/**
This is the main Dispatcher for SMM and it exits when there are no more
drivers to run. Drain the mScheduledQueue and load and start a PE
image for each driver. Search the mDiscoveredList to see if any driver can
be placed on the mScheduledQueue. If no drivers are placed on the
mScheduledQueue exit the function.
@retval EFI_SUCCESS All of the SMM Drivers that could be dispatched
have been run and the SMM Entry Point has been
registered.
@retval EFI_NOT_READY The SMM Driver that registered the SMM Entry Point
was just dispatched.
@retval EFI_NOT_FOUND There are no SMM Drivers available to be dispatched.
@retval EFI_ALREADY_STARTED The SMM Dispatcher is already running
**/
EFI_STATUS
SmmDispatcher (
VOID
)
{
EFI_STATUS Status;
LIST_ENTRY *Link;
EFI_SMM_DRIVER_ENTRY *DriverEntry;
BOOLEAN ReadyToRun;
BOOLEAN PreviousSmmEntryPointRegistered;
if (!gRequestDispatch) {
return EFI_NOT_FOUND;
}
if (gDispatcherRunning) {
//
// If the dispatcher is running don't let it be restarted.
//
return EFI_ALREADY_STARTED;
}
gDispatcherRunning = TRUE;
do {
//
// Drain the Scheduled Queue
//
while (!IsListEmpty (&mScheduledQueue)) {
DriverEntry = CR (
mScheduledQueue.ForwardLink,
EFI_SMM_DRIVER_ENTRY,
ScheduledLink,
EFI_SMM_DRIVER_ENTRY_SIGNATURE
);
//
// Load the SMM Driver image into memory. If the Driver was transitioned from
// Untrused to Scheduled it would have already been loaded so we may need to
// skip the LoadImage
//
if (DriverEntry->ImageHandle == NULL) {
Status = SmmLoadImage (DriverEntry);
//
// Update the driver state to reflect that it's been loaded
//
if (EFI_ERROR (Status)) {
//
// The SMM Driver could not be loaded, and do not attempt to load or start it again.
// Take driver from Scheduled to Initialized.
//
DriverEntry->Initialized = TRUE;
DriverEntry->Scheduled = FALSE;
RemoveEntryList (&DriverEntry->ScheduledLink);
//
// If it's an error don't try the StartImage
//
continue;
}
}
DriverEntry->Scheduled = FALSE;
DriverEntry->Initialized = TRUE;
RemoveEntryList (&DriverEntry->ScheduledLink);
REPORT_STATUS_CODE_WITH_EXTENDED_DATA (
EFI_PROGRESS_CODE,
EFI_SOFTWARE_SMM_DRIVER | EFI_SW_PC_INIT_BEGIN,
&DriverEntry->ImageHandle,
sizeof (DriverEntry->ImageHandle)
);
//
// Cache state of SmmEntryPointRegistered before calling entry point
//
PreviousSmmEntryPointRegistered = gSmmCorePrivate->SmmEntryPointRegistered;
//
// For each SMM driver, pass NULL as ImageHandle
//
Status = ((EFI_IMAGE_ENTRY_POINT)(UINTN)DriverEntry->ImageEntryPoint)(DriverEntry->ImageHandle, gST);
if (EFI_ERROR(Status)){
SmmFreePages(DriverEntry->ImageBuffer, DriverEntry->NumberOfPage);
}
REPORT_STATUS_CODE_WITH_EXTENDED_DATA (
EFI_PROGRESS_CODE,
EFI_SOFTWARE_SMM_DRIVER | EFI_SW_PC_INIT_END,
&DriverEntry->ImageHandle,
sizeof (DriverEntry->ImageHandle)
);
if (!PreviousSmmEntryPointRegistered && gSmmCorePrivate->SmmEntryPointRegistered) {
//
// Return immediately if the SMM Entry Point was registered by the SMM
// Driver that was just dispatched. The SMM IPL will reinvoke the SMM
// Core Dispatcher. This is required so SMM Mode may be enabled as soon
// as all the dependent SMM Drivers for SMM Mode have been dispatched.
// Once the SMM Entry Point has been registered, then SMM Mode will be
// used.
//
gRequestDispatch = TRUE;
gDispatcherRunning = FALSE;
return EFI_NOT_READY;
}
}
//
// Search DriverList for items to place on Scheduled Queue
//
ReadyToRun = FALSE;
for (Link = mDiscoveredList.ForwardLink; Link != &mDiscoveredList; Link = Link->ForwardLink) {
DriverEntry = CR (Link, EFI_SMM_DRIVER_ENTRY, Link, EFI_SMM_DRIVER_ENTRY_SIGNATURE);
if (DriverEntry->DepexProtocolError){
//
// If Section Extraction Protocol did not let the Depex be read before retry the read
//
Status = SmmGetDepexSectionAndPreProccess (DriverEntry);
}
if (DriverEntry->Dependent) {
if (SmmIsSchedulable (DriverEntry)) {
SmmInsertOnScheduledQueueWhileProcessingBeforeAndAfter (DriverEntry);
ReadyToRun = TRUE;
}
}
}
} while (ReadyToRun);
//
// If there is no more SMM driver to dispatch, stop the dispatch request
//
gRequestDispatch = FALSE;
for (Link = mDiscoveredList.ForwardLink; Link != &mDiscoveredList; Link = Link->ForwardLink) {
DriverEntry = CR (Link, EFI_SMM_DRIVER_ENTRY, Link, EFI_SMM_DRIVER_ENTRY_SIGNATURE);
if (!DriverEntry->Initialized){
//
// We have SMM driver pending to dispatch
//
gRequestDispatch = TRUE;
break;
}
}
gDispatcherRunning = FALSE;
return EFI_SUCCESS;
}
/**
This is the main Dispatcher for SMM and it exits when there are no more
drivers to run. Drain the mScheduledQueue and load and start a PE
image for each driver. Search the mDiscoveredList to see if any driver can
be placed on the mScheduledQueue. If no drivers are placed on the
mScheduledQueue exit the function. On exit it is assumed the Bds()
will be called, and when the Bds() exits the Dispatcher will be called
again.
@retval EFI_ALREADY_STARTED The SMM Dispatcher is already running
@retval EFI_NOT_FOUND No SMM Drivers were dispatched
@retval EFI_SUCCESS One or more SMM Drivers were dispatched
**/
EFI_STATUS
SmmDispatcher (
VOID
)
{
EFI_STATUS Status;
EFI_STATUS ReturnStatus;
LIST_ENTRY *Link;
EFI_SMM_DRIVER_ENTRY *DriverEntry;
BOOLEAN ReadyToRun;
if (!gRequestDispatch) {
return EFI_NOT_FOUND;
}
if (gDispatcherRunning) {
//
// If the dispatcher is running don't let it be restarted.
//
return EFI_ALREADY_STARTED;
}
gDispatcherRunning = TRUE;
ReturnStatus = EFI_NOT_FOUND;
do {
//
// Drain the Scheduled Queue
//
while (!IsListEmpty (&mScheduledQueue)) {
DriverEntry = CR (
mScheduledQueue.ForwardLink,
EFI_SMM_DRIVER_ENTRY,
ScheduledLink,
EFI_SMM_DRIVER_ENTRY_SIGNATURE
);
//
// Load the SMM Driver image into memory. If the Driver was transitioned from
// Untrused to Scheduled it would have already been loaded so we may need to
// skip the LoadImage
//
if (DriverEntry->ImageHandle == NULL) {
Status = SmmLoadImage (DriverEntry);
//
// Update the driver state to reflect that it's been loaded
//
if (EFI_ERROR (Status)) {
if (Status == EFI_SECURITY_VIOLATION) {
//
// Take driver from Scheduled to Untrused state
//
DriverEntry->Untrusted = TRUE;
} else {
//
// The SMM Driver could not be loaded, and do not attempt to load or start it again.
// Take driver from Scheduled to Initialized.
//
// This case include the Never Trusted state if EFI_ACCESS_DENIED is returned
//
DriverEntry->Initialized = TRUE;
}
DriverEntry->Scheduled = FALSE;
RemoveEntryList (&DriverEntry->ScheduledLink);
//
// If it's an error don't try the StartImage
//
continue;
}
}
DriverEntry->Scheduled = FALSE;
DriverEntry->Initialized = TRUE;
RemoveEntryList (&DriverEntry->ScheduledLink);
REPORT_STATUS_CODE_WITH_EXTENDED_DATA (
EFI_PROGRESS_CODE,
EFI_SOFTWARE_SMM_DRIVER | EFI_SW_PC_INIT_BEGIN,
&DriverEntry->ImageHandle,
sizeof (DriverEntry->ImageHandle)
);
//
// For each SMM driver, pass NULL as ImageHandle
//
Status = ((EFI_IMAGE_ENTRY_POINT)(UINTN)DriverEntry->ImageEntryPoint)(DriverEntry->ImageHandle, gST);
if (EFI_ERROR(Status)){
SmmFreePages(DriverEntry->ImageBuffer, DriverEntry->NumberOfPage);
}
REPORT_STATUS_CODE_WITH_EXTENDED_DATA (
EFI_PROGRESS_CODE,
EFI_SOFTWARE_SMM_DRIVER | EFI_SW_PC_INIT_END,
&DriverEntry->ImageHandle,
sizeof (DriverEntry->ImageHandle)
);
ReturnStatus = EFI_SUCCESS;
}
//
// Search DriverList for items to place on Scheduled Queue
//
ReadyToRun = FALSE;
for (Link = mDiscoveredList.ForwardLink; Link != &mDiscoveredList; Link = Link->ForwardLink) {
DriverEntry = CR (Link, EFI_SMM_DRIVER_ENTRY, Link, EFI_SMM_DRIVER_ENTRY_SIGNATURE);
if (DriverEntry->DepexProtocolError){
//
// If Section Extraction Protocol did not let the Depex be read before retry the read
//
Status = SmmGetDepexSectionAndPreProccess (DriverEntry);
}
if (DriverEntry->Dependent) {
if (SmmIsSchedulable (DriverEntry)) {
SmmInsertOnScheduledQueueWhileProcessingBeforeAndAfter (DriverEntry);
ReadyToRun = TRUE;
}
}
}
} while (ReadyToRun);
//
// If there is no more SMM driver to dispatch, stop the dispatch request
//
gRequestDispatch = FALSE;
for (Link = mDiscoveredList.ForwardLink; Link != &mDiscoveredList; Link = Link->ForwardLink) {
DriverEntry = CR (Link, EFI_SMM_DRIVER_ENTRY, Link, EFI_SMM_DRIVER_ENTRY_SIGNATURE);
if (!DriverEntry->Initialized){
//
// We have SMM driver pending to dispatch
//
gRequestDispatch = TRUE;
break;
}
}
gDispatcherRunning = FALSE;
return ReturnStatus;
}