FileCore_DiscOp
FileCore
» SWI Calls
» FileCore_DiscOp
FileCore_DiscOp
(SWI &40540)
| Entry | |
|---|---|
| R1 | Reason code + Flags |
| All other registers dependent on reason code | |
| Exit | |
|---|---|
| R0 | 0 if no error, error number and VS otherwise |
| R1 | Preserved |
| All other registers dependent on reason code | |
| N, Z and C flag preserved | |
Use
The purpose of this call is to provide a number of low-level disc operations.
Notes
The action performed depends on the reason code value in R1.
Reason Codes
| # | Hex # | Action |
|---|---|---|
| 0 | &00 | Verify |
| 1 | &01 | Read sectors |
| 2 | &02 | Write sectors |
| 3 | &03 | Read track/ID |
| 4 | &04 | Write/format track |
| 5 | &05 | Seek |
| 6 | &06 | Restore |
| 7 | &07 | Step in |
| 8 | &08 | Step out |
| 9 | &09 | Read sectors via cache |
| 15 | &0F | Specify Hard disc |
Flags
| Bit | Meaning |
|---|---|
| 4 | Given alternative defect list |
| 5 | Given sector list |
| 6 | Ignore escape |
| 7 | Ignore timeout |
| 8 – 31 | 0 or bits 2-25 of the pointer to an alternative record (ie flags=flags OR ptr<<6) |
The alternative record must be word aligned and within the first 64MB of addressable memory.
See also
Social
Follow us on
and
and
ROOL Store
Buy RISC OS Open merchandise here, including SD cards for Raspberry Pi and more.