[SOLVED]Which specification defines SATA signatures?

[tokusan]

Hello, I'm reading AHCI article of this OSDev wiki.
In the code of "Detect attached SATA devices " section, SATA signatures are encoded as C macros. (https://wiki.osdev.org/AHCI#Detect_atta ... TA_devices)

Code: Select all

#define	SATA_SIG_ATA	0x00000101	// SATA drive
#define	SATA_SIG_ATAPI	0xEB140101	// SATAPI drive
#define	SATA_SIG_SEMB	0xC33C0101	// Enclosure management bridge
#define	SATA_SIG_PM	0x96690101	// Port multiplier

My question is: which specification defines these signatures? Or are these signatures the calculated values?

Thanks.

[Octocontrabass]

Code: Select all

#define	SATA_SIG_ATA	0x00000101	// SATA drive
#define	SATA_SIG_ATAPI	0xEB140101	// SATAPI drive

These two signatures are defined by the ATA Command Set specification. They're backwards-compatible with the IBM 5170 Fixed Disk and Diskette Drive Adapter and with SFF-8020i, respectively. They are not specific to SATA.

Code: Select all

#define	SATA_SIG_SEMB	0xC33C0101	// Enclosure management bridge
#define	SATA_SIG_PM	0x96690101	// Port multiplier

These two signatures are defined by the SATA specification, but they're also listed as "reserved for SATA" in the ATA Command Set spec.

The AHCI specification defines how the four bytes of each signature are combined into a single 32-bit value.

[tokusan]

Thank you for your reply, but I couldn't find the definitions. Could you tell me which sections of these specs define these signatures?

[Octocontrabass]

In the newest ATA Command Set draft I can find, the signatures are listed in table 319 on page 536.

The SATA specification is not available to the public, but I'm sure you can find a copy somewhere at a significant discount. In revision 3.2, the signatures are figure 398 on page 731 (with a typo!) and figure 416 on page 748. In revision 3.0, the signatures are figure 228 on page 539 and figure 246 on page 556.

In the current version of the AHCI specification, the signature mapping is described in section 3.3.9 on page 29.

[tokusan]

Thank you! I found them!