[SeaBIOS] Bochs cvs + SeaBIOS git master + FreeDOS = slow load + invalid opcode

[Sebastian Herbszt]

I have tried SeaBIOS 0.5.1 on Bochs cvs with FreeDOS 1.0 Final boot floppy.
Loading from floppy was utterly slow and then FreeDOS dumped 

Invalid Opcode at 0013 0000 0202 800F 01F3 20F4 10AA 10AA 109A 0000 0000 0000 00
00
Bad or missing Command Interpreter: A:\COMMAND.COM A:\ /E:2048 /F /MSG /P=A:\FRE
EDOS\FDAUTO.BAT
 Enter the full shell command line:

Bochs log has
00477945139i[BIOS ] Booting from Floppy...
00510608951i[BIOS ] Booting from 0000:7c00
05264161428i[FDD  ] controller reset in software
05445136148i[FDD  ] controller reset in software
05625186768i[FDD  ] controller reset in software
05803824012i[FDD  ] controller reset in software
05985259728i[FDD  ] controller reset in software
05985285461i[CPU0 ] LOCK prefix unallowed (op1=0x53, attr=0x0, mod=0x0, nnn=0)

Same floppy and Bochs version work fine and fast with Bochs BIOS.

Any clues?

- Sebastian