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by Ultibo
Sun Sep 09, 2018 11:26 pm
Forum: Bare metal, Assembly language
Topic: Reasons behind MMIO base address
Replies: 3
Views: 1162

Re: Reasons behind MMIO base address

I am curious as to why they didn't just start the MMIO at 0x40000000? What we have learned from snippets of information provided over the years is that the VC4 GPU only supports a 1GB address space (which is the reason why the Pi cannot have more than 1GB) and because the GPU needs access to the pe...
by Ultibo
Wed Aug 29, 2018 10:10 am
Forum: Bare metal, Assembly language
Topic: Multiple GPU hardware layers?
Replies: 4
Views: 1534

Re: Multiple GPU hardware layers?

I know we can request 1 frame buffer at various virtual sizes through the mailbox interface, but is there a way to get multiple hardware layers from the GPU? With hardware layers I mean multiple frame buffers displayed by the GPU on top of each other with alpha transparency. The interface you are a...
by Ultibo
Mon Aug 13, 2018 11:37 am
Forum: Bare metal, Assembly language
Topic: Xinu release
Replies: 21
Views: 5053

Re: Xinu release

LizardLad_1 wrote:
Sat Aug 11, 2018 4:19 am
Are you going to release the code on GitHub or GitLab?
Maybe neither, it seems the original authors of Xinu already have.

http://reu.mscs.mu.edu/index.php/Upgrad ... berry_Pi_3
https://dl.acm.org/citation.cfm?id=3162 ... CM&coll=DL




.
by Ultibo
Tue Jun 19, 2018 12:34 am
Forum: Bare metal, Assembly language
Topic: Raspberry Pi 3B+ Bare Metal USB Driver
Replies: 41
Views: 5971

Re: Raspberry Pi 3B+ Bare Metal USB Driver

I also noticed one more thing. After waiting a few minutes for all the devices to be attached, it shows that there are 2 LAN7515 hubs... 1 = roothub 2 = LAN hub 3 = is also LAN hub..?? 4 = ethernet device 5 = mouse Hi rlatinov, The Pi3B+ has two hubs built into the LAN7515 device, this is normal an...
by Ultibo
Tue Jun 12, 2018 4:54 am
Forum: Bare metal, Assembly language
Topic: [Partly-Solved] VCHIQ/MMAL Camera access
Replies: 28
Views: 3826

Re: [Partly-Solved] VCHIQ/MMAL Camera access

But to answer your question, there is no specific initialization for the spinlock/mutex necessary to be called before they can be used. Alas, the particular case I was thinking of only applies if your lock structures (spin/mutex) require initialization before use. VCHIQ just did not respond to the ...
by Ultibo
Sun Jun 10, 2018 11:48 pm
Forum: Bare metal, Assembly language
Topic: Baking Pi issues
Replies: 8
Views: 1613

Re: Baking Pi issues

I just got a Raspberry Pi 3 B+ and wanted to do the Baking Pi tutorial http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok01.html After having some issues i discovered this thread https://www.raspberrypi.org/forums/viewtopic.php?t=82871 and did exactly the same but it doesnt work for me. I...
by Ultibo
Fri Jun 08, 2018 12:09 am
Forum: Bare metal, Assembly language
Topic: [Partly-Solved] VCHIQ/MMAL Camera access
Replies: 28
Views: 3826

Re: [Partly-Solved] VCHIQ/MMAL Camera access

This would usually trigger the VCHIQ callback which is forwarded into MMAL with reason VCHIQ_MESSAGE_AVAILABLE that does check the returned messageID to be MMAL_WORKER_BUFFER_TO_HOST and than triggers the VCHIQ_BULK_RECIEVE. But this initial callback from VCHIQ, once the buffer has been passed is n...
by Ultibo
Mon Jun 04, 2018 2:27 am
Forum: Bare metal, Assembly language
Topic: [Partly-Solved] VCHIQ/MMAL Camera access
Replies: 28
Views: 3826

Re: [Partly-Solved] VCHIQ/MMAL Camera access

Hey Schnoogle, I've the MMU setup with L1 caching active. I've no clue how to get L2 caches setup but the disable_l2cache switch in the confog.txt should deactivate it in GPU anyway if I understood it correct. Based on that I'd suggest that the disable_l2cache/enable_l2cache setting is at best irrel...
by Ultibo
Sun Jun 03, 2018 1:07 am
Forum: Bare metal, Assembly language
Topic: [Partly-Solved] VCHIQ/MMAL Camera access
Replies: 28
Views: 3826

Re: [Partly-Solved] VCHIQ/MMAL Camera access

Hi again Schnoogle, So close and yet so far! I just retested the values with our implementation, we can happily capture a 3280 x 2464 image from the camera so your 128 x 128 should be easily within limits. I can also confirm that to use the camera you must have start_x.elf (and fixup_x.dat) with the...
by Ultibo
Tue May 22, 2018 10:43 am
Forum: General discussion
Topic: Multiple framebuffer support - testers wanted
Replies: 10
Views: 2294

Re: Multiple framebuffer support - testers wanted

Would anyone be interesting in beta testing? You will need to build your own kernel and modules, and be able to install them on an SD card. There will also be a new firmware (start*.elf) required. You can already see the kernel changes in this branch on my github https://github.com/JamesH65/linux/t...
by Ultibo
Tue May 15, 2018 12:12 am
Forum: Bare metal, Assembly language
Topic: Is there any way to emulate timer interrupt in qemu?
Replies: 8
Views: 3382

Re: Is there any way to emulate timer interrupt in qemu?

I've tested the system timer (whose base address is 0x3f003000) and the local timer (whose base is 0x3f00b000). They can work on my pi3, but it seems that none of them are emulated in qemu (I use qemu 2.12, which supports -M raspi3). Can we emulate timer interrupts in qemu? Thanks. Looking at the Q...
by Ultibo
Sun May 13, 2018 11:21 am
Forum: Bare metal, Assembly language
Topic: [Partly-Solved] VCHIQ/MMAL Camera access
Replies: 28
Views: 3826

Re: VCHIQ/MMAL Camera access

You are welcome Schnoogle, please let us know how you go.

PS. We are from Australia so cold beer is good!!
by Ultibo
Sun May 13, 2018 1:14 am
Forum: Bare metal, Assembly language
Topic: [Partly-Solved] VCHIQ/MMAL Camera access
Replies: 28
Views: 3826

Re: VCHIQ/MMAL Camera access

I'm developing under windows so UART console is my friend as QEMU does not work on Windows for real debugging as far as I know and I guess VCHIQ might not be properly emulated there as well.... When doing bare metal the UART is always your friend ;) I think it could be a very long time before there...
by Ultibo
Sat May 12, 2018 1:46 am
Forum: Bare metal, Assembly language
Topic: [Partly-Solved] VCHIQ/MMAL Camera access
Replies: 28
Views: 3826

Re: VCHIQ/MMAL Camera access

Hi BR Schnoogle, Sounds like you are close to getting it working if you have got that far. Without any other information it is hard to offer much advice but I can tell you that both bulk transmit and receive work in the Ultibo port of VCHIQ, data is able to be received from the camera and we have wo...
by Ultibo
Tue May 08, 2018 3:28 am
Forum: Bare metal, Assembly language
Topic: Correct value for cntfrq_el0 in Pi 3 B+
Replies: 2
Views: 701

Re: Correct value for cntfrq_el0 in Pi 3 B+

AntonioND wrote:
Mon May 07, 2018 6:09 pm
I was wondering if the frequency of the oscillator has changed between Pi 3 B and Pi 3 B+.
No changes, the frequency of the oscillator is still 19.2MHz as per the previous models.
by Ultibo
Mon May 07, 2018 11:13 am
Forum: Bare metal, Assembly language
Topic: Audio output on the Raspberry Pi 3B
Replies: 26
Views: 7555

Re: Audio output on the Raspberry Pi 3B

At the moment I have no idea how to achieve this (I seem to say that a lot) however how could I play specific frequencies out of the raspberry pi 3.5mm audio jack. At the moment my kernel halts all processor cores that aren't core 0 and it has access to the GPIO so how can I start core 1 and use it...
by Ultibo
Fri May 04, 2018 10:52 am
Forum: Bare metal, Assembly language
Topic: Pi 3B+ Activity LED
Replies: 23
Views: 9679

Re: Pi 3B+ Activity LED

If you were in my position. How would you deal with getting information from the kernel. Can you please suggest some ideas. It's not quite clear from your question, are you doing this in bare metal or are you using Linux? If you have a way to create a thread or a task then periodically requesting t...
by Ultibo
Fri May 04, 2018 3:39 am
Forum: Bare metal, Assembly language
Topic: Pi 3B+ Activity LED
Replies: 23
Views: 9679

Re: Pi 3B+ Activity LED

I need to trigger an interrupt whenever there is low voltage and sd card access (which can be done using pin change interrupt on GPIO29 in RPI3 B+). Using mailbox service is polling operation and I have to keep running the command in loop and check the status. Can you suggest how I can do the same ...
by Ultibo
Wed May 02, 2018 11:41 am
Forum: Bare metal, Assembly language
Topic: Pi 3B+ Activity LED
Replies: 23
Views: 9679

Re: Pi 3B+ Activity LED

ankushnag14 wrote:
Wed May 02, 2018 9:30 am
Is it possible to use GPIO 29 similarly in RPi 3B version 1.2?
No, access to the activity LED on the 3B is only available via the virtual gpio or gpio expander interface which uses the mailbox functions.
by Ultibo
Tue May 01, 2018 10:38 am
Forum: Bare metal, Assembly language
Topic: Reading hardware revision code from within kernel drivers?
Replies: 3
Views: 747

Re: Reading hardware revision code from within kernel drivers?

I have a custom board that I need to support on all the versions of the Pi hardware going back to the original. I'd like to be able to determine the hardware revision code from within my kernel driver. I've found plenty of examples of user mode techniques but none from within the kernel space. I've...
by Ultibo
Sun Apr 22, 2018 11:59 pm
Forum: Bare metal, Assembly language
Topic: acking GPU interrupts
Replies: 1
Views: 634

Re: acking GPU interrupts

On a Pi3 I occasionally get a GPU interrupt (bit 8 in the core interrupt sources as listed in the QA7 document). I'm pretty sure this is low-power related, as the interrupt happens at the same time the little lightning bolt appears on the HDMI display. Is there any way to get more info on the sourc...
by Ultibo
Fri Apr 20, 2018 12:34 am
Forum: Bare metal, Assembly language
Topic: Get the state of the ACT LED on RPi 3
Replies: 10
Views: 2201

Re: Get the state of the ACT LED on RPi 3

Bellow is the code which i have written to activate "ACT" Led in RPI3 .can someone Please check this I am not getting any output if I call mailbox_write() twice. Its working if i just want to enable it by calling mailbox_write once. I think you might be tripping yourself over with your use of globa...
by Ultibo
Mon Apr 16, 2018 11:22 am
Forum: General programming discussion
Topic: How Much of the Raspbian Stack is Open Source?
Replies: 7
Views: 1924

Re: How Much of the Raspbian Stack is Open Source?

How do those libraries go about sending commands to the GPU's firmware? Is it through the mailbox API? Does this mean that the function implementations for the OpenGL ES 2.0 calls in libbrcmGLESv2.so are function wrappers to construct the real query that gets sent to the GPU's firmware via the Mail...
by Ultibo
Sun Apr 15, 2018 4:49 am
Forum: Bare metal, Assembly language
Topic: Ultibo core a bare metal environment for Raspberry Pi
Replies: 65
Views: 22007

Re: Ultibo core a bare metal environment for Raspberry Pi

Hi Everyone,

Just a quick update to let you know that along with detection of the new Pi 3B+ we have now added a USB driver to support the LAN7515 (LAN78XX) chip as well.

That means that all Ultibo core features now work with the latest Pi 3B+ as well.

Cheers and enjoy!
by Ultibo
Sun Apr 15, 2018 1:15 am
Forum: Bare metal, Assembly language
Topic: multi-core shared memory communication
Replies: 15
Views: 3865

Re: multi-core shared memory communication

I can successfully unpark the multiple cores and have them run, but I can't seem to get memory writes on one core to appear on the others. I enable the MMU and caches on all cores. I also enable the SMP bit in the AUX register (do I need to enable it the ARMv8 way instead? With the SMPEN bit in CPU...

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