- In the console getc routine, block until a character becomes ready
(no, really, we mean it). This routine should _never_ time out.
- In the console putc routine, if the UART has trouble, do NOT proceed
to print a diagnostic message, which would recursively invoke the
console putc routine ad nauseum.
This is useful in the case where an attachment's probe routine
verifies that there is indeed hardware present but something goes
"wrong" in the attach causing the device to be unusable. (Without
keeping track of this, in that case incorrect ports could be
accessed or uninitted pointers could be deferenced on open or at
other times.)
* Make the ring buffer size and water marks patchable, and allocate the buffer
separately.
* Do the ttymalloc() at attach time.
* Reorganize the receive buffer so the status and data pair are next to each
other. This is slightly faster.
* Make sure we actually do turn off interrupts in comclose() if we have DDB
configured and it's not the console. (D'oh!!!!)
* When we exhaust the current transmit run, turn off transmit interrupts in
comintr(), so we're fairly sure we don't get another one.
* Nuke the silly lsrmap[] idea; it's slower in the normal case.
* Cache the l_rint pointer in the soft interrupt routine.
things happen if we are the console.
Restore to the prevoius value (not to hardwired 8N1) because this
could be set by the serial console initialization.
Closed PR kern/4373 (Dave Huang)
Dave Huang <khym@bga.com>, with added check for broken early versions
of the 16650, taken from the Linux driver.
This should be extended to use, for example, higher trigger levels for
the bigger 16650 FIFO, and its capability for using a smaller divisor
and thus higher speeds. But this patch is very useful for 16650 users
already.
options RND_COM
in your kernel config file (along with the
pseudo-device rnd
line) to enable this. If results are positive, I will make this enabled
by default.
* 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).
