The r317143 broke cd(4) announcing at system boot time. It looks like this: cd0 at ahcich1 bus 0 scbus1 target 0 lun 0 cd0: <HL-DT-ST DVDRAM GT50N LT20> Removable CD-ROM SCSI device cd0: Serial Number M36C37K4101 cd0: 150.000MB/s transfers (SATA 1.x, UDMA2, ATAPI 12bytes, PIO 8192bytes) cd0: Attempt Note the last line. I believe it's because it uses sizeof(announce_buf), and it's a pointer now, not a table.
Proposed fix in https://reviews.freebsd.org/D14369.
A commit references this bug: Author: trasz Date: Wed Feb 21 14:05:13 UTC 2018 New revision: 329708 URL: https://svnweb.freebsd.org/changeset/base/329708 Log: Use proper buffer length (the announce_buf char pointer used to be anarray), broken in r317143. This fixes those weird "cd0: Attempt" messages at boot. PR: 222103 Reviewed by: scottl@ MFC after: 2 weeks Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D14369 Changes: head/sys/cam/scsi/scsi_cd.c