[BUG] OpenBSD 2.3-2.5 fail to boot

[win2kgamer]

In PCem-dev commit 6bd1c70, OpenBSD versions 2.3-2.5 stall during the boot process printing the following message repeatedly:

Screenshot from 2020-03-15 22-06-18.png (10.73 KiB) Viewed 5293 times

Versions 2.6-2.9 are unaffected and this issue does not occur in VirtualBox 6.1. Version 2.2 displays the error a few times and then continues booting.

Machine configuration:
Machine: [Socket 7] Shuttle HOT-557
CPU: Intel Pentium/166
Memory: 64MB
Video: Phoenix S3 Trio64
HDD: 2GB IDE
FDD: 3.5" 1.44M
CD-ROM: PCemCD 32x
Mouse: 2-button PS/2

EDIT: I just performed a test using the Adaptec 1542 SCSI adapter in place of IDE and I disabled the IDE controller in the BIOS; the issue does not occur when using SCSI.