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Diffstat (limited to 'src/include/ipxe/ata.h')
| -rw-r--r-- | src/include/ipxe/ata.h | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/src/include/ipxe/ata.h b/src/include/ipxe/ata.h new file mode 100644 index 000000000..043e37051 --- /dev/null +++ b/src/include/ipxe/ata.h @@ -0,0 +1,209 @@ +#ifndef _IPXE_ATA_H +#define _IPXE_ATA_H + +#include <stdint.h> +#include <ipxe/blockdev.h> +#include <ipxe/uaccess.h> +#include <ipxe/refcnt.h> + +/** @file + * + * ATA devices + * + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +/** + * An ATA Logical Block Address + * + * ATA controllers have three byte-wide registers for specifying the + * block address: LBA Low, LBA Mid and LBA High. This allows for a + * 24-bit address. Some devices support the "48-bit address feature + * set" (LBA48), in which case each of these byte-wide registers is + * actually a two-entry FIFO, and the "previous" byte pushed into the + * FIFO is used as the corresponding high-order byte. So, to set up + * the 48-bit address 0x123456abcdef, you would issue + * + * 0x56 -> LBA Low register + * 0xef -> LBA Low register + * 0x34 -> LBA Mid register + * 0xcd -> LBA Mid register + * 0x12 -> LBA High register + * 0xab -> LBA High register + * + * This structure encapsulates this information by providing a single + * 64-bit integer in native byte order, unioned with bytes named so + * that the sequence becomes + * + * low_prev -> LBA Low register + * low_cur -> LBA Low register + * mid_prev -> LBA Mid register + * mid_cur -> LBA Mid register + * high_prev -> LBA High register + * high_cur -> LBA High register + * + * Just to complicate matters further, in non-LBA48 mode it is + * possible to have a 28-bit address, in which case bits 27:24 must be + * written into the low four bits of the Device register. + */ +union ata_lba { + /** LBA as a 64-bit integer in native-endian order */ + uint64_t native; + /** ATA registers */ + struct { +#if __BYTE_ORDER == __LITTLE_ENDIAN + uint8_t low_cur; + uint8_t mid_cur; + uint8_t high_cur; + uint8_t low_prev; + uint8_t mid_prev; + uint8_t high_prev; + uint16_t pad; +#elif __BYTE_ORDER == __BIG_ENDIAN + uint16_t pad; + uint8_t high_prev; + uint8_t mid_prev; + uint8_t low_prev; + uint8_t high_cur; + uint8_t mid_cur; + uint8_t low_cur; +#else +#error "I need a byte order" +#endif + } bytes; +}; + +/** An ATA 2-byte FIFO register */ +union ata_fifo { + /** Value in native-endian order */ + uint16_t native; + /** ATA registers */ + struct { +#if __BYTE_ORDER == __LITTLE_ENDIAN + uint8_t cur; + uint8_t prev; +#elif __BYTE_ORDER == __BIG_ENDIAN + uint8_t prev; + uint8_t cur; +#else +#error "I need a byte order" +#endif + } bytes; +}; + +/** ATA command block */ +struct ata_cb { + /** Logical block address */ + union ata_lba lba; + /** Sector count */ + union ata_fifo count; + /** Error/feature register */ + union ata_fifo err_feat; + /** Device register */ + uint8_t device; + /** Command/status register */ + uint8_t cmd_stat; + /** LBA48 addressing flag */ + int lba48; +}; + +/** Obsolete bits in the ATA device register */ +#define ATA_DEV_OBSOLETE 0xa0 + +/** LBA flag in the ATA device register */ +#define ATA_DEV_LBA 0x40 + +/** Slave ("device 1") flag in the ATA device register */ +#define ATA_DEV_SLAVE 0x10 + +/** Master ("device 0") flag in the ATA device register */ +#define ATA_DEV_MASTER 0x00 + +/** Mask of non-LBA portion of device register */ +#define ATA_DEV_MASK 0xf0 + +/** "Read sectors" command */ +#define ATA_CMD_READ 0x20 + +/** "Read sectors (ext)" command */ +#define ATA_CMD_READ_EXT 0x24 + +/** "Write sectors" command */ +#define ATA_CMD_WRITE 0x30 + +/** "Write sectors (ext)" command */ +#define ATA_CMD_WRITE_EXT 0x34 + +/** "Identify" command */ +#define ATA_CMD_IDENTIFY 0xec + +/** An ATA command */ +struct ata_command { + /** ATA command block */ + struct ata_cb cb; + /** Data-out buffer (may be NULL) + * + * If non-NULL, this buffer must be ata_command::cb::count + * sectors in size. + */ + userptr_t data_out; + /** Data-in buffer (may be NULL) + * + * If non-NULL, this buffer must be ata_command::cb::count + * sectors in size. + */ + userptr_t data_in; + /** Command status code */ + int rc; +}; + +/** + * Structure returned by ATA IDENTIFY command + * + * This is a huge structure with many fields that we don't care about, + * so we implement only a few fields. + */ +struct ata_identity { + uint16_t ignore_a[60]; /* words 0-59 */ + uint32_t lba_sectors; /* words 60-61 */ + uint16_t ignore_b[21]; /* words 62-82 */ + uint16_t supports_lba48; /* word 83 */ + uint16_t ignore_c[16]; /* words 84-99 */ + uint64_t lba48_sectors; /* words 100-103 */ + uint16_t ignore_d[152]; /* words 104-255 */ +}; + +/** Supports LBA48 flag */ +#define ATA_SUPPORTS_LBA48 ( 1 << 10 ) + +/** ATA sector size */ +#define ATA_SECTOR_SIZE 512 + +/** An ATA device */ +struct ata_device { + /** Block device interface */ + struct block_device blockdev; + /** Device number + * + * Must be ATA_DEV_MASTER or ATA_DEV_SLAVE. + */ + int device; + /** LBA48 extended addressing */ + int lba48; + /** + * Issue ATA command + * + * @v ata ATA device + * @v command ATA command + * @ret rc Return status code + */ + int ( * command ) ( struct ata_device *ata, + struct ata_command *command ); + /** Backing device */ + struct refcnt *backend; +}; + +extern int init_atadev ( struct ata_device *ata ); + +#endif /* _IPXE_ATA_H */ |