OS_ReadSysInfo 2 (changes)
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Programmer's OS Reference SWI Manuals Calls
» Part OS_ReadSysInfo 15 – SWI Calls
» OS_ReadSysInfo 2OS
» OS_ReadSysInfo
» OS_ReadSysInfo 2
OS_ReadSysInfo 2
(SWI &58)
| Entry | |
|---|---|
| R0 | 2 |
| Exit | |
|---|---|
| R0 | Hardware configuration word 0 |
| R1 | Hardware configuration word 1 |
| R2 | Hardware configuration word 2 |
| R3 | Low half of machine ID |
| R4 | High half of machine ID |
Hardware configuration words
| Word | Bits | Use | Values | Values |
|---|---|---|---|---|
| 0 | 0-7 | Special functions chip type | 0 = none/unspecified | |
| 1 = IOEB | ||||
| 0 | 8-15 | I/O controller chip type | 0 = IOC | |
| 1 = IOMD | ||||
| 255 = unspecified | ||||
| 0 | 16-23 | Memory controller chip type | 0 = MEMC1/MEMC1a | |
| 1 = IOMD | ||||
| 255 = unspecified | ||||
| 0 | 24-31 | Video controller chip type | 0 = VIDC1a | |
| 1 = VIDC20 | ||||
| 255 = unspecified | ||||
| 1 | 0-7 | I/O chip type | 0 = none/unspecified | |
| 1 = 82C710 or similar | ||||
| 1 | 8-31 | Reserved | 0 | |
| 2 | 0-7 | LCD controller type | 0 = none | |
| 1 = type 1 (e.g. A4 portable) | ||||
| 2 = type 2 (e.g. Stork portable) | ||||
| 2 | 8-15 | IOMD variant | 0 = IOMD | |
| 1 = IOMDL (i.e. ARM7500) | ||||
| 2 | 16-23 | VIDC20 variant | 0 = VIDC20 | |
| 1 = VIDC2L (i.e. ARM7500) | ||||
| 2 | 24 | IIC bus speed | 0 = slow (100kHz) | |
| 1 = fast (400kHz) | ||||
| 2 | 25 | Clock state during idle | 0 = Keep I/O clocks running during idle | |
| 1 = Stop I/O clocks during idle | ||||
| 2 | 26-31 | Reserved | 0 |
Use
The purpose of this call is to check for the presence of various chips, returning flags.
It also reads the unique machine ID if a suitable chip is fitted to the computer; if none is, an ID of zero is returned.
Notes
The content of hardware information word 2 is generally only correct if the system is IOC or IOMD based. Modern HAL based systems typically return 0 for the whole word.
When using this call to read the machine ID, it is recommended that programs first check with OS_ReadSysInfo 12 to see if an extended machine ID is available.
If you only wish to read the old-style 64 bit machine ID, then OS_ReadSysInfo 5 can be used instead.
See also
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