[fs][fat32] trivially convert to C++

lib/fs/fat32/fat.cpp

@@ -41,7 +41,7 @@ status_t fat32_mount(bdev_t *dev, fscookie **cookie) {
     if (!dev)
         return ERR_NOT_VALID;
 
-    uint8_t *bs = malloc(512);
+    uint8_t *bs = (uint8_t *)malloc(512);
     int err = bio_read(dev, bs, 1024, 512);
     if (err < 0) {
         result = ERR_GENERIC;
@@ -54,7 +54,8 @@ status_t fat32_mount(bdev_t *dev, fscookie **cookie) {
         goto end;
     }
 
-    fat_fs_t *fat = malloc(sizeof(fat_fs_t));
+    fat_fs_t *fat;
+    fat = (fat_fs_t *)malloc(sizeof(fat_fs_t));
     fat->lba_start = 1024;
     fat->dev = dev;
 
@@ -165,12 +166,26 @@ status_t fat32_unmount(fscookie *cookie) {
 }
 
 static const struct fs_api fat32_api = {
+    .format = nullptr,
+    .fs_stat = nullptr,
+
     .mount = fat32_mount,
     .unmount = fat32_unmount,
     .open = fat32_open_file,
+    .create = nullptr,
+    .remove = nullptr,
+    .truncate = nullptr,
     .stat = fat32_stat_file,
     .read = fat32_read_file,
+    .write = nullptr,
     .close = fat32_close_file,
+
+    .mkdir = nullptr,
+    .opendir = nullptr,
+    .readdir = nullptr,
+    .closedir = nullptr,
+
+    .file_ioctl = nullptr,
 };
 
 STATIC_FS_IMPL(fat32, &fat32_api);

lib/fs/fat32/file.cpp

@@ -64,7 +64,7 @@ static inline off_t fat32_offset_for_cluster(fat_fs_t *fat, uint32_t cluster) {
 
 static char *fat32_dir_get_filename(uint8_t *dir, off_t offset, int lfn_sequences) {
     int result_len = 1 + (lfn_sequences == 0 ? 12 : (lfn_sequences * 26));
-    char *result = malloc(result_len);
+    char *result = (char *)malloc(result_len);
     int j = 0;
     memset(result, 0x00, result_len);
 
@@ -119,7 +119,7 @@ status_t fat32_open_file(fscookie *cookie, const char *path, filecookie **fcooki
     fat_fs_t *fat = (fat_fs_t *)cookie;
     status_t result = ERR_GENERIC;
 
-    uint8_t *dir = malloc(fat->bytes_per_cluster);
+    uint8_t *dir = (uint8_t *)malloc(fat->bytes_per_cluster);
     uint32_t dir_cluster = fat->root_cluster;
     fat_file_t *file = NULL;
 
@@ -169,7 +169,7 @@ status_t fat32_open_file(fscookie *cookie, const char *path, filecookie **fcooki
             if (matched) {
                 uint16_t target_cluster = fat_read16(dir, offset + 0x1a);
                 if (done == true) {
-                    file = malloc(sizeof(fat_file_t));
+                    file = (fat_file_t *)malloc(sizeof(fat_file_t));
                     file->fat_fs = fat;
                     file->start_cluster = target_cluster;
                     file->length = fat_read32(dir, offset + 0x1c);
@@ -212,10 +212,11 @@ out:
     return result;
 }
 
-ssize_t fat32_read_file(filecookie *fcookie, void *buf, off_t offset, size_t len) {
+ssize_t fat32_read_file(filecookie *fcookie, void *_buf, off_t offset, size_t len) {
     fat_file_t *file = (fat_file_t *)fcookie;
     fat_fs_t *fat = file->fat_fs;
     bdev_t *dev = fat->dev;
+    uint8_t *buf = (uint8_t *)_buf;
 
     uint32_t cluster = 0;
     if (offset <= fat->bytes_per_cluster) {

lib/fs/fat32/rules.mk

@@ -7,8 +7,7 @@ MODULE_DEPS += \
 	lib/bcache \
 	lib/bio
 
-MODULE_SRCS += \
-	$(LOCAL_DIR)/fat.c \
-	$(LOCAL_DIR)/file.c
+MODULE_SRCS += $(LOCAL_DIR)/fat.cpp
+MODULE_SRCS += $(LOCAL_DIR)/file.cpp
 
 include make/module.mk