SCSI Operation Codes
USB Mass Storage 是 USB host侧遇到最多的场景，基于 Bulk传输，使用 SCSI协议进行资源交互。当然 UFS也用到 SCSI协议，在使用 UFS的系统，我们插入 U盘经常生成的 dev节点是 /dev/sdb或者是 /dev/sde 。前面的如 /dev/sda、/dev/sdc这些节点可能就被 UFS占用了，识别 log可能就变成 “sd 1:0:0:0: [sde] …”。
在读写有坏块的 U盘时，不免会打印下面的 log。通过 opcode，就可以清楚是什么操作报的错。这里 opcode=0x28，即 READ(10)。
1 | |
我们还可以阅读 SCSI的 manual，确定这次的 READ(10) 想从 LBA 0x2b0900 读多 0x1d * block size的数据回来。
USB Mass Storage 常用的 SCSI Operation Codes 包括下面这些：
| 指令代码 | 指令名称 | 指令说明 |
|---|---|---|
| 0x00 | Test Unit Ready | 查询设备是否ready |
| 0x03 | Request Sense | 主机请求设备返回执行结果，及获取状态信息 |
| 0x12 | Inquiry | 获取设备信息 |
| 0x1A | Mode Sense(6) | 向host传输参数 |
| 0x5A | Mode Sense(10) | 向host传输参数 |
| 0x25 | Read Capacity(10) | 读取设备容量 |
| 0x28 | Read(10) | Host从设备读取数据 |
| 0x2A | Write(10) | Host写数据到存储设备 |
| 0x23 | Read Format Capacity | 查询当前容量及可用空间 |
| 0x15 | Mode Select(6) | 允许Host对外部设备设置参数 |
| 0x55 | Mode Select(10) | 允许Host对外部设备设置参数 |
| 0x1E | Prevent/Allow Medium Removal | 禁止/允许存储介质移动 |
| 0x1B | Start/Stop Uint | 启动/停止存储单元电源（写保护） |
| 0xA0 | Report LUNs | 索取设备的LUN数和LUN清单 |
| 0x2F | Verify | 在存储中验证数据 |
下面是全部的 SCSI Operation Codes:
| Code | Command |
|---|---|
| 00 | TEST UNIT READY (mandatory) |
| 01 | RECALIBRATE or REWIND |
| 03 | REQUEST SENSE (mandatory except RBC) |
| 04 | FORMAT UNIT |
| 05 | READ BLOCK LIMITS |
| 07 | REASSIGN BLOCKS |
| 07 | INITIALIZE ELEMENT STATUS |
| 08 | READ (6) |
| 0A | WRITE (6) |
| 0B | SEEK (6) |
| 0F | READ REVERSE (6) |
| 10 | WRITE FILEMARKS (6) |
| 11 | SPACE (6) |
| 12 | INQUIRY (mandatory) |
| 13 | VERIFY(6) |
| 14 | RECOVER BUFFERED DATA |
| 15 | MODE SELECT (6) |
| 16 | RESERVE (6) |
| 17 | RELEASE (6) |
| 18 | COPY |
| 19 | ERASE (6) |
| 1A | MODE SENSE (6) |
| 1B | START/STOP UNIT |
| 1B | LOAD UNLOAD |
| 1C | RECEIVE DIAGNOSTIC RESULTS |
| 1D | SEND DIAGNOSTIC |
| 1E | PREVENT/ALLOW MEDIUM REMOVAL |
| 23 | READ FORMAT CAPACITIES (MMC) |
| 24 | SET WINDOW |
| 25 | READ CAPACITY (10) |
| 28 | READ (10) |
| 29 | READ GENERATION |
| 2A | WRITE (10) |
| 2B | SEEK (10) |
| 2C | ERASE (10) |
| 2D | READ UPDATED BLOCK |
| 2E | WRITE AND VERIFY (10) |
| 2F | VERIFY (10) |
| 30 | SEARCH DATA HIGH (10) |
| 31 | SEARCH DATA EQUAL (10) |
| 32 | SEARCH DATA LOW (10) |
| 33 | SET LIMITS (10) |
| 34 | PRE-FETCH (10) |
| 35 | SYNCHRONIZE CACHE (10) |
| 36 | LOCK/UNLOCK CACHE (10) |
| 37 | READ DEFECT DATA (10) |
| 37 | INITIALIZE ELEMENT STATUS WITH RANGE |
| 38 | MEDIUM SCAN |
| 39 | COMPARE |
| 3A | COPY AND VERIFY |
| 3B | WRITE BUFFER |
| 3C | READ BUFFER |
| 3D | UPDATE BLOCK |
| 3E | READ LONG |
| 3F | WRITE LONG |
| 40 | CHANGE DEFINITION |
| 41 | WRITE SAME (10) |
| 44 | REPORT DENSITY SUPPORT |
| 45 | PLAY AUDIO (10) |
| 46 | GET CONFIGURATION |
| 47 | PLAY AUDIO MSF |
| 48 | AUDIO TRACK INDEX (not mentioned in T10 overview) |
| 49 | AUDIO TRACK RELATIVE 10 (not mentioned in T10 overview) |
| 4A | GET EVENT STATUS NOTIFICATION |
| 4B | PAUSE / RESUME |
| 4C | LOG SELECT |
| 4D | LOG SENSE |
| 50 | XDWRITE (10) |
| 51 | XPWRITE (10) /READ DISC INFORMATION CDB (in mmc5r02c 6.22.2)/ |
| 52 | XDREAD (10) |
| 53 | XDWRITEREAD (10) |
| 54 | SEND OPC INFORMATION |
| 55 | MODE SELECT (10) |
| 56 | RESERVE (10) |
| 57 | RELEASE (10) |
| 58 | REPAIR TRACK |
| 5A | MODE SENSE (10) |
| 5B | CLOSE TRACK / SESSION |
| 5C | READ BUFFER CAPACITY |
| 5D | SEND CUE SHEET |
| 5E | PERSISTENT RESERVE IN |
| 5F | PERSISTENT RESERVE OUT |
| 7E | EXTENDED CDB |
| 7F | VARIABLE LENGTH CDB |
| 80 | XDWRITE EXTENDED (16) |
| 80 | WRITE FILEMARKS (16) |
| 81 | REBUILD (16) |
| 81 | READ REVERSE (16) |
| 82 | REGENERATE (16) |
| 83 | EXTENDED COPY |
| 84 | RECEIVE COPY RESULTS |
| 85 | ATA COMMAND PASS THROUGH (16) |
| 86 | ACCESS CONTROL IN |
| 87 | ACCESS CONTROL OUT |
| 88 | READ (16) |
| 89 | COMPARE AND WRITE |
| 8A | WRITE (16) |
| 8B | ORWRITE |
| 8C | READ ATTRIBUTE |
| 8D | WRITE ATTRIBUTE |
| 8E | WRITE AND VERIFY (16) |
| 8F | VERIFY (16) |
| 90 | PRE-FETCH (16) |
| 91 | SYNCHRONIZE CACHE (16) |
| 91 | SPACE (16) |
| 92 | LOCK UNLOCK CACHE (16) |
| 93 | WRITE SAME (16) |
| 9E | SERVICE ACTION IN (16) |
| 9F | SERVICE ACTION OUT (16) |
| A0 | REPORT LUNS |
| A1 | ATA COMMAND PASS THROUGH (12) |
| A2 | SECURITY PROTOCOL IN |
| A2 | SEND EVENT (not mentioned in T10 overview) |
| A3 | MAINTENANCE IN |
| A4 | MAINTENANCE OUT (REPORT_KEY) |
| A5 | MOVE MEDIUM |
| A5 | PLAY AUDIO 12 (not mentioned in T10 overview) |
| A6 | EXCHANGE MEDIUM |
| A7 | MOVE MEDIUM ATTACHED |
| A8 | READ (12) |
| A9 | SERVICE ACTION OUT (12) |
| A9 | AUDIO TRACK RELATIVE 12 (not mentioned in T10 overview) |
| AA | WRITE (12) |
| AB | SERVICE ACTION IN (12) |
| AC | ERASE (12) |
| AD | READ DVD STRUCTURE |
| AE | WRITE AND VERIFY (12) |
| AF | VERIFY (12) |
| B0 | SEARCH DATA HIGH (12) |
| B1 | SEARCH DATA EQUAL (12) |
| B2 | SEARCH DATA LOW (12) |
| B3 | SET LIMITS (12) |
| B4 | READ ELEMENT STATUS ATTACHED |
| B5 | SECURITY PROTOCOL OUT |
| B6 | SEND VOLUME TAG |
| B7 | READ DEFECT DATA (12) |
| B8 | READ ELEMENT STATUS |
| B9 | READ CD MSF |
| BA | REDUNDANCY GROUP (IN) |
| BB | REDUNDANCY GROUP (OUT) |
| BC | SPARE (IN) |
| BC | PLAY CD (not mentioned in T10 overview) |
| BD | SPARE (OUT) |
| BE | VOLUME SET (IN) |
| BF | VOLUME SET (OUT) |
上述部分内容来自 wiki 、ymangu 和 SCSI Commands Reference Manual。更多SCSI 相关推荐查看 SCSI Commands Reference Manual、t10.org。
SCSI Operation Codes
http://xxxdk.xyz/xxx/2020/03/SCSI-Operation-Codes/