Laszlo Ersek 23d04b58e2 ArmVirtualizationPkg: Intel BDS: load EFI-stubbed Linux kernel from fw_cfg
A number of tools depend on passing the kernel image, the initial ramdisk,
and the kernel command line to the guest on the QEMU command line (options
-kernel, -initrd, -append, respectively). At the moment, these QEMU
options  work, but the guest kernel loaded this way is launched by a
minimal binary firmware that is dynamically composed by QEMU. As a
consequence, such a kernel has no UEFI environment.

This patch enables -kernel, -initrd, -append to work on top of the
ArmVirtualizationQemu firmware build. The approach it takes is different
from how the same functionality is implemented in OvmfPkg.

OvmfPkg contains a full-fledged Linux boot loader (see
"OvmfPkg/Library/PlatformBdsLib/QemuKernel.c" and
"OvmfPkg/Library/LoadLinuxLib/"). OVMF's LoadLinuxLib sets up the required
kernel environment in a sophisticated way (including x86-specific
artifacts like the GDT), calls ExitBootServices() itself (for legacy
kernels without EFI handover protocol), and jumps to the kernel (using x86
assembly).

In ArmVirtualizationPkg's PlatformIntelBdsLib, we require the kernel being
loaded to have an EFI stub -- that is, to be a genuine UEFI application.

(The EFI stub is not an additional burden for guest kernels -- the EFI
stub is a hard requirement anyway because it needs to process the DTB
heavily:
- it removes memory nodes,
- it removes memreserve entries,
- it adds UEFI properties to the "chosen" node,
- it calculates and installs virt-to-phys mappings with
  SetVirtualAddressMap() in a way that enables kexec [planned].

Kudos to Ard Biesheuvel for summarizing the above.)

An EFI-stubbed Linux guest kernel can be loaded with plain
gBS->LoadImage(). The EFI stub will look up its own
EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL instance (ie. the device path where
it has been loaded from), and it will locate the initial ramdisk named by
the "initrd" command line parameter as a *sibling file* on the same
device.

The initrd file is then loaded using the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.

This approach enables the EFI stub to load the initial ramdisk from normal
EFI System Partitions, from remote PXE/TFTP directories -- and it enables
us to provide the initrd from memory as well.

In this patch:

- We download the kernel image, the initrd image, and the kernel command
  line, using QEMU's fw_cfg interface.

- We create a read-only EFI_SIMPLE_FILE_SYSTEM_PROTOCOL instance that has
  just a root directory, with the three downloaded files in it.

- The handle that carries the simple file system has a single-node
  VenHw(...) device path (not counting the terminator node).

- We load the EFI-stubbed kernel (which is a UEFI application) with
  gBS->LoadImage(), passing "VenHw(...)/kernel" as device path. This
  causes gBS->LoadImage() to call back into our filesystem.

- Appended to the downloaded command line, we pass "initrd=initrd" to the
  EFI stub.

- Once the EFI stub is running, it loads the initial ramdisk from the
  "sibling" device path "VenHw(...)/initrd", also calling back into our
  filesystem.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16578 6f19259b-4bc3-4df7-8a09-765794883524
2015-01-02 12:08:33 +00:00

396 lines
12 KiB
C

/** @file
Copyright (c) 2004 - 2008, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2014, ARM Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "IntelBdsPlatform.h"
#include <Library/QemuBootOrderLib.h>
///
/// Predefined platform default time out value
///
UINT16 gPlatformBootTimeOutDefault;
EFI_STATUS
EFIAPI
PlatformIntelBdsConstructor (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
gPlatformBootTimeOutDefault = (UINT16)PcdGet16 (PcdPlatformBootTimeOut);
return EFI_SUCCESS;
}
//
// BDS Platform Functions
//
/**
Platform Bds init. Include the platform firmware vendor, revision
and so crc check.
**/
VOID
EFIAPI
PlatformBdsInit (
VOID
)
{
}
STATIC
EFI_STATUS
GetConsoleDevicePathFromVariable (
IN CHAR16* ConsoleVarName,
IN CHAR16* DefaultConsolePaths,
OUT EFI_DEVICE_PATH** DevicePaths
)
{
EFI_STATUS Status;
UINTN Size;
EFI_DEVICE_PATH_PROTOCOL* DevicePathInstances;
EFI_DEVICE_PATH_PROTOCOL* DevicePathInstance;
CHAR16* DevicePathStr;
CHAR16* NextDevicePathStr;
EFI_DEVICE_PATH_FROM_TEXT_PROTOCOL *EfiDevicePathFromTextProtocol;
Status = GetGlobalEnvironmentVariable (ConsoleVarName, NULL, NULL, (VOID**)&DevicePathInstances);
if (EFI_ERROR (Status)) {
// In case no default console device path has been defined we assume a driver handles the console (eg: SimpleTextInOutSerial)
if ((DefaultConsolePaths == NULL) || (DefaultConsolePaths[0] == L'\0')) {
*DevicePaths = NULL;
return EFI_SUCCESS;
}
Status = gBS->LocateProtocol (&gEfiDevicePathFromTextProtocolGuid, NULL, (VOID **)&EfiDevicePathFromTextProtocol);
ASSERT_EFI_ERROR (Status);
DevicePathInstances = NULL;
// Extract the Device Path instances from the multi-device path string
while ((DefaultConsolePaths != NULL) && (DefaultConsolePaths[0] != L'\0')) {
NextDevicePathStr = StrStr (DefaultConsolePaths, L";");
if (NextDevicePathStr == NULL) {
DevicePathStr = DefaultConsolePaths;
DefaultConsolePaths = NULL;
} else {
DevicePathStr = (CHAR16*)AllocateCopyPool ((NextDevicePathStr - DefaultConsolePaths + 1) * sizeof (CHAR16), DefaultConsolePaths);
*(DevicePathStr + (NextDevicePathStr - DefaultConsolePaths)) = L'\0';
DefaultConsolePaths = NextDevicePathStr;
if (DefaultConsolePaths[0] == L';') {
DefaultConsolePaths++;
}
}
DevicePathInstance = EfiDevicePathFromTextProtocol->ConvertTextToDevicePath (DevicePathStr);
ASSERT (DevicePathInstance != NULL);
DevicePathInstances = AppendDevicePathInstance (DevicePathInstances, DevicePathInstance);
if (NextDevicePathStr != NULL) {
FreePool (DevicePathStr);
}
FreePool (DevicePathInstance);
}
// Set the environment variable with this device path multi-instances
Size = GetDevicePathSize (DevicePathInstances);
if (Size > 0) {
gRT->SetVariable (
ConsoleVarName,
&gEfiGlobalVariableGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
Size,
DevicePathInstances
);
} else {
Status = EFI_INVALID_PARAMETER;
}
}
if (!EFI_ERROR (Status)) {
*DevicePaths = DevicePathInstances;
}
return Status;
}
STATIC
EFI_STATUS
InitializeConsolePipe (
IN EFI_DEVICE_PATH *ConsoleDevicePaths,
IN EFI_GUID *Protocol,
OUT EFI_HANDLE *Handle,
OUT VOID* *Interface
)
{
EFI_STATUS Status;
UINTN Size;
UINTN NoHandles;
EFI_HANDLE *Buffer;
EFI_DEVICE_PATH_PROTOCOL* DevicePath;
// Connect all the Device Path Consoles
while (ConsoleDevicePaths != NULL) {
DevicePath = GetNextDevicePathInstance (&ConsoleDevicePaths, &Size);
Status = BdsConnectDevicePath (DevicePath, Handle, NULL);
DEBUG_CODE_BEGIN ();
if (EFI_ERROR (Status)) {
// We convert back to the text representation of the device Path
EFI_DEVICE_PATH_TO_TEXT_PROTOCOL* DevicePathToTextProtocol;
CHAR16* DevicePathTxt;
EFI_STATUS Status;
Status = gBS->LocateProtocol (&gEfiDevicePathToTextProtocolGuid, NULL, (VOID **)&DevicePathToTextProtocol);
if (!EFI_ERROR (Status)) {
DevicePathTxt = DevicePathToTextProtocol->ConvertDevicePathToText (DevicePath, TRUE, TRUE);
DEBUG ((EFI_D_ERROR, "Fail to start the console with the Device Path '%s'. (Error '%r')\n", DevicePathTxt, Status));
FreePool (DevicePathTxt);
}
}
DEBUG_CODE_END ();
// If the console splitter driver is not supported by the platform then use the first Device Path
// instance for the console interface.
if (!EFI_ERROR (Status) && (*Interface == NULL)) {
Status = gBS->HandleProtocol (*Handle, Protocol, Interface);
}
}
// No Device Path has been defined for this console interface. We take the first protocol implementation
if (*Interface == NULL) {
Status = gBS->LocateHandleBuffer (ByProtocol, Protocol, NULL, &NoHandles, &Buffer);
if (EFI_ERROR (Status)) {
BdsConnectAllDrivers ();
Status = gBS->LocateHandleBuffer (ByProtocol, Protocol, NULL, &NoHandles, &Buffer);
}
if (!EFI_ERROR (Status)) {
*Handle = Buffer[0];
Status = gBS->HandleProtocol (*Handle, Protocol, Interface);
ASSERT_EFI_ERROR (Status);
}
FreePool (Buffer);
} else {
Status = EFI_SUCCESS;
}
return Status;
}
/**
Connect the predefined platform default console device. Always try to find
and enable the vga device if have.
@param PlatformConsole Predefined platform default console device array.
@retval EFI_SUCCESS Success connect at least one ConIn and ConOut
device, there must have one ConOut device is
active vga device.
@return Return the status of BdsLibConnectAllDefaultConsoles ()
**/
EFI_STATUS
PlatformBdsConnectConsole (
VOID
)
{
EFI_STATUS Status;
EFI_DEVICE_PATH* ConOutDevicePaths;
EFI_DEVICE_PATH* ConInDevicePaths;
EFI_DEVICE_PATH* ConErrDevicePaths;
// By getting the Console Device Paths from the environment variables before initializing the console pipe, we
// create the 3 environment variables (ConIn, ConOut, ConErr) that allows to initialize all the console interface
// of newly installed console drivers
Status = GetConsoleDevicePathFromVariable (L"ConOut", (CHAR16*)PcdGetPtr (PcdDefaultConOutPaths), &ConOutDevicePaths);
ASSERT_EFI_ERROR (Status);
Status = GetConsoleDevicePathFromVariable (L"ConIn", (CHAR16*)PcdGetPtr (PcdDefaultConInPaths), &ConInDevicePaths);
ASSERT_EFI_ERROR (Status);
Status = GetConsoleDevicePathFromVariable (L"ErrOut", (CHAR16*)PcdGetPtr (PcdDefaultConOutPaths), &ConErrDevicePaths);
ASSERT_EFI_ERROR (Status);
// Initialize the Consoles
Status = InitializeConsolePipe (ConOutDevicePaths, &gEfiSimpleTextOutProtocolGuid, &gST->ConsoleOutHandle, (VOID **)&gST->ConOut);
ASSERT_EFI_ERROR (Status);
Status = InitializeConsolePipe (ConInDevicePaths, &gEfiSimpleTextInProtocolGuid, &gST->ConsoleInHandle, (VOID **)&gST->ConIn);
ASSERT_EFI_ERROR (Status);
Status = InitializeConsolePipe (ConErrDevicePaths, &gEfiSimpleTextOutProtocolGuid, &gST->StandardErrorHandle, (VOID **)&gST->StdErr);
if (EFI_ERROR (Status)) {
// In case of error, we reuse the console output for the error output
gST->StandardErrorHandle = gST->ConsoleOutHandle;
gST->StdErr = gST->ConOut;
}
return Status;
}
/**
Connect with predefined platform connect sequence,
the OEM/IBV can customize with their own connect sequence.
**/
VOID
PlatformBdsConnectSequence (
VOID
)
{
}
/**
Load the predefined driver option, OEM/IBV can customize this
to load their own drivers
@param BdsDriverLists - The header of the driver option link list.
**/
VOID
PlatformBdsGetDriverOption (
IN OUT LIST_ENTRY *BdsDriverLists
)
{
}
/**
Perform the platform diagnostic, such like test memory. OEM/IBV also
can customize this function to support specific platform diagnostic.
@param MemoryTestLevel The memory test intensive level
@param QuietBoot Indicate if need to enable the quiet boot
@param BaseMemoryTest A pointer to BdsMemoryTest()
**/
VOID
PlatformBdsDiagnostics (
IN EXTENDMEM_COVERAGE_LEVEL MemoryTestLevel,
IN BOOLEAN QuietBoot,
IN BASEM_MEMORY_TEST BaseMemoryTest
)
{
}
/**
The function will execute with as the platform policy, current policy
is driven by boot mode. IBV/OEM can customize this code for their specific
policy action.
@param DriverOptionList The header of the driver option link list
@param BootOptionList The header of the boot option link list
@param ProcessCapsules A pointer to ProcessCapsules()
@param BaseMemoryTest A pointer to BaseMemoryTest()
**/
VOID
EFIAPI
PlatformBdsPolicyBehavior (
IN LIST_ENTRY *DriverOptionList,
IN LIST_ENTRY *BootOptionList,
IN PROCESS_CAPSULES ProcessCapsules,
IN BASEM_MEMORY_TEST BaseMemoryTest
)
{
EFI_STATUS Status;
Status = PlatformBdsConnectConsole ();
ASSERT_EFI_ERROR (Status);
//
// Process QEMU's -kernel command line option
//
TryRunningQemuKernel ();
BdsLibConnectAll ();
BdsLibEnumerateAllBootOption (BootOptionList);
SetBootOrderFromQemu (BootOptionList);
//
// The BootOrder variable may have changed, reload the in-memory list with
// it.
//
BdsLibBuildOptionFromVar (BootOptionList, L"BootOrder");
PlatformBdsEnterFrontPage (gPlatformBootTimeOutDefault, TRUE);
}
/**
Hook point after a boot attempt succeeds. We don't expect a boot option to
return, so the UEFI 2.0 specification defines that you will default to an
interactive mode and stop processing the BootOrder list in this case. This
is also a platform implementation and can be customized by IBV/OEM.
@param Option Pointer to Boot Option that succeeded to boot.
**/
VOID
EFIAPI
PlatformBdsBootSuccess (
IN BDS_COMMON_OPTION *Option
)
{
}
/**
Hook point after a boot attempt fails.
@param Option Pointer to Boot Option that failed to boot.
@param Status Status returned from failed boot.
@param ExitData Exit data returned from failed boot.
@param ExitDataSize Exit data size returned from failed boot.
**/
VOID
EFIAPI
PlatformBdsBootFail (
IN BDS_COMMON_OPTION *Option,
IN EFI_STATUS Status,
IN CHAR16 *ExitData,
IN UINTN ExitDataSize
)
{
}
/**
This function locks platform flash that is not allowed to be updated during normal boot path.
The flash layout is platform specific.
**/
VOID
EFIAPI
PlatformBdsLockNonUpdatableFlash (
VOID
)
{
return;
}
/**
Lock the ConsoleIn device in system table. All key
presses will be ignored until the Password is typed in. The only way to
disable the password is to type it in to a ConIn device.
@param Password Password used to lock ConIn device.
@retval EFI_SUCCESS lock the Console In Spliter virtual handle successfully.
@retval EFI_UNSUPPORTED Password not found
**/
EFI_STATUS
EFIAPI
LockKeyboards (
IN CHAR16 *Password
)
{
return EFI_UNSUPPORTED;
}