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by 9pi
Wed Sep 18, 2019 11:03 am
Forum: Bare metal, Assembly language
Topic: PCIe outbound address restrictions
Replies: 5
Views: 505

Re: PCIe outbound address restrictions

jdb wrote:
Wed Sep 18, 2019 10:51 am
The outbound window is fixed in the bus address range 0x6_0000_0000 to 0x7_ffff_ffff.
Fixed by the hardware? That's the conclusion I was approaching, after doing some linux experiments today, by changing the ranges in bcm2838.dtsi and finding which ones worked.

Thanks for the confirmation.
by 9pi
Wed Sep 18, 2019 8:46 am
Forum: Bare metal, Assembly language
Topic: PCIe outbound address restrictions
Replies: 5
Views: 505

Re: PCIe outbound address restrictions

Don't you have a conflict with RAM if you try to use the lower addresses? Yes, that's what I meant by the need to "sacrifice" a megabyte of RAM if mapping pcie outbound addresses at 0xFBF00000 on a 4GiB pi4. On a 2GiB pi4 there should be not conflict. A comment in the linux driver (pcie-brcmstb.c) ...
by 9pi
Fri Sep 13, 2019 8:40 pm
Forum: Bare metal, Assembly language
Topic: PCIe outbound address restrictions
Replies: 5
Views: 505

PCIe outbound address restrictions

Is it possible to map the PCIe outbound window (base address for requests from CPU to PCIe) to an address below 4GiB, ie to a 32-bit address? I know that linux maps the window at 0x600000000, which requires LPAE on arm32. I'm working on PCIe support for Plan 9 on arm32, which doesn't use LPAE. I've ...
by 9pi
Sat Sep 07, 2019 2:07 pm
Forum: Plan 9
Topic: how can I clone the plan 9 source code?
Replies: 1
Views: 392

Re: how can I clone the plan 9 source code?

There is a git repository with (a slight variant of) the Plan 9 distribution including all source code at https://github.com/0intro/plan9-contrib Raspberry pi specific part of the kernel source is found in sys/src/9/bcm This is not quite as up to date as the source in https://9p.io/sources/contrib/m...
by 9pi
Sat Sep 07, 2019 1:54 pm
Forum: Bare metal, Assembly language
Topic: Bare metal BCM43438 Driver
Replies: 24
Views: 4286

Re: Bare metal BCM43438 Driver

I am wondering where are the definition for these function calls like below cfgw(Sbaddr+1, addr>>16); cfgw(Sbaddr+2, addr>>24); I tried searching there is no way I could clone your sources repository. Please let me know if you can help me with that. Those are static functions defined earlier in the...
by 9pi
Tue Aug 27, 2019 1:12 pm
Forum: Bare metal, Assembly language
Topic: Bare metal BCM43438 Driver
Replies: 24
Views: 4286

Re: Bare metal BCM43438 Driver

Not bare metal strictly speaking, but the Plan 9 driver is another alternative example you might want to look at for information. It's under 2400 lines of C, so it should be a bit easier to follow than the Linux brcmfmac driver. To write the Plan 9 driver without a device spec, I had to read all the...
by 9pi
Fri Jul 19, 2019 1:42 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 98392

Re: Raspberry Pi 4 Thread - general discussion

Is it still possible on Pi 4, eg in bare metal or a non-linux OS, to use gpio alt settings to connect sdhost to the sdcard, or is the sdcard now hard-wired to the new SD controller exclusively? Effectively hardwired. The new controller is SDHCI compliant, so bare metal/alternate OSes should just im...
by 9pi
Tue Jul 16, 2019 7:19 pm
Forum: General discussion
Topic: Raspberry Pi 4 Thread - general discussion
Replies: 895
Views: 98392

Re: Raspberry Pi 4 Thread - general discussion

The new SD controller is an addition, not a replacement. The Broadcom SDHOST device is now unused as the Arasan SD controller now talks to WiFi. Is it still possible on Pi 4, eg in bare metal or a non-linux OS, to use gpio alt settings to connect sdhost to the sdcard, or is the sdcard now hard-wire...
by 9pi
Mon Mar 19, 2018 12:04 pm
Forum: General discussion
Topic: 3B+ ethernet: is it LAN75xx or LAN78xx ?
Replies: 6
Views: 3036

Re: 3B+ ethernet: is it LAN75xx or LAN78xx ?

The driver for the old chip is the smsc75xx
I think ithat should be smsc95xx -- I had to write a Plan 9 driver for that chip when the pi3 first came out. Unfortunately some of the registers for the lan78xx are quite different.
by 9pi
Mon Mar 19, 2018 11:24 am
Forum: General discussion
Topic: 3B+ ethernet: is it LAN75xx or LAN78xx ?
Replies: 6
Views: 3036

3B+ ethernet: is it LAN75xx or LAN78xx ?

Announcements of the 3B+ refer to the new USB hub / ethernet chip as a LAN7515, and indeed the chip on my board is labelled LAN7515. In order to adapt the Plan 9 operating system for the 3B+, I spent the weekend writing and attempting to debug a lan75xx driver. Without success. The device enumerates...
by 9pi
Sat Mar 05, 2016 1:44 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 210621

Re: The Raspberry Pi 3 Model B Q&A thread

Is there register-level documentation available for programming the SDHOST interface? ... It would be useful to be able to adapt Plan 9 to run on the Pi3 without losing access to the SD card. It turns out that the Arasan eMMC interface can still be used with the SD card, so Plan 9 works fine on the...
by 9pi
Tue Mar 01, 2016 12:01 pm
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 210621

Re: The Raspberry Pi 3 Model B Q&A thread

Is there register-level documentation available for programming the SDHOST interface? I don't see it in mentioned the "BCM2835 Arm Peripherals" document. It would be useful to be able to adapt Plan 9 to run on the Pi3 without losing access to the SD card. There are two different linux drivers for i...
by 9pi
Tue Mar 01, 2016 10:19 am
Forum: General discussion
Topic: The Raspberry Pi 3 Model B Q&A thread
Replies: 457
Views: 210621

Re: The Raspberry Pi 3 Model B Q&A thread

The Arasan eMMC block is the only block that can do UHS and this is now connected to the onboard WiFi. The Broadcom SDHOST (which doesn't do UHS modes, but can be overclocked) now talks to the SD card. Is there register-level documentation available for programming the SDHOST interface? I don't see...
by 9pi
Fri Feb 06, 2015 8:06 pm
Forum: Plan 9
Topic: Plan 9 on Raspberry Pi 2
Replies: 4
Views: 15085

Plan 9 on Raspberry Pi 2

There's a new 9pi2 kernel available in http://plan9.bell-labs.com/sources/contrib/miller which will run on the Raspberry Pi 2. So far it only activates one core; SMP coming soon.
by 9pi
Wed Mar 20, 2013 7:39 am
Forum: Plan 9
Topic: Plan 9 available
Replies: 42
Views: 63597

Re: Plan 9 available

dk379 wrote:i have tried to download boot image, but the server gives HTTP Error 500.
The Bell Labs web server for Plan 9 sources goes offline from time to time. If you keep trying, it will eventually reappear (sometimes it takes a day or two).
by 9pi
Wed Feb 27, 2013 3:10 pm
Forum: Plan 9
Topic: Plan 9 available
Replies: 42
Views: 63597

Re: Plan 9 available

I did set TIMESYNCARGS elsewhere, but it didn't seem to work. Have a look at the script /bin/termrc.local - if parameter ipconfig is set in cmdline.txt, this script should be setting TIMESYNCARGS, which will result in the /bin/termrc script calling aux/timesync. The ipconfig variable is normally de...
by 9pi
Wed Jan 30, 2013 10:22 am
Forum: Plan 9
Topic: Plan 9 available
Replies: 42
Views: 63597

Re: Plan 9 available

Any chance of sticking a changelog up somewhere/labelling images with version numbers (or at least dates) so people can see when there's a new one and which one they have? Traditionally Plan 9 hasn't had a change log, and there are no "versions". We just do a "replica/pull" from time to time and se...
by 9pi
Wed Jan 30, 2013 10:10 am
Forum: Plan 9
Topic: Non-functioning mice
Replies: 5
Views: 13333

Re: Non-functioning mice

You can add the el-cheapo Onn Optical Mouse from Wal-Mart to the list of non-working mice on Plan9. There's actually no "list" - in almost every case when someone reports a mouse problem, I have worked with them to diagnose it, and if necessary updated the Plan 9 usb mouse driver so that model of m...
by 9pi
Sun Jan 06, 2013 1:52 pm
Forum: Bare metal, Assembly language
Topic: Implementing a USB Driver
Replies: 86
Views: 20119

Re: Implementing a USB Driver

I had thought if the RISC OS driver was developed separately from the Linux driver it should be easier to understand. There's also a freebsd driver now, which appears to be all original code. It's a lot smaller and clearer to read than the linux one. Looks like it will support isochronous endpoints...
by 9pi
Sun Jan 06, 2013 9:41 am
Forum: Bare metal, Assembly language
Topic: Implementing a USB Driver
Replies: 86
Views: 20119

Re: Implementing a USB Driver

There's a lot of code already in this driver - it would be a brave man who attempted to completely rewrite it although some will try, certainly the bare metal people! Rewriting 50,000+ lines of code might take bravery, but ignoring the linux driver and just writing a new and simpler one from scratc...
by 9pi
Sun Jan 06, 2013 9:29 am
Forum: Plan 9
Topic: Plan 9 available
Replies: 42
Views: 63597

Re: Plan 9 available

So all I do is copy cmdline-demo-net.txt from one partition into the other partition where cmdline.txt resides? No, both files are in the boot partition. You can do this under Plan 9 - in a command shell window, just type this: dosmnt 1 /n/d cp /n/d/cmdline-demo-net.txt /n/d/cmdline.txt and reboot ...
by 9pi
Sat Jan 05, 2013 5:36 pm
Forum: Bare metal, Assembly language
Topic: Implementing a USB Driver
Replies: 86
Views: 20119

Re: Implementing a USB Driver

DavidS wrote:HAs any one looked at the RISC OS USB stuff yet?
The RISC OS usb host controller driver is essentially a copy of the linux driver.
by 9pi
Tue Jan 01, 2013 10:43 pm
Forum: Plan 9
Topic: Has anyone [*] actually gotten this to work?
Replies: 20
Views: 20992

Re: Has anyone [*] actually gotten this to work?

I'm sorry Plan 9 is still having trouble with your mouse and keyboard. When you asked for advice in an earlier thread, I made the suggestion below. Would you like to try that now, and report back what result you get? I suggest editing your cmdline.txt file to remove the parameter 'user=glenda' and a...
by 9pi
Thu Dec 27, 2012 8:13 pm
Forum: Plan 9
Topic: STICKY: Keeping up to date
Replies: 5
Views: 14640

STICKY: Keeping up to date

After installing Plan 9, you can use the replica/pull command to keep your system up to date with changes and corrections on the Bell Labs repository. For details, see this wiki page: http://www.plan9.bell-labs.com/wiki/plan9/Updating_an_ARM_system In particular, if you installed Plan 9 on the Raspb...
by 9pi
Mon Dec 24, 2012 9:16 am
Forum: Plan 9
Topic: GPIO with Plan 9?
Replies: 3
Views: 14188

Re: GPIO with Plan 9?

Bakul Shah has been working on a gpio driver, which I hope will be available soon. I think it's safe to predict that access to gpio ports will be presented as a set of files - that's the Plan 9 Way.

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