disabled even if it's attached. If disabled, ENXIO on open.
(2) in the case where the code32 segment len overflows the I/O hole,
instead of giving up truncate it. (In other words, revert
change (2) in rev 1.21 which i suggested mistakenly.)
(3) map bios data space in the 0->640k range with _i386_memio_map()
rather than with bus_space_map(), so that no accounting checks
are done. The checks which are done to make sure that allocation
in this range is safe are sufficient.
(4) check the return value from _i386_memio_map(), and if it indicates
an error disconnect from the APM BIOS, print an error message,
and return without having marked the device 'enabled'.
functions (which only work on memory and i/o space) to i386_memio_*,
and make bus_space_* in bus.h be #defines which invoke them. This makes
life easier for people who need to define the all of the bus_space functions
so that they work on spaces other than memory and I/O space. Also, add
an _i386_memio_map function which is like i386_memio_map but doesn't do
the extent map checking or allocation. _i386_memio_map and i386_memio_*
are for use only by machine-dependent code.
code for this was in my private tree at one time, and I must have
forgotten to g/c the constant from trap.h). Reported by
enami tsugutomo <enami@but-b.or.jp>, PR #3845.
`b_dev' value of NODEV happens and is normal if the buffer is on its way
to the underlying device strategy function for the first time.
Also, MFS sillily uses a major device number (255) which cannot be used
to index bdevsw[]. Check marked with XXXs.
call biowait() but return `success' immediately. We can return `success'
because buffers with recorded errors are not returned by getblk().
(Takes care of PR#3694).
Re-arrange cpuattach() a bit so that more initialization is done before
dealing with the FPU. Some more work is still required to de-couple
FPU detection from the autoconfiguration attach code in SMP systems.
Correct handling for Trap #2 in SunOS executables,
now that we know it is supposed to flush the cache.
(Was thought to be "some obscure FPU operation".)
