BCM module diagnostics replace timestamp probes: bringup forces EEE off and runs ECD (re-run on every reset, re-baselining past its blip), 1 Hz SNR margin + corrected counters on panel and console; X520 bench divergences bypassed and tracked in open-questions

init.go

@@ -22,6 +22,8 @@ type mountSpec struct {
 var wantMounts = []mountSpec{
 	{"/proc", "proc", unix.PROC_SUPER_MAGIC, unix.MS_NOSUID | unix.MS_NODEV | unix.MS_NOEXEC},
 	{"/sys", "sysfs", unix.SYSFS_MAGIC, unix.MS_NOSUID | unix.MS_NODEV | unix.MS_NOEXEC},
+	// The module I2C transport lives behind debugfs.
+	{"/sys/kernel/debug", "debugfs", unix.DEBUGFS_MAGIC, unix.MS_NOSUID | unix.MS_NODEV | unix.MS_NOEXEC},
 	// devtmpfs reports itself as tmpfs, which is why the magic alone is not
 	// enough to tell it apart from the directory it would be mounted over.
 	{"/dev", "devtmpfs", unix.TMPFS_MAGIC, unix.MS_NOSUID},