ATA_Op (changes)
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SATADriver
» SWI Calls
» ATA_Op
ATA_Op
(SWI &59783)
| Entry | |
|---|---|
| R0 | Flag bits |
| R1 | Length of parameter block, must be 1 (for device control), 7 (for 28-bit LBA), 11 (for 48-bit LBA) or 12 (for wide features) |
| R2 | Pointer to Parameter block for command and results |
| R3 | Pointer to buffer or scatter list |
| R4 | Length to transfer. Must be 0 if no data transfer is specified in the Flag bits |
| R5 | Timeout in centiseconds if bit 29 of the Flag bits is set |
| R6 | Address of callback routine, if bit 26 of the Flag bits is set |
| R7 | Value to pass in R12 to the callback routine, if bit 26 of the Flag bits is set |
| Exit | |
|---|---|
| R0 | Pointer to error block, or 0 if successful |
| R4 | Bytes not transferred, or 0 if transfer complete |
Flag bits
| 0 | 1 = don’t wait for DRDY before issuing command |
| 2 | 1 = data transfer uses multiword DMA or UDMA from device’s perspective (note that the host controller may actually use bus mastering even for PIO transfers) |
| 12 – 15 | device ID |
| 16 – 23 | controller/port ID |
| 24 – 25 | 00 = no transfer |
| 01 = read (bit 24 set) | |
| 10 = write (bit 25 set) |
| 26 | 1 = scatter list transfer |
| 27 | 1 = don’t poll for escape during foreground transfers |
| 28 | reserved |
| 29 | 1 = background transfer (not supported initially) |
Parameter block
Device control form:
| +0 | Features/Error |
| +0 | Device control |
28-bit LBA form:
| +0 | Features/Error |
| +1 | Sector Count |
| +2 | LBA bits 0-7/Sector No |
| +3 | LBA bits 8-15/Cylinder Low |
| +4 | LBA bits 16-23/Cylinder High |
| +5 | Device: |
| bits 0-3 – LBA bits 24-27/Head | |
| bit 4 – 0=master, 1=slave | |
| bit 6 – 0=CHS mode, 1=LBA mode | |
| +6 | Command/Status |
48-bit LBA form:
| +0 | Features/Error |
| +1 | 16-bit Sector Count |
| +3 | 48-bit LBA |
| +9 | Device: |
| bit 4 – 0=master, 1=slave | |
| bit 6 – 0=CHS mode, 1=LBA mode | |
| +10 | Command/Status |
Wide features form:
| +0 | Features bits 0-7/Error |
| +1 | Features bits 8-15 |
| +2 | 16-bit Sector Count |
| +4 | 48-bit LBA |
| +10 | Device: |
| bit 6 – 0=CHS mode, 1=LBA mode | |
| +11 | Command/Status |
Use
The purpose of this call is to perform low-level ATA commands.
Notes
If a scatter list is used, it is not updated.
See also
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