fatfs: add support for small disc sizes (less then 16 MB)

diff --git a/components/fatfs/src/ff.c b/components/fatfs/src/ff.c
index 0d7d7366bf68956df32dd4b6d94d825617c714e8..53361e50fd1f9426542b9cef2b305bb9dfc73cc4 100644 (file)
--- a/components/fatfs/src/ff.c
+++ b/components/fatfs/src/ff.c
@@ -5665,6 +5665,9 @@ FRESULT f_mkfs (
 /* Create partition table on the physical drive                          */\r
 /*-----------------------------------------------------------------------*/\r
 \r
+#define CLUSTER_SIZE   63\r
+#define SUPPORTED_FLASH_SIZE 0x1000\r
+\r
 FRESULT f_fdisk (\r
        BYTE pdrv,                      /* Physical drive number */\r
        const DWORD* szt,       /* Pointer to the size table for each partitions */\r
@@ -5675,18 +5678,21 @@ FRESULT f_fdisk (
        BYTE s_hd, e_hd, *p, *buf = (BYTE*)work;\r
        DSTATUS stat;\r
        DWORD sz_disk, sz_part, s_part;\r
-\r
+       DWORD cluster_size = CLUSTER_SIZE;\r
 \r
        stat = disk_initialize(pdrv);\r
        if (stat & STA_NOINIT) return FR_NOT_READY;\r
        if (stat & STA_PROTECT) return FR_WRITE_PROTECTED;\r
        if (disk_ioctl(pdrv, GET_SECTOR_COUNT, &sz_disk)) return FR_DISK_ERR;\r
-\r
        /* Determine the CHS without any care of the drive geometry */\r
-       for (n = 16; n < 256 && sz_disk / n / 63 > 1024; n *= 2) ;\r
+       for (n = 16; n < 256 && sz_disk / n / cluster_size > 1024; n *= 2) ;\r
        if (n == 256) n--;\r
+       if (sz_disk < SUPPORTED_FLASH_SIZE) {\r
+               cluster_size = 1;\r
+               n = sz_disk;\r
+       }\r
        e_hd = n - 1;\r
-       sz_cyl = 63 * n;\r
+       sz_cyl = cluster_size * n;\r
        tot_cyl = sz_disk / sz_cyl;\r
 \r
        /* Create partition table */\r
@@ -5699,7 +5705,7 @@ FRESULT f_fdisk (
                sz_part = (DWORD)sz_cyl * p_cyl;\r
                if (i == 0) {   /* Exclude first track of cylinder 0 */\r
                        s_hd = 1;\r
-                       s_part += 63; sz_part -= 63;\r
+                       s_part += cluster_size; sz_part -= cluster_size;\r
                } else {\r
                        s_hd = 0;\r
                }\r
@@ -5712,7 +5718,7 @@ FRESULT f_fdisk (
                p[3] = (BYTE)b_cyl;                                     /* Start cylinder */\r
                p[4] = 0x06;                                            /* System type (temporary setting) */\r
                p[5] = e_hd;                                            /* End head */\r
-               p[6] = (BYTE)((e_cyl >> 2) + 63);       /* End sector */\r
+               p[6] = (BYTE)((e_cyl >> 2) + cluster_size);     /* End sector */\r
                p[7] = (BYTE)e_cyl;                                     /* End cylinder */\r
                st_dword(p + 8, s_part);                        /* Start sector in LBA */\r
                st_dword(p + 12, sz_part);                      /* Partition size */\r