* Move some of the memory bootstrapping and the DDB startup earlier.
* Always put the IDT and the initial GDT and LDT in a separate page.
* Various minor changes.
* Call gdt_init() earlier on.
* Don't bother to check for TSS and LDT descriptors in verr_gdt().
* Nuke the sti special case for trace and breakpoint traps.
* Move some variable declarations into more appropriate locations.
Implement new ISA interface functions:
* isa_intr_alloc() - allocate an ISA IRQ
* isa_mem_alloc() - allocate ISA memory space
* isa_mem_free() - free ISA memory space
* Make it a strict hierarchy. (It was close anyway).
* Add `serial' and rename `softtty' to `softserial'.
* Make soft interrupts a bit less special-case.
been attached to the system. If, by the time mainbus wants to attach
an ISA an ISA has not yet been attached to the system, attempt to attach
an ISA to mainbus.
creating segment descriptors. Add the duplicate system call gate used by
BSD/OS 2.0 executables. Prototype setsegment() and setgate(), and fix a bogon
caught by this.
thorpej