Acpi Genuineintel---intel64-family-6-model-58 __top__ -

Examination: ACPI "GenuineIntel — Intel64 Family 6 Model 58" (Exhaustive)

Duration: 2 hours
Total marks: 100

Scope and purpose

Structure

Grading rubric: each question has precise expectations; partial credit for correct reasoning and relevant commands, tools, values.

Reference assumptions (allowed during exam)

--- SECTION A — Core concepts and identification (20 marks) acpi genuineintel---intel64-family-6-model-58

  1. (5 marks) Explain what the CPUID string "GenuineIntel — Intel64 Family 6 Model 58" conveys: vendor, instruction set width, family/model meaning, typical microarchitecture mapping. (Expect: vendor=Intel, 64-bit ISA, family/model fields decode to Family 6 Model 58 → Haswell generation; explanation of extended family/model fields; why model numbers matter for features like TSX, RDT, etc.)
  2. (5 marks) List and briefly describe three CPUID features that are commonly present or relevant for Family 6 Model 58 CPUs (e.g., SSE4.1/4.2, AVX, AES-NI, TSX — indicate which are present or absent in Haswell Model 58). (Expect correct presence/absence per Haswell.)
  3. (5 marks) Give the ACPI Device/Processor object naming conventions often used to represent CPU packages and logical processors. Explain how ACPI differentiates packages, cores, and logical processors. (Expect discussion of PR.Processor, Processor objects, _HID if present, namespace node naming like CPU0/CPU1 or CPU0PR, and use of _PPC, _STA, _PSx methods.)
  4. (5 marks) Explain the role of MP Table vs ACPI MADT in describing interrupt topology on modern Intel systems; why ACPI is preferred today.

--- SECTION B — ACPI tables and structure (20 marks)

  1. (6 marks) Given an acpidump output, identify where information relevant to Family 6 Model 58 CPU features will appear (which tables and which fields): DSDT/SSDT, FADT, MADT, SRAT, SLIT, IORT, PCCT, ERST, etc. For each listed table, describe what CPU-related information it may contain. (Expect mapping: DSDT/SSDT: processor objects, P-/C-states; MSCT: max cores/threads; MADT: APICs; SRAT: affinity/hotplug; TPM/IORT/PCCT for specific offload)
  2. (6 marks) Interpret the following hypothetical ACPI Processor object snippet (provided in exam) and state: processor ID mapping to APIC ID, _CST structure contents, P-state method naming, and hotplug capability. (Expect candidate to decode AML-like snippet and map fields.)
  3. (8 marks) Describe how SSDTs can be used to present per-core P-state tables on Haswell Model 58, and outline a minimal SSDT AML example fragment that exposes two P-states (one at 2.6 GHz, one at 1.2 GHz). Explain how OS uses _PSS or _PSD to select P-states. (Expect mention of _PSS package fields: core frequency (MHz), power (mW), latency (us), control, status; or use of _PCT, and how OS writes to MSRs or ACPI control registers.)

--- SECTION C — Power management & C-states/P-states (20 marks)

  1. (8 marks) Explain difference between ACPI C-states and P-states and how they interact on Haswell CPUs; detail typical C0–C3 and deeper S0ix/PC8 considerations in mobile Haswell. Provide expected latency and energy tradeoffs for each. (Expect approximate latencies and when OS should use each.)
  2. (6 marks) Given MSR and CPUID outputs (provided), calculate expected core frequency when in P-state with multiplier X and base bus clock 100 MHz; compute occupancy, power reduction percentage if frequency scales down from 3.0 GHz to 1.5 GHz assuming dynamic power ~ f^3 (show math). (Expect formula f^3, example numbers.)
  3. (6 marks) Design an OS-level governor policy (step-by-step algorithm) that prioritizes thermal headroom while minimizing latency for interactive workloads on this CPU model. Specify thresholds, sampling intervals, and when to prefer turbo vs sustained P-states.

--- SECTION D — Thermal and frequency management, telemetry (15 marks)

  1. (6 marks) Describe the CPU thermal sensors available on Haswell (digital temperature sensor, package vs core readings) and how ACPI/OS access them (e.g., via PECI, MSRs, platform drivers). Explain typical reporting ranges and offsets.
  2. (5 marks) Given a turbostat log excerpt showing package power, core temperature, and IA frequency over a 60-second interval (provided in exam), identify: a) moments of thermal throttling, b) when Turbo boost was engaged, c) which cores show highest activity. (Expect reading values and pointing to entries.)
  3. (4 marks) Recommend actions (firmware and OS) to mitigate sustained package power above TDP on a Haswell Model 58 laptop without reducing peak single-thread performance.

--- SECTION E — Firmware/OS integration and debugging (15 marks)

  1. (5 marks) A machine with Family 6 Model 58 reports incorrect core counts to the OS. List a prioritized troubleshooting checklist (commands to run, ACPI checks, BIOS settings, kernel parameters) and expected outputs for confirmation.
  2. (5 marks) Explain how to use acpidump + iasl to patch a buggy DSDT that misreports _CST or _PSS for this CPU. Provide commands and a safe workflow to test and revert patches.
  3. (5 marks) Describe how to interpret kernel boot messages related to CPU topology, ACPI processor registration, and microcode updates for this model; include example dmesg lines and their meaning (e.g., "smp: Bringing up secondary CPUs", "microcode: CPU0 has new patch").

--- SECTION F — AML / patching exercise (10 marks) Task: Provide a minimal signed-off SSDT-style AML (IASL source) fragment (not compiled AML binary) that defines a Processor object for CPU0 with: Examination: ACPI "GenuineIntel — Intel64 Family 6 Model

Expectations: correct IASL syntax, use of Processor declaration, _PSS and _CST packages, and comments. (10 marks)

Sample answer (concise, but must compile with iasl). Partial credit for syntactically consistent fragments.

Useful details, tools & sample commands (appendix for graders/candidates)

Marking notes for graders

End of examination.

It looks like you’ve provided a string that resembles a processor signature or ACPI identifier, likely extracted from a Linux system log (dmesg, lscpu, or /proc/cpuinfo), or from an ACPI/DSDT table.

Let me break it down for you:

Linux Kernel (intel_idle driver)

Conclusion

The string acpi genuineintel---intel64-family-6-model-58 is an unusual but decipherable artifact that points to an Intel Ivy Bridge CPU (Family 6, Model 58) being handled by the ACPI subsystem in a Linux environment, possibly with a formatting quirk. It reminds us of the deep integration between CPU microarchitecture, ACPI firmware tables, and the OS kernel.

Understanding each segment—ACPI, vendor string, 64-bit capability, and family-model-stepping—is a valuable exercise for any systems engineer working on x86 power management, hypervisors, or kernel debugging. While the dashes are anomalous, the underlying hardware is solid, well-documented, and widely deployed.

If you ever encounter this string in your logs, take a moment to appreciate the decades of standards (ACPI, CPUID, x86-64) that silently work together—most of the time, perfectly. Assess candidate mastery of ACPI and CPU identification

Further reading:

E. ACPI DSDT / SSDT Reference

Processor (CPU0, 0x01, 0x00000000, 0x06) 
    Name (_HID, "ACPI0007")
    Name (_UID, 0)
    Name (_CST)  …  // C-state latencies tuned for Family 6 Model 58
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