src/kernel --> src/

This commit is contained in:
boreddevnl
2026-03-16 00:30:47 +01:00
parent 3da1496e4f
commit fc83d7941b
630 changed files with 2 additions and 2 deletions

376
src/dev/disk_manager.c Normal file
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// Copyright (c) 2023-2026 Chris (boreddevnl)
// This software is released under the GNU General Public License v3.0. See LICENSE file for details.
// This header needs to maintain in any file it is present in, as per the GPL license terms.
#include "disk.h"
#include "pci.h"
#include "memory_manager.h"
#include "io.h"
#include "wm.h"
#include <stddef.h>
#define MAX_DISKS 26
static Disk *disks[MAX_DISKS];
static int disk_count = 0;
// === ATA Definitions ===
#define ATA_PRIMARY_IO 0x1F0
#define ATA_PRIMARY_CTRL 0x3F6
#define ATA_SECONDARY_IO 0x170
#define ATA_SECONDARY_CTRL 0x376
#define ATA_REG_DATA 0x00
#define ATA_REG_ERROR 0x01
#define ATA_REG_FEATURES 0x01
#define ATA_REG_SEC_COUNT0 0x02
#define ATA_REG_LBA0 0x03
#define ATA_REG_LBA1 0x04
#define ATA_REG_LBA2 0x05
#define ATA_REG_HDDEVSEL 0x06
#define ATA_REG_COMMAND 0x07
#define ATA_REG_STATUS 0x07
#define ATA_CMD_READ_PIO 0x20
#define ATA_CMD_WRITE_PIO 0x30
#define ATA_CMD_IDENTIFY 0xEC
#define ATA_SR_BSY 0x80 // Busy
#define ATA_SR_DRDY 0x40 // Drive ready
#define ATA_SR_DF 0x20 // Drive write fault
#define ATA_SR_DSC 0x10 // Drive seek complete
#define ATA_SR_DRQ 0x08 // Data request ready
#define ATA_SR_CORR 0x04 // Corrected data
#define ATA_SR_IDX 0x02 // Index
#define ATA_SR_ERR 0x01 // Error
typedef struct {
uint16_t port_base;
bool slave;
} ATADriverData;
// === Helpers ===
static void dm_strcpy(char *dest, const char *src) {
while (*src) *dest++ = *src++;
*dest = 0;
}
void disk_register(Disk *disk);
static int ramdisk_read(Disk *disk, uint32_t sector, uint8_t *buffer) {
(void)disk; (void)sector; (void)buffer;
return 0;
}
static int ramdisk_write(Disk *disk, uint32_t sector, const uint8_t *buffer) {
(void)disk; (void)sector; (void)buffer;
return 0;
}
static void ata_wait_bsy(uint16_t port_base) {
while (inb(port_base + ATA_REG_STATUS) & ATA_SR_BSY);
}
static void ata_wait_drq(uint16_t port_base) {
while (!(inb(port_base + ATA_REG_STATUS) & ATA_SR_DRQ));
}
// Returns 1 if drive exists, 0 otherwise
static int ata_identify(uint16_t port_base, bool slave) {
// Select Drive
outb(port_base + ATA_REG_HDDEVSEL, slave ? 0xB0 : 0xA0);
// Zero out sector count and LBA registers
outb(port_base + ATA_REG_SEC_COUNT0, 0);
outb(port_base + ATA_REG_LBA0, 0);
outb(port_base + ATA_REG_LBA1, 0);
outb(port_base + ATA_REG_LBA2, 0);
// Send Identify command
outb(port_base + ATA_REG_COMMAND, ATA_CMD_IDENTIFY);
// Check if status is 0 (no drive)
uint8_t status = inb(port_base + ATA_REG_STATUS);
if (status == 0) return 0;
// Wait until BSY clears
int timeout = 10000;
while ((inb(port_base + ATA_REG_STATUS) & ATA_SR_BSY) && --timeout > 0) {
status = inb(port_base + ATA_REG_STATUS);
if (status == 0) return 0; // Check again
}
if (timeout <= 0) return 0; // Hardware didn't respond
// Check for error
if (inb(port_base + ATA_REG_STATUS) & ATA_SR_ERR) {
return 0; // Error, likely not ATA
}
// Wait for DRQ or ERR
while (!(inb(port_base + ATA_REG_STATUS) & (ATA_SR_DRQ | ATA_SR_ERR)));
if (inb(port_base + ATA_REG_STATUS) & ATA_SR_ERR) return 0;
// Read 256 words (512 bytes) of identity data
for (int i = 0; i < 256; i++) {
uint16_t data = inw(port_base + ATA_REG_DATA);
(void)data;
}
return 1;
}
static int ata_read_sector(Disk *disk, uint32_t lba, uint8_t *buffer) {
ATADriverData *data = (ATADriverData*)disk->driver_data;
uint16_t port_base = data->port_base;
bool slave = data->slave;
ata_wait_bsy(port_base);
// Select drive and send highest 4 bits of LBA
outb(port_base + ATA_REG_HDDEVSEL, 0xE0 | (slave << 4) | ((lba >> 24) & 0x0F));
outb(port_base + ATA_REG_FEATURES, 0x00);
outb(port_base + ATA_REG_SEC_COUNT0, 1);
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);
ata_wait_bsy(port_base);
ata_wait_drq(port_base);
uint16_t *ptr = (uint16_t*)buffer;
for (int i = 0; i < 256; i++) {
ptr[i] = inw(port_base + ATA_REG_DATA);
}
return 0; // Success
}
static int ata_write_sector(Disk *disk, uint32_t lba, const uint8_t *buffer) {
ATADriverData *data = (ATADriverData*)disk->driver_data;
uint16_t port_base = data->port_base;
bool slave = data->slave;
ata_wait_bsy(port_base);
outb(port_base + ATA_REG_HDDEVSEL, 0xE0 | (slave << 4) | ((lba >> 24) & 0x0F));
outb(port_base + ATA_REG_FEATURES, 0x00);
outb(port_base + ATA_REG_SEC_COUNT0, 1);
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);
ata_wait_bsy(port_base);
ata_wait_drq(port_base);
const uint16_t *ptr = (const uint16_t*)buffer;
for (int i = 0; i < 256; i++) {
outw(port_base + ATA_REG_DATA, ptr[i]);
}
// Flush / Sync
outb(port_base + ATA_REG_COMMAND, 0xE7); // Cache Flush
ata_wait_bsy(port_base);
return 0;
}
char disk_get_next_free_letter(void) {
for (int i = 0; i < MAX_DISKS; i++) {
char letter = 'A' + i;
bool used = false;
for (int j = 0; j < disk_count; j++) {
if (disks[j]->letter == letter) {
used = true;
break;
}
}
if (!used) return letter;
}
return 0; // No free letters
}
void disk_register(Disk *disk) {
if (disk_count >= MAX_DISKS) return;
// Ensure letter is unique
if (disk->letter == 0) {
disk->letter = disk_get_next_free_letter();
}
disks[disk_count++] = disk;
}
void disk_manager_init(void) {
for (int i = 0; i < MAX_DISKS; i++) {
disks[i] = NULL;
}
disk_count = 0;
// Register A: (Ramdisk)
Disk *ramdisk = (Disk*)kmalloc(sizeof(Disk));
ramdisk->letter = 'A';
ramdisk->type = DISK_TYPE_RAM;
ramdisk->is_fat32 = true; // Ramdisk is always formatted
dm_strcpy(ramdisk->name, "RAM");
ramdisk->read_sector = ramdisk_read;
ramdisk->write_sector = ramdisk_write;
ramdisk->driver_data = NULL;
ramdisk->partition_lba_offset = 0;
disk_register(ramdisk);
}
Disk* disk_get_by_letter(char letter) {
// Uppercase
if (letter >= 'a' && letter <= 'z') letter -= 32;
for (int i = 0; i < disk_count; i++) {
if (disks[i]->letter == letter) {
return disks[i];
}
}
return NULL;
}
int disk_get_count(void) {
return disk_count;
}
Disk* disk_get_by_index(int index) {
if (index < 0 || index >= disk_count) return NULL;
return disks[index];
}
// === MBR Partition Table Structures ===
typedef struct {
uint8_t status; // 0x80 = bootable, 0x00 = inactive
uint8_t chs_first[3]; // CHS of first sector
uint8_t type; // Partition type
uint8_t chs_last[3]; // CHS of last sector
uint32_t lba_start; // LBA of first sector
uint32_t sector_count; // Number of sectors
} __attribute__((packed)) MBR_PartitionEntry;
// FAT32 partition type codes
#define PART_TYPE_FAT32 0x0B
#define PART_TYPE_FAT32_LBA 0x0C
// Check if sector contains a valid FAT32 BPB (Volume Boot Record)
static bool is_fat32_bpb(const uint8_t *sector) {
// Must have 0xAA55 boot signature
if (sector[510] != 0x55 || sector[511] != 0xAA) return false;
// Check for FAT32 filesystem string at offset 82
// "FAT32 " in the fs_type field of the BPB
if (sector[82] == 'F' && sector[83] == 'A' && sector[84] == 'T' &&
sector[85] == '3' && sector[86] == '2') {
return true;
}
// Also accept if bytes_per_sector is 512 and sectors_per_fat_16 is 0
// (FAT32 always has sectors_per_fat_16 == 0)
uint16_t bps = *(uint16_t*)&sector[11];
uint16_t spf16 = *(uint16_t*)&sector[22];
uint32_t spf32 = *(uint32_t*)&sector[36];
if (bps == 512 && spf16 == 0 && spf32 > 0) {
return true;
}
return false;
}
// Parse MBR partition table and find a FAT32 partition.
// Sets disk->partition_lba_offset and returns true if found.
static bool detect_fat32_partition(Disk *disk) {
uint8_t *buffer = (uint8_t*)kmalloc(512);
if (!buffer) return false;
// Read sector 0 (MBR or raw BPB)
if (disk->read_sector(disk, 0, buffer) != 0) {
kfree(buffer);
return false;
}
// Must have 0xAA55 boot signature
if (buffer[510] != 0x55 || buffer[511] != 0xAA) {
kfree(buffer);
return false;
}
// Check MBR partition table entries (4 entries at offset 446)
MBR_PartitionEntry *partitions = (MBR_PartitionEntry*)&buffer[446];
for (int i = 0; i < 4; i++) {
if (partitions[i].type == PART_TYPE_FAT32 ||
partitions[i].type == PART_TYPE_FAT32_LBA) {
uint32_t part_lba = partitions[i].lba_start;
// Read the partition's first sector to verify it's a valid FAT32 BPB
uint8_t *pbuf = (uint8_t*)kmalloc(512);
if (!pbuf) { kfree(buffer); return false; }
if (disk->read_sector(disk, part_lba, pbuf) == 0 && is_fat32_bpb(pbuf)) {
disk->partition_lba_offset = part_lba;
kfree(pbuf);
kfree(buffer);
return true;
}
kfree(pbuf);
}
}
// Fallback: check if sector 0 itself is a raw FAT32 BPB (no partition table)
if (is_fat32_bpb(buffer)) {
disk->partition_lba_offset = 0;
kfree(buffer);
return true;
}
kfree(buffer);
return false;
}
static void try_add_ata_drive(uint16_t port, bool slave, const char *name) {
if (ata_identify(port, slave)) {
Disk *new_disk = (Disk*)kmalloc(sizeof(Disk));
if (!new_disk) return;
ATADriverData *data = (ATADriverData*)kmalloc(sizeof(ATADriverData));
data->port_base = port;
data->slave = slave;
new_disk->letter = 0; // Auto-assign
new_disk->type = DISK_TYPE_IDE;
dm_strcpy(new_disk->name, name);
new_disk->read_sector = ata_read_sector;
new_disk->write_sector = ata_write_sector;
new_disk->driver_data = data;
new_disk->partition_lba_offset = 0;
// Detect FAT32 (with MBR partition support)
if (detect_fat32_partition(new_disk)) {
new_disk->is_fat32 = true;
disk_register(new_disk);
} else {
kfree(data);
kfree(new_disk);
}
}
}
void disk_manager_scan(void) {
// Probe Standard ATA Ports
try_add_ata_drive(ATA_PRIMARY_IO, false, "IDE1");
try_add_ata_drive(ATA_PRIMARY_IO, true, "IDE2");
try_add_ata_drive(ATA_SECONDARY_IO, false, "IDE3");
try_add_ata_drive(ATA_SECONDARY_IO, true, "IDE4");
}