ucpuid (execute CPUID instruction in debuggee)

Description of the 'ucpuid' command in HyperDbg.

Command

ucpuid

Syntax

ucpuid [Function (hex)] [SubFunction (hex)]

Description

Executes the CPUID instruction on the target debuggee and displays the structured results.

This command executes CPUID in the target debuggee (not the debugger). In local debugging mode, the debuggee and the debugger are the same machine, so the results reflect the local processor.

Parameters

[Function (hex)]

The CPUID leaf (i.e., the value placed in EAX before executing the CPUID instruction).

[SubFunction (hex)] (optional)

The CPUID sub-leaf (i.e., the value placed in ECX before executing the CPUID instruction). If not specified, defaults to 0.

Use ucpuid 0 to see the maximum supported basic CPUID leaf.

Use ucpuid 0x80000000 to see the maximum supported extended CPUID leaf.

Examples

The following example shows the result of CPUID with EAX=0 (vendor and maximum basic leaf).

1: kHyperDbg> ucpuid 0
  *******************************************************
  *               LEAF 0 HAS NO SUBLEAVES               *
  *       ANY SUBLEAF YOU ENTER WILL DEFAULT TO 0       *
  *      AND THE PROCESSOR RETURNS UNDEFINED VALUES     *
  *******************************************************

  Vendor : GenuineIntel
  Maximum supported basic leaf : 22

The following example shows the result of CPUID with EAX=0x80000000 (maximum supported extended leaf).

1: kHyperDbg> ucpuid 0x80000000
==== CPUID.(EAX=80000000H) Extended Function Information ====

  *******************************************************
  *           LEAF 0x80000000 HAS NO SUBLEAVES          *
  *       ANY SUBLEAF YOU ENTER WILL DEFAULT TO 0       *
  *      AND THE PROCESSOR RETURNS UNDEFINED VALUES     *
  *******************************************************

-- EAX --

  MaxExtendedFunctions = 0x80000008 (2147483656)

-- EBX --

  Reserved = 0x00000000

-- ECX --

  Reserved = 0x00000000

-- EDX --

  Reserved = 0x00000000

The following example shows the result of CPUID with EAX=1 (version and feature information).

1: kHyperDbg> ucpuid 0x1
==== CPUID.(EAX=01H) Version / Additional / Feature Information ====

  *******************************************************
  *               LEAF 1 HAS NO SUBLEAVES               *
  *       ANY SUBLEAF YOU ENTER WILL DEFAULT TO 0       *
  *      AND THE PROCESSOR RETURNS UNDEFINED VALUES     *
  *******************************************************

-- EAX: Version Information --

  SteppingId       = 2
  Model            = 5
  FamilyId         = 6
  ProcessorType    = 0
  ExtendedModelId  = 10
  ExtendedFamilyId = 0

-- EBX: Additional Information --

  BrandIndex        = 0
  ClflushLineSize   = 8 (cache line = 64 bytes)
  MaxAddressableIds = 8
  InitialApicId     = 1

-- ECX: Feature Information --

  SSE3                  = TRUE
  PCLMULQDQ             = TRUE
  DTES64                = FALSE
  MONITOR/MWAIT         = FALSE
  CPL Qualified DS      = FALSE
  VMX                   = TRUE
  SMX                   = FALSE
  EIST (SpeedStep)      = FALSE
  TM2                   = FALSE
  SSSE3                 = TRUE
  L1 Context ID         = FALSE
  Silicon Debug         = FALSE
  FMA                   = TRUE
  CMPXCHG16B            = TRUE
  xTPR Update Control   = FALSE
  PDCM                  = FALSE
  PCID                  = TRUE
  DCA                   = FALSE
  SSE4.1                = TRUE
  SSE4.2                = TRUE
  x2APIC                = TRUE
  MOVBE                 = TRUE
  POPCNT                = TRUE
  TSC-Deadline          = TRUE
  AESNI                 = TRUE
  XSAVE/XRSTOR          = TRUE
  OSXSAVE               = TRUE
  AVX                   = TRUE
  F16C                  = TRUE
  RDRAND                = TRUE

-- EDX: Feature Information --

  FPU                   = TRUE
  VME                   = TRUE
  DE                    = TRUE
  PSE                   = TRUE
  TSC                   = TRUE
  MSR (RDMSR/WRMSR)     = TRUE
  PAE                   = TRUE
  MCE                   = TRUE
  CX8 (CMPXCHG8B)       = TRUE
  APIC On-Chip          = TRUE
  SEP (SYSENTER/EXIT)   = TRUE
  MTRR                  = TRUE
  PGE                   = TRUE
  MCA                   = TRUE
  CMOV                  = TRUE
  PAT                   = TRUE
  PSE-36                = TRUE
  PSN                   = FALSE
  CLFSH                 = TRUE
  DS (Debug Store)      = FALSE
  ACPI (Thermal/Clock)  = FALSE
  MMX                   = TRUE
  FXSR (FXSAVE/FXRSTOR) = TRUE
  SSE                   = TRUE
  SSE2                  = TRUE
  SS (Self Snoop)       = TRUE
  HTT                   = TRUE
  TM (Thermal Monitor)  = FALSE
  PBE                   = FALSE

The following example uses a sub-leaf. For example, CPUID leaf 4 with sub-leaf 2.

1: kHyperDbg> ucpuid 4 2
==== CPUID.(EAX=04H) Deterministic Cache Parameters ====

  *******************************************************
  *             Max NumberOfSubLeaves = 3               *
  *******************************************************

---- CPUID.(EAX=04H, ECX=2) ----

-- EAX --

  CacheTypeField                   = 3 (Unified Cache)
  CacheLevel                       = 2
  SelfInitializingCacheLevel       = TRUE
  FullyAssociativeCache            = FALSE
  MaxAddressableIds(LogicalProcs)  (raw) = 0 -> actual = 1 (raw + 1)
  MaxAddressableIds(Cores)         (raw) = 7 -> actual = 8 (raw + 1)

-- EBX --

  SystemCoherencyLineSize          (raw) = 63 -> actual = 64 bytes (raw + 1)
  PhysicalLinePartitions           (raw) = 0 -> actual = 1 (raw + 1)
  WaysOfAssociativity              (raw) = 3 -> actual = 4 (raw + 1)

-- ECX --

  NumberOfSets                     (raw) = 1023 -> actual = 1024 (raw + 1)

-- EDX --

  WriteBackInvalidate              = FALSE
  CacheInclusiveness               = FALSE
  ComplexCacheIndexing             = FALSE (direct mapped)

-- Cache Size --

  Cache Size (per spec formula)    = 262144 bytes (256 KB, 0 MB)

SDK

To execute the CPUID instruction in the target debuggee, use the following function in libhyperdbg:

BOOLEAN
hyperdbg_u_request_cpuid(UINT32 FunctionId, UINT32 SubFunctionId);

Remarks

Starting from HyperDbg v0.23, this command is available.

This command is guaranteed to keep debuggee in a halt state (in Debugger Mode); thus, nothing will change during its execution.

Requirements

None

Related

cpu (check cpu supported technologies)

!cpuid (hook CPUID instruction execution)