Control) devices as console. These are microcontrollers which are either
on-board or part of an add-on card and provide terminal server, remote
power switch and monitoring functionality. For console usage these are
connected to the rest of the system via a SCC or an UART. This commit adds
support for the following variants (corresponds to what 'input-device' and
'output-device' have to be set to):
rsc found on-board in E250 and supposedly some Netra, connected
via a SAB82532, com. parameters can be determined via OFW
rsc-console RSC card found in E280R, Fire V4x0, Fire V8x0, connected
via a NS16550, hardwired to 115200 8N1
lom-console LOMlite2 card found in Netra 20/T4, connected via a NS16550,
hardwired to 9600 8N1
- Add my copyright to uart_cpu_sparc64.c as I've rewritten about one third
of that file over time.
Tested on: E250, E280R
Thanks to: dwhite@ for providing access to an E280R
OK'ed by: marcel
MFC after: 1 week
which serial device to use in that case respectively to not rely on
the OFW names of the input/output and stdin/stdout devices. Instead
check whether input and output refers to the same device and is of
type serial (uart(4) was already doing this) and for the fallback
to a serial console in case a keyboard is the selected input device
but unplugged do the same for stdin and stdout in case the input
device is nonexistent (PS/2 and USB keyboards) or has a 'keyboard'
property (RS232 keyboards). Additionally also check whether the OFW
did a fallback to a serial console in the same way in case the
output device is nonexistent. While at it save on some variables
and for sys/boot/sparc64/loader/metadata.c move the code in question
to a new function md_bootserial() so it can be kept in sync with
uart_cpu_getdev_console() more easily.
This fixes selecting a serial console and the appropriate device
when using a device path for the 'input-device' and 'output-device'
OFW environment variables instead of an alias for the serial device
to use or when using a screen alias that additionally denotes a
video mode (like e.g. 'screen:r1024x768x60') but no keyboard is
plugged in (amongst others). It also makes the code select a serial
console in case the OFW did the same due to a misconfiguration like
both 'input-device' and 'output-device' set to 'keyboard' or to a
nonexisting device (whether the OFW does a fallback to a serial
console in case of a misconfiguration or one ends up with just no
console at all highly depends on the OBP version however).
- Reduce the size of buffers that only ever need to hold the string
'serial' accordingly. Double the size of buffers that may need to
hold a device path as e.g. '/pci@8,700000/ebus@5/serial@1,400000:a'
exceeds 32 chars.
- Remove the package handle of the '/options' node from the argument
list of uart_cpu_getdev_dbgport() as it's unused there and future
use is also unlikely.
MFC after: 1 week
UARTs used to connect keyboards and not also PS/2 keyboards and only
return their package handle in case the keyboard is the preferred one
according to the OFW but otherwise still regardless of whether the
keyboard is used for stdin or not. This is simply achieved by looking
at the 'keyboard' alias and returning the corresponding package handle
in case it refers to a SCC/UART. This is change is done in order to
give the keyboard which the OFW or the user selected in OFW on boards
that support additional types of keyboards besides the RS232 ones also
preference in FreeBSD. It will be also used to determine on Sun AXi and
Sun AXmp boards whether a PS/2 or a RS232 is to be used as these are
sort of mutual exclusive there (see upcoming commit to uart_bus_ebus.c).
Note that Tatung AXi boards have the same issue but the former code
happened to already give the PS/2 keyboard preference by not identifying
the respective UART as keyboard system device there because the PS/2
keyboard node precedes the keyboard UART one in the OFW device tree of
these boards (which isn't the case for the Sun AXi).
Ok'ed by: marcel
a serial console anyway because input-device is set to keyboard and
output-device is set to screen but no keyboard is plugged in don't
assume that a device node for the input-device alias exists. While
this is true for RS232 keyboards (the node of the SCC and UART
respectively which controls the keyboard doesn't disappear when no
keyboard is plugged in) this assumption breaks for USB keyboards.
It's most likely also not true for PS/2 keyboards but OFW doesn't
reliably switch to a serial console when the potential keyboard is
a PS/2 one which isn't plugged in so this couldn't be verified
properly.
Reported by: Will Andrews <will@csociety.org>, obrien
MFC after: 1 week
for nodes hanging off of Central (untested), FireHose (untested) and
PCI (tested) busses.
- Add an additional parameter to OF_decode_addr() which specifies the
index of the register bank to decode.
These should allow to eventually add support for the Z8530 hanging off of
FireHose to uart(4) and to write support for PCI-based graphics adapters.
Suggested by: tmm (back in '03)
the address of a channel on a SCC, it returns 0 on failure. [1]
- Hardcode channel 1 for the keyboard on Z8530, the information present
in the Open Firmware device tree doesn't allow to determine this via
uart_cpu_channel(). This makes the keyboard (if one backs out rev. 1.5
of sys/dev/puc/puc_sbus.c and has both keyboard and mouse plugged in to
avoid the hang that revision works around) and consequently syscons(4)
on Ultra 2 work. There's a problem with the keyboard LEDs similar to
the one on Ultra 60 (LEDs don't get lit under X) though, instead of
lighting just a specific single one all get lit and can't be turned off
again. [1]
- Add comments about what uart_cpu_channel() and uart_cpu_getdev_keyboard()
do and their constraints.
- Improve the comments about what uart_cpu_getdev_[console,dbgport]() do,
they don't return an address (as in bus) but an Open Firmware package
handle.
Reviewed by: marcel (modulo the comments) [1]
- The claim in the commit log of rev. 1.11 of dev/uart/uart_cpu_sparc64.c
etc. that UARTs are the only relevant ISA devices on sparc64 turned out
to be false. While there are sparc64 models where UARTs are the only
devices on the ISA bus there are in fact also low-cost models where all
devices traditionally found on the EBus are hooked up to the ISA bus.
There are also models that use a mix between EBus and ISA devices with
things like an AT keyboard controller and other rather interesting
devices that we might want to support in the futute hook up to the ISA
bus.
In order to not need to add sparc64 specific device_identify methods to
all of the respective ISA drivers and also not add OFW specific code to
the common ISA code make the sparc64 ISA bus code fake up PnP devices so
most ISA drivers probe their devices without further changes.
Unfortunately Sun doesn't adhere to the ISA bindings defined in IEEE
1275-1994 for the properties of most of the ISA devices which would
allow to obtain the vendor and logical IDs from their properties. So we
we just use a simple table which maps the name properties to PnP IDs.
This could be done in a more sophisticated way but I courrently don't
see the need for this. [1]
- Add the children with fully mapped and specified resources (in the OFW
sense) similar to what is done in the EBus code for the IRQ resources
of the children as adjusting the resources and the resource list entries
respectively in isa_alloc_resource() as done perviously causes trouble
with drivers which use rman_get_start(), pass-through or allocate and
release resources multiple times, etc.
Adjusting the resources might be better off in a bus_activate_resource
method but the common ISA code currently doesn't allow for an
isa_activate_resource(). [2]
With this change:
- ppbus(4) and lpt(4) attach and work (modulo ECP mode, which requires
real ISADMA code but it currently only consists of stubs on sparc64).
- atkbdc(4) and atkbdc(4) attach, no further testing done.
- fdc(4) itself attaches but causes a hang while attaching fd0 also
when is DMA disabled, further work in fdc(4) is required here as e.g.
fd0 uses the address of fd1 on sparc64 (not sure if sparc64 supports
more than one floppy drive at all).
All of these drivers previously caused panics in the sparc64 ISA code.
- Minor changes, e.g. use __FBSDID, remove a dupe word in a comment and
declare one global variable which isn't used outside of isa.c static.
o dev/uart/uart_cpu_sparc64.c and modules/uart/Makefile:
- Remove the code for registering the UARTs on the ISA bus from the
sparc64 uart_cpu_identify() again and rely on probing them via PnP.
Original idea by: tmm [1]
No objections by: tmm [1], [2]
and that can be used as an identify function for all kinds of busses on a
certain platform. Expect for sparc64 these are only stubs right now. [1]
- For sparc64, add code to its uart_cpu_identify() for registering the on-
board ISA UARTs and their resources based on information obtained from
Open Firmware.
It would be better if this would be done in the OFW ISA code. However, due
to the common FreeBSD ISA code and PNP-IDs not always being present in the
properties of the ISA nodes there seems to be no good way to implement that.
Therefore special casing UARTs as the sole really relevant ISA devices on
sparc64 seemed reasonable. [2]
Approved by: marcel
Discussed with: marcel [1], tmm [2]
Tested by: make universe
"... uart_cpu_sparc64.c currently only looks at /options if ttyX is
the selected console. However, there's one case where it should
additionally look at /chosen. If "keyboard" is the selected input-
device and "screen" the output-device (both via /options) but the
keyboard is unplugged, OF automatically switches to ttya for the
console. It even prints a line telling so on "screen". Solaris
respects this behaviour and uses ttya as the console in this case
and people probably expect FreeBSD to do the same (it's also very
handy to temporarily switch consoles)..."
Submitted by: Marius Strobl <marius@alchemy.franken.de>
Has no doubt the change is correct: marcel
to select a serial console and debug port (resp). On ia64 these replace
the use of hints completely and take precedence over hints on alpha,
amd64 and i386. On sparc64 these variables are not yet recognised.
The reasons for introducing these variables are:
1. Hints have side-effects. They reserve the unit number for use by
isa or acpi devices and therefore cannot be used to select a pci
device. Also, the use of a unit number to select a device prior
to bus enumeration is nonsense. The new variables have no side-
effects and are not based on unit numbers.
2. Hints don't have the expression power to allow the sysadmin to
select UARTs that are not legacy PC devices and need the support
of compile-time constants to give the sysadmin some level of
flexibility.
The hw.uart.console and hw.uart.dbgport variables specify a list of
attributes. An attribute is a tag-value pair, seperated by a colon.
Attributes are seperated by a comma. Where possible, tags are the
same as those in /etc/remote (only br and pa in practice). Details
can be found in the manpage (not part of this commit).
Not tested on: amd64, pc98
and the Z8530 drivers used the I/O address as a quick and dirty way to
determine which channel they operated on, but formalizing this by
introducing iobase is not a solution. How for example would a driver
know which channel it controls for a multi-channel UART that only has a
single I/O range?
Instead, add an explicit field, called chan, to struct uart_bas that
holds the channel within a device, or 0 otherwise. The chan field is
initialized both by the system device probing (i.e. a system console)
or it is passed down to uart_bus_probe() by any of the bus front-ends.
As such, it impacts all platforms and bus drivers and makes it a rather
large commit.
Remove the use of iobase in uart_cpu_eqres() for pc98. It is expected
that platforms have the capability to compare tag and handle pairs for
equality; as to determine whether two pairs access the same device or
not. The use of iobase for pc98 makes it impossible to formalize this
and turn it into a real newbus function later. This commit reverts
uart_cpu_eqres() for pc98 to an unimplemented function. It has to be
reimplemented using only the tag and handle fields in struct uart_bas.
Rewrite the SAB82532 and Z8530 drivers to use the chan field in struct
uart_bas. Remove the IS_CHANNEL_A and IS_CHANNEL_B macros. We don't
need to abstract anything anymore.
Discussed with: nyan
Tested on: i386, ia64, sparc64
the "compatible" property too in the ns8250 case. This gets the serial
console to work on Blade 100s, where the device name is just "serial".
Reviewed by: marcel
from the SAB82532 and the Z8530 hardware drivers by introducing
uart_cpu_busaddr(). The assumption is not true on pc98 where
bus_space_handle_t is a pointer to a structure.
The uart_cpu_busaddr() function will return the bus address
corresponding the tag and handle given to it by the BAS.
WARNING: the intend of the function is STRICTLY to allow hardware
drivers to determine which logical channel they control and is NOT
to be used for actual I/O. It is therefore EXPLICITLY allowed that
uart_cpu_busaddr() returns only the lower 8 bits of the address
and garbage in all other bits. No mistakes...
It improves on sio(4) in the following areas:
o Fully newbusified to allow for memory mapped I/O. This is a must
for ia64 and sparc64,
o Machine dependent code to take full advantage of machine and firm-
ware specific ways to define serial consoles and/or debug ports.
o Hardware abstraction layer to allow the driver to be used with
various UARTs, such as the well-known ns8250 family of UARTs, the
Siemens sab82532 or the Zilog Z8530. This is especially important
for pc98 and sparc64 where it's common to have different UARTs,
o The notion of system devices to unkludge low-level consoles and
remote gdb ports and provides the mechanics necessary to support
the keyboard on sparc64 (which is UART based).
o The notion of a kernel interface so that a UART can be tied to
something other than the well-known TTY interface. This is needed
on sparc64 to present the user with a device and ioctl handling
suitable for a keyboard, but also allows us to cleanly hide an
UART when used as a debug port.
Following is a list of features and bugs/flaws specific to the ns8250
family of UARTs as compared to their support in sio(4):
o The uart(4) driver determines the FIFO size and automaticly takes
advantages of larger FIFOs and/or additional features. Note that
since I don't have sufficient access to 16[679]5x UARTs, hardware
flow control has not been enabled. This is almost trivial to do,
provided one can test. The downside of this is that broken UARTs
are more likely to not work correctly with uart(4). The need for
tunables or knobs may be large enough to warrant their creation.
o The uart(4) driver does not share the same bumpy history as sio(4)
and will therefore not provide the necessary hooks, tweaks, quirks
or work-arounds to deal with once common hardware. To that extend,
uart(4) supports a subset of the UARTs that sio(4) supports. The
question before us is whether the subset is sufficient for current
hardware.
o There is no support for multiport UARTs in uart(4). The decision
behind this is that uart(4) deals with one EIA RS232-C interface.
Packaging of multiple interfaces in a single chip or on a single
expansion board is beyond the scope of uart(4) and is now mostly
left for puc(4) to deal with. Lack of hardware made it impossible
to actually implement such a dependency other than is present for
the dual channel SAB82532 and Z8350 SCCs.
The current list of missing features is:
o No configuration capabilities. A set of tunables and sysctls is
being worked out. There are likely not going to be any or much
compile-time knobs. Such configuration does not fit well with
current hardware.
o No support for the PPS API. This is partly dependent on the
ability to configure uart(4) and partly dependent on having
sufficient information to implement it properly.
As usual, the manpage is present but lacks the attention the
software has gotten.
