> If you came here for `MmNonPagedPoolStart`, `MmNonPagedPoolEnd`, you ended up at the right place.

`NonPagedPool` in Windows has two variables that defined the start and end of the section in kernel memory. Online blog posts and tutorials show an outdated version of these two variables.

Take a look at [this old post](https://web.archive.org/web/20061110120809/http://www.rootkit.com/newsread.php?newsid=153). `_DBGKD_GET_VERSION64 KdVersionBlock` was a very important structure into the debugger block of Windows. However, if you try to find this structure in Windows 10, you will hit `KdVersionBlock == 0` (Ouch!!!). But this structure provides offset into `MmNonPagedPool{Start,End}`, how can we get those?

Luckily, both `MmNonPagedPoolStart` and `MmNonPagedPoolEnd` in Windows XP, can be found by offseting from `ntoskrnl.exe`. Rekall team are very positive that their tools doesn't rely on profiles file like Volatility but use PDB provided by Windows to find these values.

In Rekall source code, the values of those variables are:

- Windows XP: `MmNonPagedPool{Start,End}`
- Windows 7 and maybe 8: `MiNonPagedPoolStartAligned`, `MiNonPagedPoolEnd`, and `MiNonPagedPoolBitMap`
- Windows 10 below

In Windows 7, 8, another field was added to controll the allocation of `NonPagedPool`, which is why there is [this paper about pool tag quick scanning](https://www.sciencedirect.com/science/article/pii/S1742287616000062).

However, from Windows 10, the whole game change around when the global offset to those (similar) variables. Instead Windows 10 introduced a new structure `MiState`. `MiState` offset is available and we can get the variables by either:

- Windows 2015: `*((ntoskrnl.exe+MiState)->SystemNodeInformation->NonPagedPool{First,Last}Va)`
- Windows 2016: `*((ntoskrnl.exe+MiState)->Hardware.SystemNodeInformation->NonPagedPool{First,Last}Va)`

The `NonPagedBitMap` was still visible untill the May 2019 Update, here, take a look at these 2 consecutive update [`1809 Redstone 5 (October Update)`](https://www.vergiliusproject.com/kernels/x64/Windows%2010%20%7C%202016/1809%20Redstone%205%20(October%20Update)/\_MI\_SYSTEM\_NODE\_INFORMATION) and [`1903 19H1 (May 2019 Update)`](https://www.vergiliusproject.com/kernels/x64/Windows%2010%20%7C%202016/1903%2019H1%20(May%202019%20Update)/\_MI\_SYSTEM\_NODE\_INFORMATION).

Yeah, now `pool tag quick scanning` is useless (gah). Windows OS changes quite frequently right? Tell you more, I am using the Insider version of Windows in 2020, and guess what, I found out that they put another struct to point to those value. So now we need to go like this:

- Windows 2020 Insider preview: `*((ntoskrnl.exe+MiState)->SystemNodeNonPagedPool->NonPagedPool{First,Last}Va)`

Anyway, I create this project to help me with my thesis, following outdated structs online yields no result. Oh, yeah, a guy seems to be asking on [how to get `MmNonPagedPoolStart`](https://reverseengineering.stackexchange.com/q/6483) on `stackexchange`, too bad [the answer](https://reverseengineering.stackexchange.com/a/6487) is not so much helpful.

Take a look at my ntoskrnl.exe pdb file parsed.

```
PDB for Amd64, guid: 3e7ee354-590f-ac1c-62a8-ccf0b6368989, age: 1,

MiState 0xc4f280 23:324224
KdDebuggerDataBlock 0xc00a30 23:2608

struct _MI_SYSTEM_INFORMATION
  - field _MI_POOL_STATE Pools at offset 0
  - field _MI_SECTION_STATE Sections at offset c0
  - field _MI_SYSTEM_IMAGE_STATE SystemImages at offset 400
  - field _MI_SESSION_STATE Sessions at offset 4a8
  - field _MI_PROCESS_STATE Processes at offset 1550
  - field _MI_HARDWARE_STATE Hardware at offset 15c0
  - field _MI_SYSTEM_VA_STATE SystemVa at offset 1780
  - field _MI_COMBINE_STATE PageCombines at offset 1c40
  - field _MI_PAGELIST_STATE PageLists at offset 1c60
  - field _MI_PARTITION_STATE Partitions at offset 1d00
  - field _MI_SHUTDOWN_STATE Shutdowns at offset 1dc0
  - field _MI_ERROR_STATE Errors at offset 1e38
  - field _MI_ACCESS_LOG_STATE AccessLog at offset 1f40
  - field _MI_DEBUGGER_STATE Debugger at offset 1fc0
  - field _MI_STANDBY_STATE Standby at offset 20e0
  - field _MI_SYSTEM_PTE_STATE SystemPtes at offset 2180
  - field _MI_IO_PAGE_STATE IoPages at offset 2380
  - field _MI_PAGING_IO_STATE PagingIo at offset 2440
  - field _MI_COMMON_PAGE_STATE CommonPages at offset 24f0
  - field _MI_SYSTEM_TRIM_STATE Trims at offset 25c0
  - field _MI_SYSTEM_ZEROING Zeroing at offset 2600
  - field _MI_ENCLAVE_STATE Enclaves at offset 2620
  - field U64 Cookie at offset 2668
  - field Void** BootRegistryRuns at offset 2670
  - field UNNOWN ZeroingDisabled at offset 2678
  - field UChar FullyInitialized at offset 267c
  - field UChar SafeBooted at offset 267d
  - field UNNOWN* TraceLogging at offset 2680
  - field _MI_VISIBLE_STATE Vs at offset 26c0

struct _MI_HARDWARE_STATE
  - field U32 NodeMask at offset 0
  - field U32 NumaHintIndex at offset 4
  - field U32 NumaLastRangeIndexInclusive at offset 8
  - field UChar NodeShift at offset c
  - field UChar ChannelShift at offset d
  - field U32 ChannelHintIndex at offset 10
  - field U32 ChannelLastRangeIndexInclusive at offset 14
  - field _MI_NODE_NUMBER_ZERO_BASED* NodeGraph at offset 18
  - field _MI_SYSTEM_NODE_NONPAGED_POOL* SystemNodeNonPagedPool at offset 20
  - field UNNOWN TemporaryNumaRanges at offset 28
  - field _HAL_NODE_RANGE* NumaMemoryRanges at offset 48
  - field _HAL_CHANNEL_MEMORY_RANGES* ChannelMemoryRanges at offset 50
  - field U32 SecondLevelCacheSize at offset 58
  - field U32 FirstLevelCacheSize at offset 5c
  - field U32 PhysicalAddressBits at offset 60
  - field U32 PfnDatabasePageBits at offset 64
  - field U32 LogicalProcessorsPerCore at offset 68
  - field UChar ProcessorCachesFlushedOnPowerLoss at offset 6c
  - field U64 TotalPagesAllowed at offset 70
  - field U32 SecondaryColorMask at offset 78
  - field U32 SecondaryColors at offset 7c
  - field U32 FlushTbForAttributeChange at offset 80
  - field U32 FlushCacheForAttributeChange at offset 84
  - field U32 FlushCacheForPageAttributeChange at offset 88
  - field U32 CacheFlushPromoteThreshold at offset 8c
  - field _LARGE_INTEGER PerformanceCounterFrequency at offset 90
  - field U64 InvalidPteMask at offset c0
  - field UNNOWN LargePageColors at offset 100
  - field U64 FlushTbThreshold at offset 110
  - field UNNOWN OptimalZeroingAttribute at offset 118
  - field UChar AttributeChangeRequiresReZero at offset 158
  - field UNNOWN ZeroCostCounts at offset 160
  - field U64 HighestPossiblePhysicalPage at offset 180
  - field U64 VsmKernelPageCount at offset 188

struct _MI_SYSTEM_NODE_NONPAGED_POOL
  - field _MI_DYNAMIC_BITMAP DynamicBitMapNonPagedPool at offset 0
  - field U64 CachedNonPagedPoolCount at offset 48
  - field U64 NonPagedPoolSpinLock at offset 50
  - field _MMPFN* CachedNonPagedPool at offset 58
  - field Void NonPagedPoolFirstVa at offset 60
  - field Void NonPagedPoolLastVa at offset 68
  - field _MI_SYSTEM_NODE_INFORMATION* SystemNodeInformation at offset 70

struct _MI_SYSTEM_NODE_INFORMATION
  - field UNNOWN CachedKernelStacks at offset 0
  - field _GROUP_AFFINITY GroupAffinity at offset 40
  - field U16 ProcessorCount at offset 50
  - field Void BootZeroPageTimesPerProcessor at offset 58
  - field U64 CyclesToZeroOneLargePage at offset 60
  - field U64 ScaledCyclesToZeroOneLargePage at offset 68
  - field _MI_WRITE_CALIBRATION WriteCalibration at offset 70
  - field UNNOWN IoPfnLock at offset c0
```