Skip to main content

Thermal panel

The Thermal panel reports 17 temperature channels:

  • 14 on-die RTSN/PVT channels inside the Modalix SoC;
  • two SOM board-temperature channels reported by an LM96163-compatible hardware-monitoring device;
  • one Ethernet/MDIO hardware-monitor channel.

All values are degrees Celsius. They are point measurements at sensor locations, not ambient-air temperature and not an average die temperature.

Thermal max​

The top chart selects the maximum finite temperature across every thermal metric for each cache sample. The hottest sensor may change between samples. Use the individual sensor charts to identify the source.

On-die RTSN/PVT sensors​

Sentinel reads the Linux hwmon device named simaai_modalix_thermal_sensor. Its temp1_input through temp14_input map to Sentinel's rtsn_0 through rtsn_13. The kernel supplies millidegrees Celsius, which Sentinel divides by 1000; the kernel owns measurement mode, sequencing, and calibration.

Sentinel never maps /dev/mem or programs the PVT controller. Direct register access races the kernel driver and can disrupt thermal protection. There is no direct-register fallback on older images without the hwmon driver: on-die temperatures are unavailable until the kernel exposes the sensor interface. Keep kernel thermal protection enabled.

The SoC has seven physical sites. Each site is represented by an Alert-channel RTSN and a Trip-channel RTSN at the same location:

LocationAlert channelTrip channel
MLA quadrant Q0MLA-0MLA-7
MLA quadrant Q1MLA-1MLA-8
MLA quadrant Q2MLA-2MLA-9
MLA quadrant Q3MLA-3MLA-10
APUAPU-4APU-11
CVUCVU-5CVU-12
TOP, near PCIe/EthernetTOP-6TOP-13

The pair does not represent two different temperature limits in the displayed value. It represents two sensor channels feeding different hardware threshold paths at the same site. Small differences between the pair are expected.

A missing sensor or failed read is displayed as unavailable (JSON null), not zero or the previous sample. Sentinel retries on the next collection and rediscovers hwmon devices each time, including after driver rebinding.

Board and Ethernet sensors​

Display nameSourcePhysical interpretation
LM96-1lm96163 temp1_inputSOM top-side board temperature from the monitoring IC's internal sensor.
LM96-2lm96163 temp2_inputSOM bottom-side temperature from a diode on the bottom of the SOM, read through the monitoring IC.
ETH-1a800000ethernetmdio000 temp1_inputTemperature reported by the Ethernet hwmon device. The exact physical component is not yet confirmed.

Linux hwmon reports millidegrees Celsius; Sentinel divides the value by 1000. All directories are resolved by their hwmon name because hwmonN numbering can change. Sentinel does not fall back to numbered directories: an unrelated chip must never be reported as a board or Ethernet sensor.

Colors and thresholds​

  • Cyan: below 45 C
  • Green: 45 C to below 70 C
  • Red/warning: 70 C to below 85 C
  • Bold red/critical: 85 C or higher

These are Sentinel presentation thresholds. They do not replace device datasheet limits, thermal-trip behavior, or board-specific operating requirements.