, fix syntax errors.

File:

• uspace/app/mkexfat/mkexfat.c (modified) (9 diffs)

uspace/app/mkexfat/mkexfat.c

@@ -39 +39 @@
 #include <stdio.h>
 #include <libblock.h>
+#include <assert.h>
+#include <errno.h>
+#include <byteorder.h>
+#include <sys/types.h>
+#include <sys/typefmt.h>
+#include "exfat.h"
 
 #define NAME    "mkexfat"
@@ -48 +54 @@
 #define div_round_up(a, b) (((a) + (b) - 1) / (b))
 
+/** The default size of each cluster is 4096 byte */
+#define DEFAULT_CLUSTER_SIZE 4096
+
+static unsigned log2(unsigned n);
+
 typedef struct exfat_cfg {
-        uint64_t volume_start;
-        uint64_t volume_count;
+        aoff64_t volume_start;
+        aoff64_t volume_count;
         uint32_t fat_sector_count;
         uint32_t data_start_sector;
         uint32_t data_cluster;
         uint32_t rootdir_cluster;
-        unsigned bytes_per_sector;
-        unsigned sec_per_cluster;
+        size_t   sector_size;
+        size_t   cluster_size;
+        unsigned long total_clusters;
 } exfat_cfg_t;
 
@@ -71 +83 @@
 cfg_params_initialize(exfat_cfg_t *cfg)
 {
+        aoff64_t const volume_bytes = cfg->volume_count * cfg->sector_size;
+
+        /** Number of clusters required to index the entire device, it must
+         * be less then UINT32_MAX.
+         */
+        aoff64_t n_req_clusters = volume_bytes / DEFAULT_CLUSTER_SIZE;
+        cfg->cluster_size = DEFAULT_CLUSTER_SIZE;
+
+        /* Compute the required cluster size to index
+         * the entire storage device.
+         */
+        while (n_req_clusters > UINT32_MAX &&
+            (cfg->cluster_size < 32 * 1024 * 1024)) {
+
+                cfg->cluster_size <<= 1;
+                n_req_clusters = volume_bytes / cfg->cluster_size;
+        }
 }
 
@@ -99 +128 @@
         vbr->version.minor = 0;
         vbr->volume_flags = host2uint16_t_le(0);
-        vbr->bytes_per_sector = cfg->bytes_per_sectors;
-        vbr->sec_per_cluster = cfg->sec_per_cluster;
+        vbr->bytes_per_sector = log2(cfg->sector_size);
+        vbr->sec_per_cluster = log2(cfg->cluster_size / cfg->sector_size);
+
+        /* Maximum cluster size is 32 Mb */
+        assert((vbr->bytes_per_sector + vbr->sec_per_cluster) <= 25);
+
         vbr->fat_count = 1;
         vbr->drive_no = 0x80;
@@ -107 +140 @@
 }
 
+/** Given a power-of-two number (n), returns the result of log2(n).
+ *
+ * It works only if n is a power of two.
+ */
+static unsigned log2(unsigned n)
+{
+        unsigned r;
+
+        for (r = 0;n >> r != 1; ++r);
+
+        return r;
+}
+
 int main (int argc, char **argv)
 {
         exfat_cfg_t cfg;
-        aoff64_t dev_nblocks;
+        exfat_bs_t  vbr;
         char *dev_path;
         service_id_t service_id;
-        size_t sector_size;
         int rc;
 
@@ -134 +179 @@
         rc = loc_service_get_id(dev_path, &service_id, 0);
         if (rc != EOK) {
-                printf(NAME ": Error resolving device `%s'.\n");
+                printf(NAME ": Error resolving device `%s'.\n", dev_path);
                 return 2;
         }
@@ -144 +189 @@
         }
 
-        rc = block_get_bsize(service_id, &sector_size);
+        rc = block_get_bsize(service_id, &cfg.sector_size);
         if (rc != EOK) {
                 printf(NAME ": Error determining device block size.\n");
@@ -150 +195 @@
         }
 
-        rc = block_get_nblocks(service_id, &dev_nblocks);
+        if (cfg.sector_size > 4096) {
+                printf(NAME ":Error, sector size can't be greater" \
+                    " than 4096 bytes.\n");
+                return 2;
+        }
+
+        rc = block_get_nblocks(service_id, &cfg.volume_count);
         if (rc != EOK) {
                 printf(NAME ": Warning, failed to obtain device block size.\n");
@@ -157 +208 @@
         } else {
                 printf(NAME ": Block device has %" PRIuOFF64 " blocks.\n",
-                    dev_nblocks);
-
-                cfg.volume_count = dev_nblocks;
+                    cfg.volume_count);
         }
 
         cfg_params_initialize(&cfg);
+        vbr_initialize(&vbr, &cfg);