* support chip clocks != COM_FREQ, by introducing sc_frequency (for the
mainline code) and adding a frequency parameter right after the rate
parameter to comcnattach() and com_kgdb_attach().
- Make com_isa and com_multi initialize sc_frequency to COM_FREQ.
- Make i386/machdep.c and alpha/dec_xxx.c call com*attach() with the freq.
parameter.
* supio_attach_args get two more fields: a sc_ipl and a sc_arg, both ints.
- com_supio uses the first for interupt establishment (all childs will, as
soon as they exist) and the 2nd for sc_frequency.
- drsupio passes sc_ipl alway as 5, and for the "com"s, sc_arg as 16*115200
- hyper will pass sc_ipl as 6, and sc_arg as 16 * 460800
-put all early console / KGDB initialization into 1 exported function
(com_*_attach()) each, dont use global variables anymore
-use the passed tcflag_t for port settings instead of hardwiring 8N1
-at autoconfiguration attach time, decide if the attaching device is
already console / KGDB by comparing bus tag and base addr (cgd's wish)
-export a function "com_is_console()" for use by driver frontends for
this comparision
-delay setting of cn_tab->cn_dev until autoconfiguration attach
to get the minor number right
-delete unused comcnprobe() and comcninit()
-Separate KGDB port initialization and softc related stuff to allow
KGDB to be attached in early system startup, before autoconfiguration.
-Export the variables needed by md code to hand-craft bus tag/handle.
-Fix initialization to enable interrupt by line break.
-Call DDB/KGDB at line break (move DDB call from the softirq handler
to the hard handler because it should work without a tty attached too).
- No more distinction between i/o-mapped and memory-mapped
devices. It's all "bus space" now, and space tags
differentiate the space with finer grain than the
bus chipset tag.
- Add memory barrier methods.
- Implement space alloc/free methods.
- Implement region read/write methods (like memcpy to/from
bus space).
This interface provides a better abstraction for dealing with
machine-independent chipset drivers.
'cflag' for the console. Normally set to TTYDEF_CFLAG, may be
overridden by machine-dependent console attachment code, as necessary.
(Alpha uses it to set cs8 -parenb.) Files including comvar.h now
need to include <sys/termios.h>, because comconscflag is of type
tcflag_t.
substantial reworking of the multi-port drivers, as they need to frob
bits in the io-port spaces of their children. As a result, the
commulti->com attachment interface is substantially more complex.
(This may be fixable in the future by making some of the code common,
but as long as io-port allocation checking is planned, it's necessary.)