ATA_Op
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
Social
Follow us on
and
and
ROOL Store
Buy RISC OS Open merchandise here, including SD cards for Raspberry Pi and more.