DevHelp FreeLIDEntry: Difference between revisions

Latest revision as of 05:32, 11 May 2025

This service releases a Logical ID (LID). This must be done at uninstall or termination time.

Syntax

C

USHORT APIENTRY DevHelp_FreeLIDEntry (USHORT LIDNumber)

Assembler

MOV   AX,LID                  ; Logical ID from GetLIDEntry
MOV   DL,DevHlp_FreeLIDEntry

CALL  [Device_Help]

Parameters

C

LIDNumber (USHORT) - input: Logical ID from GetLIDEntry

Assembler

MOV   AX,LID                  ; Logical ID from GetLIDEntry

Return Code

C

Success indicator

Possible errors

ERROR_LID_DOES_NOT_EXIST (0x02)

ERROR_ABIOS_NOT_PRESENT (0x03)

ERROR_NOT_YOUR_LID (0x04)

Assembler

  'C' Clear if successful.

   'C' Set if error.
       AX = Error code.
            Possible errors:
               ERROR_LID_DOES_NOT_EXIST     (0x02)
               ERROR_ABIOS_NOT_PRESENT      (0x03)
               ERROR_NOT_YOUR_LID           (0x04)

Remarks

The attempt to free a Logical ID can fail if the physical device driver does not own the LID or if the LID does not exist.

DS must point to the data segment of the physical device driver. If DS was previously used in a call to PhysToVirt, it must be reset to the data segment of the physical device driver.

Example Code

C

#include  "dhcalls.h"

USHORT APIENTRY DevHelp_FreeLIDEntry (USHORT LIDNumber)

Related Functions

@@ Line 1: / Line 1: @@
-This service releases physical memory allocated by the DevHlp_AllocPhys.
+{{DISPLAYTITLE:DevHelp_FreeLIDEntry}}
+This service releases a Logical ID (LID). This must be done at uninstall or termination time.
 ==Syntax==
 ===C===
 <PRE>
-USHORT APIENTRY DevHelp_FreePhys(PULONG PhysAddr)
+USHORT APIENTRY DevHelp_FreeLIDEntry (USHORT LIDNumber)
 </PRE>
 ===Assembler===
 <PRE>
-MOV   BX,address_low          ; 32-bit physical address
+MOV   AX,LID                  ; Logical ID from GetLIDEntry
-MOV   AX,address_high         ;
+MOV   DL,DevHlp_FreeLIDEntry
-MOV   DL,DevHlp_FreePhys
 CALL  [Device_Help]
@@ Line 16: / Line 16: @@
 ==Parameters==
 ===C===
-; PhysAddr (PULONG) - input : Pointer to the 32 bit physical address of memory to be freed.
+; LIDNumber (USHORT) - input : Logical ID from GetLIDEntry
 ===Assembler===
 <PRE>
-MOV   BX,address_low          ; 32-bit physical address
+MOV   AX,LID                  ; Logical ID from GetLIDEntry
-MOV   AX,address_high         ;
 </PRE>
 ==Return Code==
 ===C===
-; Success Indicator: 0
+;  Success indicator:
 ; Possible errors:
-::Memory not freed
+:: ERROR_LID_DOES_NOT_EXIST     (0x02)
+:: ERROR_ABIOS_NOT_PRESENT      (0x03)
+:: ERROR_NOT_YOUR_LID           (0x04)
 ===Assembler===
 <PRE>
-   'C' Clear if memory freed.
+   'C' Clear if successful.
-  'C' Set if memory not freed.
+   'C' Set if error.
+       AX = Error code.
+            Possible errors:
+               ERROR_LID_DOES_NOT_EXIST     (0x02)
+               ERROR_ABIOS_NOT_PRESENT      (0x03)
+               ERROR_NOT_YOUR_LID           (0x04)
 </PRE>
 ==Remarks==
-Any memory that the physical device driver allocated by way of the DevHlp_AllocPhys should be released prior to device driver termination. Memory that was not allocated with AllocPhys cannot be freed.
+The attempt to free a Logical ID can fail if the physical device driver does not own the LID or if the LID does not exist.
+DS must point to the data segment of the physical device driver. If DS was previously used in a call to PhysToVirt, it must be reset to the data segment of the physical device driver.
 ==Example Code==
@@ Line 45: / Line 54: @@
 #include  "dhcalls.h"
-USHORT APIENTRY DevHelp_FreePhys(PULONG PhysAddr)
+USHORT APIENTRY DevHelp_FreeLIDEntry (USHORT LIDNumber)
 </PRE>