View source for ProgAddedum - Device Helper (DevHlp) Services and Function Codes

{{ProgAddedum}}
{{IBM-Reprint}}

DevHlp services include : 

{| class="wikitable"
|+ DevHlp Services
|-
! Service !! Code !! Description
|-
| [[DevHlp_CloseFile]] || 80h || Close file (system initialization time only)
|-
| [[DevHlp_FreeCtxHook]] || 64h || Free context hook
|-
| [[DevHelp_GetDOSVar]] || 24h || Return address of kernel variable
|-
| [[DevHlp_KillProc]] || 7Dh || Kill process unconditionally
|-
| [[DevHlp_OpenFile]] || 7Fh || Open file (system initialization time only)
|-
| [[DevHlp_PerfSysTrace]] || 45h || Write Software Trace information to STRACE buffer
|-
| [[DevHlp_QSysState]] || 7Eh || Get system status information
|-
| [[DevHlp_ReadFile]] || 81h || Read (system initialization time only)
|-
| [[DevHlp_ReadFileAt]] || 82h || Seek and read (system initialization time only)
|-
| [[DevHlp_RegisterKDD]] || 83h || Register driver with kernel debugger
|-
| [[DevHlp_SysTrace]] || 28h || Add information to System Trace buffer
|}

;System event notification 
{| class="wikitable"
|+ System Event Notification
|-
! Event !! Index !! Description
|-
| event_POWER || 9 || Power off event
|}

;Errata Note: DevHlp_FileOpen was removed since it was a typo: Ref: [[IBM_SDK/TK_Errata_Sheet]].