feat(fdr): Add blanton_fdr.sh for phydiag fdrstat

start / clear / rdcnt / stop send fdrstat STArt bin_group=both
Interval=30 / clear / Counters / STOp through bcmcmd on ports
'1-259,270-565', unit 0 then unit 1, and print the output as is. -u
picks one unit, -i sets the interval, -n is a dry run, FDR_PORTS
overrides the port list.

The STOp keyword is inferred from prbsstat STOp and has not been
checked on the bench.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0131orciRKrejchsuDk6UpXk

src/Script_ABC_Blanton/Blanton_Script/blanton_fdr.sh

@@ -0,0 +1,98 @@
+#!/usr/bin/env bash
+# =============================================================================
+# blanton_fdr.sh  --  SerDes FDR statistics (phydiag fdrstat), raw output
+# =============================================================================
+# Version History:
+#   V1.0.0  2026-10-21  First version. start / clear / rdcnt / stop over
+#                       'phydiag <ports> fdrstat ...' through bcmcmd, the same
+#                       way blanton_ber_debug.sh drives prbsstat. Every bcmcmd
+#                       output is printed as is -- no parsing, no PASS/FAIL.
+#
+# Sub-commands (each one runs on unit 0, then unit 1):
+#     start   phydiag '<ports>' fdrstat STArt bin_group=both Interval=30
+#     clear   phydiag '<ports>' fdrstat clear
+#     rdcnt   phydiag '<ports>' fdrstat Counters
+#     stop    phydiag '<ports>' fdrstat STOp
+#
+# ⚠️ 'stop' sends 'fdrstat STOp', by analogy with 'prbsstat STOp'. It has
+#    not been checked on the bench -- if the BCM shell rejects it, look at
+#    'phydiag help' (or 'fdrstat' with no argument) for the right keyword.
+# ⚠️ bcmcmd exits 0 even when the BCM shell refuses a command, so this
+#    script cannot tell success from failure. Read the output.
+#
+# Usage:
+#   ./blanton_fdr.sh <start|clear|rdcnt|stop> [-u 0|1] [-i <sec>] [-n]
+#     -u 0 | -u 1   one switch unit only (default: both, 0 then 1)
+#     -i <sec>      start: fdrstat Interval (default 30)
+#     -n            dry run: print the bcmcmd lines, do not run them
+#
+# Env overrides:
+#   BCMCMD_CMD=bcmcmd  FDR_PORTS=1-259,270-565  FDR_INTERVAL=30
+#   FDR_BIN_GROUP=both
+# =============================================================================
+
+BCMCMD_CMD="${BCMCMD_CMD:-bcmcmd}"
+FDR_UNITS="0 1"
+FDR_PORTS="${FDR_PORTS:-1-259,270-565}"
+FDR_INTERVAL="${FDR_INTERVAL:-30}"
+FDR_BIN_GROUP="${FDR_BIN_GROUP:-both}"
+FDR_DRY_RUN=0
+
+usage() {
+    sed -n '/^# Usage:/,/^# =====/p' "$0" | sed '$d; s/^# \{0,1\}//'
+}
+
+[ $# -ge 1 ] || { usage >&2; exit 2; }
+ACT=$1; shift
+case "$ACT" in
+    start|clear|rdcnt|stop) ;;
+    -h|--help|help) usage; exit 0 ;;
+    *) echo "[ERR ] unknown sub-command '$ACT'" >&2; usage >&2; exit 2 ;;
+esac
+
+while [ $# -gt 0 ]; do
+    case "$1" in
+        -u|--unit)
+            case "$2" in
+                0|1) FDR_UNITS="$2" ;;
+                *)   echo "[ERR ] invalid unit '$2' (use 0 or 1)" >&2; exit 2 ;;
+            esac
+            shift 2 ;;
+        -i|--interval)
+            case "$2" in
+                ''|*[!0-9]*) echo "[ERR ] invalid interval '$2'" >&2; exit 2 ;;
+                *) FDR_INTERVAL="$2" ;;
+            esac
+            shift 2 ;;
+        -n|--dry-run) FDR_DRY_RUN=1; shift ;;
+        -h|--help) usage; exit 0 ;;
+        *) echo "[ERR ] unknown option '$1'" >&2; usage >&2; exit 2 ;;
+    esac
+done
+
+# bcmcmd reads stdin -- keep it on /dev/null (see blanton_traffic_linespeed.sh V0.3.1)
+_bcm() {
+    local unit="$1"; shift
+    local cmd="dsh -c \"phydiag '${FDR_PORTS}' fdrstat $*\""
+    echo
+    echo "### [$(date '+%F %T')] unit $unit: phydiag '${FDR_PORTS}' fdrstat $*"
+    if [ "$FDR_DRY_RUN" = "1" ]; then
+        echo "[DRY ] $BCMCMD_CMD -n $unit -c ' ${cmd} '"
+        return 0
+    fi
+    "$BCMCMD_CMD" -n "$unit" -c " ${cmd} " </dev/null 2>&1
+}
+
+case "$ACT" in
+    start) SUB="STArt bin_group=${FDR_BIN_GROUP} Interval=${FDR_INTERVAL}" ;;
+    clear) SUB="clear" ;;
+    rdcnt) SUB="Counters" ;;
+    stop)  SUB="STOp" ;;
+esac
+
+for u in $FDR_UNITS; do
+    _bcm "$u" "$SUB"
+done
+
+echo
+echo "### [$(date '+%F %T')] FDR_${ACT^^}_DONE units: $FDR_UNITS"