etwenandClaude Opus 5 25e1ce0068 fix(pdb): Read the bricks on the pages the datasheet actually specifies ...

Every PDB reading came back NA, and the cause was a base error. The four
ADPM12200 bricks put each measurement on its own PMBus PAGE, written
before the read. The bring-up spreadsheet listed those page numbers in
decimal but with an 0x prefix:

    Vin  PAGE 9  -> it said 0x00   (0x09)
    Iin  PAGE 10 -> it said 0x10   (0x0A)
    Vout PAGE 2  -> it said 0x02    correct by luck
    Iout PAGE 14 -> it said 0x14   (0x0E)
    Temp PAGE 18 -> it said 0x18   (0x12)

Only Vout worked, because 2 reads the same in either base. Hence Iin and
Iout answering 0xFFFF, Temp answering 0x0000, and a Vin scale factor
having to be invented to make 50 V appear out of a page-0 register.

pwr_brick.sh reads all five bricks with the right pages and the
datasheet's DIRECT equation, X = (1/m)(Y x 10^-R - b): voltage Y x 8 mV,
current Y x 0.04 A, temperature Y x 0.01 C. Cross-checked rather than
assumed - READ_VOUT 0x05D4 decodes to 11936 mV, exactly what
'show platform voltage' reports for that rail through a separate sensor
path. The datasheet is committed alongside so the numbers are checkable.

Left flagged: Table 3 does not list READ_VIN or READ_IIN. They borrow the
voltage and current coefficients here, which is consistent with a ~50 V
input but is not something the datasheet states.

Each value is re-read until it passes three checks: not 0xFFFF, not
0x0000, and inside a plausibility window. The window is the one that
matters - this bus corrupts the HIGH BYTE only, which turns 11.98 V into
32.00 V. Positive, plausible in magnitude, and invisible to any all-ones
filter. 0x0000 is rejected for the mirror-image reason: on the
temperature register it decodes to a believable 0 C.

Adds comboA/comboB margin profiles per board. comboB is comboA with every
direction flipped, so the pair covers each rail high and low while its
neighbours sit the other way. NC channels stay nominal in both - there is
nothing to margin on an unused rail.

Script C re-enables the BMC USB journalctl dump, which had been commented
out, so that service log now reaches the master log.

Script A -> V1.1.6.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014RetWKFZFG1ZHcitQAyhwM

2026-09-02 16:35:45 +08:00

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