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feat(tools): list file in fat12 root directory
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d0p1 🏳️‍⚧️ 2024-03-03 16:38:54 +01:00
parent 060c2835f6
commit 4361041d09
1 changed files with 104 additions and 10 deletions
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114
tools/fat.c
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@ -32,7 +32,24 @@ typedef struct
uint8_t fs_type[8];
} __attribute__((packed)) BiosParamBlock;
typedef struct
{
uint8_t name[8];
uint8_t ext[3];
uint8_t attr;
uint16_t reserved0;
uint16_t creation_time;
uint16_t creation_date;
uint16_t access_date;
uint16_t reserved1;
uint16_t mod_time;
uint16_t mod_date;
uint16_t start;
uint32_t size;
} __attribute__((packed)) Entry;
static const char *prg_name;
static int sector_size = 512;
static void
fatal(const char *str, ...)
@ -48,27 +65,104 @@ fatal(const char *str, ...)
exit(EXIT_FAILURE);
}
static void
read_sector(uint8_t *dest, int sect, FILE *fp)
{
if (fseek(fp, sect*sector_size, SEEK_SET) != 0) goto fatal_sect;
if (fread(dest, 1, sector_size, fp) != sector_size) goto fatal_sect;
return;
fatal_sect:
fatal("Can't read sector %d", sect);
}
static void
dump_bpb(BiosParamBlock *bpb)
{
char label[12];
printf("Bytes per logical sector: %hd\n", bpb->bytes_per_sector);
sector_size = bpb->bytes_per_sector;
printf("Logical sectors per cluster: %d\n", bpb->sectors_per_cluster);
printf("Reserved logical sectors: %hd\n", bpb->reserved_sectors);
printf("Number of FATs: %d\n", bpb->number_of_FATs);
printf("Root directory entries: %hd\n", bpb->root_entries);
printf("Total logical sectors: %hd\n", bpb->logical_sectors);
printf("Logical sectors per FAT: %hd\n", bpb->sectors_per_FAT);
printf("Serial: %X\n", bpb->serial);
memset(label, 0, 12);
strncpy(label, bpb->label, 11);
printf("Label: '%s'\n", label);
printf("signature: %X\n", bpb->signature);
}
static void
dump_entry(Entry *entry)
{
char filename[9];
char ext[4];
int i;
if (entry->name[0] == 0x0) return;
memset(filename, 0, 9);
strncpy(filename, entry->name, 8);
memset(ext, 0, 4);
strncpy(ext, entry->ext, 3);
for (i = 7; i > 0; i--)
{
if (filename[i] == ' ')
{
filename[i] = '\0';
}
else
{
break;
}
}
printf("%s.%s\n", filename, ext);
}
static void
dump(const char *img)
{
FILE *fp;
BiosParamBlock bpb;
char label[12];
BiosParamBlock *bpb;
uint8_t buffer[512];
int root_start;
int root_size;
int i;
int j;
fp = fopen(img, "rb");
if (fp == NULL) fatal("Can't open '%s': %s", img, strerror(errno));
if (fread(&bpb, 1, sizeof(BiosParamBlock), fp) != sizeof(BiosParamBlock))
read_sector(buffer, 0, fp);
if (buffer[511] != 0xAA || buffer[510] != 0x55)
{
fatal("Can't read BPB");
fatal("MBR not found");
}
bpb = (BiosParamBlock *)buffer;
dump_bpb(bpb);
root_start = bpb->sectors_per_FAT * bpb->number_of_FATs;
root_start += bpb->reserved_sectors;
root_size = bpb->root_entries / (sector_size >> 0x5);
for (i = 0; i < root_size; i++)
{
read_sector(buffer, root_start + i, fp);
for (j = 0; j < sector_size; j+=32)
{
dump_entry((Entry *)(buffer + j));
}
}
printf("Bytes per logical sector: %hd\n", bpb.bytes_per_sector);
printf("Logical sectors per cluster: %d\n", bpb.sectors_per_cluster);
memset(label, 0, 12);
strncpy(label, bpb.label, 11);
printf("Label: '%s'\n", label);
printf("signature: %X\n", bpb.signature);
fclose(fp);
exit(EXIT_SUCCESS);
}