operands that are set during seqeuncer program download instead of at
assembly time.
Convert the sequencer code to use" downloaded constants" for four run time
constants that vary depending on the board type. This frees up 4 bytes
of sequencer scratch ram space where these constants used to be stored and
also removes the additional instructions required to load their values
into the accumulator prior to using them.
Remove the REJBYTE sram variable. The host driver can just as easly
read the accumulator to get this value.
The scratch ram savings is important as the old code used to clober the
SCSICONF register on 274X cards which sits near the top of scratch ram
space. The SCSICONF register controls bus termination, and clobbering
it is not a good thing. Now we have 4 bytes to spare.
This should fix the reported problems with cards that don't have devices
attached to them failing with a stream of "Somone reset bus X" messages.
Doug Ledford determined the cause of the problem, fixes by me.
New sequencer assembler for the aic7xxx adapters. This assembler
performs some amount of register type checking, allows bit
manipulation of symbolic constants, and generates "patch tables"
for conditionalized downloading of portions of the program.
This makes it easier to take full advantage of the different
features of the aic7xxx cards without imposing run time penalies
or being bound to the small memory footprints of the low end
cards for features like target mode.
aic7xxx.reg:
New, assembler parsed, register definitions fo the aic7xxx cards.
This was done primarily in anticipation of 7810 support which
will have a different register layout, but should be able to use
the same assembler. The kernel aic7xxx driver consumes a generated
file in the compile directory to get the definitions of the register
locations.
aic7xxx.seq:
Convert to the slighly different syntax of the new assembler.
Conditionalize SCB_PAGING, ultra, and twin features which shaves
quite a bit of space once the program is downloaded.
Add code to leave the selection hardware enabled during reconnects
that win bus arbitration. This ensures that we will rearbitrate
as soon as the bus goes free instead of delaying for a bit.
When we expect the bus to go free, perform all of the cleanup
associated with that event "up front" and enter a loop awaiting
bus free. If we see a REQ first, complain, but attempt to
continue. This will hopefully address, or at least help diagnose,
the "target didn't send identify" messages that have been reported.
Spelling corrections obtained from NetBSD.
