a heavily stripped down FreeBSD/i386 (brutally stripped down actually) to
attempt to get a stable base to start from. There is a lot missing still.
Worth noting:
- The kernel runs at 1GB in order to cheat with the pmap code. pmap uses
a variation of the PAE code in order to avoid having to worry about 4
levels of page tables yet.
- It boots in 64 bit "long mode" with a tiny trampoline embedded in the
i386 loader. This simplifies locore.s greatly.
- There are still quite a few fragments of i386-specific code that have
not been translated yet, and some that I cheated and wrote dumb C
versions of (bcopy etc).
- It has both int 0x80 for syscalls (but using registers for argument
passing, as is native on the amd64 ABI), and the 'syscall' instruction
for syscalls. int 0x80 preserves all registers, 'syscall' does not.
- I have tried to minimize looking at the NetBSD code, except in a couple
of places (eg: to find which register they use to replace the trashed
%rcx register in the syscall instruction). As a result, there is not a
lot of similarity. I did look at NetBSD a few times while debugging to
get some ideas about what I might have done wrong in my first attempt.
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
All new code is "#ifdef PC98"ed so this should make no difference to
PC/AT (and its clones) users.
Ok'd by: core
Submitted by: FreeBSD(98) development team
almost every time someone uses an address. This file is probably not
the right place to keep track of the unused addresses (or used
addresses :->).
Fixed comments on #endif's to match code.
Added defines for ASC and GSC sizes. This file is not the right place
to keep track of scanner addresses, but while there here and we
pretend to keep track of unused addresses, the sizes need to be here
too.
Sorted IO_*SIZE defines.
Fix one such THING in code to match comment.
Sort IO_GSC* into numeric order and update comments about the gaps.
Sort common SCSI addresses into alphabetical order.
Remove bogus comments about com ports having i/o size 4.
Uniformize whitespace.
Uniformize case in hex digits.
This file is very incomplete. In particular, it doesn't mention any
network cards. This doesn't matter much for the base addresses, but
it means that the comments about which addresses are free are mostly
bogus. The i/o sizes are unreliable because of split address ranges
for many devices (VGA, wd). The i/o sizes are incomplete. In
particular, there are no sizes for SCSI controllers. The bt driver
still returns a truth value instead of a size.
