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/*++
Copyright (c) 1991-1993 Microsoft Corporation
Module Name:
pxenviro.c
Abstract:
This module implements the interface to the HAL get and set
environment variable routines for a Power PC system.
Author:
Jim Wooldridge Ported to PowerPC
Environment:
Kernel mode
Revision History:
--*/
#include "halp.h"
#include "arccodes.h"
#include "prepnvr.h"
#include "fwstatus.h"
#include "fwnvr.h"
KSPIN_LOCK NVRAM_Spinlock;
ARC_STATUS
HalGetEnvironmentVariable (
IN PCHAR Variable,
IN USHORT Length,
OUT PCHAR Buffer
)
/*++
Routine Description:
This function locates an environment variable and returns its value.
Arguments:
Variable - Supplies a pointer to a zero terminated environment variable
name.
Length - Supplies the length of the value buffer in bytes.
Buffer - Supplies a pointer to a buffer that receives the variable value.
Return Value:
ESUCCESS is returned if the enviroment variable is located. Otherwise,
ENOENT is returned.
--*/
{
KIRQL Irql;
PUCHAR tmpbuffer;
//
// Check input parameters
//
if (Variable == NULL ||
*Variable == 0 ||
Length < 1 ||
Buffer == NULL)
return(ENOENT);
//
// Grab control of NVRAM
//
KeAcquireSpinLock(&NVRAM_Spinlock, &Irql);
(VOID)nvr_initialize_object(0, 0);
if ((tmpbuffer = nvr_get_GE_variable(Variable)) == NULL) {
KeReleaseSpinLock(&NVRAM_Spinlock, Irql);
return(ENOENT);
}
//
// Copy the environment variable's value to Buffer
//
do {
*Buffer = *tmpbuffer++;
if (*Buffer++ == 0) {
nvr_delete_object();
KeReleaseSpinLock(&NVRAM_Spinlock, Irql);
return(ESUCCESS);
}
} while (--Length);
//
// Truncate the returned string. The buffer was too short.
//
*--Buffer = 0;
nvr_delete_object();
KeReleaseSpinLock(&NVRAM_Spinlock, Irql);
return(ENOMEM);
}
ARC_STATUS
HalSetEnvironmentVariable (
IN PCHAR Variable,
IN PCHAR Value
)
/*++
Routine Description:
This function creates an environment variable with the specified value.
Arguments:
Variable - Supplies a pointer to an environment variable name.
Value - Supplies a pointer to the environment variable value.
Return Value:
ESUCCESS is returned if the environment variable is created. Otherwise,
ENOMEM is returned.
--*/
{
ARC_STATUS ReturnValue;
KIRQL Irql;
if (Value == NULL) return(ENOENT);
KeAcquireSpinLock(&NVRAM_Spinlock, &Irql); // Grab control of NVRAM
(VOID)nvr_initialize_object(0, 0);
// (VOID)nvr_initialize_object(nvr_system_type);
ReturnValue = nvr_set_GE_variable(Variable,Value);
nvr_delete_object(); // free object created by nvr_init_object
KeReleaseSpinLock(&NVRAM_Spinlock, Irql);
return(ReturnValue);
}
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