8 replies to this topic

[Illishar]

I'm doing some brainstorming with direct port access, from within the Netmf. I don't yet know if it's possible. The theory is sound though. If we can access the native ports (mem access), we'll be able to create 'native' drivers, without messing with the native fw. This ofc will not be performance friendly, but then again, many functions/drivers don't need performance. And these 'Managed native' drivers won't take up space in the fw, when not in use. (Cool) The attached project has not yet been testet. (My board is currently out of reach.) This is just work in progress. (Using the forum as a mid way storage

Attached Files

•  NetduinoUnsafe.zip   6.13KB   37 downloads

[CW2]

If we can access the native ports (mem access), we'll be able to create 'native' drivers, without messing with the native fw.

I had a similar idea some time ago (inspired by GHI's Register class). There is one important issue with my code, though: it does not verify the address parameter, so it will fail when an attempt is made to access an invalid (reserved) memory region.

[Illishar]

My first attempt with a managed version doesn't seem to work:

    public unsafe class Processor
    {
        /// <summary>
        /// Write directly to memory. (Meant for port access)
        /// </summary>
        /// <param name="reg"></param>
        /// <param name="val"></param>
        public static void Write(uint reg, uint val)
        {
            *(uint*)reg = val;
        }

        /// <summary>
        /// Read directly from memory. (Meant for port access)
        /// </summary>
        /// <param name="reg"></param>
        /// <returns></returns>
        public static uint Read(uint reg)
        {
            return *(uint*)reg;
        }
    }

It's a pity. It would have been an easy fix. Maybe the .NET assemblies have their own memory space or something. I'll give it a try with your unmanaged version, I think.

[Corey Kosak]

My first attempt with a managed version doesn't seem to work:
It's a pity. It would have been an easy fix.

I think you forgot to set the port enable register (offset 0), and you also swapped CODR and SODR in your routine (not that it really matters ). But even with that, I couldn't get it to work from the managed side either. I wonder what is going on.

[Illishar]

Well, I still can't get the managed version to work. But I've implemented the native Register class suggested by CW2. I've attached a sample that will toggle the LED through the Register class. (I found several errors in my previous code as you pointed out.) I've also attached a patch for the netmf containing the Register class. And I've attached the netmf binary. And I've attached the Register source. As CW2's implementation this doesn't contain any address validation. Full Control! CRASH AND BURN!

Attached Files

•  NetduinoNativeRegisterTest.zip   16.72KB   26 downloads
•  RegisterPatch.zip   16.32KB   27 downloads
•  Netduino4.1.0.a5_modded.zip   352.44KB   28 downloads
•  Netduino_Contrib_Register.zip   27.56KB   24 downloads

[Klop]

Hi Illishar, I've downloaded all your code and tried running it but get an 'Netduino.Contrib.Register' reference error in the NetduinoNativeRegisterTest project. How do you link in the native code from the Netduino_Contrib_Register project? Also tried putting in the Netduino_Contrib_Register project in my own solution and added a reference to the register projct. But when running the my app I get an unhandled exception of type 'System.NotSupportedException' when the Register.Read(uint) method is called. Do you know what to do? Thanks.

[Klop]

Hi Illishar, I got it working - forgot to upload your modded firmware

[FMode]

Do you have this patch for 4.2 ? I only need to set bits STTBRK and STPBRK in US_CR...

[FMode]

Here is the patch for 4.2 ...

Attached Files

•  42.zip   351.94KB   17 downloads