OS_NVMemory (changes)
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OS SWI Calls
» OS_NVMemory
OS_NVMemory
(SWI &76)
| Entry | |
|---|---|
| R0 | Reason code |
| Exit | |
|---|---|
| All other registers dependent on reason code | |
Use
The purpose of this call is to provide an interface that allows the full capacity of a machines NVRAM (aka CMOS RAM) to be accessed. Other calls (OS_Byte 161, OS_Byte 162) are limited in that they only provide access to the first 240 bytes of NVRAM.
Notes
The action performed depends on the reason code value in R0.
Reason Codes
| # | Hex # | Action |
|---|---|---|
| 0 | &00 | Read NVMRAM size |
| 1 | &01 | Read a byte |
| 2 | &02 | Write a byte |
| 3 | &03 | Read bytes |
| 4 | &04 | Write bytes |
| 5 | &05 | Reserved |
| 6 | &06 | Read default value used on CMOS reset |
| 7 | &07 | Set station |
See also
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