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disk: add GPT/MBR writing and disk rescan support

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This commit is contained in:
boreddevnl
2026-05-08 21:02:47 +02:00
parent 3e26332b1a
commit fd18369bd7
4 changed files with 783 additions and 108 deletions
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532
src/dev/disk_manager.c
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@@ -227,6 +227,105 @@ static int ata_write_sector(Disk *disk, uint32_t lba, const uint8_t *buffer) {
return 0;
}
static int ata_read_sectors(Disk *disk, uint32_t lba, uint32_t count, uint8_t *buffer) {
ATADriverData *data = (ATADriverData*)disk->driver_data;
uint16_t port_base = data->port_base;
bool slave = data->slave;
if (disk->is_partition && disk->parent) {
lba += disk->partition_lba_offset;
data = (ATADriverData*)disk->parent->driver_data;
port_base = data->port_base;
slave = data->slave;
}
uint64_t flags = spinlock_acquire_irqsave(&ide_lock);
while (count > 0) {
uint8_t batch = (count > 255) ? 255 : (uint8_t)count;
if (ata_wait_bsy(port_base) != 0) {
spinlock_release_irqrestore(&ide_lock, flags);
return -1;
}
outb(port_base + ATA_REG_HDDEVSEL, 0xE0 | (slave << 4) | ((lba >> 24) & 0x0F));
outb(port_base + ATA_REG_SEC_COUNT0, batch);
outb(port_base + ATA_REG_LBA0, (uint8_t)(lba));
outb(port_base + ATA_REG_LBA1, (uint8_t)(lba >> 8));
outb(port_base + ATA_REG_LBA2, (uint8_t)(lba >> 16));
outb(port_base + ATA_REG_COMMAND, ATA_CMD_READ_PIO);
for (uint8_t b = 0; b < batch; b++) {
if (ata_wait_bsy(port_base) != 0 || ata_wait_drq(port_base) != 0) {
spinlock_release_irqrestore(&ide_lock, flags);
return -1;
}
uint16_t *pptr = (uint16_t*)(buffer + (b * 512));
for (int i = 0; i < 256; i++) {
pptr[i] = inw(port_base + ATA_REG_DATA);
}
}
lba += batch;
buffer += batch * 512;
count -= batch;
}
spinlock_release_irqrestore(&ide_lock, flags);
return 0;
}
static int ata_write_sectors(Disk *disk, uint32_t lba, uint32_t count, const uint8_t *buffer) {
ATADriverData *data = (ATADriverData*)disk->driver_data;
uint16_t port_base = data->port_base;
bool slave = data->slave;
if (disk->is_partition && disk->parent) {
lba += disk->partition_lba_offset;
data = (ATADriverData*)disk->parent->driver_data;
port_base = data->port_base;
slave = data->slave;
}
uint64_t flags = spinlock_acquire_irqsave(&ide_lock);
while (count > 0) {
uint8_t batch = (count > 255) ? 255 : (uint8_t)count;
if (ata_wait_bsy(port_base) != 0) {
spinlock_release_irqrestore(&ide_lock, flags);
return -1;
}
outb(port_base + ATA_REG_HDDEVSEL, 0xE0 | (slave << 4) | ((lba >> 24) & 0x0F));
outb(port_base + ATA_REG_SEC_COUNT0, batch);
outb(port_base + ATA_REG_LBA0, (uint8_t)(lba));
outb(port_base + ATA_REG_LBA1, (uint8_t)(lba >> 8));
outb(port_base + ATA_REG_LBA2, (uint8_t)(lba >> 16));
outb(port_base + ATA_REG_COMMAND, ATA_CMD_WRITE_PIO);
for (uint8_t b = 0; b < batch; b++) {
if (ata_wait_bsy(port_base) != 0 || ata_wait_drq(port_base) != 0) {
spinlock_release_irqrestore(&ide_lock, flags);
return -1;
}
const uint16_t *pptr = (const uint16_t*)(buffer + (b * 512));
for (int i = 0; i < 256; i++) {
outw(port_base + ATA_REG_DATA, pptr[i]);
}
}
outb(port_base + ATA_REG_COMMAND, 0xE7); // Cache Flush
if (ata_wait_bsy(port_base) != 0) {
spinlock_release_irqrestore(&ide_lock, flags);
return -1;
}
lba += batch;
buffer += batch * 512;
count -= batch;
}
spinlock_release_irqrestore(&ide_lock, flags);
return 0;
}
// === Device Naming ===
const char* disk_get_next_dev_name(void) {
@@ -257,11 +356,13 @@ void disk_register(Disk *disk) {
serial_write(disk->devname);
serial_write(" (");
serial_write(disk->label);
serial_write(")\n");
serial_write(") size=");
serial_write_num(disk->total_sectors);
serial_write(" sectors\n");
}
void disk_register_partition(Disk *parent, uint32_t lba_offset, uint32_t sector_count,
bool is_fat32, int part_num) {
bool is_fat32, bool is_esp, int part_num) {
if (disk_count >= MAX_DISKS) return;
Disk *part = (Disk*)kmalloc(sizeof(Disk));
@@ -275,7 +376,8 @@ void disk_register_partition(Disk *parent, uint32_t lba_offset, uint32_t sector_
part->type = parent->type;
part->is_fat32 = is_fat32;
dm_strcpy(part->label, is_fat32 ? "FAT32 Partition" : "Unknown Partition");
part->is_esp = is_esp;
dm_strcpy(part->label, is_esp ? "EFI System Partition" : (is_fat32 ? "FAT32 Partition" : "Unknown Partition"));
part->partition_lba_offset = lba_offset;
part->total_sectors = sector_count;
part->read_sector = parent->read_sector;
@@ -294,8 +396,8 @@ void disk_register_partition(Disk *parent, uint32_t lba_offset, uint32_t sector_
serial_write(", ");
serial_write_num(sector_count);
serial_write(" sectors, FAT32=");
serial_write(" sectors, FAT32=");
serial_write(is_fat32 ? "yes" : "no");
if (is_esp) serial_write(", ESP=yes");
serial_write(")\n");
if (is_fat32) {
@@ -411,12 +513,18 @@ static void parse_mbr_partitions(Disk *disk) {
if (!buffer) return;
if (disk->read_sector(disk, 0, buffer) != 0) {
serial_write("[DISK] MBR read failed on /dev/");
serial_write(disk->devname);
serial_write("\n");
kfree(buffer);
return;
}
// Check for valid MBR signature
if (buffer[510] != 0x55 || buffer[511] != 0xAA) {
serial_write("[DISK] Invalid MBR signature on /dev/");
serial_write(disk->devname);
serial_write("\n");
kfree(buffer);
return;
}
@@ -424,6 +532,7 @@ static void parse_mbr_partitions(Disk *disk) {
MBR_PartitionEntry *partitions = (MBR_PartitionEntry*)&buffer[446];
int part_num = 1;
int part_count = 0;
for (int i = 0; i < 4; i++) {
uint32_t start = partitions[i].lba_start;
uint32_t size = partitions[i].sector_count;
@@ -446,7 +555,8 @@ static void parse_mbr_partitions(Disk *disk) {
}
disk_register_partition(disk, partitions[i].lba_start,
partitions[i].sector_count, fat32, part_num);
partitions[i].sector_count, fat32, false, part_num);
part_count++;
part_num++;
}
@@ -457,6 +567,10 @@ static void parse_mbr_partitions(Disk *disk) {
serial_write("\n");
disk->is_fat32 = true;
disk->partition_lba_offset = 0;
} else if (part_count == 0) {
serial_write("[DISK] No MBR partitions found on /dev/");
serial_write(disk->devname);
serial_write("\n");
}
kfree(buffer);
@@ -479,6 +593,8 @@ static void try_add_ata_drive(uint16_t port, bool slave, const char *name) {
dm_strcpy(new_disk->label, name);
new_disk->read_sector = ata_read_sector;
new_disk->write_sector = ata_write_sector;
new_disk->read_sectors = ata_read_sectors;
new_disk->write_sectors = ata_write_sectors;
new_disk->driver_data = data;
new_disk->partition_lba_offset = 0;
new_disk->total_sectors = sectors;
@@ -504,8 +620,6 @@ void disk_manager_init(void) {
next_drive_letter_idx = 0;
log_ok("Disk manager ready");
// NOTE: Ramdisk (A:) is no longer registered here.
// RAMFS is managed directly by fat32.c and mounted at "/" via VFS.
}
void disk_manager_scan(void) {
@@ -522,4 +636,408 @@ void disk_manager_scan(void) {
} else {
log_ok("AHCI ports initialized, skipping IDE");
}
}
static uint32_t crc32_compute(const uint8_t *data, uint32_t len) {
uint32_t crc = 0xFFFFFFFF;
for (uint32_t i = 0; i < len; i++) {
crc ^= data[i];
for (int j = 0; j < 8; j++)
crc = (crc >> 1) ^ (0xEDB88320 & -(crc & 1));
}
return ~crc;
}
#define GPT_PART_ENTRY_COUNT 128
#define GPT_PART_ENTRY_SIZE 128
_Static_assert(GPT_PART_ENTRY_COUNT * GPT_PART_ENTRY_SIZE == 32 * 512,
"GPT partition array must be exactly 32 sectors");
static const uint8_t GPT_GUID_ESP[16] = {
0x28, 0x73, 0x2A, 0xC1, 0x1F, 0xF8, 0xD2, 0x11,
0xBA, 0x4B, 0x00, 0xA0, 0xC9, 0x3E, 0xC9, 0x3B
};
static const uint8_t GPT_GUID_BASIC_DATA[16] = {
0xA2, 0xA0, 0xD0, 0xEB, 0xE5, 0xB9, 0x33, 0x44,
0x87, 0xC0, 0x68, 0xB6, 0xB7, 0x26, 0x99, 0xC7
};
typedef struct __attribute__((packed)) {
uint64_t signature;
uint32_t revision;
uint32_t header_size;
uint32_t crc32;
uint32_t reserved;
uint64_t my_lba;
uint64_t alternate_lba;
uint64_t first_usable_lba;
uint64_t last_usable_lba;
uint8_t disk_guid[16];
uint64_t partition_entry_lba;
uint32_t num_partition_entries;
uint32_t size_of_partition_entry;
uint32_t partition_entry_array_crc32;
} GPT_Header;
typedef struct __attribute__((packed)) {
uint8_t type_guid[16];
uint8_t partition_guid[16];
uint64_t start_lba;
uint64_t end_lba;
uint64_t attributes;
uint16_t name[36];
} GPT_Entry;
static void gpt_make_pseudo_guid(uint8_t *guid, const char *label, uint32_t total_sectors) {
uint32_t h = 5381;
for (int i = 0; label[i]; i++)
h = h * 33 + (unsigned char)label[i];
h ^= total_sectors;
for (int i = 0; i < 16; i++)
guid[i] = (uint8_t)(h >> ((i % 4) * 8));
guid[8] = (guid[8] & 0x3F) | 0x80;
guid[6] = (guid[6] & 0x0F) | 0x40;
}
int disk_write_gpt(Disk *disk, disk_partition_spec_t *parts, int count) {
if (!disk || !parts || count <= 0 || count > GPT_PART_ENTRY_COUNT)
return -1;
uint32_t first_usable = 2048;
uint32_t last_usable = disk->total_sectors - 34;
for (int i = 0; i < count; i++) {
if (parts[i].sector_count == 0) {
serial_write("[GPT] Error: zero-sized partition\n");
return -1;
}
uint32_t start = parts[i].lba_start;
uint32_t end = start + parts[i].sector_count - 1;
if (start % 2048 != 0) {
start = ((start + 2047) / 2048) * 2048;
parts[i].lba_start = start;
end = start + parts[i].sector_count - 1;
serial_write("[GPT] Warning: start rounded up to 2048 boundary\n");
}
if (start < first_usable || end > last_usable) {
serial_write("[GPT] Error: partition out of usable range\n");
return -1;
}
for (int j = 0; j < i; j++) {
uint32_t js = parts[j].lba_start;
uint32_t je = js + parts[j].sector_count - 1;
if (start <= je && end >= js) {
serial_write("[GPT] Error: overlapping partitions\n");
return -1;
}
}
}
uint8_t *entry_buf = (uint8_t *)kmalloc(GPT_PART_ENTRY_COUNT * GPT_PART_ENTRY_SIZE);
if (!entry_buf) return -1;
for (int i = 0; i < GPT_PART_ENTRY_COUNT * GPT_PART_ENTRY_SIZE; i++) entry_buf[i] = 0;
for (int i = 0; i < count; i++) {
GPT_Entry *e = (GPT_Entry *)(entry_buf + i * GPT_PART_ENTRY_SIZE);
if (parts[i].flags & PART_FLAG_ESP)
for (int b = 0; b < 16; b++) e->type_guid[b] = GPT_GUID_ESP[b];
else
for (int b = 0; b < 16; b++) e->type_guid[b] = GPT_GUID_BASIC_DATA[b];
gpt_make_pseudo_guid(e->partition_guid, parts[i].label, disk->total_sectors);
e->start_lba = parts[i].lba_start;
e->end_lba = parts[i].lba_start + parts[i].sector_count - 1;
e->attributes = (parts[i].flags & PART_FLAG_ESP) ? 0x01 : 0x00;
/* UTF-16LE name */
for (int c = 0; c < 36 && parts[i].label[c]; c++)
e->name[c] = (uint16_t)(unsigned char)parts[i].label[c];
}
uint32_t entry_crc = crc32_compute(entry_buf, GPT_PART_ENTRY_COUNT * GPT_PART_ENTRY_SIZE);
uint8_t *hdr_buf = (uint8_t *)kmalloc(512);
if (!hdr_buf) { kfree(entry_buf); return -1; }
for (int i = 0; i < 512; i++) hdr_buf[i] = 0;
GPT_Header *hdr = (GPT_Header *)hdr_buf;
hdr->signature = 0x5452415020494645ULL;
hdr->revision = 0x00010000;
hdr->header_size = 92;
hdr->crc32 = 0;
hdr->reserved = 0;
hdr->my_lba = 1;
hdr->alternate_lba = disk->total_sectors - 1;
hdr->first_usable_lba = first_usable;
hdr->last_usable_lba = last_usable;
gpt_make_pseudo_guid(hdr->disk_guid, disk->devname, disk->total_sectors);
hdr->partition_entry_lba = 2;
hdr->num_partition_entries = GPT_PART_ENTRY_COUNT;
hdr->size_of_partition_entry = GPT_PART_ENTRY_SIZE;
hdr->partition_entry_array_crc32 = entry_crc;
hdr->crc32 = 0;
hdr->crc32 = crc32_compute(hdr_buf, hdr->header_size);
uint8_t *mbr_buf = (uint8_t *)kmalloc(512);
if (!mbr_buf) { kfree(entry_buf); kfree(hdr_buf); return -1; }
for (int i = 0; i < 512; i++) mbr_buf[i] = 0;
mbr_buf[446] = 0x00; /* Status: Non-bootable */
mbr_buf[447] = 0x00; mbr_buf[448] = 0x02; mbr_buf[449] = 0x00; /* CHS Start: 0x000200 */
mbr_buf[450] = 0xEE; /* Type: GPT Protective */
mbr_buf[451] = 0xFF; mbr_buf[452] = 0xFF; mbr_buf[453] = 0xFF; /* CHS End: 0xFFFFFF */
mbr_buf[454] = 0x01; mbr_buf[455] = 0x00; mbr_buf[456] = 0x00; mbr_buf[457] = 0x00; /* LBA Start: 1 */
uint32_t pmbr_size = disk->total_sectors - 1;
mbr_buf[458] = (uint8_t)(pmbr_size);
mbr_buf[459] = (uint8_t)(pmbr_size >> 8);
mbr_buf[460] = (uint8_t)(pmbr_size >> 16);
mbr_buf[461] = (uint8_t)(pmbr_size >> 24);
mbr_buf[510] = 0x55;
mbr_buf[511] = 0xAA;
disk->write_sector(disk, 0, mbr_buf);
kfree(mbr_buf);
if (disk->write_sector(disk, 1, hdr_buf) != 0) {
serial_write("[GPT] Error: failed to write header\n");
kfree(entry_buf); kfree(hdr_buf); return -1;
}
for (int s = 0; s < 32; s++) {
if (disk->write_sector(disk, 2 + s, entry_buf + s * 512) != 0) {
serial_write("[GPT] Error: failed to write partition entries\n");
kfree(entry_buf); kfree(hdr_buf); return -1;
}
}
GPT_Header *bhdr = (GPT_Header *)hdr_buf;
for (int i = 0; i < 512; i++) hdr_buf[i] = 0;
bhdr->signature = 0x5452415020494645ULL;
bhdr->revision = 0x00010000;
bhdr->header_size = 92;
bhdr->my_lba = disk->total_sectors - 1;
bhdr->alternate_lba = 1;
bhdr->first_usable_lba = first_usable;
bhdr->last_usable_lba = last_usable;
gpt_make_pseudo_guid(bhdr->disk_guid, disk->devname, disk->total_sectors);
bhdr->partition_entry_lba = disk->total_sectors - 33;
bhdr->num_partition_entries = GPT_PART_ENTRY_COUNT;
bhdr->size_of_partition_entry = GPT_PART_ENTRY_SIZE;
bhdr->partition_entry_array_crc32 = entry_crc;
bhdr->crc32 = 0;
bhdr->crc32 = crc32_compute(hdr_buf, bhdr->header_size);
for (int s = 0; s < 32; s++) {
disk->write_sector(disk, disk->total_sectors - 33 + s, entry_buf + s * 512);
}
disk->write_sector(disk, disk->total_sectors - 1, hdr_buf);
kfree(entry_buf);
kfree(hdr_buf);
serial_write("[DISK] GPT written to /dev/");
serial_write(disk->devname);
serial_write("\n");
return 0;
}
int disk_write_mbr(Disk *disk, disk_partition_spec_t *parts, int count) {
if (!disk || !parts || count <= 0 || count > 4) return -1;
uint8_t *buf = (uint8_t *)kmalloc(512);
if (!buf) return -1;
for (int i = 0; i < 512; i++) buf[i] = 0;
for (int i = 0; i < count; i++) {
if (parts[i].sector_count == 0) { kfree(buf); return -1; }
uint8_t *entry = buf + 446 + i * 16;
entry[0] = 0x80;
entry[4] = 0x0C;
uint32_t lba_start = parts[i].lba_start;
uint32_t sec_count = parts[i].sector_count;
entry[8] = (uint8_t)(lba_start);
entry[9] = (uint8_t)(lba_start >> 8);
entry[10] = (uint8_t)(lba_start >> 16);
entry[11] = (uint8_t)(lba_start >> 24);
entry[12] = (uint8_t)(sec_count);
entry[13] = (uint8_t)(sec_count >> 8);
entry[14] = (uint8_t)(sec_count >> 16);
entry[15] = (uint8_t)(sec_count >> 24);
}
buf[510] = 0x55;
buf[511] = 0xAA;
int ret = disk->write_sector(disk, 0, buf);
kfree(buf);
if (ret == 0) {
serial_write("[DISK] MBR written to /dev/");
serial_write(disk->devname);
serial_write("\n");
}
return ret;
}
int disk_sync(Disk *disk) {
if (!disk) return -1;
Disk *target = disk->parent ? disk->parent : disk;
// Use device-specific sync if available
if (target->sync) return target->sync(target);
if (target->type == DISK_TYPE_IDE) {
ATADriverData *data = (ATADriverData *)target->driver_data;
if (!data) return -1;
uint64_t flags = spinlock_acquire_irqsave(&ide_lock);
if (ata_wait_bsy(data->port_base) == 0) {
outb(data->port_base + ATA_REG_HDDEVSEL, data->slave ? 0xB0 : 0xA0);
outb(data->port_base + ATA_REG_COMMAND, 0xE7);
ata_wait_bsy(data->port_base);
}
spinlock_release_irqrestore(&ide_lock, flags);
return 0;
}
return 0;
}
static void disk_remove_partitions(Disk *parent) {
for (int i = 0; i < disk_count; i++) {
if (disks[i] && disks[i]->parent == parent) {
Disk *p = disks[i];
// Unmount from VFS if it's mounted
char mount_path[32];
mount_path[0] = '/';
mount_path[1] = 'd'; mount_path[2] = 'e'; mount_path[3] = 'v'; mount_path[4] = '/';
dm_strcpy(mount_path + 5, p->devname);
extern bool vfs_umount(const char *mount_path);
vfs_umount(mount_path);
for (int j = i; j < disk_count - 1; j++) {
disks[j] = disks[j + 1];
}
disks[disk_count - 1] = NULL;
disk_count--;
i--;
kfree(p);
}
}
}
static void parse_gpt_partitions(Disk *disk) {
uint8_t *buffer = (uint8_t*)kmalloc(512);
if (!buffer) return;
if (disk->read_sector(disk, 1, buffer) != 0) {
serial_write("[DISK] GPT header read failed on /dev/");
serial_write(disk->devname);
serial_write("\n");
kfree(buffer);
return;
}
GPT_Header *hdr = (GPT_Header *)buffer;
if (hdr->signature != 0x5452415020494645ULL) {
serial_write("[DISK] GPT signature missing on /dev/");
serial_write(disk->devname);
serial_write("\n");
kfree(buffer);
return;
}
uint32_t num_entries = hdr->num_partition_entries;
uint32_t entry_size = hdr->size_of_partition_entry;
uint64_t entry_lba = hdr->partition_entry_lba;
uint8_t *entry_buf = (uint8_t*)kmalloc(512);
if (!entry_buf) { kfree(buffer); return; }
int part_num = 1;
int part_count = 0;
for (uint32_t i = 0; i < num_entries && i < 128; i++) {
uint32_t entry_lba_offset = (uint32_t)entry_lba + (i * entry_size) / 512;
uint32_t entry_sector_offset = (i * entry_size) % 512;
if (disk->read_sector(disk, entry_lba_offset, entry_buf) != 0) break;
GPT_Entry *entry = (GPT_Entry *)(entry_buf + entry_sector_offset);
bool zero = true;
for (int j = 0; j < 16; j++) if (entry->type_guid[j] != 0) { zero = false; break; }
if (zero) continue;
uint32_t start = (uint32_t)entry->start_lba;
uint32_t end = (uint32_t)entry->end_lba;
uint32_t size = end - start + 1;
if (size == 0) continue;
static const uint8_t esp_guid[16] = {
0x28, 0x73, 0x2A, 0xC1, 0x1F, 0xF8, 0xD2, 0x11,
0xBA, 0x4B, 0x00, 0xA0, 0xC9, 0x3E, 0xC9, 0x3B
};
bool is_esp = true;
for (int j = 0; j < 16; j++) if (entry->type_guid[j] != esp_guid[j]) { is_esp = false; break; }
bool fat32 = false;
if (is_esp) fat32 = true;
else {
uint8_t *pbuf = (uint8_t*)kmalloc(512);
if (pbuf) {
if (disk->read_sector(disk, start, pbuf) == 0) {
fat32 = is_fat32_bpb(pbuf);
}
kfree(pbuf);
}
}
disk_register_partition(disk, start, size, fat32, is_esp, part_num++);
part_count++;
}
if (part_count == 0) {
serial_write("[DISK] GPT found but no partitions registered on /dev/");
serial_write(disk->devname);
serial_write("\n");
}
kfree(entry_buf);
kfree(buffer);
}
int disk_rescan(Disk *disk) {
if (!disk || disk->is_partition) return -1;
disk_remove_partitions(disk);
serial_write("[DISK] Rescanning /dev/");
serial_write(disk->devname);
serial_write("\n");
uint8_t *buffer = (uint8_t*)kmalloc(512);
if (buffer) {
if (disk->read_sector(disk, 1, buffer) == 0) {
GPT_Header *hdr = (GPT_Header*)buffer;
if (hdr->signature == 0x5452415020494645ULL) {
serial_write("[DISK] GPT detected on /dev/");
serial_write(disk->devname);
serial_write("\n");
kfree(buffer);
parse_gpt_partitions(disk);
return 0;
}
} else {
serial_write("[DISK] GPT probe read failed on /dev/");
serial_write(disk->devname);
serial_write("\n");
}
kfree(buffer);
}
parse_mbr_partitions(disk);
return 0;
}