Hello Zoltan, hey list,
On Mon, Nov 21, 2016 at 07:15:21PM +0100, BALATON Zoltan wrote:
> For forth commands I've found this page useful (not sure if this is linked
> from somewhere):
Thank you, I found this (and more) last week. The OLPC sites are the
best for me:
> This is a bit confusing. There are multiple implementations of the IEEE
> standard (commonly referred to as Open Firmware) and one of these is also
> called Open Firmware. These are listed under Implementations on the left of
> the page at www.openfirmware.info. Another implementation used by QEMU for
Yes and I looked at them. But they are either very old or not usable for
ppc (too much work to implement a new arch).
> talking about Open Firmware: the standard or the implementation with the
> same name.
One thing is left which confuses me: In wikipedia and you say, that you
use the name "Open Firmware" (also, besides as name for a standard) for
an implementation. OK.
But the website gives the impression (and G 3 says), that the implementation
has the name "OpenBIOS"...
So I have two statements which don't fit well. Please remember that I am
new to this and did not live through the history.
> Actually running OpenBIOS on real hardware is not something that is well
> tested (I'm not sure if it was ever tried but I think it wasn't done
> recently) so if you try to do that be prepared for likely needing some
The OLPC project did it, e.g.
> fixing. This is true for any implementation that does not support the
> hardware you want to run it on, then you likely need to port it.
That there will be the need for porting was clear.
> it's enough to have the basics in there. Not sure how much up to date is
> this but this is discussed in the kernel documentation here:
Thank you, I missed this source.
> As for giving the device tree to OpenBIOS I think it should just know it or
> construct it from discovering the hardware as the point of the device tree
> is to describe the hardware for the operating system so the firmware should
> know the hardware and provide the device tree. It does not get it from
The "firmware" is our handmade init-assemblercode. It has to enable the
machine (beginning from Adam...) to run C-code in its RAM.
If there is no software-interface, then we provide the device-tree maybe in
forth or in a blob. Just thinking loudly.
> In fact OpenBIOS does not have that many drivers but maybe the basics are
> there, only the platform specific init code might need to be adapted for a
That would be very nice. We give it a try. Maybe with help from you / the
> new board. For ppc these would be in arch/ppc. Running on QEMU is quite a
> bit simpler as we can skip a lot of init code (such as memory controller or
> other hardware) so maybe these are not well implemented or buggy as they
> were not tested with real hardware for a while.
Did you use OpenBIOS in a recent qemu and have you been able to remote-debug
it there? I was able to load and run the old OpenBIOS code (from svn repo)
Thank you for your time and suggestions, greetings,
QEMU emulates two of the three PCI buses found on real hardware because
some clients seem to need both and fail with only one present, but
OpenBIOS only handles a single PCI bus and initialises and puts in the
device tree only one of these: the second one which is where devices are
connected and also marks it bus 0. However, clients getting info from the
device tree may not know about this and thinking there is only one PCI
bus they erroneously use the address of the first bus to access PCI
config registers for devices on the second bus which silently fails as
these requests will go to the other empty bus emulated and return invalid
values. Devices mapped via MMIO still appear to work but they may not be
correctly initialised and some cards are not detected because of this.
Until support for multiple PCI buses is implemented add an empty node in
the device tree for the uninitialised bus to let clients know about it.
This is still not entirely correct as bus-range property does not match
real hardware but this fixes detecting PCI devices (such as USB) under
MorphOS and may also fix enabling the bus master bit needed with some
network cards and allow the workarund for this to be reverted.
Signed-off-by: BALATON Zoltan <balaton(a)eik.bme.hu>
arch/ppc/qemu/tree.fs | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/ppc/qemu/tree.fs b/arch/ppc/qemu/tree.fs
index 5b6bbc6..e1708de 100644
@@ -50,6 +50,18 @@ new-device
h# ff800000 encode-int encode+ " ranges" property
+\ Add empty node for first pci bus
+\ Remove this when pci driver is fixed to handle multiple buses
+ " pci" device-name
+ " pci" device-type
+ h# f0000000 encode-int 02000000 encode-int encode+ " reg" property
+ 3 encode-int " #address-cells" property
+ 2 encode-int " #size-cells" property
+ 1 encode-int " #interrupt-cells" property
+ 0 encode-int 0 encode-int encode+ " bus-range" property
On 2016-Nov-22 09:22 , Artyom Tarasenko wrote:
> That's a very interesting point. Does EFI actually have any advantages
> over IEEE 1275?
* It's supported by Intel and many hardware vendors (drivers for their
* It has huge libraries to do many interesting things (from IPv6 to
debuggers), so system builders have many options that don't require
writing things from scratch.
* It's written in C.
At one point, I was informed that the biggest advantage was that it
didn't require Forth programmers. From a management viewpoint, that is
significant, finding good Forth programmers is a pain in the tush.
Growing your own forth programmers isn't easy, it takes a long time for
someone to learn how to write clean and maintainable Forth. And with
today's larger PROMs, Forth's compactness is no longer as important.
> For instance, Apple moved to EFI, but was their real motivation?
> Did they just wanted to ditch Forth?
I have no actual visibility into Apple's motivations, but my assumption
would be that with the move to x86, the change to EFI made sense to them.
On Fri, 11 Nov 2016, BALATON Zoltan wrote:
> For those interested in more details it seems that the pciusb.device driver
> finds the OHCI chip in QEMU but does not like it and does not claim or try to
> initialise it for some reason.
It wasn't too easy to find it but it turned out to be caused by a mismatch
between what's emulated in QEMU and what OpenBIOS put in the device tree
so when trying to access the config registers of PCI bus 1 MorphOS ended
up using PCI bus 0 which of course returned an error. After this was fixed
the USB controller is found but patches from BenH to fix the interrupt
was also needed for it to work. Patches submitted to OpenBIOS and QEMU.
> The usefulness of this activity may not be direct as MorphOS may not ever run
> on) but the bugs found and fixed during this do help making the device models
> in QEMU more accurate and help running other OSes. I think some of the bugs
> fixed this way in OpenBIOS and QEMU also helped to get MacOS running so I
> like to believe there are at least some indirect usefulness of this.
MorphOS now has input but still lacks some way to output video (this still
needs some work). But if other OSes had the same problem fixed here then
this may fix the enabling of the bus master bit for some network cards so
the patch added for that in OpenBIOS may not be needed now and fixing the
interrupt may improve mouse or sound behaviour on MacOS. I haven't tested
these, just verified that MacOS 9 and Linux still boots with these patches.
Dear list, thank you for the help with cross-compiling for ppc64 so far!
It is important but I overjumped enthusiastically the OF basics :-)
I read many webpages, hints and maybe old sites etc and solved many things.
But is there a "beginners how-to" somewhere? What I would find most usefull:
1) Best source-code to use? There is a version-1.1.zip, a svn repo and
a git repo.
2) The names are also a bit confusing when you see it first. I know about
the IEEE standard and a few things about the history (from wikipedia),
but if you for example visit the website and click on the "openfirmware"
link, the you see a page with "OpenBIOS" heading. So even if one knows
about history, there is confusion about actual used names.
3) How is the device-tree given to OF? And how does OF handle it over
to a linux kernel?
4) Minimal prerequisites on a new hardware, so that OF is able to run?
E.g. which type of RAM does it need? Does it need a stack or .text segment
or other things to run (like c-code)? ...
If these points would be clarified, the it would be much easier for
new people to help with e.g. additional targets or maybe new architectures.
Thanks for your time! Greetings,
Hello list! A few days ago I found this openfirmware and the forth in it
and wanted to try it out in a project for powerpc (64 bit).
My openbios version is latest from git (master), last patch from 2016-10-09
I used this because the version 1.1 has two bugs I stumbled upon.
I am cross-compiling on amd64 (host with debian) for ppc64 target and
therefore call the script "switch-arch qemu-ppc64".
The settings in the generated files under obj-ppc64 look OK to me.
But (there is allways this "but") I have a compile error:
panic: segmentation violation at 0xdf1ec62c
dict=0x7f0edf1ec010 here=0x7f0edf1ec638(dict+0x628) pc=0x0(dict+0x20e13ff0)
dstackcnt=0 rstackcnt=0 instruction=deadbeef
Writing dictionary core file
rules.mak:68: recipe for target 'bootstrap.dict' failed
make: *** [bootstrap.dict] Error 1
It seems that the generating of the forth dictionary fails? Where can I get
more information? The logs contain not much more info.
When I compile the same sources for target amd64, then it builds and works.
Thank you for reading (and maybe for helping)!