[BOOT:MM] Finish MmFwGetMemoryMap()

Added stub for MmMdFindDescriptorFromMdl().

BOOT/ENVIRON/INC/mm.h

@@ -53,6 +53,13 @@ MmMdRemoveDescriptorFromList (
     IN PMEMORY_DESCRIPTOR Descriptor
     );
 
+PMEMORY_DESCRIPTOR
+MmMdFindDescriptorFromMdl (
+    IN PMEMORY_DESCRIPTOR_LIST Mdl,
+    IN ULONGLONG Page,
+    IN ULONG Flags
+    );
+
 NTSTATUS
 MmMdRemoveRegionFromMdlEx (
     IN PMEMORY_DESCRIPTOR_LIST Mdl,

BOOT/ENVIRON/LIB/EFI/efiinit.c

@@ -206,6 +206,9 @@ Return Value:
     }
     BootDevice->Size = sizeof(BOOT_DEVICE);
 
+    //
+    // Memory map devices are treated as ramdisks.
+    //
     if (DevicePathType(EfiDevicePath) == HARDWARE_DEVICE_PATH && DevicePathSubType(EfiDevicePath) == HW_MEMMAP_DP) {
         MemmapNode = (MEMMAP_DEVICE_PATH *)EfiDevicePath;
         BlockDevice = &BootDevice->Block;
@@ -218,7 +221,7 @@ Return Value:
     }
 
     //
-    // TODO: Only media devices and ramdisks are currently supported.
+    // TODO: Support more devices than just HDD/CD-ROM and ramdisks.
     //
     DeviceNode = EfiInitpGetDeviceNode(EfiDevicePath);
     if (DevicePathType(DeviceNode) != MEDIA_DEVICE_PATH) {
@@ -547,7 +550,7 @@ Return Value:
 
     //
     // Convert the EFI file path into a boot file path option.
-    // TODO: UDP/PXE are not supported.
+    // TODO: Support UDP/PXE boot.
     //
     PrevOption = Option;
     Option = (PBOOT_APPLICATION_OPTION)((PUCHAR)&Entry->Options + OptionsSize);
@@ -561,7 +564,7 @@ Return Value:
     BufferRemaining -= Size;
 
     //
-    // TODO: Additional options in LoadOptions are not parsed.
+    // TODO: Parse additional options from LoadOptions.
     //
     PrevOption = Option;
     Option = (PBOOT_APPLICATION_OPTION)((PUCHAR)&Entry->Options + OptionsSize);

BOOT/ENVIRON/LIB/EFI/efimm.c

@@ -302,17 +302,18 @@ Return Value:
 
 {
     NTSTATUS Status;
-    UINTN EfiMapSize;
-    UINTN EfiMapKey;
-    UINTN EfiDescriptorSize;
-    UINT32 EfiDescriptorVersion;
-    UINTN PageCount, EfiPageCount;
     EFI_PHYSICAL_ADDRESS EfiBuffer;
     EFI_MEMORY_DESCRIPTOR *EfiMap;
-    BOOLEAN IsRamdisk;
-    MEMORY_TYPE MemoryType;
+    UINTN EfiMapKey;
+    UINTN EfiMapSize, EfiDescriptorSize;
+    UINT32 EfiDescriptorVersion;
     UINT64 EfiStartPage, EfiEndPage;
+    UINTN EfiPageCount;
+    ULONGLONG NtStartPage;
+    ULONG NtPageCount;
+    BOOLEAN IsRamdisk;
     UINT64 EfiRamdiskStartPage, EfiRamdiskEndPage;
+    MEMORY_TYPE MemoryType;
     PMEMORY_DESCRIPTOR NtDescriptor;
 
     (VOID)Flags;
@@ -347,8 +348,8 @@ Return Value:
     }
 
     EfiMapSize += 4 * EfiDescriptorSize;
-    PageCount = (ALIGN_UP(EfiMapSize, PAGE_SIZE) >> PAGE_SHIFT) + 1;
-    EfiPageCount = EFI_PAGE(PageCount);
+    NtPageCount = (ALIGN_UP(EfiMapSize, PAGE_SIZE) >> PAGE_SHIFT) + 1;
+    EfiPageCount = EFI_PAGE(NtPageCount);
     Status = EfiAllocatePages(AllocateAnyPages, EfiLoaderData, EfiPageCount, &EfiBuffer);
     if (!NT_SUCCESS(Status)) {
         DebugPrint(L"MmFwGetMemoryMap(): EfiAllocatePages() failed\r\n");
@@ -572,9 +573,55 @@ Return Value:
     }
 
     //
-    // TODO: Account for possible MDL changes due to EfiFreePages(EfiBuffer).
+    // The following code is to free the buffer and
+    // also mark the freed memory as free in the MDL.
     //
 
+    Status = EfiFreePages(EfiBuffer, EfiPageCount);
+    if (!NT_SUCCESS(Status)) {
+        Status = STATUS_SUCCESS;
+        goto exit;
+    }
+    EfiBuffer = 0;
+
+    EfiStartPage = EfiBuffer >> EFI_PAGE_SHIFT;
+    EfiEndPage = ALIGN_UP(EfiStartPage + EfiPageCount, EFI_PAGE(1));
+    NtStartPage = NT_PAGE(EfiStartPage);
+    NtPageCount = NT_PAGE(EfiEndPage) - NtStartPage;
+
+    //
+    // Find the current descriptor.
+    //
+    NtDescriptor = MmMdFindDescriptorFromMdl(Mdl, NtStartPage, MDL_OPERATION_FLAGS_PHYSICAL);
+    if (NtDescriptor == NULL) {
+        Status = STATUS_UNSUCCESSFUL;
+        goto exit;
+    }
+
+    //
+    // Create a new free descriptor, with the same
+    // attributes as the current one.
+    //
+    NtDescriptor = MmMdInitDescriptor(NtStartPage, 0, NtPageCount, NtDescriptor->Attributes, MEMORY_TYPE_FREE);
+    if (NtDescriptor == NULL) {
+        Status = STATUS_INSUFFICIENT_RESOURCES;
+        goto exit;
+    }
+
+    //
+    // Remove the current descriptor.
+    //
+    Status = MmMdRemoveRegionFromMdlEx(Mdl, NtStartPage, NtPageCount, MDL_OPERATION_FLAGS_PHYSICAL, 0);
+    if (!NT_SUCCESS(Status)) {
+        MmMdFreeDescriptor(NtDescriptor);
+        goto exit;
+    }
+
+    //
+    // Add the new descriptor to the MDL.
+    //
+    Status = MmMdAddDescriptorToList(Mdl, NtDescriptor, 0x01);
+
 exit:
     if (EfiBuffer) {
         EfiFreePages(EfiBuffer, EfiPageCount);

BOOT/ENVIRON/LIB/MM/mm.c

@@ -41,7 +41,7 @@ Return Value:
 
 {
     //
-    // TODO: Implement this.
+    // TODO: Implement this routine.
     //
 
     return STATUS_SUCCESS;

BOOT/ENVIRON/LIB/MM/mmmd.c

@@ -83,7 +83,7 @@ Return Value:
     }
 
     //
-    // TODO: Incomplete.
+    // TODO: Implement the rest of this routine.
     //
     ConsolePrint(L"MmMdpHasPrecedence() is incomplete\r\n");
     return TRUE;
@@ -386,6 +386,45 @@ Return Value:
     }
 }
 
+PMEMORY_DESCRIPTOR
+MmMdFindDescriptorFromMdl (
+    IN PMEMORY_DESCRIPTOR_LIST Mdl,
+    IN ULONGLONG Page,
+    IN ULONG Flags
+    )
+
+/*++
+
+Routine Description:
+
+    Searches an MDL for the descriptor containing a page.
+
+Arguments:
+
+    Mdl - The MDL to search.
+
+    Page - The page to search for.
+
+    Flags - MDL_OPERATION_FLAGS_*
+        MDL_OPERATION_FLAGS_PHYSICAL if Page is physical.
+        MDL_OPERATION_FLAGS_VIRTUAL if Page is virtual.
+
+Return Value:
+
+    Pointer to the descriptor if successful.
+    NULL if an error occurs.
+
+--*/
+
+
+{
+    //
+    // TODO: Implement this routine.
+    //
+
+    return NULL;
+}
+
 NTSTATUS
 MmMdRemoveRegionFromMdlEx (
     IN PMEMORY_DESCRIPTOR_LIST Mdl,
@@ -441,7 +480,7 @@ Return Value:
     }
 
     //
-    // TODO: Finish this function.
+    // TODO: Implement the rest of this routine.
     //
 
     return STATUS_SUCCESS;
@@ -490,7 +529,7 @@ Return Value:
 
     //
     // Free the descriptor from the heap.
-    // TODO: Use BlMmFreeHeap()
+    // TODO: Use BlMmFreeHeap().
     //
     ConsolePrint(L"MmMdFreeDescriptor(): need BlMmFreeHeap() to free descriptor\r\n");
     return STATUS_NOT_IMPLEMENTED;
@@ -565,6 +604,7 @@ Return Value:
     PMEMORY_DESCRIPTOR Descriptor;
 
     if (MmGlobalMemoryDescriptorsUsed >= MmGlobalMemoryDescriptorCount) {
+        DebugPrint(L"MmMdInitDescriptor(): No free descriptors available\r\n");
         return NULL;
     }