Merge patch series "fs: fat: calculate FAT type based on cluster count"
To quote the author:
This series fixes an issue where the FAT type (FAT12, FAT16) is not
correctly detected, e.g. when the BPB field BS_FilSysType contains the
valid value "FAT ".
This issue occures, for example, if a partition is formatted by
swupdate using its diskformat handler. swupdate uses the FAT library
from http://elm-chan.org/fsw/ff/ internally.
See https://groups.google.com/g/swupdate/c/7Yc3NupjXx8 for a
discussion in the swupdate mailing list.
Please refer to the commit messages for more details.
1. Added bootsector checks
Most tests from https://www.win.tue.nl/~aeb/linux/fs/fat/fat-2.html
are added in the commit 'fs: fat: add bootsector validity check'.
Only the tests VIII, IX and X are not implemented.
I also checked the Linux kernel code (v6.6) and did not find any
checks on 'vistart->fs_type'. This is the reason why is skipped them
here.
See section '2. Size comparisons' for the impact on the binary size.
2. Size comparisons
I executed bloat-o-meter from the Linux kernel for an arm64
target (config xilinx_zynqmp_mini_emmc0_defconfig):
Comparison of the binary spl/u-boot-spl between master (rev
e17d174773) and this patch
series (including the added validity checks of the boot sector):
add/remove: 0/0 grow/shrink: 1/1 up/down: 100/-12 (88)
Function old new delta
read_bootsectandvi 308 408 +100
fat_itr_root 444 432 -12
Total: Before=67977, After=68065, chg +0.13%
When compare the size of the binary spl/u-boot-spl between master this
series without the the validity checks of the boot sector:
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-24 (-24)
Function old new delta
read_bootsectandvi 308 296 -12
fat_itr_root 444 432 -12
Total: Before=67977, After=67953, chg -0.04%
So the size of the spl on this arm64 target increases by 88 bytes for
this series. When i remove the validity check the size decreases by 24 bytes.
This commit is contained in:
Tom Rini
commit
e2a9edc0ce
114
fs/fat/fat.c
114
fs/fat/fat.c
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@ -18,12 +18,17 @@
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#include <fs.h>
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#include <log.h>
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#include <asm/byteorder.h>
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#include <asm/unaligned.h>
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#include <part.h>
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#include <malloc.h>
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#include <memalign.h>
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#include <asm/cache.h>
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#include <linux/compiler.h>
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#include <linux/ctype.h>
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#include <linux/log2.h>
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/* maximum number of clusters for FAT12 */
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#define MAX_FAT12 0xFF4
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/*
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* Convert a string to lowercase. Converts at most 'len' characters,
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@ -483,6 +488,73 @@ static __u8 mkcksum(struct nameext *nameext)
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return ret;
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}
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/*
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* Determine if the FAT type is FAT12 or FAT16
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*
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* Based on fat_fill_super() from the Linux kernel's fs/fat/inode.c
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*/
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static int determine_legacy_fat_bits(const boot_sector *bs)
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{
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u16 fat_start = bs->reserved;
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u32 dir_start = fat_start + bs->fats * bs->fat_length;
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u32 rootdir_sectors = get_unaligned_le16(bs->dir_entries) *
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sizeof(dir_entry) /
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get_unaligned_le16(bs->sector_size);
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u32 data_start = dir_start + rootdir_sectors;
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u16 sectors = get_unaligned_le16(bs->sectors);
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u32 total_sectors = sectors ? sectors : bs->total_sect;
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u32 total_clusters = (total_sectors - data_start) /
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bs->cluster_size;
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return (total_clusters > MAX_FAT12) ? 16 : 12;
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}
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/*
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* Determines if the boot sector's media field is valid
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*
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* Based on fat_valid_media() from Linux kernel's include/linux/msdos_fs.h
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*/
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static int fat_valid_media(u8 media)
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{
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return media >= 0xf8 || media == 0xf0;
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}
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/*
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* Determines if the given boot sector is valid
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*
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* Based on fat_read_bpb() from the Linux kernel's fs/fat/inode.c
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*/
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static int is_bootsector_valid(const boot_sector *bs)
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{
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u16 sector_size = get_unaligned_le16(bs->sector_size);
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u16 dir_per_block = sector_size / sizeof(dir_entry);
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if (!bs->reserved)
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return 0;
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if (!bs->fats)
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return 0;
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if (!fat_valid_media(bs->media))
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return 0;
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if (!is_power_of_2(sector_size) ||
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sector_size < 512 ||
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sector_size > 4096)
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return 0;
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if (!is_power_of_2(bs->cluster_size))
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return 0;
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if (!bs->fat_length && !bs->fat32_length)
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return 0;
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if (get_unaligned_le16(bs->dir_entries) & (dir_per_block - 1))
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return 0;
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return 1;
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}
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/*
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* Read boot sector and volume info from a FAT filesystem
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*/
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@ -506,7 +578,8 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
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if (disk_read(0, 1, block) < 0) {
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debug("Error: reading block\n");
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goto fail;
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ret = -1;
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goto out_free;
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}
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memcpy(bs, block, sizeof(boot_sector));
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@ -516,8 +589,14 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
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bs->heads = FAT2CPU16(bs->heads);
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bs->total_sect = FAT2CPU32(bs->total_sect);
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if (!is_bootsector_valid(bs)) {
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debug("Error: bootsector is invalid\n");
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ret = -1;
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goto out_free;
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}
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/* FAT32 entries */
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if (bs->fat_length == 0) {
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if (!bs->fat_length && bs->fat32_length) {
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/* Assume FAT32 */
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bs->fat32_length = FAT2CPU32(bs->fat32_length);
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bs->flags = FAT2CPU16(bs->flags);
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@ -528,28 +607,11 @@ read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
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*fatsize = 32;
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} else {
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vistart = (volume_info *)&(bs->fat32_length);
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*fatsize = 0;
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*fatsize = determine_legacy_fat_bits(bs);
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}
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memcpy(volinfo, vistart, sizeof(volume_info));
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if (*fatsize == 32) {
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if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
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goto exit;
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} else {
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if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
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*fatsize = 12;
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goto exit;
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}
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if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
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*fatsize = 16;
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goto exit;
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}
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}
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debug("Error: broken fs_type sign\n");
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fail:
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ret = -1;
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exit:
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out_free:
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free(block);
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return ret;
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}
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@ -571,7 +633,7 @@ static int get_fs_info(fsdata *mydata)
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mydata->total_sect = bs.total_sect;
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} else {
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mydata->fatlength = bs.fat_length;
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mydata->total_sect = (bs.sectors[1] << 8) + bs.sectors[0];
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mydata->total_sect = get_unaligned_le16(bs.sectors);
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if (!mydata->total_sect)
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mydata->total_sect = bs.total_sect;
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}
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@ -583,7 +645,7 @@ static int get_fs_info(fsdata *mydata)
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mydata->rootdir_sect = mydata->fat_sect + mydata->fatlength * bs.fats;
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mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
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mydata->sect_size = get_unaligned_le16(bs.sector_size);
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mydata->clust_size = bs.cluster_size;
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if (mydata->sect_size != cur_part_info.blksz) {
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log_err("FAT sector size mismatch (fs=%u, dev=%lu)\n",
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@ -607,8 +669,7 @@ static int get_fs_info(fsdata *mydata)
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(mydata->clust_size * 2);
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mydata->root_cluster = bs.root_cluster;
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} else {
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mydata->rootdir_size = ((bs.dir_entries[1] * (int)256 +
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bs.dir_entries[0]) *
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mydata->rootdir_size = (get_unaligned_le16(bs.dir_entries) *
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sizeof(dir_entry)) /
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mydata->sect_size;
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mydata->data_begin = mydata->rootdir_sect +
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@ -1157,9 +1218,8 @@ int file_fat_detectfs(void)
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memcpy(vol_label, volinfo.volume_label, 11);
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vol_label[11] = '\0';
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volinfo.fs_type[5] = '\0';
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printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
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printf("Filesystem: FAT%d \"%s\"\n", fatsize, vol_label);
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return 0;
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}
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@ -34,12 +34,6 @@ struct disk_partition;
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/* Maximum number of entry for long file name according to spec */
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#define MAX_LFN_SLOT 20
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/* Filesystem identifiers */
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#define FAT12_SIGN "FAT12 "
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#define FAT16_SIGN "FAT16 "
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#define FAT32_SIGN "FAT32 "
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#define SIGNLEN 8
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/* File attributes */
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#define ATTR_RO 1
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#define ATTR_HIDDEN 2
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@ -220,7 +220,7 @@ static size_t create_fat(void *dst, size_t size, const char *filename,
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bs->root_cluster = cpu_to_le32(root_sector);
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vi->ext_boot_sign = 0x29;
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memcpy(vi->fs_type, FAT32_SIGN, sizeof(vi->fs_type));
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memcpy(vi->fs_type, "FAT32 ", sizeof(vi->fs_type));
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memcpy(dst + 0x1fe, "\x55\xAA", 2);
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@ -9,7 +9,7 @@ import re
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import os
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from subprocess import call, check_call, check_output, CalledProcessError
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def mk_fs(config, fs_type, size, prefix):
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def mk_fs(config, fs_type, size, prefix, size_gran = 0x100000):
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"""Create a file system volume
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Args:
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@ -17,6 +17,7 @@ def mk_fs(config, fs_type, size, prefix):
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fs_type (str): File system type, e.g. 'ext4'
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size (int): Size of file system in bytes
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prefix (str): Prefix string of volume's file name
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size_gran (int): Size granularity of file system image in bytes
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Raises:
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CalledProcessError: if any error occurs when creating the filesystem
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@ -24,7 +25,9 @@ def mk_fs(config, fs_type, size, prefix):
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fs_img = f'{prefix}.{fs_type}.img'
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fs_img = os.path.join(config.persistent_data_dir, fs_img)
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if fs_type == 'fat16':
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if fs_type == 'fat12':
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mkfs_opt = '-F 12'
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elif fs_type == 'fat16':
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mkfs_opt = '-F 16'
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elif fs_type == 'fat32':
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mkfs_opt = '-F 32'
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@ -36,7 +39,7 @@ def mk_fs(config, fs_type, size, prefix):
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else:
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fs_lnxtype = fs_type
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count = (size + 0x100000 - 1) // 0x100000
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count = (size + size_gran - 1) // size_gran
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# Some distributions do not add /sbin to the default PATH, where mkfs lives
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if '/sbin' not in os.environ["PATH"].split(os.pathsep):
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@ -44,7 +47,7 @@ def mk_fs(config, fs_type, size, prefix):
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try:
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check_call(f'rm -f {fs_img}', shell=True)
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check_call(f'dd if=/dev/zero of={fs_img} bs=1M count={count}',
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check_call(f'dd if=/dev/zero of={fs_img} bs={size_gran} count={count}',
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shell=True)
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check_call(f'mkfs.{fs_lnxtype} {mkfs_opt} {fs_img}', shell=True)
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if fs_type == 'ext4':
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@ -12,9 +12,10 @@ import u_boot_utils as util
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from tests import fs_helper
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supported_fs_basic = ['fat16', 'fat32', 'ext4']
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supported_fs_ext = ['fat16', 'fat32']
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supported_fs_mkdir = ['fat16', 'fat32']
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supported_fs_unlink = ['fat16', 'fat32']
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supported_fs_ext = ['fat12', 'fat16', 'fat32']
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supported_fs_fat = ['fat12', 'fat16']
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supported_fs_mkdir = ['fat12', 'fat16', 'fat32']
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supported_fs_unlink = ['fat12', 'fat16', 'fat32']
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supported_fs_symlink = ['ext4']
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#
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@ -49,6 +50,7 @@ def pytest_configure(config):
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"""
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global supported_fs_basic
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global supported_fs_ext
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global supported_fs_fat
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global supported_fs_mkdir
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global supported_fs_unlink
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global supported_fs_symlink
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@ -61,6 +63,7 @@ def pytest_configure(config):
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print('*** FS TYPE modified: %s' % supported_fs)
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supported_fs_basic = intersect(supported_fs, supported_fs_basic)
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supported_fs_ext = intersect(supported_fs, supported_fs_ext)
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supported_fs_fat = intersect(supported_fs, supported_fs_fat)
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supported_fs_mkdir = intersect(supported_fs, supported_fs_mkdir)
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supported_fs_unlink = intersect(supported_fs, supported_fs_unlink)
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supported_fs_symlink = intersect(supported_fs, supported_fs_symlink)
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@ -83,6 +86,9 @@ def pytest_generate_tests(metafunc):
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if 'fs_obj_ext' in metafunc.fixturenames:
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metafunc.parametrize('fs_obj_ext', supported_fs_ext,
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indirect=True, scope='module')
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if 'fs_obj_fat' in metafunc.fixturenames:
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metafunc.parametrize('fs_obj_fat', supported_fs_fat,
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indirect=True, scope='module')
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if 'fs_obj_mkdir' in metafunc.fixturenames:
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metafunc.parametrize('fs_obj_mkdir', supported_fs_mkdir,
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indirect=True, scope='module')
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@ -624,3 +630,44 @@ def fs_obj_symlink(request, u_boot_config):
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finally:
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call('rmdir %s' % mount_dir, shell=True)
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call('rm -f %s' % fs_img, shell=True)
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#
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# Fixture for fat test
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#
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@pytest.fixture()
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def fs_obj_fat(request, u_boot_config):
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"""Set up a file system to be used in fat test.
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Args:
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request: Pytest request object.
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u_boot_config: U-Boot configuration.
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Return:
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A fixture for fat test, i.e. a duplet of file system type and
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volume file name.
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"""
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# the maximum size of a FAT12 filesystem resulting in 4084 clusters
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MAX_FAT12_SIZE = 261695 * 1024
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# the minimum size of a FAT16 filesystem that can be created with
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# mkfs.vfat resulting in 4087 clusters
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MIN_FAT16_SIZE = 8208 * 1024
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fs_type = request.param
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fs_img = ''
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fs_ubtype = fstype_to_ubname(fs_type)
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check_ubconfig(u_boot_config, fs_ubtype)
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fs_size = MAX_FAT12_SIZE if fs_type == 'fat12' else MIN_FAT16_SIZE
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try:
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# the volume size depends on the filesystem
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fs_img = fs_helper.mk_fs(u_boot_config, fs_type, fs_size, f'{fs_size}', 1024)
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except:
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pytest.skip('Setup failed for filesystem: ' + fs_type)
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return
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else:
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yield [fs_ubtype, fs_img]
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call('rm -f %s' % fs_img, shell=True)
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|
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25
test/py/tests/test_fs/test_fs_fat.py
Normal file
25
test/py/tests/test_fs/test_fs_fat.py
Normal file
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@ -0,0 +1,25 @@
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# SPDX-License-Identifier: GPL-2.0+
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# Copyright (c) 2023 Weidmüller Interface GmbH & Co. KG
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# Author: Christian Taedcke <christian.taedcke@weidmueller.com>
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#
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# U-Boot File System: FAT Test
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"""
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This test verifies fat specific file system behaviour.
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"""
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|
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import pytest
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import re
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|
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@pytest.mark.boardspec('sandbox')
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@pytest.mark.slow
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class TestFsFat(object):
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def test_fs_fat1(self, u_boot_console, fs_obj_fat):
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"""Test that `fstypes` prints a result which includes `sandbox`."""
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fs_type,fs_img = fs_obj_fat
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with u_boot_console.log.section('Test Case 1 - fatinfo'):
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# Test Case 1 - ls
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output = u_boot_console.run_command_list([
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'host bind 0 %s' % fs_img,
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'fatinfo host 0:0'])
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assert(re.search('Filesystem: %s' % fs_type.upper(), ''.join(output)))
|
||||
Loading…
Reference in New Issue
Block a user