Hi, I was able to confirm that the current libBSD implementation scans the fdt only once. caller: https://github.com/RTEMS/rtems-libbsd/blob/f60ac53420f36060c13104f9a555f39ebc619b09/freebsd/sys/kern/subr_bus.c#L5100 callee: https://github.com/RTEMS/rtems-libbsd/blob/f60ac53420f36060c13104f9a555f39ebc619b09/freebsd/sys/kern/subr_bus.c#L969 The function BUS_NEW_PASS initialises a pass over fdt with all drivers of the current pass level.
However after trying to add another pass, I realized that all drivers are on the DEFAULT_PASS_LEVEL (max_integer). Best and thanks, Nils On Thu, 1 Aug 2019 at 11:36, Christian Mauderer < christian.maude...@embedded-brains.de> wrote: > Hello Nils, > > On 31/07/2019 14:54, Nils Hölscher wrote: > > Hi, > > > > I have been reading into the FreeBSD init code the past few days, > > especially for Driver_MODULE. > > Expect an Blog entry today or tomorrow. > > > > Because I don't have JTAG, it took me quite some time. > > I would always suggest a JTAG or some other kind of debugger for > embedded work. In a professional work environment you should try to > convince your boss that it is a big time saver (which is definitively > true) so that even an expensive debugger is a good investment > > By the way: For understanding the initialization sequence you might can > use a simulator too. For the basic sequence you can simulate any BSP and > are not bound to BBB. > > > With BUS_DEBUG enabled I saw that the problem is indeed that the pruss > > unit is discovered too early. > > Is this device tree related? > > It's possible that this is a difference in how modules are handled. I'm > not sure whether FreeBSD loads EARLY_MODULES dynamically at another time > during boot while we link everything in from the start. If that is true, > the mechanism might not work the same like in FreeBSD. You might want to > have a look at that. > > > > > I am not sure, cause the overlay I am using is from the BSD community. > > > > I added my output to a gist and link to the interesting parts. > > The EARLY_DRIVER_MODULE's are indeed loaded first. > > > https://gist.github.com/nilhoel1/dac4b9d6b1798b97846b24162ef227e4#file-bus_debug-output-log-L125 > > Nexus bus attaches and the driver goes over every discovered device and > > tries to attach the drivers in order: > > > https://gist.github.com/nilhoel1/dac4b9d6b1798b97846b24162ef227e4#file-bus_debug-output-log-L326 > > ofwbus gets discovered: > > > https://gist.github.com/nilhoel1/dac4b9d6b1798b97846b24162ef227e4#file-bus_debug-output-log-L747 > > Here the ti_pruss device gets discovered too early in the fdt and fails: > > > https://gist.github.com/nilhoel1/dac4b9d6b1798b97846b24162ef227e4#file-bus_debug-output-log-L904 > > > > I still haven't found the loop running over fdt. > > Don't have a test environment ready so this is just from a quick glance > at the code. I might have missed something: > > simplebus_attach adds all child nodes from the tree to the bus: > > > https://git.rtems.org/rtems-libbsd/tree/freebsd/sys/dev/fdt/simplebus.c#n157 > > The bus_generic_attach then loops over all children and calls their > probe and attach functions: > > https://git.rtems.org/rtems-libbsd/tree/freebsd/sys/kern/subr_bus.c#n3768 > > Best regards > > Christian > > > And it seems that the device tree only gets one iteration. > > But the BSD man page for EARLY_DRIVER_MODULE states that every > > PASS_LEVEL has an iteration. > > " > > > > The *EARLY*_*DRIVER*_*MODULE*() macro allows a driver to be > registered for a > > specific pass level. The boot time probe and attach process makes > *_multi- _ _ple passes over the device tree_*. Certain critical > drivers that provide > > basic services needed by other devices are attach during > earlier passes. > > Most drivers are attached in a final general pass. A driver > that > > attaches during an early pass must register for a specific > pass level > > (BUS_PASS_*) via the /pass/ argument. Once a driver is > registered it is > > available to attach to devices for all subsequent passes." > > > > > https://www.freebsd.org/cgi/man.cgi?query=DRIVER_MODULE&sektion=9&apropos=0&manpath=FreeBSD+12.0-RELEASE+and+Ports > > > > Best, > > Nils > > > > > > On Sun, 28 Jul 2019 at 11:34, Christian Mauderer <l...@c-mauderer.de > > <mailto:l...@c-mauderer.de>> wrote: > > > > On 28/07/2019 11:22, Nils Hölscher wrote: > > > > > > > > > On Sat, 27 Jul 2019 at 14:34, Christian Mauderer > > <l...@c-mauderer.de <mailto:l...@c-mauderer.de> > > > <mailto:l...@c-mauderer.de <mailto:l...@c-mauderer.de>>> wrote: > > > > > > On 24/07/2019 16:53, Nils Hölscher wrote: > > > > Hi, > > > > > > > > @Vijay Kumar Banerjee <mailto:vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com> > > > <mailto:vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com>>> thanks for the > > > > dtb file. > > > > I build my file from FreeBSD master. > > > > > > > > Prcm attaches now but still after the pruss driver...: > > > > " > > > > nexus0: <RTEMS Nexus device> > > > > ofwbus0: <Open Firmware Device Tree> on nexus0 > > > > simplebus0: <Flattened device tree simple bus> on ofwbus0 > > > > *ti_pruss0: <TI Programmable Realtime Unit Subsystem> mem > > > > 0x4a300000-0x4a37ffff irq 20,21,22,23,24,25,26,27 on > simplebus0 > > > > ti_pruss0: could not enable PRUSS clock > > > > device_attach: ti_pruss0 attach returned 6* > > > > simplebus1: <Flattened device tree simple bus> on simplebus0* > > > > am335x_prcm0: <AM335x Power and Clock Management> mem > > > 0x200000-0x203fff > > > > on simplebus1* > > > > > > Hello Nils, > > > > > > I'm not sure about the order. But what seems a little bit odd > > is that > > > the prcm0 is found in simplebus0 while am335x_prcm0 is found on > > > simplebus1. Maybe it's worth investigating how that order is > > created and > > > how it is handled in RTEMS. > > > > > > > > > Thanks for the information. > > > I think the way rtems initializes the bsd modules differs from the > way > > > described in the libbsd manuel. > > > But I will have to investigate that further. > > > > > > > > > > I'm not 100% sure but as far as I know the _modules_ should be > > initialized in the given order (early module prior to normal module). > > But the device detection is something different. I think there is > some > > loop in simplebus that loops over the devices and asks every driver > > whether it wants to handle that device. If yes the driver can have > it. > > If no the device is unhandled. > > > > For a module that is mentioned in the device tree I would expect that > > the order in the device tree binary is the one used. For devices > outside > > of the device tree most likely some link order is used. > > > > If you have a debugger you might want to search for the loops and > take a > > look at when they are called and how they add devices. I don't think > > that there are that many early modules yet that would use the device > > tree. So it's possible that there is some call missing that would > parse > > the device tree for early modules. > > > > > > > > > > > A general note regarding the prcm module: In RTEMS most > > (non-libbsd) > > > drivers enable their power and clocks themself. Please make > > sure that > > > the FreeBSD prcm doesn't interfere with that. Otherwise you > > might get > > > odd effects. > > > > > > Thanks I will keep that in mind. > > > > > > Best, > > > Nils > > > > > > > > > Best regards > > > > > > Christian > > > > > > > *====am335x_prcm_attach====* > > > > " > > > > > > > > Is there anything else I can do besides using > MODULE_DEPENDENCY, > > > which I > > > > already use. > > > > The prcm module is also a EARLY_DRIVER_MODULE. > > > > > > > > Best, > > > > Nils > > > > > > > > On Wed, 24 Jul 2019 at 16:04, Vijay Kumar Banerjee > > > > <vijaykumar9...@gmail.com <mailto:vijaykumar9...@gmail.com> > > <mailto:vijaykumar9...@gmail.com <mailto:vijaykumar9...@gmail.com>> > > > <mailto:vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com> <mailto:vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com>>>> > > > wrote: > > > > > > > > > > > > > > > > On Wed, Jul 24, 2019 at 7:03 PM Nils Hölscher > > > <nilho...@gmail.com <mailto:nilho...@gmail.com> > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com>> > > > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com> > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com>>>> wrote: > > > > > > > > > > > > > > > > On Wed, 24 Jul 2019 at 15:14, Vijay Kumar Banerjee > > > > <vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com> > > > <mailto:vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com>> <mailto:vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com> > > > <mailto:vijaykumar9...@gmail.com > > <mailto:vijaykumar9...@gmail.com>>>> wrote: > > > > > > > > > > > > > > > > > > > > On Wed, Jul 24, 2019 at 6:36 PM Nils Hölscher > > > > <nilho...@gmail.com <mailto:nilho...@gmail.com> > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com>> > > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com> > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com>>>> wrote: > > > > > > > > Hi again, > > > > > > > > Hi Nils > > > > > > > > I just decompiled my device tree and checked. > > > > The probe code of the prcm driver is as > follows: > > > > " > > > > static int > > > > am335x_prcm_probe(device_t dev) > > > > { > > > > printk("am335x_prcm_probe\n"); > > > > > > > > if (!ofw_bus_status_okay(dev)){ > > > > printk("ofw_bus_status_not_okay\n"); > > > > return (ENXIO); > > > > } > > > > > > > > Do you get the "ofw_bus_status_not_okay" print ? > > > > > > > > Yes. But I also see the other print. except the > > success one. > > > > > > > > if (ofw_bus_is_compatible(dev, > > "ti,am3-prcm")) { > > > > device_set_desc(dev, "AM335x Power > > and Clock > > > > Management"); > > > > printk("PROBE SUCESSFULL\n"); > > > > return(BUS_PROBE_DEFAULT); > > > > } > > > > printk("ofw_bus incompatible\n"); > > > > return (ENXIO); > > > > } > > > > " > > > > So it seems the prcm part in the device tree > > has to be > > > > compatible to "ti,am3-prcm". > > > > The thing is the decompiled device tree > states > > > just that: > > > > " > > > > prcm@0 { > > > > compatible = > > > > "ti,am3-prcm\0simple-bus"; > > > > > > > > In my device tree, it runs successfully and the > > decompiled > > > > compatible looks like : > > > > ``` > > > > prcm@200000 { > > > > compatible = "ti,am3-prcm"; > > > > reg = < 0x200000 0x4000 >; > > > > linux,phandle = < 0x4a >; > > > > phandle = < 0x4a >; > > > > ``` > > > > > > > > OK, this is awkward, cause we both should have used > > the same > > > > sources. > > > > > > > > Have you checked that your source is from the tree > > matching the > > > > libBSD HEAD > > > > commit? > > > > > > > > reg = <0x00 0x2000>; > > > > #address-cells = > <0x01>; > > > > #size-cells = <0x01>; > > > > ranges = <0x00 0x00 > > 0x2000>; > > > > phandle = <0x5a>; > > > > [...] > > > > " > > > > Any ideas would help, cause I am currently > > not able to > > > > understand this behaviour. > > > > Also without this driver even the > > dev_usb_bbb driver > > > > shouldn't work. > > > > However it attaches because it doesn't check > > for the > > > > clocks error code. > > > > > > > > I remember testing this a few days ago for my fb > > > drivers and > > > > it was attaching alright, > > > > if I remember correctly. If changing the dtb > > doesn't work > > > > for you, I won't mind checking > > > > again, this will give me a hint for the display > > issue > > > as well. > > > > > > > > I will keep you updated on this. > > > > Would you be so kind and send me your compiled > > device tree? > > > > > > > > Please find it attached in this mail. > > > > > > > > Note: I have removed the devel from the cc because the > > attachment > > > > might be > > > > big for the list. Please continue the discussion in the > > > mailing list > > > > and maybe note > > > > it somewhere that you already received the dtb from me in > > > private mail. > > > > > > > > Regards, > > > > Vijay > > > > > > > > > > > > > > > > Best, > > > > Nils > > > > > > > > > > > > > > > > On Wed, 24 Jul 2019 at 14:43, Nils Hölscher > > > > <nilho...@gmail.com > > <mailto:nilho...@gmail.com> <mailto:nilho...@gmail.com > > <mailto:nilho...@gmail.com>> > > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com> > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com>>>> wrote: > > > > > > > > Hi, > > > > > > > > I just found out that the prcm driver > > fails to > > > probe > > > > on the simplebus and therefore cannot > apply > > > itself. > > > > Seems like I am back to checking dtb. > > > > > > > > Best, > > > > Nils > > > > > > > > On Tue, 23 Jul 2019 at 14:26, Nils > Hölscher > > > > <nilho...@gmail.com > > <mailto:nilho...@gmail.com> > > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com>> > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com> > > > <mailto:nilho...@gmail.com <mailto:nilho...@gmail.com>>>> > wrote: > > > > > > > > Hi, > > > > > > > > After debugging with printk, didn't > > get the > > > > module loading working as suggested > by > > > Sebastian. > > > > I just found out that my PRU driver > > can't be > > > > attached, cause the AM35xx clock > > driver isn't > > > > loaded. > > > > The driver can be found her: > > > > > > > > > > https://github.com/RTEMS/rtems-libbsd/blob/610349693dd31d8b0efd33776516b7187cc5cda2/freebsd/sys/arm/ti/am335x/am335x_prcm.c > > > > > > > > Can anyone tell me how to load this > > driver and > > > > obisouly before I initialize my BSD > > modules? > > > > > > > > FYI: The code line that fails is > > this one, > > > cause > > > > the driver hasn't been initialized. > > > > > > > > > > https://github.com/RTEMS/rtems-libbsd/blob/610349693dd31d8b0efd33776516b7187cc5cda2/freebsd/sys/arm/ti/am335x/am335x_prcm.c#L854 > > > > > > > > Thanks, > > > > Nils > > > > > > > > > _______________________________________________ > > > > devel mailing list > > > > devel@rtems.org <mailto:devel@rtems.org> > > <mailto:devel@rtems.org <mailto:devel@rtems.org>> > > > <mailto:devel@rtems.org <mailto:devel@rtems.org> > > <mailto:devel@rtems.org <mailto:devel@rtems.org>>> > > > > > http://lists.rtems.org/mailman/listinfo/devel > > > > > > > > > > > > _______________________________________________ > > > > devel mailing list > > > > devel@rtems.org <mailto:devel@rtems.org> > > <mailto:devel@rtems.org <mailto:devel@rtems.org>> > > > > http://lists.rtems.org/mailman/listinfo/devel > > > > > > > > > > > > > _______________________________________________ > > devel mailing list > > devel@rtems.org > > http://lists.rtems.org/mailman/listinfo/devel > > > > -- > -------------------------------------------- > embedded brains GmbH > Herr Christian Mauderer > Dornierstr. 4 > D-82178 Puchheim > Germany > email: christian.maude...@embedded-brains.de > Phone: +49-89-18 94 741 - 18 > Fax: +49-89-18 94 741 - 08 > PGP: Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. >
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