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minor reformatting

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Signed-off-by: Sean Cross <sean@xobs.io>
This commit is contained in:
Sean Cross
2019-06-13 16:12:19 +08:00
parent 48f1f33c49
commit c018281728
5 changed files with 160 additions and 89 deletions
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175
src/fat12.c
View File

@@ -5,7 +5,8 @@
#include <stdio.h>
#include <ctype.h>
struct fat12_partition {
struct fat12_partition
{
struct pang_io *io;
// Number of bytes in a sector (512)
@@ -31,67 +32,79 @@ struct fat12_partition {
void *fat;
};
void fat12_write_u8(void *ptr, uint8_t val) {
void fat12_write_u8(void *ptr, uint8_t val)
{
((uint8_t *)ptr)[0] = (val >> 0) & 0xff;
}
uint8_t fat12_read_u8(void *ptr) {
uint8_t fat12_read_u8(void *ptr)
{
uint16_t val = 0;
val |= (((uint8_t *)ptr)[0] << 0) & 0xff;
return val;
}
void fat12_write_u16(void *ptr, uint16_t val) {
void fat12_write_u16(void *ptr, uint16_t val)
{
((uint8_t *)ptr)[0] = (val >> 0) & 0xff;
((uint8_t *)ptr)[1] = (val >> 8) & 0xff;
}
uint16_t fat12_read_u16(void *ptr) {
uint16_t fat12_read_u16(void *ptr)
{
uint16_t val = 0;
val |= (((uint8_t *)ptr)[0] << 0) & 0x00ff;
val |= (((uint8_t *)ptr)[1] << 8) & 0xff00;
return val;
}
void fat12_write_u32(void *ptr, uint32_t val) {
void fat12_write_u32(void *ptr, uint32_t val)
{
((uint8_t *)ptr)[0] = (val >> 0) & 0xff;
((uint8_t *)ptr)[1] = (val >> 8) & 0xff;
((uint8_t *)ptr)[2] = (val >> 16) & 0xff;
((uint8_t *)ptr)[3] = (val >> 24) & 0xff;
}
uint32_t fat12_read_u32(void *ptr) {
uint32_t fat12_read_u32(void *ptr)
{
uint16_t val = 0;
val |= (((uint8_t *)ptr)[0] << 0) & 0x000000ff;
val |= (((uint8_t *)ptr)[1] << 8) & 0x0000ff00;
val |= (((uint8_t *)ptr)[0] << 0) & 0x000000ff;
val |= (((uint8_t *)ptr)[1] << 8) & 0x0000ff00;
val |= (((uint8_t *)ptr)[2] << 16) & 0x00ff0000;
val |= (((uint8_t *)ptr)[3] << 24) & 0xff000000;
return val;
}
void fat12_set_cluster(void *fat, uint32_t cluster, uint32_t value) {
void fat12_set_cluster(void *fat, uint32_t cluster, uint32_t value)
{
uint32_t offset = (cluster * 3) / 2;
// fprintf(stderr, "Cluster %d -> %03x (%02x%02x -> ", cluster, value, ((uint8_t *)fat)[offset], ((uint8_t *)fat)[offset + 1]);
if (cluster&1) {
if (cluster & 1)
{
((uint8_t *)fat)[offset] = (((uint8_t *)fat)[offset] & 0x0f) | ((value << 4) & 0xf0);
((uint8_t *)fat)[offset + 1] = value >> 4;
}
else {
else
{
((uint8_t *)fat)[offset] = value;
((uint8_t *)fat)[offset + 1] = (((uint8_t *)fat)[offset + 1] & 0xf0) | ((value >> 8) & 0x0f);
}
// fprintf(stderr, "%02x%02x)\n", ((uint8_t *)fat)[offset], ((uint8_t *)fat)[offset + 1]);
}
uint32_t fat12_get_cluster(void *fat, uint32_t cluster) {
uint32_t fat12_get_cluster(void *fat, uint32_t cluster)
{
uint32_t offset = (cluster * 3) / 2;
uint32_t value = 0;
if (cluster&1) {
if (cluster & 1)
{
value |= (((uint8_t *)fat)[offset] >> 4) & 0x00f;
value |= (((uint8_t *)fat)[offset + 1] << 4) & 0xff0;
}
else {
else
{
value |= ((uint8_t *)fat)[offset];
value |= (((uint8_t *)fat)[offset + 1] << 8) & 0xf00;
}
@@ -101,13 +114,15 @@ uint32_t fat12_get_cluster(void *fat, uint32_t cluster) {
return value;
}
struct fat12_partition *fat12_alloc(void) {
struct fat12_partition *fat12_alloc(void)
{
struct fat12_partition *part = malloc(sizeof(struct fat12_partition));
memset(part, 0, sizeof(*part));
return part;
}
int fat12_open(struct fat12_partition *part, const char *filename) {
int fat12_open(struct fat12_partition *part, const char *filename)
{
if (!part)
return -1;
@@ -142,7 +157,7 @@ int fat12_open(struct fat12_partition *part, const char *filename) {
// Move to the root directory
part->current_cluster = part->first_offset;
///
///
fprintf(stderr, "part->sector_size: %d\n", part->sector_size);
// These are in single-unit quantities
@@ -159,9 +174,10 @@ int fat12_open(struct fat12_partition *part, const char *filename) {
fprintf(stderr, "part->cluster_count: %d\n", part->cluster_count);
fprintf(stderr, "part->cluster_bytes: %d\n", part->cluster_bytes);
fprintf(stderr, "data_bytes: %d\n", bytes);
///
///
if (1) {
if (1)
{
part->fat = malloc(part->fat_size * part->sector_size);
pang_read(part->io, part->fat_offset * part->sector_size, part->fat, part->fat_size * part->sector_size);
}
@@ -169,18 +185,21 @@ int fat12_open(struct fat12_partition *part, const char *filename) {
return 0;
}
void fat12_sync(struct fat12_partition *part) {
void fat12_reload(struct fat12_partition *part)
{
pang_read(part->io, part->fat_offset * part->sector_size, part->fat, part->fat_size * part->sector_size);
}
static int fat12_ls_foreach_sector(struct fat12_partition *part, uint32_t sector, uint32_t count,
void *data, int (*callback)(void *data, const struct fat12_dirent *dirent)) {
void *data, int (*callback)(void *data, const struct fat12_dirent *dirent))
{
struct fat12_dirent dirent;
uint8_t buf[part->sector_size];
uint32_t offset;
pang_read(part->io, sector * part->sector_size, buf, sizeof(buf));
for (offset = 0; offset < count; offset++) {
for (offset = 0; offset < count; offset++)
{
struct fat_directory_entry *entry = &((struct fat_directory_entry *)buf)[offset];
memset(&dirent, 0, sizeof(dirent));
memcpy(dirent.filename, entry->file_name, 8);
@@ -194,24 +213,29 @@ static int fat12_ls_foreach_sector(struct fat12_partition *part, uint32_t sector
return 0;
}
int fat12_ls_foreach(struct fat12_partition *part, uint32_t dir_cluster, void *data, int (*callback)(void *data, const struct fat12_dirent *dirent)) {
int fat12_ls_foreach(struct fat12_partition *part, uint32_t dir_cluster, void *data, int (*callback)(void *data, const struct fat12_dirent *dirent))
{
uint32_t sector;
if (dir_cluster < 2) {
if (dir_cluster < 2)
{
sector = part->root_offset;
uint32_t dir_entries;
uint32_t max_entries = part->root_entries;
uint32_t entries_per_sector = part->sector_size / sizeof(struct fat_directory_entry);
uint32_t loop = 0;
for (dir_entries = 0; dir_entries < max_entries; dir_entries += entries_per_sector) {
for (dir_entries = 0; dir_entries < max_entries; dir_entries += entries_per_sector)
{
uint32_t entries_to_list = entries_per_sector;
if (max_entries - dir_entries < entries_to_list)
entries_to_list = max_entries - dir_entries;
fat12_ls_foreach_sector(part, part->root_offset + loop++, entries_to_list, data, callback);
}
}
else {
else
{
sector = dir_cluster * part->cluster_size + part->first_offset;
while (dir_cluster > 1 && dir_cluster < 0xff8) {
while (dir_cluster > 1 && dir_cluster < 0xff8)
{
// dir_cluster = fat12_get_cluster(part->fd, dir_cluster);
}
}
@@ -219,27 +243,32 @@ int fat12_ls_foreach(struct fat12_partition *part, uint32_t dir_cluster, void *d
return 0;
}
void fat12_flush(struct fat12_partition *part) {
void fat12_flush(struct fat12_partition *part)
{
pang_write(part->io, part->fat_offset * part->sector_size, part->fat, part->fat_size * part->sector_size);
}
int fat12_close(struct fat12_partition *part) {
int fat12_close(struct fat12_partition *part)
{
if (!part)
return -1;
if (1) {
if (1)
{
fat12_flush(part);
free(part->fat);
}
if (-1 == pang_close(&part->io)) {
if (-1 == pang_close(&part->io))
{
return -1;
}
return 0;
}
void fat12_free(struct fat12_partition **part) {
void fat12_free(struct fat12_partition **part)
{
if (!part)
return;
@@ -253,26 +282,30 @@ void fat12_free(struct fat12_partition **part) {
*part = NULL;
}
static uint32_t fat12_find_free_cluster(struct fat12_partition *part, uint32_t start) {
static uint32_t fat12_find_free_cluster(struct fat12_partition *part, uint32_t start)
{
uint32_t cluster_value;
if (start < 1)
start = 1;
do {
do
{
cluster_value = fat12_get_cluster(part->fat, ++start);
fprintf(stderr, "Cluster %d value: %03x\n", start, cluster_value);
} while(cluster_value != 0);
} while (cluster_value != 0);
fprintf(stderr, "Found free cluster %d\n", start);
return start;
}
static int fat12_add_dirent_sector(struct fat12_partition *part, uint32_t sector, uint32_t count, const struct fat_directory_entry *new_dirent) {
static int fat12_add_dirent_sector(struct fat12_partition *part, uint32_t sector, uint32_t count, const struct fat_directory_entry *new_dirent)
{
struct fat12_dirent dirent;
uint8_t buf[part->sector_size];
uint32_t offset;
pang_read(part->io, sector * part->sector_size, buf, sizeof(buf));
for (offset = 0; offset < count; offset++) {
for (offset = 0; offset < count; offset++)
{
struct fat_directory_entry *entry = &((struct fat_directory_entry *)buf)[offset];
memset(&dirent, 0, sizeof(dirent));
memcpy(dirent.filename, entry->file_name, 8);
@@ -280,7 +313,8 @@ static int fat12_add_dirent_sector(struct fat12_partition *part, uint32_t sector
dirent.first_cluster = fat12_read_u16(&entry->first_cluster);
dirent.size = fat12_read_u32(&entry->file_size);
if ((entry->file_name[0] == 0xe5) || (entry->file_name[0] == 0x00)) {
if ((entry->file_name[0] == 0xe5) || (entry->file_name[0] == 0x00))
{
((struct fat_directory_entry *)buf)[offset] = *new_dirent;
pang_write(part->io, sector * part->sector_size, buf, sizeof(buf));
return 0;
@@ -289,37 +323,43 @@ static int fat12_add_dirent_sector(struct fat12_partition *part, uint32_t sector
return -1;
}
static int fat12_dir_update_or_add_dirent(struct fat12_partition *part, uint32_t dir_cluster, const struct fat_directory_entry *dirent) {
if (1) {
static int fat12_dir_update_or_add_dirent(struct fat12_partition *part, uint32_t dir_cluster, const struct fat_directory_entry *dirent)
{
if (1)
{
uint32_t sector = part->root_offset;
uint32_t dir_entries;
uint32_t max_entries = part->root_entries;
uint32_t entries_per_sector = part->sector_size / sizeof(struct fat_directory_entry);
uint32_t loop = 0;
for (dir_entries = 0; dir_entries < max_entries; dir_entries += entries_per_sector) {
for (dir_entries = 0; dir_entries < max_entries; dir_entries += entries_per_sector)
{
uint32_t entries_to_list = entries_per_sector;
if (max_entries - dir_entries < entries_to_list)
entries_to_list = max_entries - dir_entries;
// TODO: See if a filename already exists
if (! fat12_add_dirent_sector(part, part->root_offset + loop++, entries_to_list, dirent))
if (!fat12_add_dirent_sector(part, part->root_offset + loop++, entries_to_list, dirent))
return 0;
}
}
return 0;
}
static void fat_dirent_set_name(struct fat_directory_entry *dirent, const char *filename) {
static void fat_dirent_set_name(struct fat_directory_entry *dirent, const char *filename)
{
int i;
int ext_split = -1;
int name_off = 0;
int dirent_off = 0;
for (name_off = 0; filename[name_off] != '\0'; name_off++) {
for (name_off = 0; filename[name_off] != '\0'; name_off++)
{
if (filename[name_off] == '.')
ext_split = name_off + 1;
}
for (dirent_off = 0; dirent_off < 8; dirent_off++) {
for (dirent_off = 0; dirent_off < 8; dirent_off++)
{
if (dirent_off < (ext_split - 1))
dirent->file_name[dirent_off] = toupper(filename[dirent_off]);
else
@@ -327,7 +367,8 @@ static void fat_dirent_set_name(struct fat_directory_entry *dirent, const char *
}
name_off = ext_split + 1;
for (dirent_off = 0; dirent_off < 3; dirent_off++) {
for (dirent_off = 0; dirent_off < 3; dirent_off++)
{
if ((ext_split >= 0) && (filename[ext_split]))
dirent->extension[dirent_off] = toupper(filename[ext_split++]);
else
@@ -335,7 +376,8 @@ static void fat_dirent_set_name(struct fat_directory_entry *dirent, const char *
}
}
int fat12_write_file(struct fat12_partition *part, const char *filename, const void *bfr, uint32_t size) {
int fat12_write_file(struct fat12_partition *part, const char *filename, const void *bfr, uint32_t size)
{
// TODO: directory support
uint32_t first_cluster;
uint32_t cluster;
@@ -351,20 +393,22 @@ int fat12_write_file(struct fat12_partition *part, const char *filename, const v
fat12_write_u32(dirent.file_size, size);
fat12_dir_update_or_add_dirent(part, 0, &dirent);
while (size > 0) {
while (size > 0)
{
uint32_t bytes_to_write = size;
if (bytes_to_write > part->cluster_size * part->sector_size)
bytes_to_write = part->cluster_size * part->sector_size;
pang_write(part->io,
((cluster - 2) * part->cluster_size + part->first_offset) * part->sector_size,
bfr,
bytes_to_write);
((cluster - 2) * part->cluster_size + part->first_offset) * part->sector_size,
bfr,
bytes_to_write);
size -= bytes_to_write;
fprintf(stderr, "%s: %d bytes left\n", filename, size);
if (!size)
fat12_set_cluster(part->fat, cluster, 0xff8);
else {
else
{
uint32_t next_cluster = fat12_find_free_cluster(part, cluster);
fat12_set_cluster(part->fat, cluster, next_cluster);
cluster = next_cluster;
@@ -372,25 +416,30 @@ int fat12_write_file(struct fat12_partition *part, const char *filename, const v
}
}
static uint32_t find_root_cluster_for_file(struct fat12_partition *part, const char *filename) {
static uint32_t find_root_cluster_for_file(struct fat12_partition *part, const char *filename)
{
uint32_t file_cluster = 0;
// Find the dirent of the file
uint32_t dirent_cluster = 0;
// TODO: Support directories other than the root directory
if (1) {
if (1)
{
struct fat_directory_entry dirent;
uint32_t entries_per_sector = part->sector_size / sizeof(struct fat_directory_entry);
fat_dirent_set_name(&dirent, filename);
int i = 0;
int check_entry_i;
int sector = part->root_offset - 1; // -1 because we use it to update the entry below.
while (i < part->root_entries) {
while (i < part->root_entries)
{
struct fat_directory_entry entries[entries_per_sector];
pang_read(part->io, ++sector * part->sector_size, entries, sizeof(entries));
for (check_entry_i = 0; (check_entry_i < entries_per_sector) && (i < part->root_entries); check_entry_i++, i++) {
if (!memcmp(&entries[check_entry_i], &dirent, 11)) {
for (check_entry_i = 0; (check_entry_i < entries_per_sector) && (i < part->root_entries); check_entry_i++, i++)
{
if (!memcmp(&entries[check_entry_i], &dirent, 11))
{
entries[check_entry_i].file_name[0] = 0xe5;
pang_write(part->io, sector * part->sector_size, entries, sizeof(entries));
return fat12_read_u16(entries[check_entry_i].first_cluster);
@@ -401,23 +450,25 @@ static uint32_t find_root_cluster_for_file(struct fat12_partition *part, const c
return 0;
}
int fat12_delete_file(struct fat12_partition *part, const char *filename) {
int fat12_delete_file(struct fat12_partition *part, const char *filename)
{
// Find the root cluster of the file
uint32_t root_cluster = find_root_cluster_for_file(part, filename);
// A return value of 0 (or 1) is not a valid cluster, so there's
// nothing to do.
if (root_cluster < 2) {
if (root_cluster < 2)
{
return 0;
}
// Change the first character of the dirent to 0xe5 to indicate
// it's been deleted.
// Set all clusters in the FAT to 0x000, indicating they're free.
uint32_t this_cluster = root_cluster;
do {
do
{
uint32_t next_cluster = fat12_get_cluster(part->fat, this_cluster);
// fprintf(stderr, "This cluster: %03d Next cluster: %03d Next-next cluster: %03d\n", this_cluster, next_cluster, next_next_cluster);
fat12_set_cluster(part->fat, this_cluster, 0);

15
src/io.c
View File

@@ -5,19 +5,23 @@
#ifdef unix
struct pang_io {
struct pang_io
{
int fd;
};
ssize_t pang_write(struct pang_io *io, off_t offset, const void *buf, size_t count) {
ssize_t pang_write(struct pang_io *io, off_t offset, const void *buf, size_t count)
{
return pwrite(io->fd, buf, count, offset);
}
ssize_t pang_read(struct pang_io *io, off_t offset, void *buf, size_t count) {
ssize_t pang_read(struct pang_io *io, off_t offset, void *buf, size_t count)
{
return pread(io->fd, buf, count, offset);
}
struct pang_io *pang_open(const char *pathname) {
struct pang_io *pang_open(const char *pathname)
{
int fd = open(pathname, O_RDWR | O_CREAT, 0777);
if (-1 == fd)
return NULL;
@@ -26,7 +30,8 @@ struct pang_io *pang_open(const char *pathname) {
return io;
}
int pang_close(struct pang_io **io) {
int pang_close(struct pang_io **io)
{
if (!io)
return -1;
if (!*io)