diff options
Diffstat (limited to 'src/kernel/ide.c')
| -rw-r--r-- | src/kernel/ide.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/kernel/ide.c b/src/kernel/ide.c new file mode 100644 index 0000000..a2d3895 --- /dev/null +++ b/src/kernel/ide.c @@ -0,0 +1,189 @@ +#include <stdint.h> +#include <stdbool.h> +#include "panic.h" +#include "util.h" +#include "drive.h" +#include "pci.h" +#include "ata.h" + +#define MAX_IDE_DRIVES 8 + +struct ide_drive_info { + uint16_t base_port; + uint16_t control_port; + bool slave; +}; + +struct ide_drive_info ide_drives[MAX_IDE_DRIVES]; +drive_id_t n_ide_drives = 0; + +void spin_delay() { + for (uint32_t i = -1; i; --i) + ; +} + +//return true on error condition +bool poll(struct ide_drive_info *info) { + spin_delay(); + + uint8_t status; + + while ((status = inb(info->base_port | ATA_REG_STATUS)) & ATA_STATUS_BUSY) + ; + + return (status & (ATA_STATUS_ERROR | ATA_STATUS_DRIVE_FAULT)) || !(status & ATA_STATUS_DRIVE_READY); +} + +uint8_t ide_ata_rs(struct drive *d, uint32_t start, uint32_t count, void *buffer) { + if (start & 0xf0000000) + panic("IDE ATA driver only supports LBA28 addressing currently."); + + struct ide_drive_info *info = ide_drives + d->drive_id; + + if (start + count > d->n_sectors) + count = d->n_sectors - start; + + if (count & 0xffffff00) + panic("IDE ATA driver only supports reading up to 128k at a time currently."); + + uint32_t lba = start & 0x00ffffff; + + uint32_t spin = -1; + while (inb(info->base_port | ATA_REG_STATUS) & ATA_STATUS_BUSY) + if (!spin--) + panic("Spun out in IDE ATA reading"); + + outb(info->base_port | ATA_REG_SELECT, (info->slave ? 0xf0 : 0xe0) | (start >> 24)); + outb(info->base_port | ATA_REG_COUNT_LOW, count); + outb(info->base_port | ATA_REG_LBA0, lba); + outb(info->base_port | ATA_REG_LBA1, lba >> 8); + outb(info->base_port | ATA_REG_LBA2, lba >> 16); + + uint16_t *buffer_16 = buffer; + + for (uint16_t i = 0; i < count; ++i) { + if (poll(info)) + return i; + for (uint16_t j = 0; j < 256; ++j) + *buffer_16++ = inw(info->base_port + ATA_REG_DATA); + } + + return count; +} + +uint8_t ide_ata_ws(struct drive *d, uint32_t start, uint32_t count, void *buffer) { + panic("IDE ATA writing not implemented yet"); + return 0; +} + +uint8_t ide_atapi_rs(struct drive *d, uint32_t start, uint32_t count, void *buffer) { + //panic("IDE ATAPI reading not implemented yet"); + return 0; +} + +uint8_t ide_atapi_ws(struct drive *d, uint32_t start, uint32_t count, void *buffer) { + panic("IDE ATAPI writing not implemented yet"); + return 0; +} + +struct id_space { + uint16_t device_type;//0 + uint8_t skip1[98 - 2]; + uint16_t capabilities;//98 + uint8_t skip2[120 - (98 + 2)]; + uint32_t max_lba;//120 + uint8_t skip3[164 - (120 + 4)]; + uint32_t command_sets;//164 + uint8_t skip4[200 - (164 + 4)]; + uint32_t max_lba_ext;//200 + uint8_t skip5[512 - (200 + 4)]; +} __attribute__ ((__packed__)); + +void read_id_space(uint16_t base_port, struct id_space *to) { + uint32_t *to_32 = (uint32_t *)to; + for (uint8_t i = 0; i < 128; ++i) + *(to_32++) = ind(base_port | ATA_REG_DATA); +} + +void test_drive(uint16_t base_port, uint16_t control_port, bool slave) { + outb(base_port | ATA_REG_SELECT, slave ? ATA_SLAVE_SELECT : ATA_MASTER_SELECT); + spin_delay(); + + outb(base_port | ATA_REG_CMD, ATA_CMD_ID); + spin_delay(); + + if (!inb(base_port | ATA_REG_STATUS)) + return; + + if (n_ide_drives == MAX_IDE_DRIVES) + panic("Maximum IDE drives reached"); + + outb(base_port | ATA_REG_CONTROL, ATA_CONTROL_NO_IRQS); + + struct ide_drive_info *this_drive = ide_drives + n_ide_drives; + this_drive->base_port = base_port; + this_drive->control_port = control_port; + this_drive->slave = slave; + + struct drive data; + data.drive_id = n_ide_drives; + + uint32_t spin_out = -1; + while (1) {//wait for identify to complete + uint8_t status = inb(base_port | ATA_REG_STATUS); + if (status & ATA_STATUS_ERROR) { + uint16_t type = inb(base_port | ATA_REG_LBA1) + + (inb(base_port | ATA_REG_LBA2) << 8); + + //These two are listed on OSDev Wiki + // as being ATAPI device types. + if ((type != 0xeb14) && (type != 0x9669)) + return; + + outb(base_port | ATA_REG_CMD, ATAPI_CMD_ID); + + data.read_sectors = &ide_atapi_rs; + data.write_sectors = &ide_atapi_ws; + data.drive_type = "IDE ATAPI"; + break; + } + if (!(status & ATA_STATUS_BUSY) && (status & ATA_STATUS_DATA_READY)) { + data.read_sectors = &ide_ata_rs; + data.write_sectors = &ide_ata_ws; + data.drive_type = "IDE ATA"; + break; + } + if (!spin_out--) + panic("IDE ATA identify won't complete"); + } + + struct id_space id; + read_id_space(base_port, &id); + + if (!(id.capabilities & ATA_CAP_LBA)) + //TODO: CHS compability driver? + return; + data.n_sectors = (id.command_sets & ATA_SET_EXT) ? id.max_lba_ext : id.max_lba; + + commit_drive(data); + ++n_ide_drives; +} + +void init_ide() { + uint16_t check_from = 0; + struct pci_device *device; + //double parentheses to let gcc know this assignment isn't a mistake + while ((device = find_pci_device_from_class_and_subclass(PCI_MASS_STORAGE, PCI_IDE, check_from, &check_from))) { + ++check_from; + + uint16_t primary_base_port = device->bar0 <= 1 ? 0x01f0 : device->bar0; + uint16_t primary_control_port = device->bar1 <= 1 ? 0x03f6 : device->bar1; + uint16_t secondary_base_port = device->bar2 <= 1 ? 0x0170 : device->bar2; + uint16_t secondary_control_port = device->bar3 <= 1 ? 0x0376 : device->bar3; + + test_drive(primary_base_port, primary_control_port, false); + test_drive(primary_base_port, primary_control_port, true); + test_drive(secondary_base_port, secondary_control_port, false); + test_drive(secondary_base_port, secondary_control_port, true); + } +}
\ No newline at end of file |