diff options
Diffstat (limited to 'Library/CommonLib/EfiVar.c')
| -rw-r--r-- | Library/CommonLib/EfiVar.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/Library/CommonLib/EfiVar.c b/Library/CommonLib/EfiVar.c new file mode 100644 index 0000000..2a6e59e --- /dev/null +++ b/Library/CommonLib/EfiVar.c @@ -0,0 +1,228 @@ +/** @file
+EFI firmware variable helpers
+
+Copyright (c) 2016. Disk Cryptography Services for EFI (DCS), Alex Kolotnikov
+Copyright (c) 2016. VeraCrypt, Mounir IDRASSI
+
+This program and the accompanying materials are licensed and made available
+under the terms and conditions of the GNU Lesser General Public License, version 3.0 (LGPL-3.0).
+
+The full text of the license may be found at
+https://opensource.org/licenses/LGPL-3.0
+**/
+
+#include <Library/CommonLib.h>
+
+#include <Uefi.h>
+#include <Guid/GlobalVariable.h>
+#include <Protocol/DevicePath.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/DevicePathLib.h>
+#include <Library/BaseMemoryLib.h>
+
+//////////////////////////////////////////////////////////////////////////
+// Efi variables
+//////////////////////////////////////////////////////////////////////////
+
+EFI_STATUS
+EfiGetVar(
+ IN CONST CHAR16* varName,
+ IN EFI_GUID* varGuid,
+ OUT VOID** varValue,
+ OUT UINTN* varSize,
+ OUT UINT32* varAttr
+ ) {
+ EFI_STATUS Status;
+ CHAR8 *varData = NULL;
+ if (varSize == NULL) return EFI_INVALID_PARAMETER;
+ *varSize = 0;
+ if (varGuid == NULL) varGuid = &gEfiDcsVariableGuid;
+ Status = gST->RuntimeServices->GetVariable((CHAR16*)varName, varGuid, varAttr, varSize, varData);
+ if (Status == EFI_BUFFER_TOO_SMALL) {
+ varData = MEM_ALLOC(*varSize);
+ if (varData == NULL) {
+ return EFI_BUFFER_TOO_SMALL;
+ }
+ Status = gST->RuntimeServices->GetVariable((CHAR16*)varName, varGuid, varAttr, varSize, varData);
+ *varValue = varData;
+ }
+ return Status;
+}
+
+
+EFI_STATUS
+EfiSetVar(
+ IN CONST CHAR16* varName,
+ IN EFI_GUID* varGuid,
+ IN VOID* varValue,
+ IN UINTN varSize,
+ IN UINT32 varAttr
+ ) {
+ EFI_STATUS Status;
+ if (varGuid == NULL) varGuid = &gEfiDcsVariableGuid;
+ Status = gST->RuntimeServices->SetVariable((CHAR16*)varName, varGuid, varAttr, varSize, varValue);
+ return Status;
+}
+
+EFI_STATUS
+BootOrderInsert(
+ IN CHAR16 *OrderVarName,
+ IN UINTN index,
+ UINT16 value)
+{
+ EFI_STATUS res = EFI_NOT_READY;
+ UINT16* varBootOrderNew;
+ UINT16* varBootOrder;
+ UINTN varBootOrderSize;
+ UINT32 varBootOrderAttr;
+ UINTN BootOrderCount;
+ UINTN i;
+ UINTN j;
+ res = EfiGetVar(OrderVarName, &gEfiGlobalVariableGuid, &varBootOrder, &varBootOrderSize, &varBootOrderAttr);
+ if (EFI_ERROR(res)) return res;
+ BootOrderCount = varBootOrderSize / sizeof(UINT16);
+ varBootOrderNew = MEM_ALLOC((BootOrderCount + 1) * sizeof(UINT16));
+ if (BootOrderCount < index) index = BootOrderCount - 1;
+ for (j = 0, i = 0; i < BootOrderCount; ++i) {
+ if (j == index) {
+ varBootOrderNew[j] = value;
+ j++;
+ }
+ if (varBootOrder[i] == value) {
+ continue;
+ }
+ varBootOrderNew[j] = varBootOrder[i];
+ ++j;
+ }
+ BootOrderCount = j;
+
+ res = EfiSetVar(OrderVarName, &gEfiGlobalVariableGuid,
+ varBootOrderNew, BootOrderCount * sizeof(UINT16),
+ EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS);
+ MEM_FREE(varBootOrderNew);
+ MEM_FREE(varBootOrder);
+ return res;
+}
+
+EFI_STATUS
+BootOrderRemove(
+ IN CHAR16 *OrderVarName,
+ UINT16 value)
+{
+ EFI_STATUS res = EFI_NOT_READY;
+ UINT16* varBootOrderNew;
+ UINT16* varBootOrder;
+ UINTN varBootOrderSize;
+ UINT32 varBootOrderAttr;
+ UINTN BootOrderCount;
+ UINTN i;
+ UINTN j;
+
+ res = EfiGetVar(OrderVarName, &gEfiGlobalVariableGuid, &varBootOrder, &varBootOrderSize, &varBootOrderAttr);
+ if (EFI_ERROR(res)) return res;
+ BootOrderCount = varBootOrderSize / sizeof(UINT16);
+ varBootOrderNew = MEM_ALLOC((BootOrderCount + 1) * sizeof(UINT16));
+ for (j = 0, i = 0; i < BootOrderCount; ++i) {
+ if (varBootOrder[i] == value) {
+ continue;
+ }
+ varBootOrderNew[j] = varBootOrder[i];
+ ++j;
+ }
+ BootOrderCount = j;
+
+ res = EfiSetVar(OrderVarName, &gEfiGlobalVariableGuid,
+ varBootOrderNew, BootOrderCount * sizeof(UINT16),
+ EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS);
+
+ MEM_FREE(varBootOrderNew);
+ MEM_FREE(varBootOrder);
+ return res;
+}
+
+EFI_STATUS
+BootMenuItemRemove(
+ IN CHAR16 *VarName
+ )
+{
+ EFI_STATUS res = EFI_NOT_READY;
+ res = EfiSetVar(
+ VarName, &gEfiGlobalVariableGuid,
+ NULL, 0,
+ EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS);
+ return res;
+}
+
+EFI_STATUS
+BootMenuItemCreate(
+ IN CHAR16 *VarName,
+ IN CHAR16 *Desc,
+ IN EFI_HANDLE volumeHandle,
+ IN CHAR16 *Path,
+ IN BOOLEAN Reduced
+ )
+{
+ EFI_STATUS res = EFI_NOT_READY;
+ UINT8* varBoot;
+ UINT8* TempByteBuffer;
+ UINTN DescSize;
+ UINTN FilePathSize;
+ EFI_DEVICE_PATH_PROTOCOL* DevPath;
+ EFI_DEVICE_PATH_PROTOCOL* DevicePath;
+ EFI_DEVICE_PATH_PROTOCOL* FileNode;
+ EFI_DEVICE_PATH_PROTOCOL* FilePath;
+
+ // Prepare
+ DevicePath = DevicePathFromHandle(volumeHandle);
+ if (Reduced) {
+ DevPath = DevicePath;
+ while (!IsDevicePathEnd(DevPath)) {
+ if ((DevicePathType(DevPath) == MEDIA_DEVICE_PATH) &&
+ (DevicePathSubType(DevPath) == MEDIA_HARDDRIVE_DP)) {
+
+ //
+ // If we find it use it instead
+ //
+ DevicePath = DevPath;
+ break;
+ }
+ DevPath = NextDevicePathNode(DevPath);
+ }
+ }
+ //
+ // append the file
+ //
+ FileNode = FileDevicePath(NULL, Path);
+ FilePath = AppendDevicePath(DevicePath, FileNode);
+ FreePool(FileNode);
+ //
+ // Add the option
+ //
+ DescSize = StrSize(Desc);
+ FilePathSize = GetDevicePathSize(FilePath);
+
+ varBoot = MEM_ALLOC(sizeof(UINT32) + sizeof(UINT16) + DescSize + FilePathSize);
+ if (varBoot != NULL) {
+ TempByteBuffer = varBoot;
+ *((UINT32 *)TempByteBuffer) = LOAD_OPTION_ACTIVE; // Attributes
+ TempByteBuffer += sizeof(UINT32);
+
+ *((UINT16 *)TempByteBuffer) = (UINT16)FilePathSize; // FilePathListLength
+ TempByteBuffer += sizeof(UINT16);
+
+ CopyMem(TempByteBuffer, Desc, DescSize);
+ TempByteBuffer += DescSize;
+ CopyMem(TempByteBuffer, FilePath, FilePathSize);
+
+ res = EfiSetVar(VarName, &gEfiGlobalVariableGuid,
+ varBoot, sizeof(UINT32) + sizeof(UINT16) + DescSize + FilePathSize,
+ EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS);
+ }
+ else {
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ MEM_FREE(varBoot);
+ return res;
+}
|