I just tried to use an old USB floppy drive on my current NetBSD 9.0/amd64 machine. This is attaching the drive:
[ 84.478242] umass1 at uhub3 port 3 configuration 1 interface 0
[ 84.478242] umass1: TEAC (0x644) TEAC FD-05PUW (0000), rev 2.00/0.00, addr 6
[ 84.478242] umass1: using UFI over CBI with CCI
[ 84.478242] atapibus0 at umass1: 2 targets
[ 84.558295] sd1 at atapibus0 drive 0: <TEAC, FD-05PUW, 3000> disk removable
[ 84.628340] sd1: drive offline
This is inserting a blank floppy:
[ 93.874370] fatal integer divide fault in supervisor mode
[ 93.874370] trap type 8 code 0 rip 0xffffffff809716b3 cs 0x8 rflags 0x10246 cr2 0x756bf954a000 ilevel 0 rsp 0xffff9a0064c929b0
[ 93.874370] curlwp 0xffff96a32578a540 pid 1010.1 lowest kstack 0xffff9a0064c902c0
[ 93.874370] panic: trap
[ 93.874370] cpu3: Begin traceback...
[ 93.874370] vpanic() at netbsd:vpanic+0x160
[ 93.874370] snprintf() at netbsd:snprintf
[ 93.874370] startlwp() at netbsd:startlwp
[ 93.874370] alltraps() at netbsd:alltraps+0xbb
[ 93.884376] scan_mbr() at netbsd:scan_mbr+0x3e
[ 93.884376] readdisklabel() at netbsd:readdisklabel+0x110
[ 93.884376] dk_getdisklabel() at netbsd:dk_getdisklabel+0xc8
[ 93.884376] dk_open() at netbsd:dk_open+0x120
[ 93.884376] spec_open() at netbsd:spec_open+0x175
[ 93.894383] VOP_OPEN() at netbsd:VOP_OPEN+0x4c
[ 93.894383] vn_open() at netbsd:vn_open+0x241
[ 93.894383] do_open() at netbsd:do_open+0x103
[ 93.894383] do_sys_openat() at netbsd:do_sys_openat+0x8b
[ 93.894383] sys_open() at netbsd:sys_open+0x24
[ 93.894383] syscall() at netbsd:syscall+0x157
[ 93.904389] --- syscall (number 5) ---
[ 93.904389] 756bf88429fa:
[ 93.904389] cpu3: End traceback...
[ 93.904389] dumping to dev 0,1 (offset=611511, size=972259):
[ 93.904389] dump Skipping crash dump on recursive panic
[ 94.794968] panic: pr_item_bitmap_put: [ataspl] 0xffff96a338d39038 already freed
[ 94.794968] cpu3: Begin traceback...
[ 94.794968] vpanic() at netbsd:vpanic+0x160
[ 94.794968] snprintf() at netbsd:snprintf
[ 94.794968] pool_put() at netbsd:pool_put+0x492
[ 94.804975] ahci_bio_complete() at netbsd:ahci_bio_complete+0x177
[ 94.804975] ahci_intr_port() at netbsd:ahci_intr_port+0x23e
[ 94.804975] ahci_bio_poll() at netbsd:ahci_bio_poll+0x2b
[ 94.804975] ata_xfer_start() at netbsd:ata_xfer_start+0xaa
[ 94.804975] atastart() at netbsd:atastart+0x1d2
[ 94.804975] ahci_ata_bio() at netbsd:ahci_ata_bio+0x5f
[ 94.814982] wd_dumpblocks() at netbsd:wd_dumpblocks+0x111
[ 94.814982] dk_dump() at netbsd:dk_dump+0x172
[ 94.814982] dumpsys_seg() at netbsd:dumpsys_seg+0xd0
[ 94.814982] dump_seg_iter() at netbsd:dump_seg_iter+0x107
[ 94.814982] dodumpsys() at netbsd:dodumpsys+0x268
[ 94.814982] dumpsys() at netbsd:dumpsys+0x1d
[ 94.824988] vpanic() at netbsd:vpanic+0x169
[ 94.824988] snprintf() at netbsd:snprintf
[ 94.824988] startlwp() at netbsd:startlwp
[ 94.824988] alltraps() at netbsd:alltraps+0xbb
[ 94.824988] scan_mbr() at netbsd:scan_mbr+0x3e
[ 94.824988] readdisklabel() at netbsd:readdisklabel+0x110
[ 94.834995] dk_getdisklabel() at netbsd:dk_getdisklabel+0xc8
[ 94.834995] dk_open() at netbsd:dk_open+0x120
[ 94.834995] spec_open() at netbsd:spec_open+0x175
[ 94.834995] VOP_OPEN() at netbsd:VOP_OPEN+0x4c
[ 94.834995] vn_open() at netbsd:vn_open+0x241
[ 94.834995] do_open() at netbsd:do_open+0x103
[ 94.845001] do_sys_openat() at netbsd:do_sys_openat+0x8b
[ 94.845001] sys_open() at netbsd:sys_open+0x24
[ 94.845001] syscall() at netbsd:syscall+0x157
[ 94.845001] --- syscall (number 5) ---
Is this expected behaviour? I.e. was floppy support dropped in or prior to 9.0? I have used that drive in the past. I have an old laptop that can only boot from USB FDD running NetBSD 5.1, so around that time it still worked.