windows-nt/Source/XPSP1/NT/base/boot/efi/envvar.c

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2020-09-26 03:20:57 -05:00
/*++
Copyright (c) 2000 Microsoft Corporation
Module Name:
envvar.c
Abstract:
Provides routines to access EFI environment variables.
Author:
Chuck Lenzmeier (chuckl) 10-Dec-2000
Revision History:
--*/
#include "arccodes.h"
#include "stdlib.h"
#include "stdio.h"
#include "string.h"
#if defined(_IA64_)
#include "bootia64.h"
#endif
#include "efi.h"
#include "efip.h"
#define ADD_OFFSET(_p,_o) (PVOID)((PUCHAR)(_p) + (_p)->_o)
#include <efiboot.h>
ARC_STATUS
BlpGetPartitionFromDevicePath (
IN EFI_DEVICE_PATH UNALIGNED *DevicePath,
IN PUCHAR MaximumValidAddress,
OUT PULONG DiskNumber,
OUT PULONG PartitionNumber,
OUT HARDDRIVE_DEVICE_PATH UNALIGNED **HarddriveDevicePath,
OUT FILEPATH_DEVICE_PATH UNALIGNED **FilepathDevicePath
);
//
// Externals
//
extern VOID FlipToVirtual();
extern VOID FlipToPhysical();
extern ULONGLONG CompareGuid();
extern BOOT_CONTEXT BootContext;
extern EFI_HANDLE EfiImageHandle;
extern EFI_SYSTEM_TABLE *EfiST;
extern EFI_BOOT_SERVICES *EfiBS;
extern EFI_RUNTIME_SERVICES *EfiRS;
extern EFI_GUID EfiDevicePathProtocol;
extern EFI_GUID EfiBlockIoProtocol;
EFI_STATUS
EfiGetVariable (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
OUT UINT32 *Attributes OPTIONAL,
IN OUT UINTN *DataSize,
OUT VOID *Data
)
{
EFI_STATUS status;
FlipToPhysical();
status = EfiST->RuntimeServices->GetVariable(
VariableName,
VendorGuid,
Attributes,
DataSize,
Data
);
FlipToVirtual();
return status;
} // EfiGetVariable
EFI_STATUS
EfiSetVariable (
IN CHAR16 *VariableName,
IN EFI_GUID *VendorGuid,
IN UINT32 Attributes,
IN UINTN DataSize,
IN VOID *Data
)
{
EFI_STATUS status;
FlipToPhysical();
status = EfiST->RuntimeServices->SetVariable(
VariableName,
VendorGuid,
Attributes,
DataSize,
Data
);
FlipToVirtual();
return status;
} // EfiSetVariable
EFI_STATUS
EfiGetNextVariableName (
IN OUT UINTN *VariableNameSize,
IN OUT CHAR16 *VariableName,
IN OUT EFI_GUID *VendorGuid
)
{
EFI_STATUS status;
FlipToPhysical();
status = EfiST->RuntimeServices->GetNextVariableName(
VariableNameSize,
VariableName,
VendorGuid
);
FlipToVirtual();
return status;
} // EfiGetNextVariableName
LONG
SafeStrlen (
PUCHAR String,
PUCHAR Max
)
{
PUCHAR p = String;
while ( (p < Max) && (*p != 0) ) {
p++;
}
if ( p < Max ) {
return (LONG)(p - String);
}
return -1;
} // SafeStrlen
LONG
SafeWcslen (
PWCHAR String,
PWCHAR Max
)
{
PWCHAR p = String;
while ( (p < Max) && (*p != 0) ) {
p++;
}
if ( p < Max ) {
return (LONG)(p - String);
}
return -1;
} // SafeWclen
ARC_STATUS
BlGetEfiBootOptions (
OUT PUCHAR Argv0String OPTIONAL,
OUT PUCHAR SystemPartition OPTIONAL,
OUT PUCHAR OsLoaderFilename OPTIONAL,
OUT PUCHAR OsLoadPartition OPTIONAL,
OUT PUCHAR OsLoadFilename OPTIONAL,
OUT PUCHAR FullKernelPath OPTIONAL,
OUT PUCHAR OsLoadOptions OPTIONAL
)
{
EFI_STATUS status;
ARC_STATUS arcStatus;
EFI_GUID EfiGlobalVariable = EFI_GLOBAL_VARIABLE;
UCHAR variable[512];
UCHAR syspart[100];
UCHAR loader[100];
UCHAR loadpart[100];
UCHAR loadname[100];
PEFI_LOAD_OPTION efiLoadOption;
EFI_DEVICE_PATH UNALIGNED *devicePath;
HARDDRIVE_DEVICE_PATH UNALIGNED *harddriveDp;
FILEPATH_DEVICE_PATH UNALIGNED *filepathDp;
WINDOWS_OS_OPTIONS UNALIGNED *osOptions;
UINT16 bootCurrent;
UINTN length;
PUCHAR max;
PUCHAR osloadpart;
PUCHAR osloadname;
PUCHAR osloadoptions;
LONG l;
BOOLEAN end;
WCHAR UNALIGNED *fp;
ULONG bootDisk;
ULONG bootPartition;
ULONG loadDisk;
ULONG loadPartition;
LONG i;
PFILE_PATH loadFilePath;
PWCHAR wideosloadoptions;
WCHAR currentBootEntryName[9];
//
// Get the ordinal of the entry that was used to boot the system.
//
length = sizeof(bootCurrent);
status = EfiGetVariable( L"BootCurrent", &EfiGlobalVariable, NULL, &length, &bootCurrent );
if ( status != EFI_SUCCESS ) {
return ENOENT;
}
//
// Read the boot entry.
//
swprintf( currentBootEntryName, L"Boot%04x", bootCurrent );
length = 512;
status = EfiGetVariable( currentBootEntryName, &EfiGlobalVariable, NULL, &length, variable );
if ( status != EFI_SUCCESS ) {
return ENOENT;
}
//
// Verify the boot entry.
//
max = variable + length;
//
// Is it long enough even to contain the base part of the EFI load option?
//
if ( length < sizeof(EFI_LOAD_OPTION) ) {
return ENOENT;
}
//
// Is the description properly terminated?
//
efiLoadOption = (PEFI_LOAD_OPTION)variable;
l = SafeWcslen( efiLoadOption->Description, (PWCHAR)max );
if ( l < 0 ) {
return ENOENT;
}
devicePath = (EFI_DEVICE_PATH *)((PUCHAR)efiLoadOption +
FIELD_OFFSET(EFI_LOAD_OPTION,Description) +
((l + 1) * sizeof(CHAR16)));
osOptions = (WINDOWS_OS_OPTIONS UNALIGNED *)((PUCHAR)devicePath + efiLoadOption->FilePathLength);
length -= (UINTN)((PUCHAR)osOptions - variable);
//
// Does the OsOptions structure look like a WINDOWS_OS_OPTIONS structure?
//
if ( (length < FIELD_OFFSET(WINDOWS_OS_OPTIONS, OsLoadOptions)) ||
(length != osOptions->Length) ||
(WINDOWS_OS_OPTIONS_VERSION != osOptions->Version) ||
(strcmp(osOptions->Signature, WINDOWS_OS_OPTIONS_SIGNATURE) != 0) ) {
return ENOENT;
}
//
// Is the OsLoadOptions string properly terminated?
//
wideosloadoptions = (PWCHAR)osOptions->OsLoadOptions;
l = SafeWcslen( wideosloadoptions, (PWCHAR)max );
if ( l < 0 ) {
return ENOENT;
}
//
// Convert the OsLoadOptions string to ANSI.
//
osloadoptions = (PUCHAR)wideosloadoptions;
for ( i = 1; i <= l; i++ ) {
osloadoptions[i] = (UCHAR)wideosloadoptions[i];
}
//
// Parse the device path to determine the OS load partition and directory.
// Convert the directory name to ANSI.
//
loadFilePath = ADD_OFFSET( osOptions, OsLoadPathOffset );
#if 0
//
// turn this on to see the device path to the loader executable and device
// path to the operating system
//
BlPrint(TEXT("Device Path = %s\r\n"), DevicePathToStr( devicePath ));
BlPrint(TEXT("Embedded Device Path to OS = %s\r\n"), DevicePathToStr( (EFI_DEVICE_PATH UNALIGNED *)loadFilePath->FilePath ));
DBG_EFI_PAUSE();
#endif
arcStatus = BlpGetPartitionFromDevicePath(
(EFI_DEVICE_PATH UNALIGNED *)loadFilePath->FilePath,
max,
&loadDisk,
&loadPartition,
&harddriveDp,
&filepathDp
);
if (arcStatus != ESUCCESS) {
return arcStatus;
}
sprintf( loadpart,
"multi(0)disk(0)rdisk(%d)partition(%d)",
loadDisk,
loadPartition );
fp = filepathDp->PathName;
l = 0;
while ( (l < (99 - 9 - strlen(loadpart))) &&
((PUCHAR)fp < max) &&
(*fp != 0) ) {
loadname[l++] = (UCHAR)*fp++;
}
loadname[l] = 0;
//
// Translate loader device path to partition/path.
//
arcStatus = BlpGetPartitionFromDevicePath(
devicePath,
max,
&bootDisk,
&bootPartition,
&harddriveDp,
&filepathDp
);
if (arcStatus != ESUCCESS) {
return arcStatus;
}
//
// Form the ARC name for the partition.
//
sprintf( syspart,
"multi(0)disk(0)rdisk(%d)partition(%d)",
bootDisk,
bootPartition );
//
// Extract the path to the loader.
//
fp = filepathDp->PathName;
l = 0;
while ( (l < (99 - 9 - strlen(syspart))) &&
((PUCHAR)fp < max) &&
(*fp != 0) ) {
loader[l++] = (UCHAR)*fp++;
}
loader[l] = 0;
//
// Create the strings that the loader needs.
//
if ( Argv0String != NULL ) {
sprintf( Argv0String, "%s%s", syspart, loader );
}
if ( OsLoaderFilename != NULL ) {
sprintf( OsLoaderFilename, "OSLOADER=%s%s", syspart, loader );
}
if ( SystemPartition != NULL ) {
sprintf( SystemPartition, "SYSTEMPARTITION=%s", syspart );
}
if ( OsLoadOptions != NULL ) {
sprintf( OsLoadOptions, "OSLOADOPTIONS=%s", osloadoptions );
}
if ( OsLoadFilename != NULL ) {
sprintf( OsLoadFilename, "OSLOADFILENAME=%s", loadname );
}
if ( FullKernelPath != NULL ) {
sprintf( FullKernelPath, "%s%s", loadpart, loadname );
}
if ( OsLoadPartition != NULL ) {
sprintf( OsLoadPartition, "OSLOADPARTITION=%s", loadpart );
}
return ESUCCESS;
} // BlGetEfiBootOptions
ARC_STATUS
BlpGetPartitionFromDevicePath (
IN EFI_DEVICE_PATH UNALIGNED *DevicePath,
IN PUCHAR MaximumValidAddress,
OUT PULONG DiskNumber,
OUT PULONG PartitionNumber,
OUT HARDDRIVE_DEVICE_PATH UNALIGNED **HarddriveDevicePath,
OUT FILEPATH_DEVICE_PATH UNALIGNED **FilepathDevicePath
)
{
ARC_STATUS status;
EFI_DEVICE_PATH UNALIGNED *devicePath;
HARDDRIVE_DEVICE_PATH UNALIGNED *harddriveDp;
FILEPATH_DEVICE_PATH UNALIGNED *filepathDp;
LOGICAL end;
ULONG disk;
ULONG partition;
//
// Find the MEDIA/HARDDRIVE and MEDIA/FILEPATH elements in the device path.
//
devicePath = DevicePath;
harddriveDp = NULL;
filepathDp = NULL;
end = FALSE;
while ( ((PUCHAR)devicePath < MaximumValidAddress) &&
!end &&
((harddriveDp == NULL) || (filepathDp == NULL)) ) {
switch( devicePath->Type ) {
case END_DEVICE_PATH_TYPE:
end = TRUE;
break;
case MEDIA_DEVICE_PATH:
switch ( devicePath->SubType ) {
case MEDIA_HARDDRIVE_DP:
harddriveDp = (HARDDRIVE_DEVICE_PATH UNALIGNED *)devicePath;
break;
case MEDIA_FILEPATH_DP:
filepathDp = (FILEPATH_DEVICE_PATH UNALIGNED *)devicePath;
break;
default:
break;
}
default:
break;
}
devicePath = (EFI_DEVICE_PATH UNALIGNED *)NextDevicePathNode( devicePath );
}
//
// If the two necessary elements weren't found, we can't continue.
//
if ( (harddriveDp == NULL) || (filepathDp == NULL) ) {
return ENOENT;
}
//
// Determine the disk number of the disk by opening the given partition
// number on each disk and checking the partition signature.
//
partition = harddriveDp->PartitionNumber;
disk = 0;
while ( TRUE ) {
EFI_PARTITION_ENTRY UNALIGNED *partEntry;
status = BlGetGPTDiskPartitionEntry( disk, (UCHAR)partition, &partEntry );
if ( status == EINVAL ) {
return ENOENT;
}
if ( status == ESUCCESS ) {
if ( memcmp(partEntry->Id, harddriveDp->Signature, 16) == 0 ) {
break;
}
}
disk++;
}
//
// Return information about this disk, and about the device path.
//
*DiskNumber = disk;
*PartitionNumber = partition;
*HarddriveDevicePath = harddriveDp;
*FilepathDevicePath = filepathDp;
return ESUCCESS;
} // BlpGetPartitionFromDevicePath