Migrate XTLDR to C++

xtldr/efiutils.cc

@@ -0,0 +1,457 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtldr/efiutils.cc
+ * DESCRIPTION:     EFI related routines for XT Boot Loader
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#include <xtldr.h>
+
+
+/**
+ * Reboots into UEFI firmware setup interface.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlEnterFirmwareSetup()
+{
+    EFI_GUID Guid = EFI_GLOBAL_VARIABLE_GUID;
+    PULONGLONG SetupSupport = NULLPTR;
+    ULONGLONG Indications;
+    EFI_STATUS Status;
+
+    /* Check if booting into firmware interface is supported */
+    Status = BlGetEfiVariable(&Guid, L"OsIndicationsSupported", (PVOID*)&SetupSupport);
+    if(Status != STATUS_EFI_SUCCESS || !(*SetupSupport & EFI_OS_INDICATIONS_BOOT_TO_FW_UI))
+    {
+        /* Reboot into firmware setup is not supported */
+        BlDebugPrint(L"WARNING: Reboot into firmware setup interface not supported\n");
+        if(SetupSupport)
+        {
+            BlFreeMemoryPool((PVOID)SetupSupport);
+        }
+        return STATUS_EFI_UNSUPPORTED;
+    }
+
+    BlFreeMemoryPool((PVOID)SetupSupport);
+
+    /* Get the value of OsIndications variable */
+    Indications = 0;
+    Status = BlGetEfiVariable(&Guid, L"OsIndications", (PVOID*)&Indications);
+
+    /* Enable FW setup on next boot */
+    Indications |= EFI_OS_INDICATIONS_BOOT_TO_FW_UI;
+    Status = BlSetEfiVariable(&Guid, L"OsIndications", (PVOID)&Indications, sizeof(Indications));
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Failed to update OsIndications variable */
+        return Status;
+    }
+
+    /* Reboot into firmware setup */
+    BlRebootSystem();
+
+    /* Must not reach this point, just make the compiler happy */
+    return STATUS_EFI_SUCCESS;
+}
+
+/**
+ * Exits EFI boot services.
+ *
+ * @return This routine returns status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlExitBootServices()
+{
+    PEFI_MEMORY_MAP MemoryMap;
+    EFI_STATUS Status;
+    ULONG Counter;
+
+    /* Boot Services might be partially shutdown, so mark them as unavailable */
+    BlpStatus.BootServices = FALSE;
+
+    /* Allocate buffer for EFI memory map */
+    Status = BlAllocateMemoryPool(sizeof(EFI_MEMORY_MAP), (PVOID*)&MemoryMap);
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Memory allocation failure */
+        BlDebugPrint(L"ERROR: Memory allocation failure (Status Code: 0x%zX)\n", Status);
+        return Status;
+    }
+
+    /* Zero fill the buffer and initialize counter */
+    RtlZeroMemory(MemoryMap, sizeof(EFI_MEMORY_MAP));
+    Counter = 0xFF;
+
+    /* Attempt to exit boot services */
+    while(Counter > 0)
+    {
+        /* Get memory map each time as it can change between two calls */
+        Status = BlGetMemoryMap(MemoryMap);
+        if(Status != STATUS_EFI_SUCCESS)
+        {
+            /* Failed to get new memory map */
+            return Status;
+        }
+
+        /* Exit boot services */
+        Status = EfiSystemTable->BootServices->ExitBootServices(EfiImageHandle, MemoryMap->MapKey);
+        if(Status == STATUS_EFI_SUCCESS)
+        {
+            break;
+        }
+
+        /* Decrement counter */
+        Counter--;
+    }
+
+    /* Return EFI status code */
+    return Status;
+}
+
+/**
+ * Gets the address of a reqested system configuration table.
+ *
+ * @param TableGuid
+ *        Supplies a GUID of the configuration table.
+ *
+ * @param Table
+ *        Supplies a pointer to the memory area where the table address will be stored.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlGetConfigurationTable(IN PEFI_GUID TableGuid,
+                        OUT PVOID *Table)
+{
+    SIZE_T Index;
+
+    /* Iterate through all system configuration tables */
+    for(Index = 0; Index < EfiSystemTable->NumberOfTableEntries; Index++)
+    {
+        /* Check if this table matches requested table */
+        if(RtlCompareGuids((PGUID)&(EfiSystemTable->ConfigurationTable[Index].VendorGuid), (PGUID)TableGuid))
+        {
+            /* Found requested table, return success */
+            *Table = EfiSystemTable->ConfigurationTable[Index].VendorTable;
+            return STATUS_EFI_SUCCESS;
+        }
+    }
+
+    /* Table not found */
+    *Table = NULLPTR;
+    return STATUS_EFI_NOT_FOUND;
+}
+
+/**
+ * Gets the value of the EFI variable.
+ *
+ * @param Vendor
+ *        Supplies a pointer to the unique vendor GUID.
+ *
+ * @param VariableName
+ *        Supplies a pointer to tge NULL-terminated string containing the variable name.
+ *
+ * @param VariableValue
+ *        Supplies a pointer to the buffer, where the variable value will be stored.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlGetEfiVariable(IN PEFI_GUID Vendor,
+                 IN PCWSTR VariableName,
+                 OUT PVOID *VariableValue)
+{
+    EFI_STATUS Status;
+    PVOID Buffer;
+    UINT_PTR Size = 0;
+
+    /* Allocate a buffer for storing a variable's value */
+    Size = EFI_MAXIMUM_VARIABLE_SIZE * sizeof(PWCHAR);
+    Status = BlAllocateMemoryPool(Size, (PVOID*)&Buffer);
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Memory allocation failure */
+        return Status;
+    }
+
+    /* Attempt to get variable value */
+    Status = EfiSystemTable->RuntimeServices->GetVariable((PWCHAR)VariableName, Vendor, NULLPTR, &Size, Buffer);
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Failed to get variable, probably not found such one */
+        return Status;
+    }
+
+    /* Get variable value and return success */
+    *VariableValue = Buffer;
+    return STATUS_EFI_SUCCESS;
+}
+
+/**
+ * Returns a random value based on the initialized RNG buffer.
+ *
+ * @param RNGBuffer
+ *        Supplies a pointer to the RNG buffer.
+ *
+ * @return This routine returns a random value.
+ *
+ * @since XT 1.0
+ *
+ * @see https://en.wikipedia.org/wiki/Xorshift
+ */
+XTCDECL
+ULONGLONG
+BlGetRandomValue(IN OUT PULONGLONG RNGBuffer)
+{
+    /* Recalculate RNG buffer with XORSHIFT */
+    *RNGBuffer ^= *RNGBuffer >> 12;
+    *RNGBuffer ^= *RNGBuffer << 25;
+    *RNGBuffer ^= *RNGBuffer >> 27;
+
+    /* Return random value */
+    return *RNGBuffer * 0x2545F4914F6CDD1D;
+}
+
+/**
+ * Checks whether SecureBoot is enabled or not.
+ *
+ * @return Numeric representation of SecureBoot status (0 = Disabled, >0 = Enabled, <0 SetupMode).
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+INT_PTR
+BlGetSecureBootStatus()
+{
+    EFI_GUID VarGuid = EFI_GLOBAL_VARIABLE_GUID;
+    INT_PTR SecureBootStatus = 0;
+    INT_PTR VarValue = 0;
+    UINT_PTR Size;
+
+    Size = sizeof(INT_PTR);
+    if(EfiSystemTable->RuntimeServices->GetVariable((PWCHAR)L"SecureBoot", &VarGuid,
+       NULLPTR, &Size, &VarValue) == STATUS_EFI_SUCCESS)
+    {
+        SecureBootStatus = VarValue;
+        Size = sizeof(INT_PTR);
+        if((EfiSystemTable->RuntimeServices->GetVariable((PWCHAR)L"SetupMode", &VarGuid,
+           NULLPTR, &Size, &VarValue) == STATUS_EFI_SUCCESS) && VarValue != 0)
+        {
+            SecureBootStatus = -1;
+        }
+    }
+
+    /* Return SecureBoot status */
+    return SecureBootStatus;
+}
+
+/**
+ * Initializes the RNG buffer with random bytes from the default EFI RNG algorithm.
+ *
+ * @param RNGBuffer
+ *        Supplies a pointer to the RNG buffer.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlInitializeEntropy(PULONGLONG RNGBuffer)
+{
+    EFI_GUID RngGuid = EFI_RNG_PROTOCOL_GUID;
+    PEFI_RNG_PROTOCOL Rng;
+    EFI_STATUS Status;
+    ULONGLONG Seed;
+
+    /* Initialize variables */
+    Rng = NULLPTR;
+    Seed = 0;
+
+    /* Locate RNG protocol */
+    Status = EfiSystemTable->BootServices->LocateProtocol(&RngGuid, NULLPTR, (PVOID *)&Rng);
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Failed to locate RNG protocol, return status code */
+        return Status;
+    }
+
+    /* Get RNG value using the default algorithm */
+    Status = Rng->GetRNG(Rng, NULLPTR, 8, (PUCHAR)&Seed);
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Failed to get RNG value, return status code */
+        return Status;
+    }
+
+    /* Initialize RNG state and return success */
+    *RNGBuffer = Seed ? Seed : 1;
+    return STATUS_EFI_SUCCESS;
+}
+
+/**
+ * Loads an EFI image into memory.
+ *
+ * @param DevicePath
+ *        Specifies a device path from which the image is loaded.
+ *
+ * @param ImageData
+ *        Supplies a pointer to the memory are containing a copy of the EFI image.
+ *
+ * @param ImageSize
+ *        Supplies the size (in bytes) of the EFI image.
+ *
+ * @param ImageHandle
+ *        Supplies a pointer to the memory area, where an EFI_image handle will be stored.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlLoadEfiImage(IN PEFI_DEVICE_PATH_PROTOCOL DevicePath,
+               IN PVOID ImageData,
+               IN SIZE_T ImageSize,
+               OUT PEFI_HANDLE ImageHandle)
+{
+    /* Load EFI image */
+    return EfiSystemTable->BootServices->LoadImage(FALSE, EfiImageHandle, DevicePath, ImageData, ImageSize, ImageHandle);
+}
+
+/**
+ * Reboots the machine.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlRebootSystem()
+{
+    /* Reboot machine */
+    return EfiSystemTable->RuntimeServices->ResetSystem(EfiResetCold, STATUS_EFI_SUCCESS, 0, NULLPTR);
+}
+
+/**
+ * Sets a value of an EFI variable.
+ *
+ * @param Vendor
+ *        Supplies a pointer to the unique vendor GUID.
+ *
+ * @param VariableName
+ *        Supplies a pointer to tge NULL-terminated string containing the variable name.
+ *
+ * @param VariableValue
+ *        Supplies the contents of the variable.
+ *
+ * @param Size
+ *        Supplies the size of the variable data buffer.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlSetEfiVariable(IN PEFI_GUID Vendor,
+                 IN PCWSTR VariableName,
+                 IN PVOID VariableValue,
+                 IN UINT_PTR Size)
+{
+    ULONG Attributes;
+
+    /* Set EFI variable */
+    Attributes = EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS;
+    return EfiSystemTable->RuntimeServices->SetVariable((PWCHAR)VariableName, Vendor, Attributes, Size, VariableValue);
+}
+
+/**
+ * Shuts down the machine.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlShutdownSystem()
+{
+    /* Shutdown machine */
+    return EfiSystemTable->RuntimeServices->ResetSystem(EfiResetShutdown, STATUS_EFI_SUCCESS, 0, NULLPTR);
+}
+
+/**
+ * Puts the system to sleep for the specified number of milliseconds.
+ *
+ * @param Milliseconds
+ *        Supplies the number of milliseconds to sleep.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+VOID
+BlSleepExecution(IN ULONG_PTR Milliseconds)
+{
+    EfiSystemTable->BootServices->Stall(Milliseconds * 1000);
+}
+
+/**
+ * Executes a loaded EFI image entry point.
+ *
+ * @param ImageHandle
+ *        Provides a handle of loaded image, that will be started.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlStartEfiImage(IN EFI_HANDLE ImageHandle)
+{
+    return EfiSystemTable->BootServices->StartImage(ImageHandle, NULLPTR, NULLPTR);
+}
+
+/**
+ * Waits for one or more EFI events.
+ *
+ * @param NumberOfEvents
+ *        Supplies the number of events to wait for.
+ *
+ * @param Event
+ *        Supplies the array of events to wait for.
+ *
+ * @param Index
+ *        Receives the index of the event that was signaled.
+ *
+ * @return This routine returns status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlWaitForEfiEvent(IN UINT_PTR NumberOfEvents,
+                  IN PEFI_EVENT Event,
+                  OUT PUINT_PTR Index)
+{
+    return EfiSystemTable->BootServices->WaitForEvent(NumberOfEvents, Event, Index);
+}