8GB & 4GB RPi4 updated to arm-unstable booting on SD and NFS.
I do not know when it began, the issue likely predates my first use of the net HOOK.
But if the hook is activated in your mkinitcpio.conf, the wifi driver crashes and you end up with no wifi device. The net hook is required for booting via NFS.
Dec 14 18:20:36 client kernel: ------------[ cut here ]------------
Dec 14 18:20:36 client kernel: WARNING: CPU: 0 PID: 123 at crypto/rsa-pkcs1pad.c:540 pkcs1pad_verify+0x154/0x180
Dec 14 18:20:36 client kernel: Modules linked in: cfg80211(+) rfkill brcmutil overlay zram zsmalloc
Dec 14 18:20:36 client kernel: CPU: 0 PID: 123 Comm: systemd-udevd Not tainted 5.10.0-rc7-1-MANJARO-ARM #1
Dec 14 18:20:36 client kernel: Hardware name: Raspberry Pi 4 Model B Rev 1.4 (DT)
Dec 14 18:20:36 client kernel: pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--)
Dec 14 18:20:36 client kernel: pc : pkcs1pad_verify+0x154/0x180
Dec 14 18:20:36 client kernel: lr : public_key_verify_signature+0x204/0x334
Dec 14 18:20:36 client kernel: sp : ffff800011d9b6d0
Dec 14 18:20:36 client kernel: x29: ffff800011d9b6d0 x28: ffff80001146b020
Dec 14 18:20:36 client kernel: x27: 000000001f030000 x26: 000000000000010e
Dec 14 18:20:36 client kernel: x25: ffff0001045ff800 x24: ffff000103c90d00
Dec 14 18:20:36 client kernel: x23: ffff0001045ff000 x22: ffff000103e6dac0
Dec 14 18:20:36 client kernel: x21: ffff800011d9b788 x20: ffff000100890480
Dec 14 18:20:36 client kernel: x19: ffff0001045ff000 x18: 0000000000000002
Dec 14 18:20:36 client kernel: x17: 0000000000000007 x16: 0000000000000000
Dec 14 18:20:36 client kernel: x15: ffff800010bb28a0 x14: 0000000000000004
Dec 14 18:20:36 client kernel: x13: ffff0001045ff7ff x12: ffff80001067e8d8
Dec 14 18:20:36 client kernel: x11: 0000000000000007 x10: 0101010101010101
Dec 14 18:20:36 client kernel: x9 : ffff8000105bc834 x8 : 0000000000000100
Dec 14 18:20:36 client kernel: x7 : 0000000000000000 x6 : 0000000000000600
Dec 14 18:20:36 client kernel: x5 : 0000000000000000 x4 : fffffe0003ef2400
Dec 14 18:20:36 client kernel: x3 : 000001ffffe00002 x2 : 0000000000000600
Dec 14 18:20:36 client kernel: x1 : 0000000000000000 x0 : 0000000000000000
Dec 14 18:20:36 client kernel: Call trace:
Dec 14 18:20:36 client kernel: pkcs1pad_verify+0x154/0x180
Dec 14 18:20:36 client kernel: public_key_verify_signature+0x204/0x334
Dec 14 18:20:36 client kernel: x509_check_for_self_signed+0xb8/0x13c
Dec 14 18:20:36 client kernel: x509_cert_parse+0x16c/0x1e4
Dec 14 18:20:36 client kernel: x509_key_preparse+0x30/0x1b0
Dec 14 18:20:36 client kernel: asymmetric_key_preparse+0x6c/0xb0
Dec 14 18:20:36 client kernel: key_create_or_update+0x184/0x434
Dec 14 18:20:36 client kernel: regulatory_init+0x194/0x294 [cfg80211]
Dec 14 18:20:36 client kernel: cfg80211_init+0x80/0xe8 [cfg80211]
Dec 14 18:20:36 client kernel: do_one_initcall+0x54/0x2d0
Dec 14 18:20:36 client kernel: do_init_module+0x60/0x29c
Dec 14 18:20:36 client kernel: load_module+0x21e4/0x2820
Dec 14 18:20:36 client kernel: __do_sys_finit_module+0xb8/0xfc
Dec 14 18:20:36 client kernel: __arm64_sys_finit_module+0x2c/0x40
Dec 14 18:20:36 client kernel: el0_svc_common.constprop.0+0x84/0x1f0
Dec 14 18:20:36 client kernel: do_el0_svc+0x30/0xa0
Dec 14 18:20:36 client kernel: el0_svc+0x20/0x30
Dec 14 18:20:36 client kernel: el0_sync_handler+0x1a4/0x1b0
Dec 14 18:20:36 client kernel: el0_sync+0x174/0x180
Dec 14 18:20:36 client kernel: ---[ end trace 0f472a12ddda9418 ]---