Removable Media Status Notification Feature Set and Removable Media Feature Set (Changes and additions to ATA/ATAPI-4) *** PROPOSAL ONLY ***

Transcription

1 DOCUMENT STATUS Revision 0-18 March Ron Stephens Revision 1-21 May Terry Miller and Christopher Mayne Revision 2-2 June Christopher Mayne American National Standard for Information Systems Removable Media Status Notification Feature Set and Removable Media Feature Set (Changes and additions to ATA/ATAPI-4) *** PROPOSAL ONLY *** Secretariat Information Technology Industry Council Approved mm dd yy American National Standards Institute, Inc. 1

2 6.6 Removable Media Status Notification Feature Set and Removable Media Feature Set This section describes two feature sets that secure the media in removable media storage devices using the ATA/ATAPI interface protocols. First, the Removable Media Status Notification Feature Set, intended for use in both ATA and ATAPI devices. Second, the Removable Media Feature Set, intended for use in ATA devices only. Only one of these feature set is enabled at any time. If the Removable Media Status Notification Feature Set is in use then the Removable Media Feature Set is disabled and vice versa. The reasons for implementing the Removable Media Status Notification Feature Set or the Removable Media Feature set are: to prevent data loss caused by writing to new media while still referencing the previous media s information to prevent data loss by locking the media until completion of a cached write to prevent removal of the media by unauthorized persons Removable Media Status Notification Feature Set The Removable Media Status Notification Feature Set is the preferred feature set for securing the media in removable media storage devices. This feature set uses the SET FEATURES command to enable Media Status Notification. Media Status Notification gives the host system maximum control of the media. The host system determines media status by issuing the GET MEDIA STATUS command and controls the drive eject mechanism via the MEDIA EJECT command (ATA devices) or the START/STOP UNIT command (ATAPI devices). While Media Status Notification is enabled ATA devices execute MEDIA LOCK and MEDIA UNLOCK commands without changing the media lock state (no-operation). While Media Status Notification is enabled the eject button does not eject the disk. Media Status Notification is persistent through medium removal and insertion and is only disabled via the SET FEATURES command, HARD RESET, SOFT RESET (ATA - SRST), DEVICE RESET (ATAPI - 0x08 command), EXECUTE DRIVE DIAGNOSTICS, or power-on-reset. The following task file commands are defined to implement the Removable Media Status Notification Feature Set. GET MEDIA STATUS MEDIA EJECT SET FEATURES (ENABLE MEDIA STATUS NOTIFICATION) SET FEATURES (DISABLE MEDIA STATUS NOTIFICATION) Note for ATAPI devices: ATAPI devices control the media eject mechanism via the START/STOP UNIT packet command. 2

3 The preferred sequence of events to use the Removable Media Status Notification Feature Set is as follows: 1. Host system checks the device type, ATA or ATAPI, via the device signature in the task file registers. 2. Host system issues the IDENTIFY DEVICE command (ATA devices) or the IDENTIFY PACKET DEVICE command (ATAPI devices) and checks word-0, bit-7 (removable media device) and word-83, bit-4 (Removable Media Status Notification Feature Set Supported). 3. Host system uses the SET FEATURES command to enable Media Status Notification which gives control of the media to the host. At this time the host system checks the Cylinder High register to determine if : a. the device is capable of locking the media b. the device is capable of power ejecting the media c. Media Status Notification was enabled prior to this command 4. Host system periodically checks media status using the Get Media Status command to determine if any of the following events occurred: d. no media is present in the device (NM) e. media was changed since the last command (MC) f. a media change request has occurred (MCR) g. media is write protected (WP) 3

4 6.6.2 Removable Media Feature Set The Removable Media Feature Set is intended for ATA devices only. This feature set operates with Media Status Notification disabled. The MEDIA LOCK and MEDIA UNLOCK commands are used to secure the media and the MEDIA EJECT command is used to remove the media. While the media is locked the eject button does not eject the disk. Media status is determined by checking the media status bits returned by the MEDIA LOCK and MEDIA UNLOCK commands. The GET MEDIA STATUS command executes but always returns zero in the media status bits when Media Status Notification is disabled The following task file commands are defined to implement the Removable Media Feature Set. MEDIA EJECT MEDIA LOCK MEDIA UNLOCK The preferred sequence of events to use the Removable Media Feature Set is as follows: 1. Host system checks for device type ATA via the device signature in the task file registers. 2. Host system issues the IDENTIFY DEVICE command and checks word-0, bit-7 (removable media device) and word-82, bit-2 (Removable Media Feature Set Supported). 3. Host system periodically issues MEDIA LOCK commands to determine if: c. no media is present in the device (NM) - media is locked if present d. a media change request has occurred (MCR) 4

5 6.6.3 GET MEDIA STATUS Command code DAh Feature set Removable Media Status Notification Feature Set - Mandatory for devices implementing the Removable Media Status Notification Feature Set. Removable Media Feature Set - Optional for devices implementing the Removable Media Feature Set Protocol Non-data protocol, see section Inputs Features na na na na na na na na Command DAh Normal outputs Error na Status na 0 na na 0 Status register - BSY - shall be cleared to zero, indicating the command is complete. ERR - shall be cleared to zero. 5

6 Error outputs If the device does not support this command, the device shall return a Command Abort error. Error na WP MC 0 MCR ABRT NM 0 Status na 0 na na 1 Error register - ABRT - This bit shall be set to one if the device does not support this command. NM to MCR by STATUS device and WP media one the - only This - device. for shall write set command each bit bit reset the shall protected. The execution bit this be again device and be set bit set only after to for of shall to one GET subsequent set each reset when for the if MEDIA if no the each execution bit this media the eject again media execution STATUS bit device is button after for of present insertions. the subsequent detects each until of is pressed GET execution the media MEDIA drive. eject is by has inserted the of button STATUS This the been user GET bit into presses. inserted. command shall while MEDIA the detected be drive. the set The Prerequisites DRDY set equal to one Description When returns MCR executed button and Media pressed, zeros periodically NM, Status in are as the etc. defined valid WP, Notification to only determine MC, above. while MCR is Media When enabled if and media NM Media Status this status bits. command Status Notification The has definitions changed, Notification returns is enabled. e.g.; of is media disabled new This media status command this bits inserted, bits command WP, WP, ismc, MC, eject 6

7 6.6.4 MEDIA EJECT Command code EDh Feature set Removable Media Status Notification Feature Set - Mandatory for task file devices implementing the Removable Media Status Notification Feature Set. - Prohibited for devices implementing the PACKET Command Feature Set. Removable Media Feature Set - Mandatory for task file devices implementing the Removable Media Feature Set. - Prohibited for devices implementing the PACKET Command Feature Set Protocol Non-data protocol, see section Inputs Normal outputs Features na Device/Head obs na obs DE na na na na V Command EDh Error na Status na 0 na na 0 7

8 Error outputs If the device does not support this command, the device shall return a Command Abort error. Error na na na na na ABRT NM na Status 0 1 DF na 0 na na ERR Error register - ABRT - This bit shall be set to one if the device does not support this command. NM - This bit shall be set to one if no media is present. Status register - DF - This bit shall be set to one if a device fault occurred. ERR - This bit shall be set to one if any Error register bit is set to one Prerequisites DRDY set equal to one Description This unlocks media command lock. the media causes if locked, any pending and ejects operations the media. to complete, The device spins keeps down track the of device only one if needed, level of 8

9 6.6.5 MEDIA LOCK Command code DEh Feature set Removable Media Status Notification Feature Set - Optional for task file devices implementing the Removable Media Status Notification Feature Set. - Prohibited for devices implementing the PACKET Command Feature Set. Removable Media Feature Set - Mandatory for task file devices implementing the Removable Media Feature Set. - Prohibited for devices implementing the PACKET Command Feature Set Protocol Non-data command, see Inputs Normal outputs Features na Device/Head obs na obs DE na na na na V Command DEh Error na Status na 0 na na 0 9

10 Error outputs If the device does not support this command, the device shall return a Command Abort error. Error na na na na MCR ABRT NM na Status 0 1 DF na 0 na na ERR Error register - ABRT - This bit shall be set to one if the device is not capable of locking the media. NM MCR been - detected - This bit bit by shall the be be device. set set to to one one if if no the media device is present. is locked and a media change request has Status register - DF - This bit shall be set to one if a device fault occurred. ERR - This bit shall be set to one if any Error register bit is set to one Prerequisites DRDY set equal to one Description This Status register) no Subsequent additional If been Error When button, until the Error the command register detected Notification by media register levels setting perform MEDIA and locked, unlocked by LOCKED can of bit the is media be shall enabled, MCR no device. LOCKED ERR the used and action. be condition locks. status bit commands, set to media If this in lock state, to a the returned media command one. is is the Status Error cleared. the present, media, The while change device shall register device will the if indicate Media shall request return media and shall keeps respond Status good whether is has be shall track ERR in set status been Notification to to bit of a LOCKED the set media one. only detected, in (no media to the one ERR the Status is state, LOCKED level change disabled the bit in register MCR of do the media request not. state Status bit If set to has Media in lock. and one, the 10

11 6.6.6 MEDIA UNLOCK Command code DFh Feature set Removable Media Status Notification Feature Set - Optional for task file devices implementing the Removable Media Status Notification Feature Set. - Prohibited for devices implementing the PACKET Command Feature Set. Removable Media Feature Set - Mandatory for task file devices implementing the Removable Media Feature Set. - Prohibited for devices implementing the PACKET Command Feature Set Protocol Non-data command, see Inputs Normal outputs Features na Device/Head obs na obs DE na na na na V Command DFh Error na Status na 0 na na 0 11

12 Error outputs If the device does not support this command, the device shall return a Command Abort error. Error na na na na na ABRT NM na Status 0 1 DF na 0 na na ERR Error register - ABRT - This bit shall be set to one if the device does not support this command. NM - This bit shall be set to one if no media is present. Status register - DF - This bit shall be set to one if a device fault occurred. ERR - This bit shall be set to one if any Error register bit is set to one Prerequisites DRDY set equal to one Description This Media Status command Status register) Notification can and be perform used is enabled to no unlock action., this the device, command if Media will return Status good Notification status (no is ERR disabled bit in. the If If the media is present, the media shall be set to the UNLOCKED state and no Error register bit shall be set to one. The device keeps track of only one level of media lock. A single MEDIA UNLOCK command unlocks the media. If command, a media change the media request shall has be ejected been detected when the by MEDIA the device UNLOCK prior to command the issuance completes. of this 12

13 6.6.7 SET FEATURES Command code EFh Feature set General feature set Mandatory for all devices. Set transfer mode subcommand is mandatory. Enable/Disable write cache subcommands are mandatory when a write cache is implemented. Enable/Disable Media Status Notification subcommands are mandatory if the Removable Media feature set is implemented. All other subcommands are optional Protocol Non-data protocol, see section Inputs Table other registers, 19 defines such the as value the of Sector the subcommand Count register in to the pass Feature additional register. information Some subcommands to the device. use Normal outputs See the subcommand descriptions. Features Subcommand code Sector Count Subcommand specific Sector Number Subcommand specific Cylinder Low Subcommand specific Cylinder High Subcommand specific Device/Head obs na obs DE na na na na V Command EFh 13

14 Error outputs If command any subcommand error. input value is not supported or is invalid, the device posts an Aborted Error na na na na na ABRT na na Device/Head obs na obs DEV na Status na 0 na na ERR Error register - ABRT - This bit shall be set to one if this subcommand is not supported or if command parameters are invalid. Status register - ERR - This bit shall be set to one if the ABRT bit in the Error register is set to one Prerequisites DRDY set equal to one Description This device At subcommands power features. on, or are is after Table used vendor a 19 hardware by defines the specific. host reset, these to establish the features. default parameters setting of which the functions affect the specified execution by of the certain Table 19 SET FEATURES register definitions Value (see note) 01h Retired 02h Enable write cache 03h Set transfer mode based on value in Sector Count register. Table 20 defines values. 04h Obsolete 31h Disable Media Status Notification 33h Obsolete 44h Obsolete 54h Obsolete 55h Disable read look-ahead feature 5Dh Enable release interrupt 5Eh Enable Service interrupt 66h Disable reverting to power on defaults 77h Obsolete 81h Retired 82h Disable write cache 84h Obsolete 88h Obsolete 14

15 95h Enable Media Status Notification 99h Obsolete 9Ah Obsolete AAh Enable read look-ahead feature ABh Obsolete BBh Obsolete CCh Enable reverting to power on defaults DDh Disable release interrupt DEh Disable Service interrupt NOTE All values not shown are reserved for future definition Enable Media Status Notification Inputs Features 95h Device/Head obs na obs DE na na na na V Command EFh 15

16 Normal outputs Error na Cylinder Low VER Cylinder High RSVD RSVD RSVD RSVD RSVD PEJ LOCK PENA Status na 0 na na 0 Cylinder Low register - VER - This field shall contain the Media Status Notification version supported by the device (currently 0x00). Cylinder High register - PENA - This bit shall be set to one if Media Status Notification was enabled prior to the receipt of this command. LOCK preventing PEJ capable device. a RSVD software - - This shall physically bit EJECT manual bit be shall must shall cleared command. eject be be ejecting set set operation. to to zero. to one the. zero one if media the if if the when device has a is only software capable a power unlocks EJECT of eject locking the mechanism media command the when media, is that it sent receives is to the Description Subcommand code 95h enables Media Status Notification, and clears any previous media lock state. This subcommand returns the device capabilities for media eject, media lock, previous state of Media Status Notification and the current version of Media Status Notification supported Disable Media Status Notification Subcommand state. subcommand If Media has code Status no 31h effect. Notification disables Media is disabled Status when Notification this subcommand leaves is the received media in thean unlocked 16

17 6.6.8 Error Register Changes to Task File Commands While Media Status Notification is Active The READ, following READ changes VERIFY, shall READ be MULTIPLE, made to error READ register DMA values and READ for these DMA task QUEUED file read commands: Error na UNC MC 0 MCR ABRT NM 0 Status na 0 na na ERR Error register - ABRT - This bit shall be set to one if the device does not support this command. NM MCR command. UNC - - media This bit The bit status shall device be is be only set shall set to cleared if to one data one if its is if the no by uncorrectable. internal a media Get Media is media changed present. Status request change since or has detected a last media been issuance state. access detected of this command. by device. The WRITE, following WRITE changes MULTIPLE, shall be WRITE made DMA to error and register WRITE values DMA QUEUED for these task file write commands: Error na WP MC 0 MCR ABRT NM 0 Status na 0 na na ERR Error register - ABRT - This bit shall be set to one if the device does not support this command. NM MCR The WP - device This - media bit shall bit status shall clear be is be only set its set internal to if cleared to the one one media if if media no by a media is Get write changed Media is protected. present. detected Status since request last or state. has media issuance been access detected of this command. by device. 17

18 The following changes shall be made to error register values for the task file seek command: Error na na MC 0 MCR ABRT NM 0 Status na 0 na na ERR Error register - ABRT - This bit shall be set to one if the device does not support this command. NM MCR command. - This - media bit The bit status shall device be is be only set shall set to cleared to one one if its if the no by internal a media Get Media is media changed present. Status request change since or has detected last media been issuance access detected state. of command. this by device RESET Removable Media Status Notification Feature Set: Power Up Reset, Hard Reset, Device Reset (ATAPI Command 08), SOFT RESET (ATA SRST) and EXECUTE DEVICE DIAGNOSTIC disable Media Status Notification. Media Status Notification must be re-enabled after any of the previous reset conditions occur. All media status is reset when Media Status Notification is disabled because a reset condition occurred. Any pending media change (MC) or media change request (MCR) is cleared when the Media Status Notification reset condition occurs Removable Media Feature Set: Power Up Reset, Hard Reset and EXECUTE DEVICE DIAGNOSTIC clear the Media Lock (LOCK) state and the Media Change Request (MCR) state. SOFT RESET (ATA SRST) clears the Media Lock (LOCK) state, clears the Media Change Request (MCR) state and preserves the Media Change state (MC). Need to add new commands to Annex E Table E.2 - Commands sorted by command value Command Name Command Code GET MEDIA STATUS DAh MEDIA LOCK DEh MEDIA UNLOCK DFh MEDIA EJECT EDh 18

19 Need to alter Identify Device Information of Table 11. Table 11 Identify device information (concluded) Word F/V 83 F Command sets supported. If words 82 and 83 =0000h or FFFFh command set notification not supported Shall be cleared to zero Shall be set to one Reserved 1=Removable Media Status Notification feature set supported 1=Advanced Power Management feature set supported 1=CFA feature set supported 1=READ/WRITE DMA QUEUED supported 1=DOWNLOAD MICROCODE command supported 86 V Command set/feature enabled. If words 85, 86, and 87 = 0000h or FFFFh command set enabled notification is not supported Reserved 1=Removable Media Status Notification feature set enabled 1=Advanced Power Management feature set enabled 1=CFA feature set supported 1=READ/WRITE DMA QUEUED supported 1=DOWNLOAD MICROCODE command supported R Reserved 127 F Removable Media Status Notification feature set support Reserved 00=Removable Media Status Notification feature set not supported 01=Removable Media Status Notification feature set supported 10=Reserved 11=Reserved Words 82-84: Features/command sets supported If bit 4 of word 83 is set to one, the device supports the Removable Media Status Notification Feature set. Words 85-87: Features/command sets enabled If bit 4 of word 86 is set to one, the Removable Media Status Notification feature set is enabled. Words : Reserved Word 127: If bit 0 of word 127 is set to one and bit 1 of word 127 is cleared to zero, the device supports the Removable Media Status Notification Feature Set. Bits 15 through 2 of word 127 are reserved and shall be cleared to zero. 19

20 Need to alter Identify Packet Device Information of Table 13 Table 13 Identify packet device information (concluded) Word F/V 83 F Command sets supported. If words 82 and 83 =0000h or FFFFh command set notification not supported Shall be cleared to zero Shall be set to one Reserved 1=Removable Media Status Notification feature set supported Reserved 1=DOWNLOAD MICROCODE command supported 86 V Command set/feature enabled. If words 85, 86, and 87 = 0000h or FFFFh command set enabled notification is not supported Reserved 1=Removable Media Status Notification feature set enabled Reserved 1=DOWNLOAD MICROCODE command supported R Reserved 127 F Removable Media Status Notification feature set support Reserved 00=Removable Media Status Notification feature set not supported 01=Removable Media Status Notification feature set supported 10=Reserved 11=Reserved Words 82-84: Features/command sets supported If bit 4 of word 83 is set to one, the device supports the Removable Media Status Notification Feature set. Words 85-87: Features/command sets enabled If bit 4 of word 86 is set to one, the Removable Media Status Notification feature set is enabled. Words : Reserved Word 127: If bit 0 of word 127 is set to one and bit 1 of word 127 is cleared to zero, the device supports the Removable Media Status Notification Feature Set. Bits 15 through 2 of word 127 are reserved and shall be cleared to zero. 20

21 OUTSTANDING ISSUES There is a conflict in Error register bit definitions for the task file command WRITE VERIFY when Media Status Notification is enabled. The conflicting Error register bit definitions occur for the previously defined UNC bit and the newly defined WP bit. (TBD till June meeting) 21